How can I cut a few seconds at the beginning of a large video file? I have a large (~3GB) video file and I would like to trim just a few seconds at the beginning (~3s).

What would be the fastest way to do this without having to process all the video file?

Try this:

Open the file in the Quicktime player -- it'll have to be Quicktime Pro.
Select the frames that you want to remove with the input and output markers.
Hit 'Delete.'
Then save as a 'self-contained' movie.


Same exposure settings on 2 different DLSRs (Canon SL1 and 70d) created differently exposed image? I recently purchased a Canon SL1 as a second camera to my Canon 70d. Today I had my first shoot, and I noticed something weird with the exposure. Both of my cameras were set to 1080 24fps, 50 shutter speed, 2.8 aperture, and ISO 200. However, the Canon Sl1 was underexposed. To create the same exposure as the Canon 70d, I needed to bump the SL1's ISO to 400. Shouldn't camera's with the same settings reproduce a similarly exposed image?

Thanks!
-Wes

Simple answer is No.

Now to be a little more technical. It is all down to build, sensor type, style, size etc and of course the camera being stuff like, consumer, semi-pro, professional etc.

A little more.
Cameras like the SL1 which would be classed as consumer would not have the same build or sensor quality as a professional or possibly semi-pro same goes for sensor sizes etc.

I have a Canon 7D and a Canon 100D both of which I can use but I have to expose slightly differently on the 100D due to it being a lesser quality camera, even though it has basically the same sensor and specs (which is why I bought it). Most things you can correct it in post as long as I've thought about a little bits before hand.

This would also be the same for the built in colour profiles in the camera. Which  is why a lot of people start to build there own or put on preset ones like cinestyle.


How to switch New Composition Settings Duration from Base 25 (time) to Frames? In the tutorial I am doing the instructor has their Composition Settings enabling them to input the amount of Frames they would like the Composition to be. Picture is a little faded, it says "Frames @ 24 fps"

image http://assemblyx.net/Untitled-1.png

Now my Composition Settings only allow me to set in time.

image http://assemblyx.net/Untitled-2.png

How can I set in Frames?

Oddly enough, this has to be done in the composition window itself.  In the top left-hand corner of your timeline window, you know the little orange numbers that tell you the current timecode?  If you CMD + click on that (ctrl + click on windows), it'll switch to Frames instead of timecode.

When you hit CMD + K to bring up the composition settings again, you'll see that Duration and the other relevant categories are now shown as Frames instead of timecode.

Note that this will shift your whole timeline to Frames (including the markers on the timeline itself), which you may or may not want.  If you just want to have it for frames while you're editing the composition settings, though, you can always just CMD + click on the number in the upper lefthand corner of the timeline to switch it back to timecode.


Is there a microphone / video setup that requires little to no post-production? I'm trying to record one take per day of someone reading a story in from of a camera in a vlog-like format, but I don't have a ton of time for post-production.

Most advice articles on a vlog setup tend to make recommendations around either (a) quality or (b) budget. But what technical specifications and features (or brands) would you look for if you're creating a setup that seeks to reduce the time it takes to do various post-production activities. Namely:

is there a microphone that eliminates pops and ambient noise automatically
is there a way to sync up audio and video automatically? Is the best solution here a USB mic? I know in the past USB mics have produced whirring sound?
are there any more tips and tricks to time if you're doing a lot of recordings? Automated scripts, etc?

I still imagine some lightweight editing is needed, but otherwise I'm wondering how elegantly we can get from record to upload while still maintaining good video & audio quality.

What I would do is concentrate on the setup in front of the camera, to make sure that what you're recording is the best quality it can be, in order to avoid the need for post.

Set up your lights so that you have good, soft-ish (no harsh shadows) lighting that is well colour balanced. A 3-point light setup is the standard way of lighting interview subjects, but you could also get away with a single keylight and reflector, or keylight, reflector and back light. A good simple portrait setup is detailed in this very good tutorial.

Pay attention to the background. A flat white wall is going to make the shot look flat and boring, but heaps of clutter could be distracting. Pay attention to the lighting levels—havign the background at the same exposure as the foreground may make your subject disappear, it can be good to slightly under-expose your BG. This is definitely not a rule; have a look at this reel, and pay attention to the backgrounds to get a good idea of how to do it right.

Check your white balance and exposure before shooting. Auto exposure may work, but it is usually better to use manual, to avoid it changing during the shot, or over-compensating for white or dark objects in the shot. Most cameras can do a custom balance off a white card held in the same position as your subject.

Try and get the location as quiet and dead as possible. No mic will automatically eliminate background sound. Directional mics will limit the pickup pattern to a narrow beam, but low frequency rumble (e.g. street noise or wind noise) will still cut through.

The absolute best way to minimise background noise is to get the mic as close to the sound source as possible. Sound intensity falls off with the square of the distance, so going twice as far away means one quarter the intensity. So to get the most signal versus noise you want the mic to be close to the signal, and away from the noise. A boom mic (a micstand will do for a seated subject) is a good way to do this, because the head of the subject is usually near the to of the frame, meaning you can have the mic close to the top of the subject's head, and if it's directional, pointed at their mouth. Having the mic above the subject and away from their breath will help eliminate p-pops.

Lapel mics are another way of getting the mic close to the subject, but can be affected by clothing noise.

By "dead", I mean less reverberation. Don't record in a bathroom; a room with carpet, soft furniture and as few hard surfaces as possible will work best. A bedroom is actually pretty good usually.

Good cameras (including some better consumer grade cameras) will have an external mic input. This removes the need to synch audio and pictures in post. Then you can just use a standard analog mic with a cable; on a budget this will give you the best bang for your buck.

If you have the subject well lit, with a good sound setup, and the camera correctly exposed and balanced you've eliminated a lot of post work. You could set up a standard grade if you want to tweak it more, eg. adding a LUT or a 'look' to make it really pop. If you keep your shoot settings the same, then you can just use the same grade each time, and still achieve great results.


h264 compression keeps same number of frames? I'm trying to understand how h.264 compression works. So far I have clear what I, P, and B frames are and how are they used. But I'm unsure of is if after this process the number of original input frames are kept or not.

In other words, if a raw video file containing 20 frames going into a h.264 encoder block, will the output compressed file have same number of frames?

I am not sure of my answer. The explanation at the end of it.*

Yes. The number of frames should not change. With one possible exception, I know of.

First of all, normally a compressor takes some steps.

Grab a keyframe
Compares the difference between groups of pixels and if the difference is below one defined parameter it uses the same data to render them.
And now compares the difference between adjacent frames and again, if the difference is below a threshold it uses the same data, using the keyframe as a reference to be compared with.

If the keyframe fails to load you see the glitches, where the image is smushed because you are seeing the "differences" of the frame, but with an incorrect reference image.

The exception is that some programs need to round the number of frames after a keyframe. Let us imagine you defined a keyframe every 10 frames for easy calculations.

Now your clip needs to have 105 frames. Some programs will render the exact number of frames, but some programs could try to render the full "group" of frames attached to the previous keyframe, trying to render 109 frames, or some other could try to end in a keyframe, 110 on this case.

I am not sure about my answer because, although it as happened to me on some programs, I can not recall that it was specifically using the h264 codec.


How do I temporarily disable Davinci Resolve nodes? I'm new to Resolve (free version). As a programmer I kind of assumed that unconnected nodes, being unconnected, wouldn't interact with the process in any way. Apparently I was wrong.

What I'm trying to do here is find out an easy way to try out a completely different approach to grading the clip without losing the previous settings.

In the screenshot:
3 isolated nodes containing the previous grading and 1 new node for trying out alternative grading. Even though the new node has very visible adjustments, I only see the original clip in preview.

I also tried removing all the previous nodes. Only then the new node begins to work, and as soon as I add another node that is of course initially unconnected, the preview returns to the clip's default state.

⌘-D will disable the currently selected node.  Resolve really doesn't like to have loose nodes floating around, so either disable them, or delete them.  But since you're talking about creating a new, experimental node structure, what you really want to do is create a new local version.  Right click on the clip thumbnail and select Local versions-> create new version.  This basically creates a copy of your node structure that you can return to whenever you like.  After issuing the command, you'll see that the name of the new version appears under the thumbnail to let you know which one you're working on.  To revert to the original (or select from any number of alternate versions), right click the thumbnail again and choose versionName->Load.


Increase framerate in post-production? I know this is doable because many higher-dollar televisions on the market today are able to take a 24fps input and smooth out the frames for an effective framerate up to 960fps (for Sony).

Would it be possible to take footage that was shot at 24fps and increase it, say, to 60fps? Surely there exists software which can do this.

I'm interested in increasing the framerate of the footage itself rather than relying on a display to smooth out the frames just for compatibility's sake.

There are several methods for interpolating additional frames if you want to slow down footage beyond its original frame rate.

First: duplicating frames. Pros: very fast, easy. Cons: low quality, causes stuttering, even with fairly small decreases in playback speed.

Second: cross fading between neighbouring frames. Basically each frame is dissolved into the next one. This will work well for a lot of footage down to say 1/3 of the original speed, after that it gets a bit obvious. Pros: fast, relatively easy, lots of software does it. Cons: limited capability.

Third: using motion estimation algorithms to create frames from neighbouring frames. Basically you apply a morph between neighbouring frames, with some intelligent tracking of pixel motion to create realistic motion. Pros: very good results with some footage, even with large slow-down. Cons: compute intensive, so slow to render. Not many apps do it, especially free/cheap ones. Can cause weird and very obvious artefacts when the tracking goes wrong–in fact, I've rarely been able to get this to give satisfactory results with real-world footage. If you have simple movement against a plain background, e.g. green-screen footage, it can work really well, but for any complex scene you generally get all sorts of really obvious weirdness.

The final techniques is still under development, and will probably keep getting better. AI is looking very promising as a tool for this kind of thing, so we may see some quality gains soon.

P.S. I'd say that Sony claim about interpolating 24fps to 960fps is 99.999% marketing bullshit.


Using delogo twice to mask a Video I know that the below line will mask the video

ffmpeg -i "aunt1.mp4" -vf delogo=x=4:y=0:w=120:h=22 -c:a copy au1.mp4

However I want to delogo in two sections of the video in one command. I tried this separated by comma but didnt work

ffmpeg -i "aunt1.mp4" -vf delogo=x=4:y=0:w=120:h=22, delogo=x=40:y=50:w=120:h=22 -c:a copy au1.mp4

You haven't mentioned what doesn't work, so taking a guess:

ffmpeg -i "aunt1.mp4" -vf "delogo=x=4:y=0:w=120:h=22, delogo=x=40:y=50:w=120:h=22" -c:a copy au1.mp4


Cross Dissolve not available in between clips [Premiere CS6] I'm trying to add a cross dissolve effect in between two clips. Premiere doesn't allow me to do it between the first and the second clip.

Does anyone know the reason?

Do your clips have overlap?  If you put the clips end to end, running them right up to the end of the file and beginning of the file, then there is no video for Premiere to apply a dissolve to.  You need to have sufficient video left in the clip to complete the transition.


Final Cut Pro 7: File Error: Unknown file The sequence is composed of a jpg followed by an mp4. When the jpg is not present, after I hit Command + R, the sequence can render without errors. When the jpg is present, after I hit Command + R, the sequence cannot render and it returns a message "File Error: Unknown file."

Final Cut Pro may not recognize your file location. Did you change the location of the jpg after you imported it into the sequence? If so, you may have to locate it again.


Can I use unlicensed music as soundtrack for a video? I'm shooting a 1 min. promo video for an iPhone app startup. Can I use unlicensed music as long as I mention the artists on the closing credits? Are there any other resources available to help understand how copyright applies here?

The short answer? No.

The long answer: No, copyright law requires you to have an appropriate licence from the copyright holders (usually the record label - not the artist - if they're in a record deal!)

There are three distinct rights for every piece of music:

Phonogram copyright (the sound recording) (symbol: ℗, "P" in a circle)
Composition, score, artwork, cover design, lyrics, which can all be included in one overarching copyright registration per musical work (symbol: ©, "C" in a circle)
The Publishing right, considered separately by some

Each of these rights may be 'assigned' to a third party (e.g., a publisher or a record label) and this is what usually what happens when a track is released by a label. However you may be able to 'encourage' the artist to grant a licence for the music's use if the project is cool or they like it. Ultimately the person who has control of the sound recording copyright is the person to request a licence from.

You are in breach of copyright law if you use a copyrighted piece of music without a licence - moreso if you exploit that copyrighted composition for commercial gain (use it to represent the product or service, even if it's just background music). Whilst I think the current system of licensing music is crazy, that's just how it works for the time being.

Occasionally artists are willing to 'look the other way' if you agree a licence arrangement after the finished work using their copyrighted music is released -- this may not even be a cash payment, it may just be promotion with the band, song name and iTunes link at the bottom of the screen. However, arranging a license 'after the fact' still compromises you from a legal perspective, and you could be forced to stop using that music in your own work (and, worst case, be taken to court for copyright infringement) if the artist or label doesn't like it.

I concur with the other answerer's suggestion to seek Creative Commons licensed music; Jamendo is a good site to start on, and even if the initial license is CC-NC you can communicate with the artist to request a commercial use licence (or to be granted an exemption).

You may also wish to try sites like these to seek appropriate sync licenses for music for a reasonable cost:

SongTradr (https://www.songtradr.com/licensemusic)
Getty Images, formerly iStock Audio (https://www.gettyimages.co.uk/Music)
Shutterstock (https://www.shutterstock.com/music/)
AudioJungle (https://audiojungle.net/)
StockMusic.net (https://stockmusic.net/)
Epidemic Sound (https://www.epidemicsound.com/)
Music Gateway (https://www.musicgateway.com)

Things are moving to subscription-based for licensees, so you may find over time, if you want to licence a track, contacting a musician direct is a better choice. (Or consider one of the YouTube Library tracks...)

Rob Hardy on FilmmakerFreedom has a good writeup of some other 2019 options: https://filmmakerfreedom.com/blog/stock-music-showdown-2019

This older post from NoiseCreators has a list of other outlets and licensing sites, some of which may be defunct but may help on a sync quest. http://noisecreators.com/2016/06/21/a-list-of-40-sites-that-will-help-you-license-your-music/

Also have a read around and decide who you may wish to deal with from an ethical or business stance.
https://www.digitalmusicnews.com/2019/03/21/songtradr-12-million-funding/
https://www.gearslutz.com/board/music-for-picture/1194031-quot-music-wanted-quot-libraries-like-songtradr-taxi-etc.html

(I initially recommended YouLicense.com but they closed down mid-2018.)

Sync is big money. As the rise of digital msuic and streaming has increased, so has global sync revenue. I'd suggest you read https://www.synchtank.com/blog/sync-licensing-in-2017-a-look-at-the-trends-and-figures/ and https://musicindustryblog.wordpress.com/2019/05/03/music-sync-a-market-ripe-for-change/ if you're unfamiliar with the market.


Object moving to a position I didn't specify I'm trying to do the following:

At 0;00;00;00 orange triangle is offscreen and begins to move towards the center.
At 0;00;03;00 orange triangle arrives at position 243, 135.
At 0;00;03;00 orange triangle begins to move to the left.
At 0;00;07;00 orange triangle arrives at position 137, 135.

From 0;00;03;00 to 0;00;03;05 the object begins sliding to the right, reaching the position 246, 135. I didn't tell it to do that, nor to even go in that direction. Any idea why it's happening? I've attached a video and a picture below that hopefully should help explain.

Vimeo link

Thanks for any help.

It's because of Spatial Interpolation.
You need the spatial interpolation to be set to linear, and by default it is set to Auto Bezier.

Right click on the keyframe at 3'00, and select Keyframe Interpolation.  Change the Spatial Interpolation to linear, and it should solve the problem.

What's happening:

Instead of drawing straight lines (linear lines) between your positions on the screen, after effects is drawing curves (bezier curves).  When you tell your object to "double back" on itself, AE tries to draw a curve to this effect, causing a little knot or bounce forward at the 3'00 mark.

You can choose how AE interprets changes in space, as described, but you can also choose how it interpolates time too (Temporal interpolation).  Setting temporal interpolation to bezier often produces nicer results than linear, as it allows objects to slowly come to a stop, rather than suddenly stopping at a keyframe, which is how objects in the real world respond (due to weight, friction, gravity etc).


FFmpeg run multiple filters in parallel from C API I successfully applied a FFmpeg filter from C API (my previous question here). I see the filters are running sequentially. Now the question is, how can I run multiple filters in parallel? If run sequentially, that causes so much delays.

I'm using ffmpeg as the base for stream processing. As we receive the streams, I need to apply 2 filters and produce metadata in parallel. Of course, with minimum delay issues.

Filters cant really run in parallel because they can modify frames, and you can’t modify a frame in two threads at the same time. You can make a copy of the frame and run two filter graphs.


Looking for video software for analysing videos I have a security camera on my car which is triggered by motion detection.
Each time it happens it records about 10 seconds in dual cameras which end up with two files A_[timestamp]for front, B_[timestamp] for rear view.

I want a suggestions for free/paid software which can do the following:

Open all videos of type A or B at once and linking them to one  timeline viewable video- please note I prefer not to create a new long video out of all, just to view them sequential with being able to adjust time more fast/slow in the timeline.
Being able to analyze video and tagging the sections which persons are recognized.

It's possible that this question is a duplicate of one of the questions below:

What Beginner Video Editing Software Should I Use?

Free video editing software


ffplay - Live capture video gradually lags behind I have a Magewell capture device that I'm trying to preview with ffplay.  It works great, except over time the video will become choppy and lag behind the actual live feed.  Right clicking on the ffplay window will sync it back up, however continuously right clicking it is obviously not a good solution.

I am using a command similar to the following to display my capture:

ffplay -f avfoundation -pix_fmt 0rgb -framerate 60 -i "1:none"

How do I get it to remain synced the entire time?  Viewing ffplay stats shows that there is a buffer that gets filled over time and right clicking clears it.  You can also force this by pausing the stream and unpausing.  I need it to display without filling the buffer at all.

I've tried using this and it helps to some extent, but doesn't completely disable the buffer:

-probesize 32 -sync ext

With that it takes longer to fill as most frames are dropped if it can't read them fast enough, however it does still fill up over time.

So I solved this by simply adding an audio stream instead of having "none" selected.  Doing this makes -framedrop (default) work properly.  I left the master clock as default as well (audio) instead of changing it to ext.


Combine audio and video file without creating a 3rd file if this is the wrong place to post this let me know.

I want to download a very large video (9.1GiB) from youtube on my device and I have ~10GB free storage space for it.
Because it's youtube, I have to download video and audio separately and combine them afterwards. I'd normally do that using ffmpeg. I'd have to let it create the combined video in a new ~9.1GiB file because it can't overwrite it's input. The video only file of similar size must exist during the whole process.
Problem is: I can't store 2 9.1GiB files, only one.

The possible solutions would be to edit the video only file to have an audio stream or have a super intelligent buffer system that'd delete the parts of the video only file that have already been copied into the new file.

Is there any program that is capable of doing that or do you know a different solution to this problem?
-Atemu

(Sorry for my bad german)

I found a solution to my problem:

Ffmpeg can use a http stream as input:

ffmpeg -i YoutubeVideoOnlyURLHere -i YoutubeAudioOnlyURLHere -c copy -map 0:0 -map 1:0 Path/to/outputFile.mp4

You can get the needed URLs from
youtube-dl -f bestvideo,bestaudio --get-url https:www.youtube.com/watch?v=XXXXXXXXXXX


Rendering bits from multiple GoPro 7 footage into one file to save space and time without loosing quality I would like to render bits from multiple GoPro 7 (4k 60fps) footage into one file to save space and time in future (browsing).
So instead of keeping 100 footage files, there would be just one file with compilation of usable clips.
I would like to do this without loosing quality or frame rate.
What are the best settings in Premiere to save the closest possible output to the original?
I understand the resolution and frame rate needs to be set up to match the footage, but what about other settings which could possibly make Premiere manipulate the frames as little as possible?

What you are looking for are lossless codecs. Export with the exact same settings that your footage was recorded in, but use a codec such as Prores4444xq or DNxHD, with no subsampling and 16 bit video-depth.


do TV broadcasts provide localized advertisements by altering the TV photo In TV broadcasts of football matches (soccer matches) there are often long displays along the side of the football field that show advertisements. I guess that these displays are made up of electronic lamps, but in the future it might be possible (albeit technically very difficult) to add the advertisements by just post-processing the TV photo in a computer. In this way TV companies could broadcast international football matches with localized advertisement, for instance with one type of advertisement per country.

Do you know of any examples from TV broadcasts of sport events, where image post-processing have altered the TV photo to adjust for different advertisements?

What a great idea -- you should enter the marketing field!

I don't know if anyone has thought to do localized advertisements yet, but image post-processing is routinely used, at least on American football broadcasts, to track the field and the marker lines thereupon, so as to provide various forms of in-game analysis.

If they can do that, I'm sure they could turn the field-side displays into green screen to show localized TV advertisements on, but if that happens, then the spectators at the physical location aren't able to see the advertisements! So some of this probably has to do with whether it's the TV station or the Stadium that sells those ads, and whether or not localized broadcast ad revenue would be more lucrative than installed non-processed ads.


Kdenlive composite effect not stretching I am using Kdenlive to edit a school project and I need to use small amounts of a green-screen effect. I have seen several tutorials and understand how to do it, but the composite effect will not stretch. In every tutorial I have seen the composite starts large and is able to stretch, but when I do it it starts small and will not stretch. I cannot find any handles to stretch it with. I can use the glove to move it around, but not stretch it. Any help is appreciated!

I had the same issue.  Use the "Composite and Transform" transition instead.


How do I build a circle which serves as a particle attracter using After Effects Trapcode Particular? I want all particles that I emitted to settle down on a circle shape after animating them in space. What would be perfect is to be able to draw a circle shape which works as a particle attractor after a certain time.

I would recommend you use a different plugin, use the shatter plugin.

Follow the steps in this tutorial

http://www.macprovideo.com/hub/after-effects/after-effects-text-that-blows-away-like-sand

This will let you break apart your circle into particles. Then when done the composition, simply pre-comp the layer and use the time/time-reverse layer to let the particles come into a circle.

While it seems a little backwards(literally) to do it this way, I think this is the best way to accomplish what you are trying to do.

You won't be able to get a particle attractor or other advanced functions like that unless you are working in cinema 4d or other 3 rendering software.


Rearange order of audio tracks in Premiere Let's say I have the following arrangement of my audio tracks:

x ----------
y ----------
z ----------

and I want to have them arranged this way instead:

x ----------
z ----------
y ----------

What's the easiest way for me to make this happen?

(As an example, in Reason, I would grab the audio track I wanted to move and then simply place it where I want it. This does not seem to work in Premiere.)

As you have discovered Premiere Pro doesn't let you move the tracks as easily as that (I wish it did!)

Fastest method would be to create 1 or 2 empty tracks (right click on a track label and select Add Tracks) then use the Track Select Tool  ('A' on the Keyboard) to quickly select an entire track:

(Click and hold lets you select and move the track at the same time).

You could also select an entire track, Cut it, move your other tracks around, then Paste it back into a new track (you can choose which track it gets pasted into by clicking on the Track labels, Premiere will paste into the top most highlighted track)


How would I produce unevenly colored subtitles with aegisub I would like to put text on screen that would have non-even colour. I.e. if the text were "subtitle", "s" would be in say white and "e" in gray. Is there a way to accomplish this using Aegisub/ASS subtitle format? So far, it let me do anything I needed with graphical subtitles, but I cannot figure how to do this one.

(On a related note - what is the best way to ask ASS-related questions since the aegisub forum is down?)

One can use the Hydra Aegisub plugin from here: https://unanimated.github.io/ts/scripts-manuals.htm#hydra

And it all works.


Is it possible to download m3u8 as separate files using ffmpeg? I know it is possible to download playlist and concatenate it on the fly with something like this:

ffmpeg.exe -protocol_whitelist "file,http,https,tls,tcp" -i input.m3u8 -codec copy output.mp4

But I need to get all playlist files separated. Is there a ffmpeg option for that?

Maybe I misunderstood the question.

  Do you want to download each segment in the playlist as an mp4?

if you know the length of time of the segments, you could do**

ffmpeg -i  'https://example.com/hls/index.m3u8 \
-f segment -segment_time 10  -c copy  -y out%03d.mp4

just match the segment time.


Blending Two Shots for Continuity I have been watching Zach King videos on YouTube (the Vine magic guy) and I'm curious how to edit two shots together so that body movements stay the same, yet an element is brought into the shot.  I'm ot even sure what the name for this is.

An example is in the link below.  In the first two Vine videos starting at 3:03, he clearly meshes two shots together somehow but the placement of his body stays consistent.  Immediately after, he makes it appear as if he pulled a cat out of his computer screen (again, obviously two shots) but his body movements stay consistent.

Very easy to do, well theoretically.  On cut actor freezes his body, friends places the prop - in this instance the cat, on action the actor continues his movement.  The quicker and non intrusive the introduction of the prop, the less movement the actor will have and the more seamless the cut will look.

The main thing to remember here is to be prepared to have a lot of takes.. it will take time to get it right.


Should you shoot flat when shooting with a DSLR? I've read a bit about how it can be useful to use a "flat" profile for shooting video on a DSLR which produces only compressed video. For example as described in this article. The reasoning is that most lossy compressors (like H.264) will do more compression in the darks, removing that data and making it impossible to adjust in post. (For example, if you brighten it, you'll get bright gray squares instead of whatever data was there before compression.)

The author of the above seems reasonable. He worked at LucasFilm and has directed many music videos and feature film VFX shots. It doesn't seem like he's suggesting some fad, but is talking from experience.

In the answer to [Post-production workflow: VFX before color correction? workflow: VFX before color correction), this was included in the accepted answer:

  As far as low contrast and low saturation, I would disagree rather strongly with shooting for low contrast/low saturation. This is how you get noisy, low quality color. Your camera has a limited number of colors it can describe, if you ignore a large portion of that color space, then you can't describe as many colors and the resolution of your color after boosting the saturation and contrast will be very greatly reduced.

These sound contradictory to me, but maybe I'm misunderstanding. Is the advice to shoot flat good advice for DSLRs with lossy compression or not?

There are two schools of thought on this topic but nothing I know has suggested that shooting with a flat profile is a bad thing. Here is what I understand:

1) When shooting with Canon DSLRs, it's generally advised that you shoot with a flat profile (Technicolor cinestyle, Prolost, etc.) and over expose (but don't clip!!) and you get a picture with much more detail, specifically in the shadows. Here is a video showing this: https://vimeo.com/73909925

It's rather long, but the entire series is good. In there he specifically shows the effects of shooting standard and exposing correctly v.s. shooting flat and over exposing. Lots of detail in the shadow is preserved when performing the latter.

2) A lot of more professional film makers (Shane Hurlbut, and Stillmotion) suggest that you should use a color profile that best matches your final color result. Less work is needed in post, and  you have a better feel for your film. I think I see this school of thought from professionals more often because the gear they own has high dynamic range and retains so much information anyways, so detail isn't something to worry about.

Personally, I'm not a professional and I record with a Canon 550D but I use the Standard Profile when exposing my shot (aka, over exposing) and switch to technicolor cinestyle when I hit record to give me more color grading flexibility in post.


Gravity gimbal and effect from overall weight With gravity gimbals like Steadicam, does the weight of the camera and the weight of the counterweights together have an overall impact to the stabilising effect? That is, suppose the same drop time in two setups where one has a 200g camera whilst the other has a 1kg camera. Will the stability be better in one?

Actually, what is the term for non-motorised stabilisers? It seems "gimbals" seem to refer to motorised stabilisers these days.

Any thought appreciated.

Gimbals are nothing more than a ball bearing (or a complex series of ball bearings; or even simply a sharp point which rests on a surface which allows it to move on a 2 axis level), which using weights balanced correctly provide a "zero gravity" effect on both the camera and the counterweight.

This doesn't apply to electronic gimbals which use servos, a microprocessor, and sensors to electronically move the gimbal head.

That said:

Yes weight will play a role in the overall stability of the camera unit.

I have taught workshops on camera technique, and I often joke that if you want to get steadier footage from a small lightweight camera (think GoPro), gafftape it to a brick.

Mass requires energy to move. So the lighter the object, the easier it is to move. Try to shake a marble around with your hand grasping it with two fingers, then do the same with a bowling ball. The motion, if you tracked it, would be both smoother, and more stable - smoother arcs, turns, etc, with the object that has more mass.

So with a steadicam rig (which I used to own a full blown rig capable of holding cameras in the 30lb range); a heavy camera with a heavy counterweight, which is properly balanced with give you far steadier shots, SPECIFICALLY with vibration. As a large heavy object is hard to "vibrate". So the little shakes, will be minimized by the mass added to the camera.

What's most important, if using a steadicam type rig is that you have perfect balance, that is, if you turn the camera 90 degrees (thus shooting sideways) the camera will stay in that position.

You do not want to set it up so the unit is counterweight heavy, keeping the camera upright.

The camera should be able to "hold" any position, angle, on any axis, and not return to upright.

If the camera is not balanced this way, you will encounter what is known as steadicam wobble. This is where the balance is off, and by the operators movement the effects of inertia and momentum push and tug differently on the camera vs the counterweight.

Lastly, the term for non-motorized stabilizers is a camera stabilizer. There is no one term; but steadicam is a goto term used by most.

Now as far as motorized stabilizers, none of what I said factors in, because the motorized stabilizers I own and have worked with, do not use weights, rather they use servos, and tension systems which differ than their non-electronic counterparts.

If you are using a light weight camera, and non-electronic steady system; you will achieve better results by adding ballast to both the camera and the counterweight. The ballast you add can be steel plates with holes drilled, cheeseplates, anything that has weight, and that you get the unit balanced to where it is not bottom heavy.


How to DISABLE--NOT REMOVE subtitle tracks from an MKV file from the command line? ATTENTION:

  THIS QUESTION IS ABOUT DISABLING--NOT REMOVING SUBTITLE TRACKS FROM MKV FILES FROM THE COMMAND LINE. PERIOD.

  It IS NOT about REMOVING subtitles by REMUXING with mkvmerge or any other tool. There are literally thousands of threads about removal by remuxing. That's precisely why I started this thread about DISABLING NOT REMOVING subtiles. I could not find a single thread about that.

  It is NOT about GLOBALLY DISABLING subtitles in any PLAYER. That is obviously trivial and doesn't need any explanation. I don't need/want to do that and, if I did, I obviously wouldn't have taken the time to research the topic at hand and publish my findings in this thread.

  I shouldn't have to add this disclaimer but there have been a number of, in most cases demeaning, 'answers' that reveal a distinct misunderstanding of the OP, suggesting irrelevant 'solutions', and/or criticizing this hack as being 'O-h-h-h-so-difficult' if you want to re-enable the subtitle track at a later date. As I pointed out numerous times, anyone who can understand my answer and who knows how to use the command line will find this task trivial. Those who don't SHOULD NOT ATTEMPT this hack.

  The answer has already been given as this is the entire point of this thread. So any new answers are either superfluous or, in SOME cases, irrelevant. I will no longer respond to irrelevant 'answers' or comments or demeaning remarks by users who, judging by their reputations, should know better. Any such abuse will be flagged accordingly.

  I welcome any CONSTRUCTIVE suggestions that ADHERE TO THE TOPIC, in a COMMENT, but any 'answers' or negative comments will be unanswered and flagged as inappropriate.

Now that THAT is out of the way, let us begin…

I couldn't find out how to do this anywhere so I thought I'd share this hack with others who, like me, want to DISABLE, NOT REMOVE, subtitles in MKV files.

There are times when you don't want the subtitles that are embedded in a file and you don't want to have to disable subtitles every time you play such a file or globally disable subtitles in every player you happen to have. Or you may want to automatically use a subtitle (srt) file that is preferable.

Sure, you can completely REMOVE subtitles with mkvmerge:

mkvmerge --no-subtitles "inputfile.mkv" -o "outputfile.mkv"

But this is heavy-handed and a real pain if you have a bunch of multi-GB files. It takes lots of time and disk space to de- and re-mux every file. So I turned to mkvpropedit which edits the properties of the subtitle track header in milliseconds. Note that this tool is installed when you install  MKVToolNix. Unfortunately, it is not at all obvious how to use this wonderful tool for the task at hand. Here's an example of the properties of a subtitle track as given by mkvinfo:

| + A track
|  + Track number: 4 (track ID for mkvmerge & mkvextract: 3)
|  + Track UID: 11363869179551629452
|  + Track type: subtitles
|  + Default flag: 0
|  + Lacing flag: 0
|  + Codec ID: S_TEXT/UTF8
|  + Name: CC

Despite the default flag setting 0 (false), the subtitle track is still active by default in players. I later read in the mkvmerge documentation "If no track is set to be the default track then mkvmerge will promote the first track of each type that it finds to be the default track. This is consistent with the behavior of various media players." I'm not sure if this means that it sets the default flag to 1 or somehow otherwise arranges for the track to be the default, but it seems maybe the latter.

I tried adding the track enabled property set to false but it didn't work.

mkvpropedit --edit track:4 --set flag-enabled=0 "inputfile.mkv"

| + A track
|  + Track number: 4 (track ID for mkvmerge & mkvextract: 3)
|  + Track UID: 11363869179551629452
|  + Track type: subtitles
|  + Default flag: 0
|  + Lacing flag: 0
|  + Codec ID: S_TEXT/UTF8
|  + Name: CC
|  + Enabled: 0

What player are you using?

Unless you have the "forced" flag set, it's a player option whether subtitles are displayed automatically or not and in which language if you have several subtitle tracks.

First, set the "default-flag" to false:

mkvpropedit video.mkv --edit track:s1 --set flag-default=0

Then lookup your player preferences.

In VLC (2.0.8), I had to follow these instructions:

  To disable subtitles by default, select "Preferences", then "Show
  All". Select "Input/Codecs". On the "Subtitle Track ID" selection
  window, change the value to "-1".

and also set the preferred language to "none".

In SMplayer, uncheck Preferences / Subtitles / "Select first available subtitle".

Once your "default" flag is set to false for all subtitle tracks, it only depends on your player preferences.


What is the best way to make Windows compatible with .MOV format? What is the best way to make Windows compatible with .MOV format? I am looking for solutions other than using QuickTime to play .MOV movies on my Windows 8 machine. I want Windows to support .MOV (via Windows Media Player, Xbox Video, or whatever the default movie player happens to be.)

.MOV is a container format, not a video format. As such it can contain media in any number of 'tracks' of audio, video, subtitles etc. In particular, video tracks may use any supported codec, not just Apple-specific ones. It's very common to see H264 encoded video in a MOV file, and H264 is widely supported on Apple, Windows and Linux platforms.

So if you control the encoding, use H264 and you'll have nearly universal compatibility. If you don't control the encoding, you have to insure that the target system supports the codec used, which puts you in a bind because there are dozens of codecs and a given system may not have yours installed.


Encoding 720p 29.97 fps video, options in Adobe Media Encoder are 23.976, 24 or 59.94 fps A little confused here, I have a video file that's 720p @ 30.303 fps.

Working on it in Premiere Pro CC 2014 and ready to encode the file and the options I get for h.264 Blu-ray under frame rate are 23.976, 24 or 59.94 fps, no 29.97 fps.

What am I missing here?  I think I don't want to be choosing the frame rate that's double right?

Thanks!

The Blu-ray standard doesn't allow this framerate with this resolution.
https://forums.adobe.com/thread/622722

Your options are either upscale your resolution to 1080i/p or to change your framerate to 24fps.
The former will probably produces fewer artifacts.


Easiest way to create video with multiple videos on loop i would like to attempt doing a video of me playing a song (with several instruments).

So i want to create multiple videos... each with with a instrument (like people usually do)

so if i have 4 different instruments playing together i will have 4 videos which then will be fit on 1 video at same time.

I was wondering what's the easiest way to achieve this.
Which software do you advice? (free and paid)

my experience on this is just doing something here and there with youtube and windows media editor software (which i cant remember the name)

You need a stage with an area for each instrument, and video yourself standing in that area while playing that instrument, then overlay each instrumental track onto a master track. It's a type of clipping, selecting portions of the video by reducing the frame width keeping the height, and glueing/synchronising them side by side.

Many of the newer Video editing software can do this. (Even some of the free ones)  It boils down to lighting and timing, to be the same for each instrument you play or the effect is spoilt.


How do I turn audio into video (that is, show the waveforms in a video)? I have to create a video. Part of it involves "showing" a radio interview. Rather than just having a black screen and listening to the audio, I'd like to have a varying waveform on the screen and a caption.

Is there any free or cheap tool I can use that will do this?

If I ask a friend to do it, is there anything in the Adobe Creative Suite that can do the job?

You can use ffmpeg to create video from audio using several filters.

ahistogram

Convert input audio to a video output, displaying the volume histogram.

ffmpeg

ffmpeg -i input.flac -filter_complex \
"[0:a]ahistogram,format=yuv420p[v]" \
-map "[v]" -map 0:a output.mp4

ffplay

ffplay -f lavfi "amovie=input.flac, asplit [a][out1]; [a] ahistogram [out0]"

See the ahistogram documentation for more options and examples.

aphasemeter

Convert input audio to a video output, displaying the audio phase.

ffmpeg

ffmpeg -i input.wav -filter_complex \
"[0:a]aphasemeter=s=1280x720:mpc=cyan,format=yuv420p[v]" \
-map "[v]" -map 0:a output.mp4

ffplay

ffplay -f lavfi "amovie=input.wav, asplit [a][out1]; [a] aphasemeter=s=1280x720:mpc=cyan [out0]"

See the aphasemeter documentation for more options and examples.

avectorscope

Convert input audio to a video output, representing the audio vector scope.

ffmpeg

ffmpeg -i input.mp3 -filter_complex \
"[0:a]avectorscope=s=1280x720,format=yuv420p[v]" \
-map "[v]" -map 0:a output.mp4

ffplay

ffplay -f lavfi "amovie=input.mp3, asplit [a][out1]; \
[a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]"

See the avectorscope documentation for more options and examples.

showcqt

Convert input audio to a video output representing frequency spectrum with musical tone scale.

ffmpeg

ffmpeg -i input.mp4 -filter_complex \
"[0:a]showcqt,format=yuv420p[v]" \
-map "[v]" -map 0:a output.mp4

ffplay

ffplay -f lavfi "amovie=input.mp4, asplit [a][out1]; [a] showcqt [out0]"

See the showcqt documentation for more options and examples.

showfreqs

Convert input audio to video output representing the audio power spectrum. Audio amplitude is on Y-axis while frequency is on X-axis.

ffmpeg

ffmpeg -i input.mp4 -filter_complex \
"[0:a]showfreqs=mode=line:fscale=log,format=yuv420p[v]" \
-map "[v]" -map 0:a output.mp4

ffplay

ffplay -f lavfi "amovie=input.mp4, asplit [a][out1]; [a]  showfreqs=mode=line:fscale=log [out0]"

See the showfreqs documentation for more options and examples.

showspectrum

Convert input audio to a video output, representing the audio frequency spectrum.

ffmpeg

ffmpeg -i input.oga -filter_complex \
"[0:a]showspectrum=s=1280x720,format=yuv420p[v]" \
-map "[v]" -map 0:a output.mp4

ffplay

ffplay -f lavfi "amovie=input.oga, asplit [a][out1]; \
[a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]"

See the showspectrum documentation for more options and examples.

showwaves

Convert input audio to a video output, representing the samples waves.

ffmpeg

ffmpeg -i input.m4a -filter_complex \
"[0:a]showwaves=s=1280x720:mode=line:rate=25,format=yuv420p[v]" \
-map "[v]" -map 0:a output.mp4

ffplay

ffplay -f lavfi "amovie=input.m4a, asplit [a][out1]; [a] showwaves [out0]"

See the showwaves documentation for more options and examples.

showvolume

Convert input audio volume to a video output.

ffmpeg

ffmpeg -i input.mka -filter_complex \
"[0:a]showvolume=f=1:b=4:w=720:h=68,format=yuv420p[vid]" \
-map "[vid]" -map 0:a output.mp4

ffplay

ffplay -f lavfi "amovie=input.mka, asplit [a][out1]; [a] showvolume=f=255:b=4:w=720:h=68 [out0]"

See the showvolume documentation for more options and examples.

Notes

See FFmpeg Wiki: H.264 Encoding Guide for more detailed information regarding output quality.
format=yuv420p makes sure that libx264 uses a pixel format that is compatible with crappy players like QuickTime.
Instead of re-encoding by default, you can use -c:a copy to stream copy the audio if your output container format supports the audio format. Think of stream copying (re-muxing) like a copy and paste – no re-encoding.

Get ffmpeg

You should always use a recent version since development is very active. Links to builds of ffmpeg for Windows, OS X, and Linux are available on the FFmpeg Download page. Or you can follow a step-by-step guide to compile ffmpeg.


Can I set the start number for image sequence output? I am using ffmpeg to convert from video to an image sequence as follows:

ffmpeg -i video.webm image-%03d.png

The first image is labelled 001, but I want it to be labelled 098. Is it possible to set that value in the ffmpeg invocation?

The image sequence muxer has a start number option, so

ffmpeg -i video.webm -start_number 98 image-%03d.png


Adobe encore - Highlight button with image My question is simple, is it possible to add images as highlights to buttons with Adobe Encore?

I have just tried it and it appears a white box instead of my image when I hover buttons in my DVD menu. I've been searching around and didn't find any solution. Found some people with the same problem but I don't find anywhere a solution for this problem.

I did my menu in Photoshop as named the image layer as (=1) Hightlight so it would appear when I hover buttons and appears the white box instead of the image.

Best regards.

Sounds like it may be some kind of a processing glitch.  Menus don't actually do an overlay when you mouse over them, they display a different image.  If you export one button with highlight and one without, you can specifically set the hover image of the button to be the one with the highlight.  You specifically have options for selected, unselected and hover.

If you need more detail about how to do this specifically, I can put together some screenshots when I get to my editing workstation, but I seem to recall it being relatively easy to find in the properties of the button.


What is this effect used by a lot of voice actors called? I am looking for a specific voice effect that I have listened to in many videos on YouTube and other places. I don't know what it is called and it also does not sound natural. Here are examples -

Arpha Hub - Explainer Video

Addison Anderson

Ankit Arora

Do you notice the subtle 'errrrr'/crunchiness/vibration/distortion/robotic sound at the end of many words? I understand it may be difficult to understand by my explanation but hope someone recognizes it.

I would like to know if this effect has a name or something to search further into it or is there is a YouTube tutorial somewhere that I can follow, to begin with.

Any kind of pointers would help.

This is not an effect, it's the way these people talk. Some people have a rather raspy voice, other a smooth one. There is no effect to make your voice more raspy, unfortunately.


Can individual tracking points be edited in After Effects? I solved a rather long scene in After Effects for camera tracking.  Later, I realized that the tracking point I chose "jumped" out of its stable position for a split second.  This only became apparent after I had attached a graphic to that point.

Re-doing the analyze/solve steps is rather time consuming.  I was wondering if the tracking data for the point I have chosen is accessible and whether it is possible (and easy) to edit out the offending data point/points.

(I can't comment because I don't have 50 reputation yet lol)

By the way, if I got what you mean you just have to move with the Selection Tool the keyframe on the Composition screen.

For making the path smoother and more accurate the sub-Pen Tool called Convert Vertex Tool.

Finally, on the timeline thanks to Graph Editor, add dynamicity to the animation in-between frames (delay and advance).


Simulating 1080p pan shot by cropping stationary 4K fisheye footage? I want to achieve a panning shot, but I can't move my camera. The camera is stationary for reasons outside of the scope of this question.

Can I throw on a fisheye lense, film in 4K, and then process it to appear as if I'm panning the camera from 1 corner of the frame in the original footage to the other side of the frame? I don't think this is the same as 4K live cropping, as I imagine I would need to do some processing to invert the barrel effect.

Does this make sense mathematically? Will the result look any good, or will it be "obviously wrong"? What is the best way to get a good result?

Yes, you can do this successfully. I did it with an overhead 4K action camera with a fixed fisheye lens (YouTube video here).

You'll want to remove the distortion in software to "square it up". Then you have some room to zoom in and pan. However, you effectively lose some resolution with the lens correction. You can only zoom in so far before it's noticeable.  Obviously it's not as crisp as nice 1080 video, but it may be perfectly fine depending on your requirements.


Having problems with fade in I have a video with an overlay that i need to fade in. When i add a crossfade it starts fully opaque and then fades out. The exact opposite of what i want to achieve. How do i reverse the crossfade effect without also reversing the video?

If the overlay has transparency, you could use an Add strip instead. Then keyframe the Multiply setting for it going from 0.0 (invisible) to 1.0 (fully visible).


Can modern cameras (BMCC, Red, Arri, etc) record to a drive over ad-hoc wifi? Is there a solution that bifurcates drives and camera bodies?

At first glance it seems feasible that camera bodies could be equipped with 802.11ac mimo and transmit the raw image data to a drive at a DIT workstation.

Is there any tech hurdle in making this happen?

Any camera with an HDMI or SDI output can can stream via wifi using a Teradek Cube (http://teradek.com/pages/cube).

This setup will allow you to monitor and record via iOS or computer. It also supports remote recording over the internet (decoder needed).

In addition to WiFi, Terdek also supports 3G/4G/LTE cellular networks via a USB modem.


ffmpeg scale and overlay then output yuv got corrupted video I wanted to scale a video input (1.webm) and keeping it's aspect ratio,
then overlay to make it centered, with following command:

  ffmpeg -y -hide_banner -i 1.webm -filter_complex "color=color=Black:size=640x480:d=7.420[bg];[0:0]scale=w='iwmin(640/iw,480/ih)':h='ihmin(640/iw,480/ih)'[scaled];[bg][scaled]overlay=x=(W-w)/2:y=(H-h)/2" -an -f rawvideo -c:v rawvideo -s:v 640x480 -pixel_format yuv420p 1.yuv

the output seem corrupted, dark area in original video turns purple or pink, and it's blinking.

I edited the command to remove the overlay filter, with following command:

  ffmpeg -y -hide_banner -i 1.webm -filter_complex "[0:0]scale=w='iwmin(640/iw,480/ih)':h='ihmin(640/iw,480/ih)'" -an -f rawvideo -c:v rawvideo -s:v 640x480 -pixel_format yuv420p 1.yuv

this time, the output seem fine.

I can't figure out what is going wrong, please help.

I suspect this has to do with lack 1-1 correspondence between the frame timings in the color and video, but in any case, you can just run

ffmpeg -y -hide_banner -i 1.webm
       -vf "scale=w=640:h=480:force_original_aspect_ratio=decrease,
            pad=640:480:(ow-iw)/2:(oh-ih)/2"
       -an -f rawvideo -pix_fmt yuv420p 1.yuv


FCPX Cross dissolve sometimes causes jump on stabilized video I've seen this before, but I want to get to the bottom of it (I hope) so I can prevent it from happening again. I have a video with a few dozen stabilized clips. Looks good, though I want cross dissolves between each clip. That works fine, but sometimes going in or out of the transition causes a jump, as if the stabilization settings were different for the transition. For an example, take a look at this video... especially the start and end of the clip that runs from 00:31-00:43.
http://dangoodspeed.com/shared/12n-downtown-schenectady-fire

Instead of using a crossfade transition effect, use opacity keyframes in the video animation menu.
Select your clip and press "control + v".


Avoiding motion blur from a network camera I'm a newbie here. I have a problem that I don't really understand. Hopefully, someone can share their experience.

If I have an ip camera of

1) 640x480(sensor width = 3.6mm),

2) focal length from 5 to 50mm,

3) need to record 30fps,

What is the suitable shutter speed to be use to avoid motion blur?Assuming that the object distance to camera is 30ft (80 ppf needed =~ 13.5mm lens focal length needed).

Shutter speed and motion blur are inversely proportional.  The higher the shutter speed, the less amount of motion blur, so crank up the shutter speed as high as it will go.  If the exposure comes out too dark, add more lights.  Keep in mind that high shutter speeds in combination with fluorescent or HMI light can produce scrolling banding due to the power cycle frequency.


Editing with music: what workflow produces the best results? What would produce the best result, in terms of quality?

So I like to go out and take some random dynamic, smooth, clips of places around my neighborhood with my Flycam, but I'm wondering what would be the best workflow;

find and edit out the unusable parts of the footage (like the heads and tails), then find a nice, ambient, relaxed type music, and add it in, fine tuning the clips so it matches the music (cuts on the beat, etc).

or

Find the music first, then edit clips according to the music so it matches.

Which do you think would be faster, easier, and produce a better result? What are some pros and cons of each?

I use Premiere.

Sooner or later you have to look at your video and make choices.  A term of the art is to "create video selects".  And the organizational technique used in Premiere Pro is called a "stacked timeline" or a "pancake timeline"(with more details explained here).  But to ease into these (and answer your question)...

You absolutely need to go through your footage to find the good stuff.  Don't think of it as "editing out the unusable parts", but rather "find, mark, and label the good parts".  Labeling is key because that's how you are going to find the good stuff later.  Mark in and out points to quickly get rid of useless "flying to" and "flying from" parts of your footage.

Quoting from 1, "By stacking 2 timelines on top of each other…an editor can now access an entire reel of selects in chronological order (or whatever order desired) and instantly drop them into the active timeline below. To accomplish this layout…first open both timelines by clicking on them in the Project Panel. Drag the Selects timeline tab and hover over the top quarter of the Master timeline. Once it turns a purple color, release the tab and you’re in Pancake Land! By not having to bounce between tabbed timelines and using copy/paste…the process of analyzing and deciding which shot makes it into the cut is streamlined and intuitive. You can playback the Selects timeline in the program panel or hit the “match frame” keyboard shortcut and play it back in the source panel. Then just insert edit or drag-and-drop the shots you want into the Main timeline. Another very nice feature of this edit workflow is that the shots you pull from the Selects (top) timeline remain in their original position and are duplicated into the Main (bottom) timeline."

Another thing to keep in mind is that the construction and ordering of the selects timeline is up to you.  You can order your footage chronologically, by subject, by altitude, whatever your labeling system and sorting system might be.  Make metadata work for you!

At this point you probably have an idea of what your true "hero" footage is, and how much time you can fill with the top 95% of your material.  (Or you have an idea how deeply you have to scrape the barrel to create a 2-3 minute video.)  This will give you an idea of to find the right matching music--both thematically and in length.  And it will give you an idea whether you are better off to start cutting the video to the audio, or vice-versa.

Usually the best results are those that make the best elements speak best, both by themselves and together in ensemble.  If something sticks out like a sore thumb, take it out.  If you realize there's a shot that would make the video complete and you don't have it, maybe (in your case) you can rig up the flycam and get it.  Most video editors don't have that luxury because the footage is a given and they cannot just ask for more.

As your video converges with the audio, you will get a sense of just how important it is to align visual and audio "beats".  Keep working until every visual moment is reinforced by the audio, and vice-versa.


lavfi virtual device - the same parameters for ffmpeg and ffplay The command

ffplay -f lavfi -graph testsrc2=d=1[out0];sine=d=1[out1] test.mp4

works fine. But the same arguments for ffmpeg (instead of ffplay)

ffmpeg -f lavfi -graph testsrc2=d=1[out0];sine=d=1[out1] test.mp4

produce only the error

[NULL @ 00000000006934c0] Requested output format 'lavfi' is not a suitable output format
test.mp4: Invalid argument

What's wrong with it?

Note:

From the FFmpeg documentation for the lavfi:

  Currently only video data is supported.

It seems that's not true nowadays, at least ffplay works fine with audio (see my first command).
Or I incorrectly interpret this sentence?

But just in case I tried using the filtergraph testsrc2=d=1[out0];testsrc=d=1[out1] instead, with the same results — ffplay — OK, ffmpeg — the same error.

The ffmpeg tool can work with multiple inputs and outputs so the parser looks for -i to demarcate input options. The lavfi device will read the graph from the input argument

Use

ffmpeg -f lavfi -i "testsrc2=d=1[out0];sine=d=1[out1]" test.mp4


High quality ogv files - possible? I'm converting mov (or flv or mp4) files into ogv. Unfortunately, the programs I've been using (Miro, FFMPEG's ogv plugin) have terrible encoding that appears extremely fuzzy.  Does anyone have recommendations for less compressed files in this format? Is it possible? Software recommendations?
Thanks.

You can encode to Theora video and Vorbis audio with ffmpeg if it has been compiled with --enable-libtheora and --enable-libvorbis. Depending on your ffmpeg version the default settings may not provide good enough quality. Therefore you must add some additional parameters to enable a constant quality type of mode for the video.

Theora video

Adjust video quality with the -qscale:v (or the alias -q:v) option. The valid range to set video quality with libtheora is -1 to 10. A higher value is a higher quality.

Note: More modern alternatives such as VP8 can provide better quality at lower bitrates. See the FFmpeg: VP8 in WebM Encoding Guide for more info.

Vorbis audio

Adjust audio quality with the -qscale:a (or the alias -q:a) option for VBR audio. The valid range to set audio quality with libvorbis is 0 to 10. A higher value is higher quality. See the Recommended Vorbis Encoder Settings to get an idea of what values to use. The default of -q:a 3 will be used if you omit -q:a or -b:a.

Note that ffmpeg supports two Vorbis encoders: the external library libtheora (-c:a libvorbis) and the native Vorbis encoder (-c:a vorbis -strict experimental). The native encoder is experimental, does not compare well to libvorbis, and usage is not recommended.

Example

The following command will create a good quality output for both video and audio:

ffmpeg -i input -c:v libtheora -c:a libvorbis -q:v 6 -q:a 5 output.ogg

Getting ffmpeg

Make sure to always use a recent ffmpeg build and refer to the current documentation specific to your build since options can change. See the FFmpeg download page for various ways to acquire ffmpeg or follow one of the FFmpeg compile guides.

Also see

FFmpeg documentation on libtheora
FFmpeg documentation on libvorbis


How to *stream* audio over multiple scenes in Flash? I must use "stream" because the video must sync with audio.

Suggestions I found on Google:

1) Use Event mode. I am aware the "Event" mode will play over multiple scenes, but it does not force audio sync, which causes major problems with audio sync.

2) Don't use scenes. This is what I'm working on now, but it's a nightmare solution - trying to transfer many layers from many scenes so they all line up again.

I would even be open to trying other software, but flash is the only vector animation program I've found that allows for easy animation and freehand vector drawing (unlike Illustrator-type programs that make you take all day dragging curve points).

I faced a similar problem with a music video. Multiple scenes trying to keep every thing lined up and some lip scync toward the end.  Had a hell of a time trying to get it all to match up with the music- scene changes, action, and lip scync. As the audio was located in scene 1 I did not want to try to cut up the song and try to get it to play correctly over numberous scenes. since the audio disappears when you're working on a different scene it all becomes guesswork trying to estimate the number of frames required for every scene in order to come out where you need to be.
Then it accurred to me to use a line timer to solve the problem. Here is what I did and kept the scenes rather than moving at all to one timeline:

If you are using music in your animation, determine the beat of the audio.  lets say in this case 14 frames per beat (Use an audio editor to determine beat rate.)
Make sure your frame rate in flash is the same as your audio in the audio editor. My case was 29.97 fps
Create a small graphic lets say a red square. Have it appear every 14 frames for a duration of 2 frames.  Repeate pattern until you reach the end of the scene. Always
make sure you end the pattern with it one frame short of repeating the marker.  The rest of your scene layer/s should fall somewhere within this last timing pattern. Don't worry if they are not lined up yet.
Begin new scene. Start your timing pattern at the first frame with a timing marker. Repeat #3, as per need.  (Short cut: copy and paste timing layer using copy frames command by right clicking on layer. Note you will need to add 1 frame to the layer right after the first new timing mark per paste if your time line is longer than your intial paste & if you paste more than one time it will need to be done for each paste.) Saves a ton of time.

5 Remove extra timing marks. End as you would in #3.

6 Here is the tricky part and requirews a little thinking, but this will line every thing up and get it to run to the beat. Add or remove frames in the rest of your layers to the end of your marker frames but just before a new timeing marker appears.  in other words if your final timing marker in the scene is only 4 frames from the end of your current layer subtract the frames so the layer ends before the last timeing marker. so you now at some point need to add these frames back in.  You may be able to do this in the next scene. The way to keep track of this:

formula for tracking:
**

1. A# = added number of frames;
2. R# = removed number of frames;
3. NA# = need to add number of frames;
4. NR# = need to remove number of frames;

**

Sample of how it gets used:
**

1. N0  Scene 1 R4  NA4;
2. NA4 Scene 2 A6  NR2;
3. NR2 Scene 3 R10 NA8;
4. NA8 Scene 4 A8  NR0;

**

Okay here is the logic behind this chart. Starting at the begining of frame 1 scene 1 you are at 0 (N0)**You do not need to add frames to the beginning of this scene. If you remove 4 frames to get to where you need to be in association with your timing marks(R4)** Then you need to add them back in (NA4). Carry over the NA4 to the next line on the chart or scene (NA4 Scene 2). next you had to add 6 frames in scene 2 (A6) since you already needed to add 4 frames and you added 2 more than what you needed you now need to subract these 2 extra frames at some point Need to Remove 2 frames (NR2)
 hence (NA4 Scene 2 A6  NR2)
next line:
NR2 Scene 3 R10 NA8 Needed to remove 2 frames in scene 3, you removed 10 frames you now need to add 8 frames back in.
next line:
NA8 Scene 4 A8  NR0 needed to add 8 frames in scene 4, you added 8 frames which just happens to end at the right spot on the timing marker layer.   Now everything is synced up you can add additional scenes making sure that you end your scene as described in number 3 of these instructions.  Everything should sync up perfectly.  If you have any problems you may have to adjust one or two frames either direction in previous scenes to make up for the lag that flash has.
you always want to get back to a 0 point or (N0)
Also now that the time markers are blinking during your animation you can also add lineup/sync other animations that occur within the scene to the beat of the music.


Sync audio and video, equipment? I need some help or tips in the area of video and audio sync. Think a music videoclip, where the audio is recorded independently to create a master audio track and then the video will follow along. Not interested at all in the audio recorded with the videocamera.

I'm experienced with the audio part, but have done only one video project of this nature with iMovie (absolute noob and not willing to invest much in video editing software at the moment).  While editing, it was an absolute pain to get everything in sync, lips motion with lyrics, ... I had to do it by hand drag and dropping frames around the audio track. Waste of time.

I was wondering if there's anything I can do while recording either the audio or the video that would easy this process. I do have semi-pro audio equipment with timing signals like SMPTE and things like that but I've never used them, not sure if they would be of any help for this.

Thanks!

Haha! In movies about movies you always see this clap in the beginning of a shot. The one where the take number and everything is written on with chalk. And they hold it in front of the cam and make one loud clapping noise with it.

Well, if you have ever wondered what this ritual is for, congrats! You have found the problem to the solution ;-))

You get a video frame on which you see the clap closing and at the same time you can see the noise level peeking in the audio recording.

The poor mans version of this is to tell one of your actors to do the clap with her hands.


How to check video, AB test, on different screens: balancing colors, etc Is there a standard way of checking a render as it would be seen on different screens (iPads, monitors, tvs, whatever) for colors etc..
Maybe AB/Testing software? (Wanted to add the tag ab-testing, but my rep isn't high enough yet)

As a reference I have a song & corresponding music video (see link below).
I'm wondering if I affected (washed out) the colors too much. I'd like to know the differences on different screens. How can you effectively check on different screens (on your own pc). Reference:

Thanks,
Yves

The standard way to deal with this is to use color calibration.  Unfortunately, color accuracy on consumer devices tends to be all over the charts.  There is no way to guarantee that the color will be similar, even on multiple of the same model of device, or even on the same exact device over time.

Thus, the best practice is to setup a color calibrated environment that you can verify the content looks correct in.  You can then run your encodings for different profiles and compare them in an environment where you know the differences will show up clearly.  The results on end user devices may vary based on how good their screens actually are, but building to a standard high quality, calibrated display should produce the best overall outcome across devices.

If you want to get really advanced, you can also generate or obtain ICC profiles of the average for the device screen you want to display the video on.  This profile can then be applied to the video on a calibrated display to alter the colors to be similar to that produced by the device.  It still won't take in to account pixel density though.  If you want to know exactly what it will look like on a display, there is no substitute for actually sending it to that display since pixel layout and density, as well as the surface type and size, make a gigantic difference in the way the video looks.

Using the device itself is also helpful for ensuring that the video can decode and play smoothly within the constraints of the device.


Tool to find Duplicate Video files ignoring tags I am looking for an automated method to identify duplicated video files from my large collection of videos.

I have used fslint to do this in the past, but I started fixing the EXIF tags on my videos, which makes fslint identify them as different files.  The only difference between the original file and the modified files are the EXIF tags, which in most cases have simply been time-shifted to correct for timezone or camera offset.  The videos have not had any encoding or conversion of any type.

Is there a tool something that I can use to identify duplicate videos based only on the AV streams, i.e. ignoring the tags?  I'm essentially looking to duplicate fslint-like functionality, but ignoring the EXIF tags.  Does such a tool exist?

I have a suspicion that ffmpeg can be used to do this, but all I've been able to find so far is this answer, which shows how to blend two video streams together and display the difference.  Doing so "works" in the sense that I get a solid green screen with my duplicate files (indicating no pixel differences), but I can't use that in a script to handle hundreds of comparisons because I still have to visually inspect the result.

Is there a way to get ffmpeg to give a yes/no answer?

I've seen this answer, but found the answer to be entirely too manual.  I need an automated process that can go through large filesets in one run.

It might be overkill in your situation since the videos aren't actually different resolutions, frame rates and or codecs, but still :
As with another answer https://video.stackexchange.com/a/33521/32436 :

You could check out https://theophanemayaud.github.io/video-simili-duplicate-cleaner/ (macOS binaries available) It's open source, based on vidupe and QT : https://github.com/kristiankoskimaki/vidupe (windows binaries available but no "auto deletion based on specific criterion")
The idea is to extract a few (eg 2, the first and the last) frames, and compare them. If the duration is close, and the frames look similar : you've got a duplicate.
It uses opencv for frame comparison, and ffmpeg for frame extraction (ffmpeg is also for video metadata which is very useful when trying to tell which video to keep !). Since it's open source, you can improve it to fit your needs !

Because it looks at the video data, you shouldn't have problems of tags or other metadata that has changed !


Premiere Pro PC timeline only plays for a few frames and then no Audio after installing Miraizon DNxHD / ProRes Codec Since installing Miraizon DNxHD / ProRes Codec I am not able to play my timeline in real-time. It gives me a few frames and then the video freezes and audio keeps playing. I changed from Performance mode to Memory mode and now it will play through, however if I stop and start a couple times. It reverts to the former behavior. Specs of my system and project below.

I have Premiere Pro CC 2014 on a Windows 8 PC i7-4930 16GB RAM. Drive structure: Win/Programs on 256GB SSD, Project/Media on 1TB SSD, Preview/DB on 5TB RAID 0 7200 Seagates.

I'm working on a shortform project, basically 5 sequences comprising 18mins of a 22min show. Two streams of prores from from a 5D,6D 2 cam shoot, and I'm putting slides, stockfootage, and titles in.

I was able to play my timelines in real-time just fine (preview format DNx 115 1080p 23.976) until installing Miraizon DNxHD / ProRes codec. I got it because the editor putting the final show/QC together is on FCP7.. anyhow after installation I notice my preview files were gone -not surprising-. If I delete my preview files I get a couple clean playbacks (after they regenerate) and then the original behavior, same if I restart PPro.

I tried running the QT installer and "repairing" that after someone suggested that the QT SDK might be the issue. No difference. Makes more sense to re-install DNxHD codec from avid probably- I'll do that next.

Has anyone had a similar issue or Can you suggest what might be going on?

According to Miraizon support this is a peculiarity in Premiere Pro handling of ProRes that causes it to interact "very inefficiently" with the the codec. There is an update forthcoming but until then they suggested this as a work-around:
Move the AppleProResDecoder.qtx from the /Quicktime/QTSystem/ folder to a temp folder.

I still get some inconsistencies with various files under these circumstances such as "Media Pending" messages that aren't resolved and spotty playback.
This is currently working for me:
For editing:
Leave the AppleProResDecoder.qtx in /Quicktime/QTSystem/ and move the MProResCodec.qtx from the /Quicktime/QTComponents/ folder to a temp folder. Restart PPro.
When I'm ready to export my ProRes:
Then when I'm ready to export to ProRes, I move the MProResCodec.qtx back to the /Quicktime/QTComponents/ folder and move the AppleProResDecoder.qtx into the temp folder.
Restart PPro.


What are the audio production capabilities in Sony Vegas Pro because I see mostly plug-ins only? I have read that from the NLE video editors Sony Vegas Pro is better than the competitors in terms of the audio editing capabilities. But using it there still seem to be a limited set. Mostly the editing is the addition of plugin effects or to open the audio in another editor. Am I missing something which the program allows?

If you are judging Vegas Pro audio editing on native effects than I don't think it has any edge over others.

I have been using the Pro version for about 18 months now and I find it pretty darn good overall. I am also learning Adobe Premiere and After Effects CS5.5, so far I think Vegas has the edge on the audio for sure.

However, are you aware that Vegas Pro audio editing has the ability to add as many audio tracks as your system can handle (stereo or mono), treat each track with a pan position feature, set individual volume (amplitude) envelopes for each clip, boost or buck the audio overall output of each track, name each track, size the vertical and horizontal view of the audio track as you see fit, record directly to any track, cut any audio clip any way you want, reverse an audio clip with two mouse clicks, and edit Dolby 5.1? And this is only a partial list of some of the built in controls available.

UPDATE: I omitted one feature that I really love, both audio and video tracks can have their order rearranged very easily. With a simple mouse click and drag, you can put that bass line near the drum track or move the voice-over above the music track. I like to move audio tracks as I am building them to keep it tiddy.
:>

This list is not complete and does not include the native sound effects which as mentioned earlier are rather standard with any NLE: reverb, EQ, pitch shift, delay, etc. And yes, AFAIK, it can accept plugins but I have never needed any at this point so I am not aware what plugins are compatible.

I have both Vegas Pro 10 and the home version of Sony Sound Forge. I can export an audio clip to Sound Forge for further effects, it's sort of like Audacity on steroids. As far as I know you can render your audio portion to several formats and export to anything that has the same format. I haven't tried this, but I would think you could easily export your audio as a .wav to Audacity but I have never needed to export the audio for further processing except to test it with Sound Forge, and in that exercise, I just had to copy paste the clip--easy.

I have made video content with Vegas Pro that has had as many as 18 stereo tracks with no issues.

Remember Vegas was originally a multi track audio editor.

I think the best answer is for you to try the trail version of Vegas Pro 11 for free for 30 days and kick the tires and then take a spin:

http://www.sonycreativesoftware.com/download/trials/vegaspro?keycode=64506

Disclaimer:
I should mention that I sort of have one hand tied behind my back on this answer as it would be so much more useful to launch Vegas when answering this to review the features. My version of Vegas lives on a machine that is not accessible from the network for security reasons and that location is about 8 miles from where I am typing this.


How can I put a VP9 video stream into a QuickTime/MOV container? FFmpeg has no trouble putting all sorts of weird video codecs into QuickTime/MOV containers, including utvideo, hap, snow, ffv1, and cinepak. This makes sense, as it is my understanding that the MOV format should be extendable to any type of video stream.
However, when I ask FFmpeg to put a vp9 video stream into a MOV container, FFmpeg refuses.
$ ffmpeg -i file-with-vp9-video-and-opus-audio.webm -vcodec copy -acodec pcm_s16be test.mov

[...]

[mov @ 0x7fbb1b822400] vp9 only supported in MP4.
Could not write header for output file #0 (incorrect codec parameters ?): Invalid argument

Due to stupid and buggy software which is out of my control, I need a way to get VP9 streams into MOV containers. I cannot use a different container format, including mp4 or mkv. (I might be able to use WebM, but that does not support PCM audio.)
Is there another way to do this? It doesn't need to be with ffmpeg, but it does need to be with a UNIX program which I can automate in a shell script.

Edit: Quick note, I'm not opposed to doing something super weird, like muxing into an mp4 and then hex editing the header (just as an example, I don't know if the formats are close enough for that).
Which is to say, it can be a total hack. The software I'm working with will absolutely refuse to open anything that isn't a MOV, even though I have given it the capability to decode vp9.

For my use case, it was enough to do:

ffmpeg -i file-with-vp9-video-and-opus-audio.webm -f mp4 -vcodec copy -acodec aac_at test.mov

This is cheating, really. The output isn't actually a MOV file, but rather an mp4, which uses a similar but not identical structure. Even so, it successfully coerced the program I'm using into opening the file.
Notably, outputting an mp4 and changing the file extension does not work, so the above command is producing output that's somehow different from an actual mp4. I obviously don't understand all the intricacies of how these containers work, but it was enough for today!


See layers beneath the solid I'm editing in After Effects I have imported a photo into one layer and I created an opaque solid on top of it.
I want to animate the solid with the Brush tool (Write on).
When I enter layer edit mode for the solid I can't see the photo layer underneath it, and hence can't use the photo as a guide for the Brush tool.

Is there a way to increase layer transparency so I can temporarily see a guiding layer beneath it?

Don't apply the brush tool to the solid - apply it to your photo instead.  There is an option in the tool to choose whether to apply the brush over the image, or to reveal the image.  When you're drawing your brush strokes, set it to apply over the image.  When you're ready to animate the strokes, set it to reveal the image.


What are the key PC specs for best editing HD videos? My wife bought a GoPro Hero3 for some simple home video: kids, holidays, etc.

The problem is that some videos are not playing very well on our old PCs.  We want to buy a new one for video editing. As far as I understood, such a computer should have as strong of a CPU as possible and plenty of RAM. It seems that the video card also has some role, but it's not as important as CPU/RAM in general. Is this assumption correct?

Dealing with HD video has two main components.  The first is the ability to decode the highly compressed video (which is computationally intensive) and then is the ability to deal with the large uncompressed data (which is bandwidth intensive).

The fastest encoders/decoders use the GPU on the graphics card to improve performance as a GPU is far more capable at attacking the problems related to rendering and compression than a traditional CPU is.  So if you have one of these, then the GPU is by far the most important piece.  If you don't however, then the CPU becomes by far the most important piece as encoding/decoding on a CPU is very, very intensive.

As far as dealing with the uncompressed data, the relatively small compressed files will be decompressed into memory and then played out of memory, so it is important to have high speed RAM, but not necessarily the need for a lot of it for play back.  For editing on the other hand, quantity becomes a bigger factor since the more video that can be stored in memory, the smoother your editing experience will be.

Finally, you have the hard drives.  It is very helpful if these are quick for loading videos (particularly for editing) and also for working as scratch disk (where editing stores temporary files that don't fit in memory), however it is probably the least critical part.  This can change though if you start working with higher quality, less compressed video where the file sizes start getting larger.

So, to summarize, GPU is highest priority if your software can use it, otherwise CPU and then speed of memory, quantity of memory and speed of hard drive in that order.  CPU is still second most important if you do have GPU processing support.  If you don't, then GPU is of almost no importance at all.


One long continuous shot, sped-up until it becomes "live" I have an idea for a video project (that I will need to commission a studio to produce for me), but at this early stage I don't even know whether my idea is feasible.
The idea involves turning (hours of) continuous/uninterrupted footage from a single camera into a short (circa half-hour) film by varying the speed of playback so as to speed over "boring" sections whilst still drawing attention to key moments of interest: that is, some parts might be sped up by as much as 64x, whilst other parts could be slowed right down (even to a frozen frame).  Is this sort of sped-up/slowed-down effect from a single continuous shot known by some particular name?
Where this idea gets more complicated is that playback is to begin whilst the footage is still being shot, becoming real-time/live once it catches up to the present.  Is this sort of transition from recorded footage to live broadcast known by some particular name?
Practicalities
I envisage the recorded footage being transferred from camera to editor in "chunks" (e.g. initially of a half-hour each, reducing in duration toward the end until the feed is live).  Each such chunk could then be worked on to produce a (shorter) "chunk" of final film that is immediately forwarded to the presentation display and enqueued for playback.
When it is time for playback to begin, the enqueued chunks would start playing in turn whilst further chunks continue to be added to the queue.  Once the footage is live, these chunks would amount to little more than a typical video stream (so some small buffer will be required to cope with network and processing delays—but the smaller the delay, the better).
I appreciate that (in order for the different sections of film to playback smoothly and comfortably, without any judder/strobing/etc, yet have sufficient definition to be interesting), various camera settings such as shutter speed will need to be varied according to how that particular section of footage is to be played-back.
I also understand that some computationally expensive interpolation may be required to smooth out the transitions, and this will add delay to the editing process...
Questions
My principal question is whether this idea is feasible, or completely unrealistic?  Perhaps the time that would be required to edit the footage would alone make such a project impossible?
If it is feasible, then I'd like to understand the key risks to the project from the videographer's perspective (aside from network/comms failure between camera/editor/presentation).  What other challenges do you foresee, and how might one tackle them?
I've tried contacting a few professional studios about this idea, but so far haven't had much response.  I've probably approached the wrong sorts of places, who perhaps don't have the resources that would be necessary to turn such a crazy idea into reality.  What sorts of studios should I be looking for, and what capabilities should I ensure they have?

The answer above answers half of your question, and yes, it is trivial for anybody who has used a non-linear editor (NLE) such as Premiere Pro, Final Cut, Resolve, etc., to do speed ramp effects.  The film Koyaanisqatsi features many visual effects that include speeding up and slowing down time, which may help you better imagine the possibilities of the medium.  But NLEs are really only for off-line production.

To answer your second question about doing this while actually shooting, the short answer is no, nobody has built an off-the-shelf system for doing this.  The concept of "instant replay" (encompassed in a system such as the NewTek 3Play 425) illustrates how live feeds and recently (immediately) recorded clips can be used together while slowing down the playback rate.  And while it's theoretically possible to speed up playback rate (subject to available content in some buffer), it's not anything anybody has tried to do.  Instead, people edit offline and present a finished product after editing.


How to record myself while not noticing myself? I am using an Android Oreo phone. I would like to make a video of myself, but while I make it, I want the screen to go blank. This is so that looking at myself on the phone while I record will not interfere with how I end up appearing on the video. This way I can also think about how I would look at another person while I pull the face in thinking about, and then see for myself what my face looks like, so as to be able to foresee how I come across and what I can guess the other person's reaction would be, as seen by reacting myself to myself.

Any suggestions on how to go about doing this?

the easy way ? Yeah. Use a post-it note.


Is there a mathematical equation to compute the bitrate of a Cisco H.264 stream? I'm working on adaptive streaming for video. As I'm using a Cisco Open H.264 Encoder, I'm testing multiple configurations for the encoder. A configuration consists in a several of parameters (bps, fps, slice_mode, usage_type, rateconol_mode, keyframeInterval). I also have the width and height of the image to encode.

Is there a mathematical equation to get fps from the bps and vice versa in order to apply the best fps value to be adequate with the bps and the opposite.

No, because it's content dependent. Video with high motion contains more information than a nearly still scene does. Hence it takes more bits to encode.


Wrong frame-rate, corrupted playback of isom/mp4 files remuxed from H.264/AC3 MPEG-TS NOTE: This question is superceded by this new one, please do not answer below this post.

What happened?

[Edit] DVB file ('file1') in TS format of H.264/AC3@50i cannot be properly remuxed into any of the following formats: isom/mp4; QuickTime MOV; Matroska
Another DVB file ('file2') in TS format of MPEG-2/MP2@59.94i can be properly remuxed into any of the following formats: MPEG; isom/mp4. QuickTime MOV and Matroska are not tried.
[Update] Still another one in TS format of H.264/AAC@29.97p can be properly remuxed into isom/mp4 without a hitch, not requiring any ffmpeg switches other than -i, -c copy.

Technical details

FFMpeg reports millions of the following error messages, with or without any possible combination of these switches: -fflags +genpts, -fflags +igndts, -fflags +discardcorrupt

Command line is ffmpeg.exe -fflags +igndts -fflags +genpts -fflags +discardcorrupt -i INPUT -c copy -format mp4 OUTPUT
Error Message 1:
    [mp4 @ address] pts has no value
    Last message repeated xxx times
Error Message 2:
   [mp4 @ address] Non-monotonous DTS in output stream 0:0. Previous ... Current ... Changing to ... , blah blah

AVIDemux completes operation with wrong metadata and faulty playback. File properties and playback behaviour resembles that created by FFMpeg

Frame-rate becomes variable, should be 50i
Average frame-rate is not the correct value, showing very strange numbers
Playback frame-rate is abnormal, oscillating btw. 59.94 and 39.xx

[Edit] MP4box reports the following warnings for 2 times, and produces jagged picture with wrong frame-rate as mentioned above. If you view the resultant video very carefully you will see the image with many blocks; this is not found in the original file.

Command line is  mp4box.exe -fps 50 -add "INPUT#video" OUTPUT
Error Message:
   [MPEG-2 TS] PID xx PCR discontinuity signaled but diff is small (diff xx us - PCR diff xx vs prev PCR diff 0) - ignore it

My questions, in detail

1   What on earth is "DTS" and "PTS"? They seem to be obsructing a successful remux.
2   Is this due to corrupted file or software bug (see https://trac.ffmpeg.org/ticket/4768 and https://trac.ffmpeg.org/ticket/502)?
3   If this is a software bug what are the work-arounds?
4   Any workable solution that remuxes MPEG Transport Streams to MP4 are welcome. MPEG-TS takes up too much overhead and are not well supported across platforms and systems.

Diagnostic Information
-   MediaInfo dump of file1,  file2, and  file1 remuxed into mp4 by FFMpeg
http://pastebin.ca/3966322

To answer part of your question (and add a couple of other abbreviations you will run into):

PTS = Presentation Time Stamp
DTS = Decode Time Stamp
PCR = Program Clock Reference
SCR = System Clock Reference

MPEG elementary streams reorder the frames for transmission. The PTS indicates the order that the frames should be re-assembled into. The DTS lets the decoder know if a frame needs to be decoded earlier than it is displayed (because a P or B frame references it). The PCR or SCR are the time scale that the PTS and DTS reference.

tstools and other transport stream analyzers can help you determine if the PCR/PTS/DTS issue is in the source file or not.


After effects | How do I copy an image source from layer to another programatically? My comp setup is as follows:
- layer 1: image
- layer 2: duplicated from layer one

I'm looking for an expression or any other method (Could be a plugin recommendation) so when I change the image of layer 1, it automatically updates layer 2!

It depends how you mean:

Option 1:
If you put the image in Layer 1 inside a Comp, then any change to the image inside the Comp will change in both Layer 1 and Layer 2 (assuming you also put the Comp on Layer 2).

Option 2:
You could put a load of different images inside a comp, a different one on each frame.
Then in your master comp, place this comp, but assign Time Remap to the comp, to choose to hold on a specific frame.  Then when you want to change the held frame, just keyframe to the different time in your first comp.

Option 3:
If you really mean to change the image programmatically, you could use something like Templater Rig, where you can set a load of different file paths to images, and then assign them to different comps programmatically.


Add multiple mp3 files to an mp4 file with ffmpeg I would like to add multiple mp3 files to an mp4 file.
For adding a single mp3 to an mp4, I used this command with success:

"-i /path/to/mp4File -i /path/to/soundmp3File -codec copy -shortest path/to/output/fileWithSound"

But I'm stuck with adding another mp3. I tried this, but it didn't work:

"-i /path/to/mp4File -i /path/to/soundmp3File1 -i path/to/soundmp3File2 -codec copy -shortest path/to/output/fileWithSounds"

How can I make it work with multiple audio files?

Use

-i /path/to/mp4File
-i /path/to/soundmp3File1
-i path/to/soundmp3File2
-map 0 -map 1:a -map 2:a
-codec copy -shortest path/to/output/fileWithSounds

FFmpeg will automatically select one video and one audio stream from among all the inputs. -map options are required to include all streams.


Loading large videos in After Effects takes ages the first time. Any way to improve it? They are really big videos, of several gigabytes, with 100-150mbps bitrate. These files load and play normally with any player. I don't think they are hard to decode, it's just that they have a very high bitrate. Taking them in After Effects, however, takes several minutes. It takes 2-5 minutes for a video to appear in the timeline, and then the preview takes again extra 2-5 minutes to load the first time. After these two long loads, the video plays smoothly in the AE preview panel and I don't have any problem. What is causing these long loads? Is there a way to improve them?

If performance is sluggish, I would make sure the videos are the same resolution and frame rate as the format you plan to deliver your final video in.
So if the videos you are trying to import are 4K, but you're working in HD in After Effects, I would transcode the videos down to HD.
Also use a non-GOP codec like ProRes instead of h264/mp4.  They perform better when editing, because the software doesn't have to "look ahead" across multiple frames in order to work out how to draw the current frame.