Repeating Flashing Text in After Effects I'm using After Effects CS6, and I'm deliberately trying to recreate the look of a cheap camcorder. I want that stereotypical red "REC" text and big red dot in a corner of the screen, and I want it to blink off and on. I want the "ons" and "offs" spaced one second apart, like so:

ON ==[one second]=> OFF ==[one second]=> ON ==[one second]=> OFF

And so forth. However, animating this by hand is a huge pain. How can I automate this animation? Would an expression work, or is there a way to tell After Effects to loop certain keyframes?

Thank you.

This can be done easily with a mixture of time remapping and an expresison. Simply precomp the text animated as once on, once off (keyed out manually), then drop it into your main comp and apply the following expression:

loop_out("cycle",0)

Then, just extend the composition for as long as you would like it to loop.


Why HD broadcast camcorder still pictures quality (still frame from video) beat out DSLR? I've taken pictures with a HD broadcast camcorder and a DSLR at the same event. When I get the still pics from camcorder footage, the image appears to be more professional/outstanding feeling than the DSLR's. That makes me almost give up on shooting still pics with a DSLR.

Why does the picture quality from the HD broadcast camcorder beat out DSLR? Even if the total pixel count is less?

(notice: broadcast camcorder means XDCAM HD or better)

My guess, what you are seeing is most likely the result of the better color detection and processing with the sensor and image data and the better depth of field provided by a high quality professional lens.

There is far, FAR more to image quality than simple resolution.  The color accuracy of the sensor, the dynamic range, shadow detail, vibrancy and contrast of the processed image, the reduced amount of aberrations as a result of better optics, the better quality of out of focus parts of the image due to better aperture designs, the extra background blur as a result of wider open apertures, etc, etc, all impact the image quality substantially, especially for viewing on a screen.

Unless you are printing the image or zooming in on it, a 1080p HD camera has the same resolution as a DSLR when you are displaying it on a computer screen (since the computer screen itself likely doesn't display much more than 1080p, possibly even less).  So for looking on a screen, the other factors are the only thing that matter and any professional camera will far outweigh it.

Also note that a good DSLR will beat the pants off even a high end video camera in terms of image quality for still images, but you need to have a good quality DSLR and a good quality lens to beat a professional quality video camera (at the 1080p kind of resolution).

You shouldn't expect the image quality to be better on a camera which costs, in total, less than some of the batteries for the massively more expensive video camera, but I'd put the still image quality of my 5D Mark iii and 24-70 f/2.8 II optics ($6,000 total) up against any $100,000 camcorder you want to bring out.  Even for video, Arri cams will beat it, but shooting RAW footage, it's only a slightly noticeable difference to a professional eye between the RAW video that the 5D Mark iii ($3,500) can shoot versus footage from the $50,000 ARRI camera.


ffmpeg - mapping an audio file with 2 channels to a video file? I have a video file and an audio file (that contains 2 channels) and i want to map the video to stream 0 of the resulting file and the audio file to the next stream/s.

Since the audio file has 2 channels, would i have to map it to 2 separate streams? (1 and 2 of the resulting file)
Or just one stream?

Finally, how should i go about doing that?
I've only tried mapping with video files so i'm not sure how to do it with audio ones.

Thanks!

Channels are conjoint tracks within a single stream, so a stereo audio WAV has one stream which contains two channels. If this is what you have, use

ffmpeg -i video -i audio -map 0:v -map 1:a output

If they are distinct streams, then the above command will still map all the streams, but for explicit specification, use

ffmpeg -i video -i audio -map 0:v -map 1:a:0 -map 1:a:1 output


How to add quiz to video in kaltura kmc editor on vpaas? I looked at tutorials, but I don't see the quiz button in the toolbar on the left, only "advertisement" button.

You don't add quiz to video.

Instead, you create a video quiz by selecting Add New, then Video Quiz

The Kaltura knowledge pages on this give you a full tutorial, and should be your first stop for this sort of thing.


Should I cut footage into clips whilst I'm logging it? I'm logging some DV tapes. Currently literally just capturing into Premiere as AVI DV capture format, and writing what is happening and the timecode with pen and paper. I've got the feeling I'm going to have to go back and chop up the footage later. I've got 50 tapes so I want to streamline my workflow early on so I don't leave myself with mammoth tasks that I could have avoided. Plus I'm new to this ...

There is no right or wrong answer here.  I've done both before for projects of your scale.  There are factors that work in favor of both.

For recording whole tapes while you take notes by hand, the pros are:

Least amount of calendar time to capture and edit.
Technically simple.
Requires detailed viewing and review of footage, which may catch issues earlier. (Note, you still CAN review footage in detail for clip logging, but you also don't have to.)

Cons are:

Requires your attention for the entire length of capture to make sure you don't miss anything.
Doesn't allow for as easy use of DV tapes as a backup mechanism. (You can save the start and stop time for the whole tape, but can't import a single clip.)
Requires manual splitting of clips after, however this operation is fairly quick as you have a listing of time codes on which to split.

Conversely, for batch logging of individually logged clips the pros are:

You can fast forward through tapes to get the clip identification done more quickly that watching all the footage in real time during capture.
Allows you to easily go back and double check a missed transition's time without interfering with capture.
Requires only periodic presence during actual capture.
Since meta data for clips is electronic and based on exact time code, DV tapes function as an additional backup.  Footage can be re-captured in a frame accurate manner in the future.
Clips come out as distinct files with well documented meta data.

Cons of individual logging:

Requires more time overall.  You aren't actually capturing while you are identifying the clips and the extra time you spend up front is generally longer than you would have spent splitting clips after, both due to the seek time for tapes as well as the time to enter electronic meta data instead of simply writing it down during playback.
More complicated technically.  You need to actually fill out the meta data for the files to make most effective use of this logging technique and it is more complicated/time consuming than simply writing it down on a pad of paper.

Overall, it really comes down to how organized you want the data to be and how much time you have.  If you need the project done in the minimum amount of calendar time, capture it all and log as you go.  You can alternately do scene breaks as you go as well.

If you more calendar time, are sure of your captured footage, want some additional long term organization and don't want to have to supervise it attentively for 50+ hours, then use clip logging in advance and batch capture the tapes to fill out the clips.

I've moved on to a file based workflow, but when I was shooting DV, I would almost exclusively capture tape at a time for live events (needed fast turn around) and batch log for anything that wasn't a live event (wanted the organization).  I'd also typically still setup a batch log even for the full tape capture, just to maintain the DV backup of the video, even if it then required capturing the entire tape if I needed to recover the footage.


How to configure crtmpserver for live streaming? This is what I would like to do.

A Linux laptop has a webcam connected to it and captures video and audio in real time
The laptop sends the live video and audio stream to another Linux server which has a better internet connection than the laptop, via RTSP or RTMP or something similar
Any clients that wish to view the stream connect to the Linux server by means of some software such as VLC

The steps 1 and 3 are not a problem, I think I know how to do them. But:

How do I configure the Linux server in step 2 so that it accepts an RTSP stream input and publishes it in some address such as rtsp://my.ip.address/stream.mp4 for example, which can be opened in VLC by any computer? Is crtmpserver the right tool for this? And how do I configure it? I've read like ten different web pages that explain some example configurations for crtmpserver but haven't really found what I was looking for.

I'm pretty sure you can use vlc to both stream and restream it. I use vlc to stream all my tv channels to all my devices(rtsp, mp4, html5).

Search for vlc media player streaming like

https://www.videolan.org/doc/streaming-howto/en/ch04.html


how to blur a short scene in a video I need a software which can blur a scene from a video file. I have thought about VirtualDub and Adobe Premiere but I am not sure if they provide the desired functionality.

My requirement is to blur a some-seconds scene for example blur the scene from 10:12 to 10:45 in a video file.

You can use ffmpeg, and you currently have a choice of four video filters that can blur: boxblur, sab, smartblur and unsharp. These filters can use the enable option for timeline support, so you can apply the blurring effect to a certain duration if desired. You can view what filters have timeline support with ffmpeg -filters.

Example

This example will apply the blur from 22-113 seconds, then again from 275-286 seconds:

ffmpeg -i input.avi -vf "boxblur=enable='between(t,22,113)',boxblur=enable='between(t,(60*4)+35,286)" -codec:a copy output.avi

You can enter seconds or have it calculate seconds for you as shown in the example.
Expression evaluation is not my best area. You may find a method to declare the filter just once.
Note that, since you only want to modify the video, the audio can be stream copied from the input to the output without re-encoding. This is faster than re-encoding and will preserve the quality. This is something most editors, such as Premiere, do not support without additional shenanigans.

Preview

If you have ffplay you can get a preview instead of encoding, watching, re-encoding...

ffplay -i input -vf smartblur

Getting ffmpeg

Builds are available for Windows, Linux, and OS X users. See the FFmpeg Download page, but of course you can always compile ffmpeg too.


capturing video from VHS flickers I am trying to record all my old VHS tapes. I bought a video grabber, usbtv 4-1.2:1.0: Fushicai USBTV007 Audio-Video Grabber, but somehow that does not work well. I tried using VLC, but that has some strange effects. Often it shows past frames while running. Maybe some buffering is needed? I also tried ffmpeg, but that gives me a lot of errors, and also those past frames in between. Maybe the driver is not that good? I also tried in Windows using the software that came with it, called honestech vhs to dvd. That appears to not show the flickering/past frames issue, but it barely has any configuration options, so I would rather not use it.

Does anybody have any experience with this?

Thx.

I did this a few years ago, digitized dozens of my family's old home videos.

The way I did it was, as at the time I was doing it from home and didn't have a IO device such as a DeckLink, I simply used a MiniDV Portable Recorder I got off eBay; which allows composite, component, and S-Video In.

Once the VHS tapes were transferred to my "Digital Intermediate" so to speak, I simply did a standard FireWire Capture using Premiere.

This also provided me with a set of DV Master Tapes as a backup.

You can likely get a used MiniDV HDV Record Deck off eBay for a few hundred dollars now that tape is dead; and just flip it when done (basically no cost if you can sell it for what you pay for it).

Going straight from Analog Tape, really requires a real IO device such as a DeckLink card to get good results, and a DeckLink card with analog IO will be much more expensive.


FFMpeg concat demuxer corrupted output (freezed video on some concatenated parts) I have big videos with different types of properties and trying to collect some part of these videos by ffmpeg.

I use this command to cut specific parts:

scale video >> scale png >> pad scaled_video >> add icon to padded_scaled_video >> encode.

  ffmpeg.StartInfo.Arguments = @"/c ffmpeg.exe -i " + VideoIn + " -i " +
  imageIn + " -filter_complex \"[0:v]
  scale='if(gt(a,6/4),480,-2)':'if(gt(a,6/4),-2,320)' [scaledv], [1:v]
  scale=iw*.5:ih*.5 [scaledicon], [scaledv]
  pad=480:320:(ow-iw)/2:(oh-ih)/2:black [scaledpaddedv],
  [scaledpaddedv][scaledicon] overlay=25:25,setsar=1:1 [finalv]\" -map
  \"[finalv]\" -map 0:a" + " -ss " + startCut.ToString() + " -c:v
  libx264 -preset slow -crf 20 -c:a aac -t " + duration.ToString() + " "
  + VideoOut + " -y -report";

Which works perfectly.

and then try to merge these videos with this command:

  ffmpeg.StartInfo.Arguments = "/c ffmpeg.exe -f concat -safe 0 -i \"" +
  concatTextDirectory + "\" -c copy -vf \"subtitles=\\'" + videoInSrt +
  "\\':force_style='FontName=DejaVu Serif,FontSize=26'\" -c:v libx264
  -preset slow -crf 20 -c:a aac " + videoOut + " -y -report";

Which again works ok if cutted video parts are from the same type of video, and if they aren't there will be no video and only audio or jittery video on non-similar video parts.
The first cutted video part is dominant on other parts.

Question is most of the time video parts are not from the same video type and output is not playable. How could I cut video parts to be similar in properties to work without problem on concatenation part?

This is -report log output:
https://drive.google.com/open?id=0B_kWzdnSIxuQY09QWWZGVTBPdHM

Glad you fixed your problem. For anyone else coming across the question...

The problem is that concat demuxer only works when multimedia streams are the same.

As described here, all files must have the same streams (same codecs, same time base, etc.).

So you have to use a filter, forcing a re-encode. See this reference.


Adobe Premiere CS6 search slidebar CS6 has made it easier for me by making me have to use the keyboard to fast forward without having to hold it, but i preferred the control of being able to use the sort of slidebar.

Does anybody know a way to get this sliding bar speed controller back?

This feature was completely removed in CS6. However, you can now use the keys J, K, and L to scrub the footage.


Why do some camcorders record in 1080i? Why do some camcorders record in 1080i? Does it have any technical or visual advantages over 1080p?

Let's suppose that all media players and TVs which can handle 1080i can also handle 1080p. Is there still an advantage of 1080i?

It uses a lower data rate (within the TV, not for the actual signal) and is cheaper to produce.  That is all.  The only difference is that if you are going to view it on a 1080i display, then shooting in 1080i would look slightly smoother since half the information updates every half a frame rather than updating the whole thing at once, but 1080p is preferable pretty much hands down on a 1080p display.

Interlacing just means that the upper and then lower fields update alternately.  It's less difficult to fake interlacing than it is to deinterlace, but you still get some artifacts displaying a progressive scan image on an interlaced display because of how things update.


How to independently produce 3D Movies when 3D-TV's are discontinued? Big TV-Screen companies like LG, Sony, Samsung and Sharp have announced that they'll discontinue to produce 3D-TV's.

What impact does it have to small independent film producers, that produce 3D films?
How are you able to set up and test your 3D footage, before showing in in Theaters and festivals?

Do you have to keep using "old" monitors and screens or will Screens in "the normal" (affordable) price range still be avavable to the public? (Does a company have annunced to keep continuing screens no matter what?)

Some are using VR headsets, some work with anaglyph glasses. With some plug-ins (such as the Dashwood 360 VR Toolbox, as one example), you can use popular headsets like the Oculus Rift. But many will convert the left and right eye to red/cyan and blend them so you can use those silly paper glasses from your childhood. Simple, but effective!


What is the underlying difference between motion compensation and motion estimation? I know that motion estimation has to do with calculating motion vectors, but where does motion compensation come into play. Can't we just do it with motion vectors, since, we are still calculating the differences in the displacement of the blocks in the reference and the target frames.

Motion compensation is the use of the motion estimation information to achieve compression.  If you can describe the motion, then you only have to describe the changes that occur after compensating for that motion.

I used this article as a primer.  Basically the first involves how you determine what movement is happening and the other is then used to determine what information changed after the movement and to describe what changes need to occur for playback.


How do I deselect the Blade Edit Mode in DaVinci Resolve? I was just learning DaVinci Resolve and accidently clicked Blade Edit Mode

It's now shown as follow.  red

How do I deselect it?

So you can just click Arrow button, or press "A". To select blade again, press "B".

Now that you know how to turn the mode on and off, you may want to learn a little more about what it is. The blade tool is very convenient thing to cut video instead of dragging by the end of footage.

I'd strongly recommend considering "Blade + select + delete" editing. It's working tool.

Now there are two ways to use interface in such editors:

Point and click.
Short cuts.


Background size for 4K UHD Shooting I would like to create a background/backdrop for a video, but I am having quite a hard time deciding on the best dimensions for the backdrop. I will be shooting at 3840 x 2160. Is there a way to determine the dimensions based on the resolution? The idea would be to have a backdrop that completeoly 'fills' the frame of the camera, if that makes sense.

I tried playing with different options in Photoshop and Illustrator. i.e. I created a document with the dimensions 3840 x 2160 at 300DPI (since it's for print), determined it would come out as roughly 32.51 x 18.29cm, and then multiplied until I got a reasonable set of dimensions (i.e. multiplying 8 times = 260.8 x 146.32cm). But somehow, it seems wrong because I would need to place the camera at a certain distance from the background to capture it all.

I'm quite sure there's no rule or anything like that for this, but I would really appreciate any help/pointers on this one!

There is a rule for something like this, however, it has nothing to do with image resolution.  To calculate the area of a scene a camera will cover, you need to know a few things:  A) Distance to subject.  This one's easy.  B) the focal length of the lens, and C) the sensor size, also sometimes called "film back" or "gate".  If your image width to height ratio is the same as your sensor's you probably won't need to know D) aspect ratio, but for some cameras you will, so I'll include it for good measure.

From there, you should be able to use any number of online FOV calculators to tell you the area of your image.  Here is a link to one I found with a Google search.  The website also explains most of this better than I can and includes the mathematical formulae.

If you've ever used a magnifying glass to focus light onto a point, you're probably aware that the shape of the light it creates is circular.  The same phenomenon happens inside a camera.  Your camera's sensor sits inside of this circle.  Now, if you imagine your sensor divided into many tiny pixels, you should get an appreciation for why resolution does not affect this equation.  It doesn't matter how finely you chop up the rectangle -- whether it's 3840, 1920, 960, or eight pixels wide -- the sensor doesn't grow or shrink.  It always fits within the image circle.


positioning Trapcode Particular Obscuration Layer correctly Using Trapcode Particular, I'm trying to position an obscuration layer so that half of my particles (spherical emitter) are being seen, then I rotate it around and see the other side of the sphere of particles.  But, I can't seem to position  the emitter and the obscuration layer correctly with respect to my other 3d layers (AE classic 3d). I can see all elements in wireframe mode except the emitter and obscuration layer. Any tips or tricks?

To see in wireframe objects, which is parts of effects (like emitter), just put in the scene Null Object and parent your effect point (emitter, etc) to it. After that, to adjust your point, adjust Null Object position.

Null Objects are visible in wireframe.


How is it customary to pay a video editor - global or per-hour? Hope this is on-topic.

It is often that assesing the amount of work required for editting a video is a very hard task. This makes the payment issue a bit complicated.

I assume there is no one standart for this, but still, is there a recommended, customary payment system that helps making the deal fair for both parties?

My experience is that it really depends on the situation and the editor.  I personally have done both hourly and project rate editing.  Typically I'll only take project rates if it is clear how much time it will take (ie, a simpler project), but it will really depend on your area and what particular editor you are working with.

I'd suggest having estimates of what you are willing to pay for either option and then simply ask them which method they prefer and then supply them with that number.  If you have a preference one way or the other, you might also ask them if they would consider the method you prefer.


Video formats with alpha channel Which non-obscure video formats with semi opacity are there?

I want to create clips with that format to have as overlay of other videos, so the format better has to be supported by main video editing programs.

I'm assuming that by formats you mean codecs. The following are codecs that work in either Quicktime (.mov), AVI, and MXF containers, or as image sequences saved as discrete files.

Commonly used in the industry:

Apple Animation (has been around forever, 8 bit support only)
Apple ProRes 4444 (probably the most widely used? I have no data, just guessing)
Avid DNxHD & DNxHR (this could be just as widely used)
GoPro Cineform
PNG Sequence With Alpha (my favourite, allows for faster multi-instance renders), also TIFF sequences (ditto, but bigger files)

More obscure:

Avid Meridien
other image sequences: Cineon DPX, Maya IFF, OpenEXR, Targa


Is it possible to merge two ffmpeg commands into one? I'm using ffmpeg to do two things - add a transparent watermark to the whole video, and also add a title intro image. I'm using the following command to add the watermark:

ffmpeg -i original.mp4 -i watermark.png -filter_complex "overlay=W-w-45:H-h-35" watermarked.mp4

And this command to add the intro:

ffmpeg -itsoffset 2 -i watermarked.mp4 -r 25 -loop 1 -i intro.png -filter_complex "[1:v] fade=out:50:10:alpha=1 [intro]; [0:v][intro] overlay=shortest=1 [v]" -map "[v]" -map 0:a output.mp4

I'm concerned that by processing the video twice, I'm losing quality. Is there a way to add the watermark and the intro with just one ffmpeg command / just one pass on the video?

(I understand the first ffmpeg command above, but I'm a bit lost with the second one - I managed to get it working based on code I saw somewhere)

Can't test the below now, but it should be

ffmpeg -itsoffset 2 -i original.mp4 -i watermark.png -loop 1 -t 2.5 -i intro.png -filter_complex "[2:v] fade=out:50:10:alpha=1 [intro]; [0][1]overlay=W-w-45:H-h-35[main];[main][intro] overlay=eof_action=pass [v]" -map "[v]" -map 0:a output.mp4


Is it better to have a player application stretch the video or to use a resolution that matches the video file? I have a Samsung LN40A550 LCD TV, purchased in 2008.  I have a 2011 mac mini connected via HDMI, and I use VLC Media Player to play tv/movies, most often x264/mkv files.

The native resolution of the TV is 1920x1080 so that's what I have the mac set to output most often, and I get video files with the same resolution whenever I can.  However, often the video files I get are only 1280x720.

So my question is:  Will it look better to leave the mac set to the 1920x1080 resolution, and then have VLC's full screen mode stretch the 1280x720 image to 1920x1080, or will it look better to set the mac to output a 1280x720 signal, and then VLC doesn't do any stretching.

By "look better", i mean picture quality and the shading / filling in of pixels, not frame rate or anything CPU performance related, obviously the latter would have less CPU load.

That's really a loaded question.  In general, the rest of your content is going to look better if you leave the computer at native resolution and let the computer scale the video.  If for example you have a video that is a slightly different size, then you would end up scaling to get the resolution setting and again to get the native resolution of the display.  The TV should be able to take into account more information about the exact display too, so I'd leave the computer at native resolution and let software scale it.


Join 2 videos to play at the same time Let's say that I have a file1.avi and a file2.avi. Each one of these files is the same size, for instance 300x100.

How could I join them, so that both of them would play the first 10 seconds of each video at the same time, one on top of the other, in a 300x200 video?

Use

ffmpeg -i file1.avi -i file2.avi -filter_complex "[0][1]vstack" -t 10 joined.avi

This will stack the videos vertically and play the first 10 seconds of each. Remove the -t option if the videos are longer and you wish to extend the output. This command also uses the default parameters to encode the video i.e. codec will be MPEG4 Part 2 (Xvid..). If there's any audio, the track from the first video will be used and encoded as MP3.


What is the benefit to using multiple RED rocket cards? Could someone please explain to me when it might be necessary to use multiple RED rocket cards in the same computer?  Does an additional card significantly improve workflow speeds for lower resolution video (such as 1080p), or is an additional card only useful 2k, 4k, etc?

The RedRocket card provides encoder and decoder support via specialized hardware that can do particular calculations well.  Having multiple cards doubles the amount of calculations that can be done.  Since at least some of the calculations can be done in parallel, having multiple cards increases the amount of processing power available.  It probably wouldn't be much of an additional advantage after hitting real time, but could probably allow for better scrubbing.


How long should video clips be to be in sync with a 90 BPM song? I am making a home vacation video set to music. The song I selected has a BPM of 90.

I want the video clips to match the beat, so for example, every time you hear the beat a new video clip begins. How would I determine how long the video clips should be? If there is an equation I can use for other BPMs as well that would be great.

If you want a new image at every beat, start with the frame rate of your video. 30 frames per second gives 1800 frames per minute. Divide that by 90 to get the number of frames per beat, in this case 20. So if you change the image every 20 frames the pace will be the same. You do have to align the cuts with the beat; just matching the pace is only part of the battle.

In the general case:

(FPS x 60) / BPM = number of frames per beat


What is a good efficient way to isolate clips from long movies? I am making a video that is an analysis of various films. My hope is to get clips from the movies to demonstrate various points I'm talking about.

I'm using Kdenlive on Ubuntu. One issue is that it seems like loading a whole movie length video slows it down making it hard to move around to the right frames (the computer is an i5 with 4GB RAM, so it's not a particularly slow computer).

The main problem, though, is that I want to select sections and edit them out so I can have them as clips ready to include in my master edit. However, if I go through the render process, I'll end up affecting the compression and video quality settings.

Is there a way I can specify a start and end point in hours, minutes, and seconds, and then output that portion into a new file, without changing the quality of the video?

Perhaps something at the command line? That way I could scan through the video using a more efficient player like VLC or something, and pick out my start and stop times there.

Additional note, in case it matters: I don't need the sound, just the image.

What format is your long video? The seeking performance problem may not be in Kdenlive but in your movie. If you aren't yet, you should consider using a container format that has index tables.

Now regarding extracting a clip from a movie, I believe you can do that with ffmpeg, specifying a codec named "copy" and setting a start position and a duration (in seconds):

ffmpeg -ss <start-position> -i <source-filename> -vcodec copy -acodec copy -t <duration> <destination-filename>


Sources to learn more about Audio/Video compression, codecs, algorithms etc. I was quite surprised when I learned the fact that the MP3 codec is extensively based on the Fourier Transform. I'd like to learn more about these topics in general. When I say more I mean the working principles of these technologies.

For even more clarity, I would prefer something like this video produced by Xiph.org

Compression codecs and methods are also based extensively in the field of Psychoacoustics.  For this, I thoroughly recommend the books available from the Focal Press, such as this one


animating a line that is a 3d layer in after-effects What I'd like to do

I'm trying to draw a 2D smiley face with the pen tool on a 3D layer...and then change it to a frown (or a sad face). I was able to do this in as 2D layer...but I'd need help on doing it as 3D layer.

Why I'm using 3D Layers in the first place

I'm using a camera (attached to a null layer) to zoom in and out of certain images I have in my animation (which are imported from illustrator). I've realized that you have to have 3D layers if you're gonna pan and zoom with the camera tool!

What's the Problem

It's close to impossible to draw using the pen tool if the pen layer is 3D. Even if I do get something drawn, I can't figure out how to animate it as a 3d layer.

Any tips?

The way I normally go about drawing paths in AE is by using the stroke effect with masks

Create an Adjustment Layer
Create Mask Paths for the smiley face
Add the Stroke effect to the Adjustment Layer
Make the Adjustment layer 3D and then position it where you want
Animate the Mask Path to animate the mouth

http://i.stack.imgur.com/MF5pX.png

Note:

For some reason the stroke effect doesnt work on open paths when there is more than one mask on a layer. So I put the eyes on one Adjustment layer, and made a second Adjustment layer for the mouth. Then I turned OFF 3D on the layers, PreComped them together, and made the PreComp a 3D layer.

Have a look at what I did: http://www.filehosting.org/file/details/334754/Smiley_Face.aep


How do I record video for more than 30 minutes at a time with a Canon A1400 PowerShot? I'm planning to send a Canon A1400 PowerShot to the edge of space with a weather balloon (we will figure out how to keep the temperature in our payload box suitable, so that is not a pertinent issue to the question). Unfortunately I believe it can only record 30 mins/4GB of 720p at a time. Our flight's duration is 3 hours and we want to capture all of that.

Can I program the A1400 with CHDK to recursively capture video till the memory card fills up? That is, start recording another video (almost) right after the 30 mins/4GB design limit is reached. If so, I would appreciate a script for the same!

Yes, CHDK should be able to do this.  There are actually scripts available on their wiki for this.  Basically, you have to tell it to press the video start button, wait a second or two for it to start, then begin polling to see if the get_movie_status has changed to the status for being done recording.  You then wait a second and repeat.

You'll also want to make sure you remove the 30 minute time limit with CHDK itself if available on your camera (under the video menu).  If it is, then you should only be limited by the 4gb file size limit and the script should restart the video.


GoPro why high frame rate does not reduce time On latest GoPro 4 Silver with 64 GB

when i set 1080p 30fps i get estimated 4 hour recording time but when i double the framerate it not only does not shoren it actually increases so with 1080p 60fps it shows ~4.5 hour.

How is that?

The GoPro4 Silver model uses the same bitrate for 1080p-30 as 1080p-60 and hence the recording times are similar. This does mean that fewer bits are allocated per frame in the 60fps mode, although since the codec H264 uses inter-frame compression, the difference won't be as stark.


focal length vs shutter speed vs fps I'm confused about the relationship between focal length and shutter speed, and the relationship between shutter speed and FPS. Can somebody explain in more detail here? What I read is that shutter speed=1/(2*fps) at least, while shutter speed=1/focal length.

Edited
If i have an ip camera of 640x480(sensor width =3.6mm), focal length from 5 to 50mm, need to record 30fps, what is the best shutter speed to be use?assuming that the object distance to camera is 60ft.

Shutter speed and focal length are completely independent parameters, focal length determines angle of view (how much scenery you get in your shot). Shutter speed determines how long each part of the image sensor is exposed for, and therefore it determines the brightness of the image, and how much blur is caused by moving objects.

The quantity that most commonly relates the two is camera shake. It is often advised that to avoid camera shake the shutter speed must be 1/focal-length. This is presumably where you've gotten this equivalence from. The rule is a guideline only and depends on your technique and degree of enlargement in the final image. A better guideline is shutter-speed = 3/focal-length

FPS, or frames per second is the number of images per second recorded by your camera. It is related to shutter speed in that shutter-speed + latency < 1/FPS. If each frame takes more than a 60th of a second to expose, then you are not going to be able to cram more than 60 exposures in a second! There is a nonzero amount of time required to recock the shutter mechanism (if necessary) and readout and store the image, which is the latency. In stills cameras not designed for continuous readout the latency can increase as buffers become full, causing the maximum obtainable FPS to drop.

The formula shutter speed = 1/(2*FPS) relates to a shutter angle of 180 degrees, which is a concept from film cine cameras whereby the film can only be exposed for a maximum of half the intra-frame time, because of the rotating shutter. This rule is still obeyed by digital filmmakers to ensure "cinema like" motion to the image, compared to if shutter speed = 1/FPS which gives more fluid "TV like" motion.


How did they make the nice moving shots in this video? https://prismic.io/ - has a very nice explainer video and I was wondering how they made the nice "tilted" sliding effect on the screencast video? Also... how are they making the video being focused on the center, but blurry on the sides?

I know it's probably a bit of a noob question, but I'm still relatively new to AE.

It's two very basic tools in After Effects.  The first is simply either a perspective correction or a 3d transform depending on which way you want to do it coupled with an x/y movement across the frame.

There are also a few different ways you can approach the blur such as using a layer as the basis of the amount of blur and using a mask or using a filter that supports a blur that changes with the distance from center (I think there is a built in filter to do this under the blur filters, but if not, I'm sure there are third party ones.)


What are motion graphics? What are motion graphics?  What software can I use to create them?  What should someone trying to produce a video with motion graphics know?

Motion graphics is a form of 2d or 3d animation based around moving graphics.  It can include such things as moving titles, animated presentations and graphs, animated background (motion backs), whiteboard animations, animated product demonstrations and more.

It can range in complexity from relatively simple (such as basic moving titles) to extremely advanced multi-layered projects laid out in 3d using numerous interacting objects.  Software such as Adobe After Effects and Apple Motion are often used for producing motion graphics.  It is also possible to produce some motion graphics in Adobe Flash, though it is more designed for pure 2D animations.  At the time of this writing, there wasn't much in the way of good open-source motion graphic software.

Motion graphics can be deceptive in the apparent simplicity when well done.  If you have no experience in the field, you should be prepared to encounter a lot of issues and challenges when trying to make a really good looking motion graphic.  It takes animation, graphic design and editing skills to produce a very high quality motion graphic and the tools themselves are complex beasts that can take a while just to learn the tool-set.

If you are looking for a professional looking motion graphic on a quick time table and you have no experience in the field, your best bet is likely to hire an experienced professional to do the work for you.  If you are looking to do it for your own purposes, it is an interesting field, but be sure not to set your bar too high.  Start simple and learn from there.  It is a field that can take months to years to get good in.


Help needed editing music more precisely in Premiere I have shot a video with 23,976 FPS and now need to expand the timeline to double that, so I can make more precise edits with the music.

But Premiere Pro only allows certain FPS

Is there a way to set custom FPS? As there isn't even a 48p Option like Hobbit used.

Or are there other better ways to edit music more precisly within Pr?

Perhaps the quickest option for better accuracy of audio editing would be to right-click on the actual numbers of the timeline and select "Show Audio Time Units" ?


How do I create a video of typing math symbols I am creating a training video on Calculus using my Mac, and I need to enter mathematical symbols such as integration and summation signs on my video. (The video is just a screen capture of me writing equations in sequence on the screen, until the solution is derived)

I bought a Wacom tablet thinking I would just hand-write everything on a graphics app and capture it in Camtasia. However it is difficult to draw a good looking symbol by hand using these devices

So now I am thinking to use type, but then how do you type an integral between limits without a lot of preparation for each equation, to produce things that look like this or this.

Does anyone know of a good way to type math symbols directly onto a screen in real time (or very near)?

MS Word has an equation editor,  but I would like to type character by character, and the equation editor forces you to set all of the characters and then renders them into a single image.

You could be clearer about what 'on my video' means. Does that mean: composited with other moving pictures in your video; or does it mean: in a sequence all by itself that's edited into your video? Or something else? And what video tools can you use?

For compositing use a compositing tool like Adobe After Effects. After Effects would also be perfect for building the 'typing on' sequence of symbols that you want.

If you don't have access to After Effects, why not build your sequence as a set of Photoshop layers which you can then export as an image sequence. Import that sequence into Quicktime (Pro), then re-export as a .mov using a codec that makes sense for you project. If you don't have access to Photoshop you can still do this with any cheap graphics software. Just 'manually' output identically sized images and name your output files sequentially. Tell Quicktime Pro to import them as a sequence.

Another idea:

create a single good image (similar to the ones that you provided links for) of the complete expression or equation that you want to 'type on' the screen.
import into Adobe Illustrator or PhotoShop.
create a series of white 'masks' (just rectangles) to cover each term in the expression or equation) and put each one on it's own layer, in the sequence in which you'll want them revealed.
De-select the eyeball on each layer, in sequence, to hide the 'mask' for that layer and reveal each term in sequence. Run Camtasia as you do this and you'll have the 'typed-on' movie you're looking for. You could pre-record your audio so that you'd have a good sense of timing for the reveal of each term.


Is 8 Bit 4:2:0 chroma subsampling "good enough" for chroma key? My school bought a Panasonic 4K camcorder (which I don't remember exactly which model) pointed at a green screen and this got me thinking.
If it's a HC-X1000 with it's tiny sized sensor and 8 Bit 4:2:0 (In HDMI output too!) it probably means it won't record green screen and subject transition nicely.
So what I wonder is. Is 4:2:0 really enough for chroma key? I have heard even 4:2:2 has problems when it comes to chroma key so I am worried and would like some clarification
Also, If I downscale 4k 4:2:0 to 1080p somehow will it mean it will become 4:2:2 footage? I have thought about trying to do this then doing some recent "Artificial Intelligence Supersampling" wizardry to push it back to 4k

"Good enough"? Sure. I wouldn't love to work with subsampled footage for keying, though. You want to maximise resolution, minimise or avoid subsampling and avoid spill. If your screen is well lit, you got the best circumstances.
So yeah, on paper, a chromatically subsampled file will give you more artefacts and jagged edges in your matte compared to a prores4444 or raw-recording. It is still a workable compression, though. Just try to optimise everything else I mentioned.


Is this projector capable of 1080i resolution? From the specs of the projector:

  DLP - 4000 lumen - 1024 x 768 - 480p - 720p - 1080i - 3D Ready - 6.4 pounds

They state the resolution is 1024x768, but then they add 1080i, from wikipedia:

  The term 1080i assumes a widescreen aspect ratio of 16:9, implying a
  frame size of 1920×1080 pixels.

I'm a bit confused, what the resolution of this projector?

Yes

Most projectors support multiple resolutions.  The specifications list all resolutions supported by the projector.

The projector you are asking about will handle 1024x768, 480p, 720p, and 1080i.


What kind of effect is that? How can I replicate it? I'm trying to replicate this effect on the logo whose it starts with a fade and then these “bubbles” filling the logo until complete.

Demo:

Well, the fade effect I can replicate :D. But this other effect I can't find anything like that in after effects. Any tips?

This is a very simple animation, actually. Here's how you could do it the easy and cheap way:

Create a solid with the size of your composition
apply "fractal noise" to it
Set the transform, brightness and contrast of fractal noise so that you have small drops instead of large shapes. You might want to set the complexity to one and experiment with the settings until you like the look.
Click the stopwatch on the brightness and lower it so much that the solid is completely black
go forward about 2 seconds and raise the brightness so that the entire solid is completely white.
Now create a text-layer under the solid and type your text
Set the "Track Matte" of your text-layer so that it takes a luma-mask from the solid above

Now, the luminance of your animated solid determines the alpha-channel of your text-layer, making it appear piece by piece. However, the effect looks sort of cheap in my opinion. For a better result, I would recommend you try to use a particle simulation (such as particular, not a free plugin unfortunately) and use the text layer as your emitter. You let the Text dissolve into dust like in avengers, and simply reverse the sequence, so that the text is being built from dust.

I hope I was able to help, have a wonderful day :)


Animate title mask from location a to b in Adobe Premiere CC 2017 I am very new to Adobe Premiere, but have worked with Final Cut Pro a long time ago, so you can say, I understand the basics.

I am attempting to create a "fancy" lyrics video. Fancy in the sense that the lyric text (a Title in Adobe Premiere) gets filled with a different a colour in sync with the artist singing the song.

I am attempting to achieve this with a mask (solid colour) placed over the title, but I do not know how I can animate the mask from location A to location B. I have created a Screencast to show where I'm stuck.

Any help would be greatly appreciated.

You need to use keyframes instead of tracking. You can find them here:

For better understanding of how they work, read about them, or watch the video.
Long story short, you need to create keyframe in the first place, where motion starts. After that you need to have keyframe in every place, where is key place of position. If you will just move the mask, after creating first keyframe, other ones will be created automaticly, after you move mask.

To create keyframe, press on the middle round button, in the place highlighted on screenshot above.


Should I rather be shooting 1080/50i or 720/50p for 25fps web use? The camera here is a Samsung HMX-Q10P (P likely stands for PAL: the N model would have 60fps instead).

The videos I upload usually are 25fps either way, but strictly speaking 1080/50i will never give me the odd lines when dropping every second frame, so I rely on the deinterlacing algorithm of my video editor (Shotcut in this case which may use ffmpeg or other stuff internally) to deliver reasonable content.

I've made a few attempts at fast moves of the camera shooting 1080/50i and I have not been able to see noticeable staircasing when creating 25fps output from that by reexporting from the video editor.  However, I am not sure how much quality deterioration the interpolation of the odd scanlines will cause.

So assuming the desire for best results, would I be better off shooting in 1080/50i or in 720/50p for videos without global movement (fixed mount, no zoom while shooting) and moderate local movement (close-captured single musician), and how would those considerations change given different material?

If you're mainly concerned about the staircasing, consider where the video will be watched. If interlaced video is shown on a display made for interlaced video, it appears ok. If you play it on a progressive display (such as a computer monitor) the staircasing is easily noticeable even for little horizontal movements (of the camera or of the subjects). For details see https://cardinalpeak.com/blog/interlaced-video-and-computer-monitors/

Best is if you never have to deal with interlaced video if possible.


Why does my video show wrong colors after import into after effects? I would like to edit a video, but as I import it into AfterEffects it does not show the correct colors. VLC does show the correct colors. It's not the codec, because h264 is supported by aftereffects. It is not the edit lists. The imported video looks like this.

I suspect alpha has somethin to do with it, because if I decativate alpha (ALT + 4) the screen becomes white.

After rendering it still looks like this.

I'm at a loss where to look for the cause, please give me some hints where this is coming from and/or how to get rid of it.

I'd recommend trying to convert the source file to another file type before importing into After Effects.
Maybe try the media encoder, vlc or an ffmpeg variant.
If you can, convert to an intermediate mov-codec or an image sequence like tiff.
If your file seems fine in VLC etc. this might work.


Add semi-transparent box around subtitle Hey guys how can I add box around subtitle like on picture with ffmpeg
here is mi current command

ffmpeg -i movie.mkv -strict -2 -vf "subtitles=subtitle.srt:force_style='FontName=ubuntu,fontsize=30',scale=720:-1" -qscale:v 3  Movie.avi

Use

ffmpeg -i movie.mkv -strict -2 -vf "subtitles=subtitle.srt:force_style='FontName=ubuntu,fontsize=30,BorderStyle=3,OutlineColour=&H80000000',scale=720:-1" -qscale:v 3  Movie.avi

See Style Fields and Data Types for tag info and color syntax.


Syncing Shogun Footage with PluralEyes? I can't get my video footage to sync with my audio in PluralEyes 3. Here's what I tried...

I shot some interviews today using a Sony a7s and Atomos Shogun. I recorded almost everything through the Shogun but then my battery died on me and I recorded the last few clips just through the Sony. For audio, I recorded from a Sennheiser boom through a Zoom H4n.

I imported everything into Premiere Pro and made 2 sequences: one for the Shogun footage and one for the clips just recorded on the Sony. I sent the Sony sequence to PluralEyes 3 and it synced fine. But when I sent the Shogun footage to PluralEyes 3, it wouldn't sync. I tried importing the footage straight to PluralEyes (instead of sending it from Premiere) and that also didn't work. It won't sync at all; all the clips are red.

I double-checked that the Shogun recorded audio and it did. It recorded 4 channels, but 2 of them are silent. The H4n recorded in stereo (just in the left channel though).

Has anyone else experienced this problem? Any suggestions on how to sync my footage?

I am on Premiere CC 2015, which has its own PluralEyes equivalent for synchronizing audio under the "Merge" function. (I think it was also on CC 2014 but I am not sure what version originated audio sync functionality.)

Select your two clips in your bin and merge them (it's under "Clip"). In the menu, under "Synchronize Point" choose "Audio" and make sure the "Track Channel" dropdown is set to a track that has audio on it. The Shogun material I was using had audio on track 3.


Auto upload (ftp) video file once it's finished encoding I'm in a live production, and I'm clipping hundreds of short videos all day every day. What I'd like to do is use some application to set a watch folder, and as soon as I hit stop on the encoder, and the file is complete, it automatically uploads to a root directory on a specified ftp site.

I've tried using winscp, autover, and many others, but I keep running into several issues: 1) If I set a watch directory, and the file starts encoding, it's changing file size every second, so the application basically tries to do a new upload every 1 second on a file that's not even complete. So that doesn't work. And 2) The ftp has a cron job that pulls the file out of the root once the upload is complete, so it disappears from the remote, so some of the apps detect this as a change and try to reupload all the past videos.

What I'm looking for is an app that I can point to a folder, and say "Don't upload old files that aren't changing in size, don't try to sync directories, just wait for new files to show up, and keep checking their size every 5 seconds, after 5 seconds pass and the size hasn't changed, upload to this ftp."

But so far I'm striking out. Any help would be appreciated.

My clipping machines are Windows 7, but I also use Windows 8.1 / 10.

Maybe someone will chime in with an app suggestion that directly fulfills your need, but here's a temporary workaround - a bit convoluted, but should work.

Create two folders A and B.
Set folder A as the destination folder in the encoder.
Apply a suffix to all the output files being generated, something innocuous like ENC e.g. Clip2015-09-25-23232-ENC.mov - this step assumes that there may be other non-actionable files in the folder. Skip if not so.
Set up a batch job that runs periodically, whose first command is to rename all files with the suffix, like by adding a prefix or another suffix. And whose 2nd command is to move all files with the new prefix to folder B
While the encoder is working on a file, it has a lock on it, and so only completed files will get renamed. And only those will be moved to B.
Use any of your aforementioned FTP apps to watch folder B and transfer files.


converting to .MJP files I would like to convert some short videos to .MJP format, and none of my preferred tools for video conversion can do this. Can anybody suggest free software that can achieve this? OSX preferred, but Windows is available if necessary.

EDIT:

All I can tell you is that I have a (newish) device that has a video screen and contains a memory card holding four .MJP files that can be shown on the screen.

The videos play, with sound, so I know the files are valid. If I copy them over to my Mac, no software that I've found can play them.

I would like to replace the video files that the device shows, but this requires converting my videos to .MJP format. I have put one of the existing files at https://app.box.com/s/kbtvfbpowqwbp1aym88m if anybody wants to examine it.

http://www.openthefile.com/ext/mjp/4458 and http://www.fileinfo.com/extension/mjp both suggest mplayerx (http://mplayerx.org/) can play them. It would make sense to post a file for people to examine. If mplayer or ffmpeg can play them, chances are mencoder or ffmpeg can encode to the format.


Recording 4K H.264 from HDMI to External Media I've been searching for an answer to this but haven't been able to find anything definitive.

I use an Orah 4i 360 livestream video camera. It sends the camera video to a stitching box. The stitching box sends out 4K (4096x2160) H.264 prestitched 360 video over RTMP. It also can record to internal SD card. But it can't record internally at the same time it is outputting over RTMP.

In order to record the livestream, you have to use the HDMI 2.0 output, which also sends the the same H.264 mp4 video, but without the RTMP 360 control data.

I need to record the 4K mp4 video from HDMI to an external HD or SD card.
Since it is already encoded mp4, even though 4K, it doesn't really need the data record rate that something like an Atomos Ninja Inferno or Black Magic options. They record RAW uncompressed video, and you pay for that. I only need to record mp4, even though 4K from HDMI.

So, does anyone know of a cheaper solution than Atomos has to record 4K HDMI mp4 to an external HD or SD card?

Would you consider using a computer equipped with a 4K HDMI capture card like BlackMagic Intensity Pro 4K, to write to that SD card?

This will be cheaper than buying a recorder and you will have full control over how you capture this 4K stream over HDMI.


kazam no sound and no red border for screencast kazam worked fine on ubuntu 19.04, recording audio and video, and showing the red rectangular border during screencast recording;

after installing ubuntu 20.04, kazam (from the repository) records video with no sound and does not show the red border as a visual cue so you know which part of screen is recorded

I looked at pavucontrol and nothing is muted, the sound is fine, it is just that kazam is not recording the sound

Also, going to File-Preferences in Kazam, in the General tab, the speaker sound is set to off. I can set it on, to max even, but there is no OK or Apply button, so as soon as I close this dialog, upon returning, the speaker sound shows again off as before.

I tried editing the

~/.config/kazam/kazam.conf

file manually and set audio_toggled = True and restarted kazam but there was no effect

I tried xvidcap which I used to use before kazam, but after building it from source, I found it records each frame in a separate xwd file. So the solution appears to be to give up on kazam, just like on xvidcap.

I found that ffmpeg can be used to record a screencast like this. First, find out the screen resolution

xrandr

next, find out the audio source - we are looking for the number of the source that says alsa_output

pactl list sources

then start the screencast

ffmpeg -video_size 1920x1080 -framerate 20 -f x11grab -i :0.0 -f pulse -ac 2 -i 4 output.mp4

in this command, 1920x1080 is the screen resolution output from xrandr

-i 4  is the source number of alsa_output from pactl list sources

-ac 2 set 2 audio channels

-f pulse expected format is pulse audio

-i :0.0 video input from main screen

-f x11grab video input format is X server output format

the video is saved in output.mp4 and to stop the screencast, go to the terminal window and control-C


Get better focus on Canon DSLR's I need some advises and opinions on how to get better manual focus while shooting video on Canon DSLR's ex. T2i, T3i, etc. Since these haven't got any focus indicators or anything like, like for example GH4 with focus peaking while shooting, although it is possible to get that with Magic lantern, I'm interested in native way. The problem is that you have to go from the eye and assume that focus is right, and I often find after importing videos on PC that focus is way off. How can I improve my workflow, and get better focus?

Probably the best thing you can do is get an external monitor. the electronic viewfinders on most DSLRs are too low resolution to be able to judge focus critically. Many of these monitors have built in edge peaking, or focus detection tools as well to make it even easier. Unfortunately to get a decent high resolution external monitor is going to cost the price of the camera again.


Parent Pick Whip Not Showed On Effect Transform Keyframing I wanted to parent the effect transform expression to the tracking motion (null object)

When I saw the tutorials.. it showed me to click and drag the pick whip, but on my after effects there are no pick whip on the side of transform value

Expressions aren't parented. They use the same kind of widget but it's not the one in the parent column.

You need to enable expressions on the property by alt-clicking the stopwatch. Now you'll see the expressions pickwhip, as well as the dropdown with the expressions menu and so on. You'll know that expressions are applied because the value will turn red.


How do I prevent Quality loss in the beginning of a video? My company transcodes videos sent in by users (recorder by our own screenrecording software)

I use FFMpeg to do the work using this command:

 /ffmpeg/ffmpeg -i in.mov -vcodec libx264 -fpre /ffmpeg/ffpresets/libx264-slower.ffpreset   -y out.flv

The purpose is to prepare the video for viewing in browser.

The problem is that the first 10, or so, seconds the quality is really poor.

What can cause this? and how can i fix it?

Preset settings:

coder=1
flags=+loop
cmp=+chroma
partitions=+parti8x8+parti4x4+partp8x8+partb8x8
me_method=umh
subq=8
me_range=16
g=250
keyint_min=25
sc_threshold=40
i_qfactor=0.71
b_strategy=2
qcomp=0.6
qmin=0
qmax=69
qdiff=4
bf=3
refs=5
directpred=3
trellis=1
flags2=+bpyramid+mixed_refs+wpred+dct8x8+fastpskip
wpredp=2
rc_lookahead=50

Exampel of an input video

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '84f42bcb67ac616635ef6f99057bbbc46d418295.mov':
Metadata:
    major_brand     : qt
    minor_version   : 537199360
    compatible_brands: qt
    creation_time   : 2012-03-07 13:45:16
  Duration: 00:15:56.00, start: 0.000000, bitrate: 4108 kb/s
    Stream #0.0(eng): Video: qtrle, rgb24, 1680x945, 3401 kb/s, 13.61 fps, 1k tbr, 1k tbn, 1k tbc
    Metadata:
      creation_time   : 2012-03-07 13:45:16
    Stream #0.1(eng): Audio: pcm_s16be, 44100 Hz, 1 channels, s16, 705 kb/s
    Metadata:
      creation_time   : 2012-03-07 13:45:16

Fixed by updating FFMpeg to newer version


ffmpeg: concat Results in "Buffer queue overflow" and Short Audio I have this video file that at one point introduces an async of ~1 second. So I tried to make it work by duplicating a short segment at that point as it's silent there:

$ ffmpeg -i DFW.mp4.mkv -filter_complex '
[0:a] aselect=n=3:e=lt(t\,18*60+42.100)+gt(t\,18*60+41)*2 [as] [ae] [am];
[am] asplit [am1] [am2];
[as]  asetpts=PTS-STARTPTS [as];
[am1] asetpts=PTS-STARTPTS [am1];
[am2] asetpts=PTS-STARTPTS [am2];
[ae]  asetpts=PTS-STARTPTS [ae];
[as] [am1] [am2] [ae] concat=n=4:a=1:v=0 [a]' -map 0:v -map '[a]' -c:v copy DFW-1.mp4

In other words I have

as the start until 18:41.000
ae the end from 18:42.100
am the middle section between 18:41.000 and 18:42.100, which should be repeated once

The segmentation works, the concatenated audible part sounds good. However, ae turns out to only be ~5 seconds short and ffmpeg starts to print spammy "Buffer queue overflow, dropping"-lines. The entire video is 1h30 long leaving me with plenty of silence until the end.

In other words the video and audio are fine until about 18:48.000 and the remaining 1h11 of the video has no audio.

Why is ffmpeg doing that and how can I fix it?

I also tried to include a silence audio segment instead as plan B, but failed.

Assuming there are no timestamp discontinuities in the audio, a simple atrim and a null segment should work.

ffmpeg -i DFW.mp4.mkv -filter_complex '
[0:a]asplit[a][b];
[a]atrim=0:1122.1[pre];
[b]atrim=1122.1,asetpts=PTS-STARTPTS[post];
anullsrc,atrim=0:1.1[seg];
[pre][seg][post]concat=n=3:a=1:v=0[a]' -map 0:v -map '[a]' -c:v copy DFW-1.mp4


How does GSpot calculate "Recommended display size" I've got a video and I thought it's size was 640x480 and this is shown on GSpot.

However also in the container section of GSpot it is saying

 Recommended Display Size: 853 x 480

does anyone know where it get's this from?

1) If it is calculated what from?

2) If it is a property of the file while isn't it the same as the width x height?

I don't know what tags or fields are present in a .MP4 file, but something is flagging the file as having a 16:9 'display aspect ratio' (shown as "dar" in GSpot), while the 'pixel aspect ratio' (par) is 4:3.

((480 * 16) / 9) = 853


Decrease size of a avi video with lowest quality loss I have been working on an animation with Blender. Further I rendered it at 24 fps at 1080p resolution.
The problem is that the rendered video is around 30 seconds and has size around 4.3 GB.
Is there any way to decrease the size without losing much quality?

Now you've actually finished your question, the simple answer is to encode it using h.264/mp4. Blender can render to h.264, using ffmpeg video in the render settings but the better way is to render to image sequences and convert.
Since you have a render, you can convert it to h.264 / mp4 without having to re-render. There are many ways to do this, ffmpeg being one of the best, but if you prefer a GUI then Handbrake is a good option.


How to achieve the "magic swipe" effect in this video? How to achieve the "magic swipe" effect in this video (at 0:16)?

https://www.facebook.com/diplycrafty/videos/1867777256617888/

Is it necessary to use After Effects? Can other open source software do so too?

Assuming you're using a layer based compositor (like After Effects) you need two layers. The top layer has the half-painted box with the hand swiping over it. The bottom has the fully painted box, and no hand, but everything else is the same as the first shot.

Now you need to make a matte that corresponds to the trailing edge of the hand, and extending (roughly) to the the top left of the screen and down the left side. As the hand moves across this matte will follow it, so that at the start it is not over the box, and at the end it completly covers it. the easiest way to do this would be to trace the hand, but there are other ways like rotobrush in After Effects. Apply this matte to the top layer so that it hides everything inside it.

Alternatively you could shoot the hand over a green background and use chroma keying to remove the background. Then use a simple matte to reveal the painted box, with the transition hidden by the hand layer. You could even get away with a single still image of the hand, animated to look like it was moving, if the movement is fast and simple enough.

It's certainly doable with After Effects, but You could use Blender or any compositor or NLE that has the capability to create moving mattes


Can i record continuously, keeping just the last N minutes? I'd like to use a GoPro Hero2 or 3+ black to record video continuously, but want it to store only the last N minutes (or megabytes).

Is this possible?

From the manual, I believe no, but I probably am not the first user thinking about such a feature?

Short answer: no.
Long answer, maybe. You have very limited scripting ability via the auto update function of the camera. You simply drop a text file called "autoexec.sh" on the SD card before turning the camera on and the camera will execute the script. Though I haven't seen a script that would do something like infinite recording by erasing the oldest part of the recording.

Maybe you are able to delete certain files from the SD card via the scripting interface, in that case you wouldn't be able to do seamless infinite recordings but you could record in N minute intervals and delete the oldest file after x recordings when you know that you probably have nearly used up the sdcard space.

You might also be able to do this by doing said interval recordings and have the GoPro's wifi webserver monitored by a computer that deletes the oldest file on the camera once you reach critical storage space.
In case deleting via the camera script interface isn't doable.

All needed info about this hack can be found here (horrible site but lots of information) and some existing scripts here.


Convert high frame video to slow motion video I recorded a "slow-motion" video with my Android phone and transferred it to my Windows computer. Now I have an MP4 file with a frame-rate of 240 fps. But when I play the video, it plays at normal speed.  I want to create a video that I can upload to YouTube or Facebook that plays at 1/8 speed (30 fps).

I thought I could do that with the free Movie Maker that comes with Windows. But when I select 1/8 speed it comes out chunky. It looks like the software converted the video to 30 fps when it loaded, and is now playing back that 30 fps video at 1/8 speed.  I'm guessing that Movie Maker can't do what I want.

How do I create a video so that when someone plays that video they see it in slow-motion?

You can use ffmpeg, a free command-line tool, to do this:

ffmpeg -i input.mp4 -vf setpts=8*PTS -r 30 -crf 18 output.mp4

This slows down the video 8 times and output is 30 FPS.


Process for crafting disparate travel footage I shot 40 hours of mini dv tape of cycling to India. I worked with a professional film company, who gave me some tuition beforehand. However, in the end the film company decided to produce the film about my mate who I was also travelling with and make a love story about it. However, I've got a bunch of footage out of which I think there is enough quality material to make a 1 hr film.

How can I craft this travel footage into a worthwhile product?

I'm currently logging a tape per day, with timecodes and paper notes, and keeping a record of clips I consider to be worthy of going into the film. What other methods can I add into my process to sort out my footage and what methods can I use to craft a story?

If this was me, I would log all the tapes with notes and do a rough outline  (on paper) as to what I would like to have.

I would then go and do a rough cut (very rough tbh), putting all the content I want in a order that makes a bit of sense. you can then see how long it is, if its to long you know you can cut it down, if its to short then you might have to rethink your idea or find more footage to use.

I would choose some music (if you are going to have some) for background, montages etc then do another cut to the music getting closer to your final time limit-ish

Sit back give it a week or so go back watch it through and see if you like the way it is being told but have a open mind while doing this.

Do another refined edit of things you didnt like when you watched it back, move things around, change up the flow etc etc.

Watch again and keep doing the last step till your happy with output and story, making sure it wont bore someone watching or confuse them.

get a focus group (Friends, family) to watch it and let them be critical about it to see if they like, understand etc get there feedback and do a final cut.

Final stages are getting the sound levels and colours looking good then let people watch it

OR

get a editor who knows how to tell a good story and ask them if they will help you edit the footage down or get their help in the last stages to refine it all.

There is a good course called Inside the Edit https://insidetheedit.com/ it is a little pricey but it will give you what you want I think, If I have the money I would do it but I just go with my feelings and the above


I am getting "Stream specifier ' ' in filtergraph description" in ffmpeg I am generating 10 seconds of silence using an image. Here is my command

ffmpeg -loop 1 -framerate 24 -t 10 image.jpg -f lavfi -t 10 -i anullsrc -filter_complex "[0][1]concat=n=2:v=1:a=1" out.mp4

Also, I have tried

ffmpeg -loop 1 -framerate 24 -t 10 beach.jpg -f lavfi -t 10 -i anullsrc -filter_complex "[0:v][1:a]concat=n=2:v=1:a=1" out.mp4

I am getting following errors

ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
  built with Apple clang version 11.0.0 (clang-1100.0.33.17)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.2_2 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, lavfi, from 'anullsrc':
  Duration: N/A, start: 0.000000, bitrate: 705 kb/s
    Stream #0:0: Audio: pcm_u8, 44100 Hz, stereo, u8, 705 kb/s
Stream specifier '' in filtergraph description [0][1]concat=n=2:v=1:a=1 matches no streams.

ffmpeg -loop 1 -framerate 24 -t 10 beach.jpg -f lavfi -t 10 -i anullsrc -filter_complex "[0:v][1:a]concat=n=2:v=1:a=1" out.mp4
ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
  built with Apple clang version 11.0.0 (clang-1100.0.33.17)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.2_2 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, lavfi, from 'anullsrc':
  Duration: N/A, start: 0.000000, bitrate: 705 kb/s
    Stream #0:0: Audio: pcm_u8, 44100 Hz, stereo, u8, 705 kb/s
Stream specifier ':v' in filtergraph description [0:v][1:a]concat=n=2:v=1:a=1 matches no streams.

Your command is missing the -i token for the image input, so it should be

ffmpeg -loop 1 -framerate 24 -t 10 -i image.jpg -f lavfi ...

However, for the actual task at hand, the concat filter is not required.

ffmpeg -loop 1 -framerate 24 -t 10 -i image.jpg -f lavfi -t 10 -i anullsrc out.mp4


Can you encode intra-frame videos from inter-frame without loss? I'm aware of the differences between intra and inter, but I'm not the most savvy about reencoding them after the fact.  Is encoding with intra from an inter-coded video the same as if you originally used intra to begin with?  Or does it need to be kept as intra from the start to preserve complete images?  Maybe I didn't search well enough, but I'm surprised I couldn't find info on this anywhere.

An encoder receives and works upon uncompressed frames and does not know or care about the encoding of the source stream.

To avoid any information loss, you have to set lossless mode. For x264, this is by done by adding -qp 0 to your ffmpeg command. But for most purposes, strict mathematical losslessness is not required. See What's the difference between "visually lossless" and real lossless and what does this mean for future encodes?


Combining high res photo with low res video in a static shot Suppose I have a 1080p video of a static shot with minimal motion and little change in lighting, and a higher res (~ 18 megapixels) still photograph of the same setup.

How would I go best about using the extra resolution of the photo if I wanted an ever higher res video output (say, 4K)?

My naive idea would be to scale up the 1080p video in an AF composition and use a blending mode for it to influence the still photograph below. I'd have to do rotoscoping to isolate the moving parts and put them on top (upscaled)..

Is there a better way?

To extract the moving things, I'd try a difference matte. There's a tutorial on doing it in After Effects here and another one here. You'll need to somehow extract the static background, probably by averaging a few (or several) frames of it together. Then use the techniques described above to subtract out the static stuff from the moving stuff. (Maybe a combo of garbage mattes and difference matte could do it? Depends on the footage.)

Once you've done that, combining the moving matted footage over the hi-res image (probably using a "Normal" blend mode) should get you what you want. I'd be interested to know how it looks in the end. I've seen composites that looked bad because the composited object had a different amount or type of grain from the background. I suspect being at a different resolution may be just as bad, given that the grain will be huge compared with the background, but since I've never done it, I can't say for sure. Good luck!


DIY 120fps video recording and instant replay I am trying to build cheap recording and instant replay system using two or three GoPro4 cameras. The idea is that I can put cameras on stands, connect them with computer and record two or three different scenes at the same time at 720p, 120fps. Is this possible with wifi connection to receive 2 or 3 signals from GoPros and record them simultaneously to a computer?

The next thing I need is the ability to rewind certain scene/camera recording (while still recording in the background) and just preview instant replay of a specific time frame or maybe even frame by frame.

Is this possible? Can someone point me in the right direction for some kind of software or additional hardware I would need in order to accomplish this?

I believe the answer is no, no, and no, for several reasons.

First off, GoPro don't support their cameras as broadcast cameras.  They are person video recording devices.  I tried using the HDMI output of a Hero3+ camera to feed into a studio broadcast system, and when it didn't work the response was "it's not supposed to".  The Hero3+ (and I presume the Hero4) do have ways of sending video over wifi so that you can get a vague idea of what the camera sees, but it's nothing like full resolution.  So the first "no" is that you cannot really extract good video from the GoPro in real-time.  You have to record it and them dump the card.

The second "no" is that 120fps is just barely starting to be supported at the video transport layer.  Yes, people have been talking about gaming consoles that can achieve 120+ fps for some time, but actually driving that kind of speed to a monitor?  Very hard.  And impossible with the HDMI output of the Hero4, which is limited to 60p: https://gopro.com/support/articles/hero4-hdmi-output-information

The third "no" is getting that 120fps input into your computer.  There is screen recording software that can scrape 120fps output from your GPU, but recording 120fps of 720p (or greater) is still a very specialized thing that's outside your "cheap recording and instant replay system" parameters.  There are video capture cards that claim 120fps recording, but they are cheating: they are multiplexing 4 SD signals (thus really recording 4x 30 fps and calling it 1x 120 fps).


Can I copy and paste all keyframed parameters (settings and effects) from one layer to another in Adobe After Effects CS6 within a single composition? As the question title says. Is there a shortcut, or some way to do this?
Single composition suffices.

The only thing I found is to copy all effects, by selecting a layer → effects panel → CTRL + A to select all effects → CTRL + C to copy → Go to other layer → effects panel → CTRL + V to paste the effects.

The aforementioned process copies all effects and their keyframes, but not the individual settings. The settings of each effect is the default. That being said, I am surprised to see that they are actually keyframed.

Also, it doesn't copy other keyframed parameters (non-'effects'), such as Position, or Opacity.

Is there a way to copy all keyframed parameters exactly from one layer to another?

I'm working with Adobe After Effects CS6. Thank you.

If you go to the sequence window you can hit uu (that's double tapping the u key), to show all modified properties. Then copy all the keyframes and values (drag the cursor over the whole timeline area, including the I-beams for non-animating properties (the ones that are highlighted in blue) and copy.

If you want to copy properties that are default for one layer on to another you could use ~ instead of uu, that will show all properties of the layer.

Note that there are some effects and properties that you can't copy, they're usually things that have a custom value, like the source layer for effects that use other layers, e.g. compound blur.


How can I overlap content in Windows Movie Maker? Say I want to overlap another video on top of the one already playing. How do I do this? There seems to be no option to do so in the actual menus.

There's no native support for any sort of "Picture-in-Picture" functionality in Windows Movie Maker, so unfortunately, what you are asking cannot be done in WMM.


I want to run two 24/7 livestreams at once, both these streams will be on Youtube, is it possible? I want to run two 24/7 livestreams at once (both on Youtube), using an intel nuc device with the assistance of obs studio software, is this possible?

If not, how can I run 2 24/7 streams at once without needing two computers?

I think that will depend on the platform. I don't think YouTube allows that, unless you use two accounts. Either way, the answer is to open two instances of the upstream program (or browser for web based). Your only technical limits are your up speed and processing. Naturally, some platforms specifically block it. If we're working with recorded material, not actual live streams, then any consumer grade laptop should work.


What are the main limitations on using the following setup to boost frames per second capturing? Suppose I have two identical cameras, a red camera and a blue camera, that can both shoot videos at 1000 frames per second. If I set them up in the following set up, using a half-silvered mirror to capture the object highlighted in green, could I not technically achieve 2000 frames per second by simply overlapping the two sets of data I get from the red and the blue cameras? (e.g., take the first frame from the red camera, the second frame from the blue camera, and so on?) In effect I could double the frames per second of any camera with correct timing with the following set-up, though I've personally never touched a camera so I don't know the limitations that cameras could impose on realizing this dream of mine. I'm not too sure if this is off-topic either, sorry if it is.

You could get twice the frame rate if (big if) the taking times of the cameras were shifted by 1/2 millisec. In other words, the frame R1 is time stamped 0.0010 sec and the frame B1 is time stamped 0.0015 sec, and so on. Sync would have to be centrally driven, and registration would have to be perfect.

That leads to the problem that the frames from camera B would be horizontally reversed WRT the frames from camera R. This could be overcome, just something to consider when trying to register the images.


Changing color of numbers in stock exchange AE template with expressions I just wondering if there a way to optimize the way of changing color of numbers in stock exchange template by using expressions? When I put the +before the number it turns green and if -,it turns red.

This is probably not the shortest way of doing it, but it's quick and easy:

Make a null layer with a slider
Make a text layer with green text
Link the source text in your text layer to the slider in the null layer.

You should see an expression like this:
thisComp.layer("slider null").effect("Slider Control")("Slider")

Now add an expression to the Opacity control in your text layer. This is going to make the Opacity go to 0 if the slider value is below zero, or 100 if it is zero or above:
if(thisComp.layer("slider null").effect("Slider Control")("Slider")>=0) {100} else {0};

Now duplicate the green text layer

Rename it "red text"

Change the text colour to red

Edit the expression on the red text layer's Opacity control to this:
if(thisComp.layer("slider null").effect("Slider Control")("Slider")<0) {100} else {0};

Now the red text layer should only be visible when the slider value is lower than zero.
Screenshot of the whole thing below:

If you want a leading "+" before the positive values, you could also make an "if/else" statement in the green Source text control, so you only see a "+" when the value is above zero - something like this:
if(thisComp.layer("slider null").effect("Slider Control")("Slider")>0) {"+" + thisComp.layer("slider null").effect("Slider Control")("Slider")} else {thisComp.layer("slider null").effect("Slider Control")("Slider")};


Where do I find the standard licensing agreement on a video that's on YouTube? Where do I find the licensing agreement on a video so I know if I can use it or not?

From YouTube's help pages:

The standard YouTube licence remains the default setting for all uploads.

And Fair Use typically does not apply on the standard licence. See here for specifics, and when it does apply. The other option is Creative Commons:

Creative Commons licences provide a standard way for content creators to grant someone else permission to use their work. YouTube allows users to mark their videos with a Creative Commons CC BY licence.

Videos licenced under CC by Attribution 3.0 have this in the info under the video (you may need to click on Show More)

Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.


What benefit would I get from using Apple Compressor instead of just exporting from Final Cut Pro X? I have Final Cut Pro X 10.1.4. I usually always use the "share" option to export my video and select whatever format I want to share with. Usually either "Master File" or "YouTube". I also see the option to "Send to Compressor". I researched Apple Compressor and I am trying to figure out if it is worth the money. Does it really export with better options than just what can be done with Final Cut Pro? Also, to convert to different formats I have used Miro Video converter and Handbrake. Does Apple Compressor have a much better system or output than either of these other video converters? Just want to know if it is really worth the $50 USD for Apple Compressor.

Thanks for any input.

The export settings you are using in Final Cut Pro X are preset Compressor settings and the export itself is actually using the Compressor engine (but with no user control). Compressor allows you control over those settings and to save your own custom presets.

For instance, you may want to export an MPEG2 file with a particular bitrate, letterbox 16:9 footage in a 4:3 file, export to Vimeo with custom settings, or any other number of possibilities. If you wanted all of these outputs, you could batch process them. These, and other, codec/compression options can be configured in Compressor and saved as custom presets. Those saved custom presets then appear as available Share options in FCPX.

Compressor allows for encoding without requiring FCPX to be open, or for converting files that don't originate from a FCPX project among other benefits. It also provides a preview window that allows you to compare your source video to processed video before committing.

I still sometimes use Handbrake for h.264 files. It's very fast, clean, and free. In those cases, I will export a ProRes "master file" out of FCPX to bring into Handbrake.

Compressor is not a perfect program, but it is very useful. A lot of it depends on your workflow needs. If you like exporting directly from FCPX, but need custom share options, then Compressor is probably worth it  for you. If you are content with the presets or a workflow with other software, then perhaps not


How to remaster the Old movies to the High Resolution Quality using FFMPEG? How to remaster the Old movies to the High-Resolution Quality using FFMPEG?

Friends,

I want to remaster the Old movies to High-Resolution Video & Audio. How this can be achieved using FFMPEG.

You cannot magically pull out more resolution than the material you have. If it's 1920x1080, the resolution can only get smaller, i.e. 1280x720. There are options like Nvidia's Ai-Upscaling, but it works rather bad when applied to faces, which you'll probably run into. Another method might be to use Red Giant's Upscalers. They use more advanced upscaling methods than After Effects bicubic scaling - however, upscaling 720p to 1080p will not result in a regular fullHD image.


"stringy" polarized water effect Scenario

I saw this on a vimeo video and I want to try and recreate it. I've been using the various particle systems in after effects CC but I can't figure out how to get the particles to be "sticky" to one-another.

Question

How can I create a stringy / ropey water dribble effect similar to the clip below?

https://cl.ly/a576fc863a00

Per @Mark's comment I used blender to do this. I followed this tutorial for making a stream of water and modified the water emitter to be 0.1x0.1 meters so that it makes a stringy / gooey like effect.


Use ffmpeg to extract 15 frames at specific intervals I'm new to using ffmpeg, but I want to extract 15 consecutive frames (resized to 320x240) at specific time intervals from an existing video.
What I have so far is this:

ffmpeg -ss 30 -i inVideo.mp4 -vframes 15 out%d.png -s 320x240

While this does create 15 frames at the 30 second mark, they are not resized.
Also, if I have this in a loop, the output images will be overwritten.
I want to create a total of 9 time intervals with 15 frames/images each.
Any idea of how I can accomplish that?

Thanks for all your help!

The basic template is
ffmpeg -i inVideo.mp4
  -vf "select='between(t,30,30.5)+between(t,45,45.5)+between(t,73,73.5)'"
  -s 320x240 -vsync 0 out%d.png

The select filter expression selects all frames in each of the three ranges. I've chosen an endpoint 0.5 seconds greater than the start point under the assumption that the video is 30 frames per second. Adjust accordingly.
Frame sizing is an output option so it has to appear before the output it is meant for.


What technique is used: Falling Whistles video Off topic question, but I'm wondering is there a name for the technique being used in this Falling Whistles: Be a Whistleblower for Peace video? It has a stop motion animation feel to it.

Link: https://vimeo.com/7351545

More specific:

How are they animating the text
How are they doing the rotate in and out transitions (Are they
rotating in the entire precomp file?)

Any help would be appreciated.

It has a stop motion animation feel to it.

With standard keyframes, motion is interpolated between two points smoothly.
The 'stop motion' effect is achieved by using hold keyframes instead.

  How are they animating the text

Usually the answer to these questions are keyframes, lots and lots of keyframes. Specifically keyframes on scale, position, rotation and occasionally opacity.

The timewriter effect applied to individual characters or words can be easily achieved in After Effects using the 'Animate Text' effect.

The subtle 3D text effect at 00:35 can be achieved using the 'Basic 3D' effect. In the current version of AE the effect is listed as obsolete but it's easy to use.

Also most of the text are used as masks on top of photographs to add a texture.

  How are they doing the rotate in and out transitions (Are they
  rotating in the entire precomp file?)

It's likely that individual elements such as text and images are being rotated individually with the rotation offset of each element at different places.


Attach a video to a static image? Well, its not my area and i am a little bit scrappy with this.
So we have this little device , that we want to show how a real human hand stick to some different places .(for example door,window,gate ,etc)
Because we cant go physically over 50 locations, i was thinking about this

I will picture one video, where a hand stick the device to some flat green/blue area, then replace that area with a different picture(s) .

1.Is it possible to make this look real (so a normal eye cant tell)?

Is there any better colour to use on the background ?

3.What is the simplest software that do that on a mac? Can iMovie do that ?

Thank you.

The effect you are looking for is Chroma Key, and it is supported by iMovie (according to this Apple documentation).  The color green is typically used (and the technique known as Green Screen) because green is not the color of human skin, and thus easy to distinguish.  When green is a color that must be used in the scene (for example, if your subject is Kermit the Frog), then Blue Screen is used (and the technique is known as Blue Screen).  Sometimes no color works, in which case, people use bright white or dark black.  Chroma key software can work for those, too, but technically it's a Luma Key in that case.

As for making it look real--that's a skill.  But now that you know the name of the technique, you can find articles that explain how best to do it, and the pitfalls to avoid.


Multivideo player with histograms? Is there a tool that can play multiple videos while displaying a histogram of each video simultaneously?

IDK how well this would work. Prob. not at all for vids with differing GOPs, but you could try using something to mirror your keystrokes to multiple windows.

Autohotkey can do that on Windows.  On GNU/Linux, Terminator can send keystrokes to multiple gnome-terminal tabs at once, so you could control mplayer that way (since it reads the tty as well as accepting keystrokes to its windows.)  I'm sure there's a way to dual-box games on GNU/Linux by mirroring keystrokes to arbitrary windows, I've just never had occasion to go looking.

If any open-source player has the kind of histogram you're looking for, and an existing API for writing GUI frontends, then in theory it shouldn't be too hard to (pay a coder to) hack something up that sends seek-to-a-position commands to multiple instances of a player.  This could solve loss of sync problems after seeking, if you get that with blindly driving multiple players.

ffmpeg has a histogram filter. From an example in the ffmpeg docs: play a vid with a filtered version side-by-side: -vf 'split[a][b]; [a]pad=iw*2:ih[src]; [b]histogram[filt]; [src][filt]overlay=w'. I just changed deshake to histogram.


What's a good camera to shoot a low-budget short film with? My budget is around $750. So far I have come up with Canon 550D and I think it's a great choice to shoot a low-budget short film. I am just seeking your advice to see if there is any better alternative I can use with this budget. Cameras with Flip-out screen are preferred. Any advice would be appreciated!

The short answer is anything that works for you. IMO, the 550D is a fine choice if it works for you.

The long answer? Even if you need to postpone the film, make sure your script is FLAWLESS. Shooting with a Red can't save an awful script, but I've seen some ~awesome~ shorts & features shot with a Fisher Price PXL-2000 and the Flip.

Beyond that, understand lighting. Know where your light is coming from and how to use it to make your scenes less muddy or grainy (unless that's what you're going for stylistically). Consumer camcorders are less light-sensitive than their professional brethern.

Also, make sure you can record decent sound. In most cases, on-board microphones are crap. That being said, bad sound makes a mediocre script awful. amazing sound can make mediocre scripts a touch less painful to watch.

One other thing you may want to try: network with other filmmakers and see what they're using. See if you can rent or borrow cameras to see what you like to work with. Who knows? I've shot films and donated my gear to the cause because the script was AWESOME. You may run into someone who's willing to support your vision with a camera donation.

But start with your script.


How to prevent ffmpeg from dropping metadata? When I am simply copying a.MOV (from my iPhone) to c.MOV, ffmpeg drops a lot of metadata, (including the time and location of the video).

I tried -metadata, but ffmpeg still drops the information (it seems that the metadata is not dropped when ffmpeg prints Output #0, but is dropped when I use ffprobe to see metadata of the output file)

What should I do to force ffmpeg preserve these metadata?

$ ffmpeg -i a.MOV -c copy c.MOV -y
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'a.MOV':
  Metadata:
    major_brand     : qt
    minor_version   : 0
    compatible_brands: qt
    creation_time   : 2018-03-...
    com.apple.quicktime.location.ISO6709: .../
    com.apple.quicktime.make: Apple
    com.apple.quicktime.model: iPhone ...
    com.apple.quicktime.software: 11....
    com.apple.quicktime.creationdate: 2018-03-...
  Duration: 00:00:01.77, start: 0.000000, bitrate: 7868 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1280x720, 7707 kb/s, 30 fps, 30 tbr, 600 tbn, 1200 tbc (default)
    Metadata:
      creation_time   : 2018-03-...
      handler_name    : Core Media Data Handler
      encoder         : H.264
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 87 kb/s (default)
    Metadata:
      creation_time   : 2018-03-...
      handler_name    : Core Media Data Handler
    Stream #0:2(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
    Metadata:
      creation_time   : 2018-03-...
      handler_name    : Core Media Data Handler
    Stream #0:3(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
    Metadata:
      creation_time   : 2018-03-...
      handler_name    : Core Media Data Handler
Output #0, mov, to 'c.MOV':
  Metadata:
    major_brand     : qt
    minor_version   : 0
    compatible_brands: qt
    com.apple.quicktime.creationdate: 2018-03-...
    com.apple.quicktime.location.ISO6709: .../
    com.apple.quicktime.make: Apple
    com.apple.quicktime.model: iPhone ...
    com.apple.quicktime.software: 11....
    encoder         : Lavf57.71.100
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1280x720, q=2-31, 7707 kb/s, 30 fps, 30 tbr, 19200 tbn, 600 tbc (default)
    Metadata:
      creation_time   : 2018-03-...
      handler_name    : Core Media Data Handler
      encoder         : H.264
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 87 kb/s (default)
    Metadata:
      creation_time   : 2018-03-...
      handler_name    : Core Media Data Handler
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame=   23 fps=0.0 q=-1.0 Lsize=     732kB time=00:00:01.76 bitrate=7827.5kbits/s speed= 971x
video:921kB audio:9kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.291216%
$ ffprobe c.MOV
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'c.MOV':
  Metadata:
    major_brand     : qt
    minor_version   : 512
    compatible_brands: qt
    encoder         : Lavf57.71.100
  Duration: 00:00:00.77, start: 0.000000, bitrate: 7819 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1280x720, 7707 kb/s, 30 fps, 30 tbr, 19200 tbn, 38400 tbc (default)
    Metadata:
      handler_name    : DataHandler
      encoder         : H.264
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 92 kb/s (default)
    Metadata:
      handler_name    : DataHandler
$

Other answers here are only working with the "known" meta keys, for custom/arbitrary meta keys, -map_metadata 0 is not sufficient to keep them all.
In my transcoder project, a lot of camera makers like to inject custom meta keys in the MP4/MOV container, and I want to keep them in the transcoded MP4/MOV files. After a lot of head scratching, ffmpeg do have a switch for this purpose:
-movflags use_metadata_tags

Credit goes to the author of this thread and Google:
https://superuser.com/questions/1208273/add-new-and-non-defined-metadata-to-a-mp4-file