Technique that seems to freeze everything in the world except the camera What is the name of the shooting technique that seems to freeze everything in the world except the camera you're shooting? The camera can travel a certain path and nothing moves in the scene, even things that are falling are as if they were frozen in the air.

Unfortunately I can not remember any examples at the moment ....

It's called "Bullet Time" and was popularized by the movie The Matrix.  The effect is achieved by using many, many cameras to all shoot stills at the same time, and then effect of motion around the subject is achieved by animating across the different simultaneous images.

To make the effect more believable, the still camera has to really freeze the motion (because motion blur from a given camera-subject relationship contradicts the eye's expected motion blur that would come from motion tracing the path of the camera array that gives bullet time its distinctive look).  But perfectly still images usually make for fake-looking video, so to make it look more believable, motion vectors are derived from the sequence of stills and motion blur is then applied to the stills, completing the effect.

n.b.  Motion cameras that cam capture stills (from GoPro snapping away at 12fps to RED WEAPONs cranking out 96 fps at 6K resolution) can be used as a source for the stills.  This provides the opportunity for a two-dimensional bullet-time effect: in one dimension one can move through time as usual and in the other one can slide across space while freezing time.  This surf video from 2010 demonstrates the two-dimensional possibilities with a shed-load of GoPro cameras.


Is it illegal for me to download DaVinci Resolve 17 just because I don't work for a company? Is it illegal for me to download DaVinci Resolve 17 just because I don't work for a company? The website is asking me to fill out a company that I am affiliated to but I am just a lone guy who want to do things for fun. Is it okay to download this?

Yes, it’s ok*, as long as you’re downloading the free version (not the one that says “Studio”) of Resolve and not trying to circumvent their copyright protection.  When you download the software, they ask that you provide some information about yourself so that they can understand their market demographics.  If you don’t work for  a company, just put that, “self-employed,” “hobbyist,” “none,” or similar.  Even if you accidentally download the Studio version (happens all the time, and vice-versa, because both versions are similarly-named), you won’t be able to use it without paying for a license.  You are required to agree to their EULA to use either version.  Ultimately, it’s your responsibility to read it before you agree to it.  Trying to use the Studio (paid) version without paying for it would get you in trouble.  When you do pay for the Studio version, Blackmagic doesn’t require all of the demographic info, although I think you’re required to register the software before they’ll give you tech support over the phone.
*I’m not a lawyer.


Why do VHS tapes degrade in two different ways when copied? Generation loss occurs when a VHS tape is copied, the copy is copied again, and so on. I have seen two different patterns in how video and sound degrade.

In one type, horizontal bleeding starts in early generations. Colour bleeds, then is lost. Horizontal tracking becomes very poor. Timing of both image and sound remains good for many generations. Example

In the other type, ringing artefacts appear. Colour forms horizontal bands in the primary colours, and takes more generations to disappear completely. The video speeds up, slows down, sometimes repeats, and the audio track desyncs. Horizontal tracking takes much longer to degrade. Example

What causes each of these two patterns, and why do they differ so much?

This is a difficult question to accurately answer; because you haven't detailed out the exact setup of how the tapes are being duplicated.

First, VHS is an Analog format, and the video signal is typically output via a composite connection. Some higher end VHS consumer units did have component out, either by RGB or via S-Video Out. This connector would yield a higher quality transmission from your feed deck vs your record deck.

So signal loss plays a big factor, especially if the decks are connected via composite (co-axial) connection, as all color information, along with luminance information, is on the same channel.

Using S-Video at least separates out the Blue and Red Values; and pairs luminance with Green.

Quality of the decks comes into play. Are we talking consumer decks; or professional Sony Editing/Duplicating decks. In their hey-day, The Sony Editing Decks, which were the size of about 3 normal VCRs tall, and 1.5 times as wide; were highly accurate in terms of carriage speed for the tape. The highest end decks were nearly frame accurate. They allowed pre-roll, where the decks would back up the tape, get the tape up to speed, and then insert edit in the record at the correct designated frame.

Lastly; if the decks are not synced, there will be slippage regardless... It's analog not digital.

The only way to maintain that both decks sync frame for frame is via genlock. The unit most popular during the Pro-VHS days was called a "Kitchen Sync", it was basically a black burst generator that had a bunch of outputs that all of your decks (they made different size syncs); would connect to, and all the decks would keep in sync with the master clock.

Without that; it's impossible.

Finally; VHS over time stretches, becomes brittle, there's different quality tape, it's magnetic, so it's susceptible to loss of information based off magnetic contact.

Cheers!


How to monitor system sound and mic using Rode Podcaster? Just set up my new Rode Podcaster and trying to figure out how to monitor both the mic and the system sound from my mac.  Using it for podcasting, so I want to be able to monitor myself and the person I'm interviewing.  The Podcaster mic includes a line out for monitoring, but it doesn't include system sound.  Conversely, jacking my headphones into the computer allows me to monitor the other person I'm speaking w/ (typically via skype) but not the mic.

Help!

In general, I'd say don't bother. Just do a bit of pre-recording testing to make sure your input levels are good. You're not going to want to tweak the input levels a bunch while you're recording, anyways. That would just be distracting to you and the other people that are recording.

But if you really want to, and you're on a Mac, check out "Line In" from Rogue Amoeba: http://rogueamoeba.com/freebies/ - I just tried it out, and it works great.

If you're on windows, this may work http://answers.microsoft.com/en-us/windows/forum/windows_vista-pictures/how-to-get-the-microphone-sound-through-speakers/1643d977-5dfb-4eca-9330-3b16370e7646 though I haven't tried it (don't have my windows machine ready to try it out). There are other options, as well, like software packages you can purchase.

One thing you need to know, though, is that you'll end up with a small delay between your actual voice and what you're hearing through your headset. It's not much of a delay, but it is noticeable. This can be confusing if you're not used to it. You might accidentally start to slow down or pause or get mixed up because you're hearing yourself slightly after the moment that you are speaking. It tends to make people think they are interrupting someone else, and can cause stumbles in speaking.

If you've done any studio recording, this shouldn't be too much of a problem. But if you've never done anything like that, it can be disconcerting. So if you're going to go down the path, be sure to practice recording yourself with this feature on. Get used to the way it works, and the output levels that you need for the recording vs what you are hearing.


How to enlarge/zoom into a specific area in After Effects This may be a simple question but I can't find the answer anywhere online.

I have a psd image of a desk with different object on it including paperwork. I want to be able to enlarge/zoom into sections of the paperwork to show areas that are important to the viewer. Once zoomed in I then want to zoom back out to the original image and then zoom back into a different section.

Is this possible and if so, how do I do it?

You need to animate the anchor point. This is the point towards which an image will zoom if you increase its scale. So when you zoom in to the paperwork you have to put the anchor point under the paperwork.

Trouble is the anchor point is also the point at which the image is attached to the composition, so moving it will normally cause the image to move. After Effects has a tool call the "Pan Behind" tool , which deals with this problem. It moves the anchor point of a layer and at the same time adjusts the layer's position in the composition to match so that the layer doesn't move. To use the Pan Behind tool hit the letter y.

So to zoom in to one point, zoom out, and then zoom in to another point you need to first set keyframes for your position, anchor point, and of course scale properties. Do this at the time when your first zoom starts. With the Pan Behind tool adjust the anchor point (and thus the position as well) so that it's sitting under the papers, then animate your zoom in, and out.

The keyframe for your anchor point and position should be made "hold keyframes" so that they won't change until their next keyframe, at which point they will change instantly. Otherwise you'll have to set position and anchor points each time you set a scale keyframe (which would work too, but it's more work and harder to edit). Select the position and anchor point keyframes, right-click on one and choose Toggle Hold Keyframe from the context menu, or from the top menu by choosing Animation > Toggle Hold Keyframe.

Now go to the time when you want to zoom into something else on the desk. Use the pan behind tool again to set the anchor point (and position at the same time), then add scale keyframes for your zoom. Rinse, repeat.


libx265 NUMA pool configuration misleading I have the following scenario: Using libx265 and a dual-socket system (thus 2 NUMA nodes) I want to encode videos using ffmpeg and libx265. libx265 can be configured to use thread-pools which are isolated to one NUMA node, using its --pools-parameter (docs).
There a few examples in the docs which I do not fully comprehend. The examples there are for a 4-node system. Quoting from the doc:

'+'  is a special value indicating all cores detected on the node
'*'  is a special value indicating all cores detected on the node and all remaining nodes
'-'  is a special value indicating no cores on the node, same as '0'
A thread pool dedicated to a given NUMA node is enabled only when the number of threads to be created on that NUMA node is explicitly mentioned in that corresponding position with the –pools option. Else, all threads are spawned from a single pool. The total number of threads will be determined by the number of threads assigned to the enabled NUMA nodes for that pool. The worker threads are be given affinity to all the enabled NUMA nodes for that pool and may migrate between them, unless explicitly specified as described above.

I am not sure how the thread-count and the pool-count can be explicitly specified and would be happy if someone could explain these examples, taken from the docs:

"+,-,+"   - allocate one pool, using only cores on nodes 0 and 2

Q: Why is this not allocating 2 pools on nodes 0 & 2?

"8,8,8,8" - allocate four pools with up to 8 threads in each pool

Q: Why is this now allocating 4 pools, while the next example

"8,+,+,+" - allocate two pools, the first with 8 threads on node 0, and the second with all cores on node 1,2,3

Q: .. is only allocating 2 pools?

In my case, I will have access to 2 nodes x 12 "cores" and was thinking of 1-3 ffmpeg encoding-processes per node (which would yield pool sizes of 12, 6 or 4 "cores").

As the excerpt below says,

  A thread pool dedicated to a given NUMA node is enabled only when the
  number of threads to be created on that NUMA node is explicitly
  mentioned in that corresponding position

"+,-,+"  --> no numerals stated, hence a single pool.

"8,+,+,+" --> numeral for node 0, hence that's one pool. The other nodes have no numerals, hence any threads spawned there are managed within a consolidated (2nd) pool.

No experience with NUMA, just parsing the quoted doc.


Cleaning tracked keyframes in After Effects I'm new to After Effects and played with Mocha for After Effects a bit (which is v.easy to pick up) and was wondering: If I have a bunch of dense set of keyframes as a result of tracking, is there an After Effects option/script that can clean the data (reduce keyframes but maintain easing/timing) ?
Is this possible ? If so, how ?

Just select all the keyframes you want reducing and use the built-in plugin called 'smother' which will convert your set of baked keyframes back into a bezier curve.


What do the colors in the timeline render bar in After Effects signfify I have searched the web and PDF manual for clarification on what the colors signify on the render bar over the timeline in after effects but for some reason I cant find a resource covering them all.

Here's what I've found

No Color - not rendered
Green - rendered into RAM
Blue - rendered into Global performance Cache

My questions

Is this above correct?
Are there any other colors? - ( I had thought there was a yellow and a red but I think these are used in Premiere Pro not After Effects )

All of the information is correct, to be clear:

Green cached on RAM
Blue cached on disk

Pressing 0 on the num pad you will notice that on the blue line frames will render faster then on the none line.
Of course it will skip the green line because this process is called "Preview RAM" and as I have just said Green means written on the RAM.

No any other colours in AE.


How can I apply the same keyframe pattern to multiple still images in Adobe Premiere? Here's what I mean by that. I'm making a short video with still images, but each one is animated Ken Burns style by gradually zooming in, or shifting position from left to right, or both. Sometimes, I'd like the motion to be diagonal as well.

My problem is that I want each animation to proceed at the same speed, but I can't find a good way to do this from one image to another. The only way I can see to make the animation is to create a keyframe at the in point, set the position or the scale, and then do the same at the out point. But it's nearly impossible to work out the right values for position or scale so that the transition from in to out happens at the same speed for one image as it does for another.

So, is there a way to create an animation by specifying the speed of the motion rather than the absolute start and end values?

Simply create your motion keyframes on your longest clip placed on your timeline (or use a dummy clip which exceeds your longest clip by a few frames or even a second in case you later add an even longer clip/image to the sequence).

Once you have added you "start" motion position, set the keyframe, then the "end" motion position (I am guessing you will be doing pushes and pulls).

Select the clip on the sequence. CTRL-C Copy.  Then use the C select tool (arrow) to lasso and select ALL the clips you want to apply the motion effect to.

Right mouse click the selected clips in the sequence, then click Paste Attributes.

This will paste the motion from your longest clip to all the clips; with the same relative speed. The keyframe for you "end" motion position on clips shorter than your "longest/dummy" clip will simply not be visible in the effects panel; because the keyframe will be out of range and past the tail of the clip.

However, the same speed motion will be applied.

If you are doing more than just a slow push or pull, or are dealing with various image sizes/aspect ratios; you may need to do a few "template moves" and apply the Paste Attribute command to the clips that require that specific move.

If you need to reset the motion; select the clips on the sequence; right mouse click; remove effects; click motion, click ok.

I would recommend also:

Run ALL your images through Image Processor using Adobe Bridge; and upres them larger than your sequence size. So if your working in a 1920x1080 workspace; use Tools; PhotoShop; Image Processor -> Resize Image (Then set a "SQUARE VALUE" of 2500 w by 2500 h).  This will box in all your images to meet either an X or Y value of 2500 px depending on the orientation of the image.

Do not use Scale to Frame Size- as you will lose image quality on any push ins past 100%. Upresing your images using Image Processor will import all your images into PPro, and they will be larger than your sequence; so you have pull room, and push room, to go in and out, without your images pixelating.

You may want to go higher than 2500 px. I'd recommend 2-3x your horizontal resolution. (So if 1080p, scale them all to roughly 5000/5000).  Photoshops resizing will provide much better results than PPro when moving/pushing in past 100% if your image doesnt meet your 1920 Width (if working in 1080).

Hope this solves it for you.


How can I create a 1920x1080p25 preset in Premiere Pro CS4? I need to edit some source material that comes in 1920x1080p25, with a pixel aspect ratio of 1.

However, I'm missing the presets for this, and the closest I can find is HDV 1080p25, which would be 1440x1080 at a pixel aspect ratio of 1.3333. When I try to customize it, I obviously can't just change the PAR or the frame size.

How do I create a sequence that handles my 1920x1080 content?

I don't use CS4 but in CS5.5 you can do it this way: Open the Composition dialog, open the Settings tab, and choose Custom as preset (this should be the first entry). Now you can change all parameters. To save you preset, click the button Change preset at the lefthand bottom.


Cropping VR video afterwards I have mp4 SBS 180 VR videos made for Oculus Rift. I'd like to crop the videos a little (simulate the zoom) and then downscale to "cardboard" resolution so it would be smoothly playable on mobile devices.

Some mobile players have already zoom function built in, but this should work as a workaround for keeping the picture sharp (working down from the big resolution) at the expanse of FOV.

Pretty soon I realized I can't simply crop the whole video. I have to crop both sides separately and then join them together as they were.

Could you point me to video-editing software (preferably free and fast to learn) that would allow me to do such thing?

Using the mask image below, you can use ffmpeg to crop and output a MP4 with the visual content bounded in the same elliptical shape as the mask
ffmpeg -i input.mp4 -loop 1 -i 360mask.png \
       -filter_complex "[0]split[a][b]; \
        [a]crop=iw/2:1522:0:300,crop=iw*0.8:ih*0.8,scale=960:-1,pad=960:960:0:150[l]; \
        [b]crop=iw/2:1522:iw/2:300,crop=iw*0.8:ih*0.8,scale=960:-1,pad=960:960:0:150[r]; \
        [l][r]hstack[c]; [c][1]alphamerge[ca]; [1][ca]overlay=shortest=1"    vr.mp4

The video is split into two cropped halves to a rectangle which exactly bounds the visual area, then cropped to 80% along each of its dimensions, and then scaled and padded to a 960x960 canvas, rejoined to form a 1920x960 frame. Then the mask is applied to form the elliptical cut-out.
Mask

This is the basic technique. The visuals in your supplied image aren't centered, so I customized the crop expressions based on measurements within an image editor.


Creating wave interference in After Effects I want to create a wave interference in Adobe After Effects, such as

            . I've already started with a radio wave, as shown below.
However, I'm not sure how to
a) Make the wave interact with other layers, such as those below:

b) Make 2 waves interfere with each other

I'm using Adobe After Effects 15.1.1, and I have Trapcode.

I think this requires a 3D effect rather than a 2D effect like Radio Waves. You might be able to achieve something like this using Trapcode Form.

Adding a bit more detail:

Make a radio wave using a black background and white waves..  Make the white waves quite thick, and have the radio waves start on the left of the screen.

Precomp the radio waves into their own comp

Ini the outer comp, add a blur to make the waves fall off gently instead of being hard black/white transitions.

Duplicate the inner comp in the Project tab, to make a second unique version of the comp

Drag this second comp into your main comp

Edit the origin position of the second radio wave comp, so that the second one starts towards the right of the screen.

You should now have something like this:

Make a new solid layer in your outer comp

Add Trapcode Form to it

Set it up using Strings, using settings as shown:

Key thing is to set the Displacement on the Z axis to correspond to the radio waves pre-comp you've made (and make the radio waves pre-comp invisible).


Why would a company put black lines around the picture in their DVD? I bought a series of children's educational DVD's and they all have these black lines on all four sides of the picture, throughout the whole video.

This is the first time I've ever seen this. Why would anyone do this? Is there any benefit?

I'm trying to understand the motivation of the DVD's creator for doing this.

FWIW, the DVD's are aimed at a market where a significant part of the consumer base will view them on old/small TV's. Maybe something like TV's that were widely used in the West in the 80's.

Old/small TVs tended to overscan their images.  The "title-safe" area was about 90% of the original image.  The DVD's format ensures that despite such overscanning, everything in the image is visible, including the titling shown in red at the bottom of the image, which is hard up against the limit of the frame and thus requires that the image be reduced so that a 10% overscan does not clip it off.


Error FFMPEG when convert video to MP4 with baseline presset I have this command in ffmpeg:

ffmpeg -i '/var/www/sites/default/files/private/videos/original/reel para web en loop_2_2.mp4' -vf 'scale=640:480' -strict experimental -vco
dec 'h264' -vpre 'libx264-baseline' -acodec 'aac' -vprofile 'baseline' -ac '2'
 -y /tmp/1379483589-52393fc5e233e.mp4

And I have the following pressets:

libvpx-1080p50_60.ffpreset  libvpx-720p50_60.ffpreset  libx264-ipod320.ffpreset
libvpx-1080p.ffpreset       libvpx-720p.ffpreset       libx264-ipod640.ffpreset
libvpx-360p.ffpreset        libx264-baseline.ffpreset

And this is the result:

ffmpeg version N-56279-g5295407 Copyright (c) 2000-2013 the FFmpeg developers
  built on Sep 15 2013 03:43:12 with gcc 4.7 (Ubuntu/Linaro 4.7.3-1ubuntu1)
  configuration: --prefix=/usr --enable-gpl --enable-libass --enable-libmp3lame
--enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-
libx264 --enable-nonfree --enable-version3
  libavutil      52. 43.100 / 52. 43.100
  libavcodec     55. 31.101 / 55. 31.101
  libavformat    55. 16.102 / 55. 16.102
  libavdevice    55.  3.100 / 55.  3.100
  libavfilter     3. 84.100 /  3. 84.100
  libswscale      2.  5.100 /  2.  5.100
  libswresample   0. 17.103 /  0. 17.103
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/var/www/sites/default/files/private/vi
deos/original/reel para web en loop_2_2.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42mp41
    creation_time   : 2013-09-12 17:30:22
  Duration: 00:00:39.32, start: 0.000000, bitrate: 3190 kb/s
    Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv), 720x4
80 [SAR 40:33 DAR 20:11], 2991 kb/s, 29.97 fps, 29.97 tbr, 29970 tbn, 59.94 tbc
(default)
    Metadata:
      creation_time   : 2013-09-12 17:30:22
      handler_name    : Mainconcept MP4 Video Media Handler
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 18
9 kb/s (default)
    Metadata:
      creation_time   : 2013-09-12 17:30:22
      handler_name    : Mainconcept MP4 Sound Media Handler
[NULL @ 0xab9d980] [Eval @ 0xbfd87b9c] Undefined constant or missing '(' in 'wpr
ed'
[NULL @ 0xab9d980] Unable to parse option value "wpred-dct8x8"
[NULL @ 0xab9d980] Error setting option flags2 to value -wpred-dct8x8.
Output #0, mp4, to '/tmp/1379483589-52393fc5e233e.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42mp41
    Stream #0:0(eng): Video: h264, yuv420p, 640x480 [SAR 15:11 DAR 20:11], q=-1-
-1, 90k tbn, 29.97 tbc (default)
    Metadata:
      creation_time   : 2013-09-12 17:30:22
      handler_name    : Mainconcept MP4 Video Media Handler
    Stream #0:1(eng): Audio: aac, 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      creation_time   : 2013-09-12 17:30:22
      handler_name    : Mainconcept MP4 Sound Media Handler
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> libx264)
  Stream #0:1 -> #0:1 (aac -> aac)
Error while opening encoder for output stream #0:0 - maybe incorrect parameters
such as bit_rate, rate, width or height

What is the problem in my command? I have baseline profile in ffmpeg. Or I need do one more step?
I need that this file playing in iPhone in MP4. Because I use JW Player.

This looks to me like an actual issue with the scripts in the preset vs your build of FFMpeg.  It appears that the syntax of options being passed to the encoder are incorrect (particularly something related to "wpred" and a missing parens) and since they are not specified in your command line, I can only assume it is the preset that is the problem.  I would suggest trying either a different version, a different build or a different source for your copy of FFMPEG and see if you have better luck.


Custom formula for keyframe automation - Adobe Premiere Pro Is it possible to enter custom math/scripting formulas for keyframe animation inside Premiere Pro?

Not from within premiere. You would need to do that in AfterEffects.

AfterEffects is better suited to do animation regardless. Once you've set up your compositions, you can then import them directly into premiere and lay them into a sequence using Bridge.

This way you can easily jump back and forth between AE and PPro and any changes made to your AE Comp will immediately update in PPro provided you have Bridge and the Dynamic Link Option enabled.


Accurate automated closed captioning I have been looking into automated closed captioning and the accuracy of the services found so far is poor.

I am looking to caption a number of 1hour + presentation recordings so manual captions isn't a feasible option.

Are there any worth while automated services out there??

YouTube's automated closed captions are actually getting better and better (and it's free!). Even if you don't use the automated (speech-to-text) captions in YouTube, it has a neat tool that pauses while you type a transcript (or lets you upload a transcript) and then automatically adjusts all the timings. You can find it in the Closed Captions section of any video you've uploaded.


How to: Add Chapters, Sections, markers to video files to help direct access, skipping/ fast forwarding? How to: Add Chapters, Sections, markers to video files to help direct access, skipping/ fast forwarding?

PS: Asking for Non ISO video file formats that support these: MKV does for sure, I am wondering about other most popular video file formats such as:

MPG
MP4
AVI
M4V
MKV
FLV
MOV/ QT

https://superuser.com/questions/240981/how-to-add-chapters-or-bookmarks-to-movies
The above similar question was for Mac only, and this one is asking for bit more.

What video file formats support such markers
How can a person easily add such markers to existing video files?

PS: Prefer a free/ non-commercial way of doing so on Windows.

MP4 format does support chapters. You can use free Drax utility to create them. Please note that not all video players support MP4 chapters. You need to find one that does (VLC ?)


ffmpeg scaler options not working https://ffmpeg.org/ffmpeg-scaler.html

ffmpeg -i in.png -vf scale=3840:2160 -sws_flags lanczos out.png

-vf scale=3840x2160:flags=lanczos

I went down the list upscaling a 720p image to 4k using the various ones on the documentation, lanczos is input above. I tried the variation below as well. I noticed 0 difference after tossing them in gimp and zooming in and comparing....exact same. I also noticed it doesn't matter what I type, i could call them something wrong or spell them wrong and the command works the same. They don't seem to be applying at all. Is there any indication in command prompt as to what scaling algorithm is being used so I can confirm ? I didn't see any difference.

Use the print_info flag to see what the scaler is doing, example from an actual conversion:

-filter:v "scale=w=1280:h=-2:flags=print_info+bicubic"

Part of the relevant output:

[Parsed_scale_0 @ 000001d8187fef00] w:1280 h:-2 flags:'print_info+bicubic' interl:0
[swscaler @ 000001d819bc7fc0] bicubic scaler, from yuv420p to yuv420p using MMXEXT
[swscaler @ 000001d819bc7fc0] 1920x804 -> 1280x536
Parsed_scale_0 @ 000001d8187fef00] w:1920 h:804 fmt:yuv420p sar:1/1 -> w:1280 h:536 fmt:yuv420p sar:1/1 flags:0x1004

Edit:  I also always use "-loglevel verbose", don't know if that changes the level of detail the scaler filter outputs.


Encode video for html5 and javascript controlled playback I want to create something like Apples Mac Pro product page http://www.apple.com/de/mac-pro/ where html5 video playback is being controlled via javascript (by manually setting the currentTime attribute of the video). It works perfectly when I use their video but not at all with my own videos. How can I convert my videos so that they play back nicely?

Using ffmpeg I tried everything I could think of like

removing the audio track
decreasing the videos dimensions
decreasing the framerate
setting the framerate to 30fps (like in apples video)
converting their video to jpgs and create a video from those frames (i thought maybe the color-spectrum made a difference (mainly black))
different options for quality (-crf [18-30] -preset [veryslow-veryfast])
decreasing the length of the video (apple’s video is 47s long)

I also tried some different options of handbrake but nothing helped.

http://movies.apple.com/media/us/mac-pro/2013/16C1b6b5-1d91-4fef-891e-ff2fc1c1bb58/videos/macpro_main_desktop.mp4

ffmpeg -i macpro_main_desktop.mp4

shows:

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'macpro_main_desktop.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 1
    compatible_brands: mp42mp41
    creation_time   : 2013-10-16 22:55:31
  Duration: 00:00:47.03, start: 0.000000, bitrate: d kb/s
    Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 1120x840, 2797 kb/s, 30 fps, 30 tbr, 30 tbn, 60 tbc (default)
    Metadata:
      creation_time   : 2013-10-16 22:55:31
      handler_name    : Apple Video Media Handler
    Stream #0:1(eng): Data: none (rtp  / 0x20707472), 139 kb/s
    Metadata:
      creation_time   : 2013-10-16 22:55:31
      handler_name    : hint media handler

here is an example of the videos I encoded via ffmpeg:

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video-720-main-30fps.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf56.15.102
  Duration: 00:05:00.49, start: 0.033333, bitrate: 420 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 284 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

The Apple video uses a profile with fewer reference frames and also carries a streaming hint track.

The following ffmpeg command template should create a quick seeking MP4 file:

ffmpeg -i input -c:v libx264 -profile:v baseline -x264opts keyint=3:min-keyint=2 -{other video encoding parameters} -{audio encoding parameters} -movflags +faststart+rtphint output.mp4

Given the profile and GOP sizes set, compression effiency won't be great.


How to record multiple days worth of video without interrruption I'm working on breaking a world record for continuous game play, multiple days, with my brother and tried to use my MBP to record it all but Quicktime kept stopping.

Questions: Does someone have a better solution for continuously recording that video file?
Does someone have suggestions for how I should/can easily edit that ginormous file?

The problem with recording video while also playing is that you are forced to split processing time between video compression and the game.  Your best bet for this kind of extended recording is a real-time encoder that can take the load off the CPU, however such devices are not particularly cheap.  Devices such as the BlackMagic Intensity and Matrox MX02 will perform such a real time encoding task, however they cost $200 to $500.

For best results, I would suggest outputting to an HDMI splitter and using a completely separate computer for recording with the capture interface installed on the secondary computer.  This should also greatly reduce the space required since real time encoding hardware will provide a much higher degree of compression than real time CPU only encoding.


Issues importing iStock comps into After Effects So I'm downloading a placeholder video FLV comp from iStockphoto.com (right click, save-link as under any video preview). When adding the downloaded FLV to AE, it comes up with an import error, saying that it is damaged or unsupported.

It plays fine in VLC, so using VLC, I convert/save it to other formats, but it still will not play in After Effects. Closest I've come is by converting to MP4, which at least imports into After Effects, but shows the flat error green screen instead of the actual footage.

Anyone know how I can import an iStock comp into AE?

After Effects works better with codecs that compress each frame individually (intra-frame codecs).  FLV files compress across multiple frames (inter-frame), as do mp4 files.  If you can get your FLV successfully converted to a codec like ProRes, it should work correctly in After Effects.  FLV files are quite unreliable in conversion- there's a post here that might help - it seems most people use the (now deprecated) open source Perian codecs to get this to work:

https://forums.creativecow.net/thread/8/1038982

Your best bet is probably to find source stock material in a format that is easier to work with (most videos on iStock are now mov/mp4 which should be easier to convert)

(NB - I'm not sure this is really an After Effects question.)


What are the most common project formats for modern NLE software? For my sound syncing tool I'd like to implement saving project to file which will be suitable for most modern non linear editors. I try to avoid looking into each proprietary format of major vendors, because some of them are closed binaries.

Surprisingly there is only Apple provides clear description of its XML-project format.

So far I know about these formats:

Advanced Authoring Format (AAF)
Open Media Framework Interchange (OMFI/OMF)
Edit decision list (EDL) - plaintext

Are there any other common XML or plain-text based project formats to transfer between different software applications?

Those are the three that are industry standard, XML is a useful one to include though because Final Cut (which oddly is still highly utilized in the industry) uses it.  Also XML can easily talk between all Adobe applications and Da Vinci.


stitch rawvideo with ffmpeg - Picture size 0x0 is invalid I'm trying to create a timelapse video from several images that I'm fetching from a website. In order to make this faster, my plan was split the workload between multiple cores, each fetching their respective frames (I'm streaming the images to ffmpeg stdin):

ffmpeg -f image2pipe -vcodec mjpeg -i - -f rawvideo part_N

Then I wanted to stitch the rawvideo parts to an mp4:

ffmpeg -f rawvideo -i part_0 -f rawvideo -i part_1 ... output.mp4

But I'm getting the following error:

Picture size 0x0 is invalid`

rawvideo has no metadata so you have to supply all parameters. Since your input is mjpeg (edit: sequence), just keep it as that.

ffmpeg -f image2pipe -vcodec mjpeg -i - -c copy -f mjpeg part_N

Generate a text file like this

file part_0
file part_1
file part_2
...
file part_N

and then

ffmpeg -f concat -safe 0 -r 30 -i list.txt output.mp4

here -r is the desired framerate. Default is 25.


Browser-based non-webrtc webcam capture I have a small hobby project based on live streaming. My streaming server likes RTMP. Currently, the broadcasters use native solutions like OBS, FFmpeg or VLC for publishing webcam and mic input to my streaming server. I want a browser-based solution for this publishing bit.

I'd want to avoid Flash as far as possible (ready-made solutions that can be plugged in directly are okay).

The other option I have been exploring is WebRTC. I don't mind the insufficient browser support but can't seem to figure out how to publish it to an RTMP server.

In short, I need either:

A Flash-based live webcam stream capturing software that I can use with little tweaking.
A way of publishing WebRTC streams to an RTMP server.
Any other way of capturing webcam and mic streams in the browser.

Thanks in advance!

as an AD.3

you can use HLS or you can use WebRTC with h264 or webm DASH
for DASH it somewhat blurry form me (no straight answer for ffmpeg), but as for the HLS this is supported in a straightforward fashion look here

Some time ago I was looking for a way to publish an h264 stream from the IPCam without the need of extra user actions.
I came across Janus Gateway, this bit of software consumes RTP streams (amongst others types of media) and publishes it as WebRTC media to the browser.
So basically I did the following:

used ffmpeg as an rtsp client and encoder to publish audio and video (separately) as RTP streams
I have setup Janus streaming plugin to accept h264 RTP stream and audio stream (descriptions are coming from the RTSP sdp file)

and it worked just nice.
I had some issues with the h264 from the IPcam so I had to re-encode it using x264 to be visible in the browsers.
Ideally Janus has a support for RTSP, but it seems it's lacking option of interleaved TCP transport of RTP and RTCP, and besides I had to re-encode the stream one way or another.
This are the configs I  have used:

Janus - file janus.plugin.streaming.cfg:

[h264-sample]
type = rtp
id = 1
description = H.264 live stream test
audio = yes
video = yes
audioport = 8005
audiopt = 8
audiortpmap = PCMA/8000
videoport = 8004
videopt = 126
videortpmap = H264/90000
videofmtp = profile-level-id=42e01f\;packetization-mode=1

the ffmpeg stream feeding the pipes should look like that (you can of course re-encode whatever you like in this fashion):

ffmpeg -rtsp_transport tcp -i rtsp://hostname:port/description.sdp \
-an -c:v h264 -profile:v baseline -preset ultrafast -tune zerolatency -f rtp rtp://localhost:8004 \
-vn -acodec copy -f rtp rtp://localhost:8005


Camcorder vs. not a camcorder and separate audio and video recording I'm not even a beginner yet - I've never owned a video camera in my life.

However, I want to buy one, set it up on a tripod and use a remote control to film myself talking about various topics, then put the videos on my websites.

I learned that a camcorder is a portable video camera that records both visual and audio. So my question is simple: What do you call a NON-PORTABLE video camera that records visual and audio both? (I always assumed video cameras recorded both visual and audio by default.)

My videos will all include soundtracks, so I either need a video camera that does both, or I could attach a microphone to my Mac and record an audio track at the same time that I'm recording a visual with my video camera.

In fact, that's another question I have: Would there be any advantages to recording a visual and audio separately (but simultaneously), using a video camera and an audio recorder built into my laptop? (Or should I post that as a separate question?)

Terminology

In theory, a camcorder is a video camera that also records video. A long time ago, this was an important distinction, since movie cameras (which are analog and record to film) and other now somewhat obsolete cameras didn't have inbuilt recording capabilites.

(DISCLAIMER: opinionated paragraph ahead!) This distinction doesn't really matter anymore, since most video cameras are camcorders anyway, and/or can record to film and on a digital storage simultaneously (on a professional level). I have really seen the term 'camcorder' used more often to distinguish inexpensive consumer-level cameras from full-fledged, professional video cameras. Since the technology of those aren't fundamentally different (any more), this terminology has lost much of it's meaning.

  I learned that a camcorder is a portable video camera that records both visual and audio

I don't know where you heard this, but I don't think that's correct. At least I have never seen it used in that way, but then again, people are mixing up the terminology all the time and especially terms like that that have to some extent lost their original meaning get used in all kinds of contexts and meanings.

Most cameras will record both audio and video. Prosumer-level and some consumer-level cameras will both have an inbuilt microphone as well as an audio jack for external ones. I'm not sure about high-end professional cameras having inbuilt microphones, but at that level you really only use external microphones, since the internal ones have some shortcomings (see External vs. internal microphones).

  What do you call a NON-PORTABLE video camera that records visual and audio both?

A video camera. Or call it whatever you like, it doesn't really matter.

External vs. internal microphones

As mentioned, most cameras on a prosumer-level (which seems to be the right type of camera for your purpose) will have an inbuilt microphone and an audio jack to record with an external microphone. I would definitely recommend you use a good microphone. So many Youtube channels are unwatchable because of their terrible audio quality. And while even low-cost cameras have pretty good video quality nowadays, the audio quality is usually very poor.

Internal mics suffer from some problems. For instance, they are by design built in to the camera, so in most cases they won't be close to the source of the sound. Combine that with the fact that they are usually omnidirectional (i.e. they record sound from every direction) and they are generally not of high quality and you will get noisy, unclear audio with much reverb and ambient noise. Poor sound quality is one of the first things that people will notice about your video, and at least for me it's a reason to quit your video and never come back.

Your questions sounds like you plan on recording your videos at home. In that case, I would recommend a solid desktop microphone (that is one that has it's own stand). Depending on what microphone and camera you get, you might be able to plug it into the camera and use it as an external mic for your video recording, but you will probably have to connect it to a computer and record your audio from there. While editing, you can use the wave form of the camera's audio or automatic matching to match your external audio recording to your video.


Does using component cable help improve video quality? I have a standard definition (SD) set top box which has three jacks for its output(Red,white,yellow). I recently bought a Sony TV which has WXGA (1280x800) resolution and 5 jacks for input which has "Component IN" written near the input. I was wondering that , if I use a component cable as a replacement for my existing Red,White,Yellow cable (using the same SetTopBox), will it help to improve the picture quality. The current video quality is not too sharp and has significant motion-blur. I am asking this since the Sony installation guy told me a component cable will provide a better output keeping the same set top box.

It won't make a difference because your box is SD. No amount of signal inserted in it would make it look HD. To show HD, you need HD ready equipment.


Unknown stream found in container (likely a subfile): need help identifying/opening it There's a video I need to view, foreign language film. I was checking it with ffmpeg, and it seemed legitimate except the third stream was something I've never seen before. I want to know what it is and how to view the stream's contents.

I tried dumping it with

ffmpeg -dump_attachment:t:0 subs.txt -i input.mp4

Yet the file that was dumped is invisible...but showed up a number in the file folder. I'm using windows 8.1 and hidden folders/files are set to visible. Maybe my command is wrong and this is a subfile... instead of a information file..(i tried s:0 instead but no difference)? Or I can't dump this? Should I change from .txt to some other extension or what do I need to do to dump and view it?

I just don't know what it is, and i want to know what it is. If we assume it's a subfile, I should be able to open it in a text editor right? So how can I do that...preferably a safe way of doing so.

The 3rd stream in your input is a regular stream. Attachments are basically extradata attached to streams.

You would use

ffmpeg -i input.mp4 -map 0:2 -c copy -f data subs.txt


Emulate iMovie PIP exchange effect in Final Cut Pro X I'm exporting a project from iMovie to Final Cut Pro X.

Not all tracks are exported properly, mainly the pip tracks.

What I want to do is to re-make in FCPX the same pip effect that in iMovie is named "exchange" (or something like this, my version is not in english).

Is there some fast way to to that in FCPX or I have to play with the keyframes each time?

You have to create the effect in Motion.  I'm not sure what the iMovie effect looks like, but I use this technique on a daily basis. In my setup, there are actually six separate effects; left_panel_in, left_panel_static_, left_panel_out, right_panel_in, right_panel_static, right_panel_out.  This allows me to go between a 1-up and 2-up configuration at any point in time, and to do so consistently throughout multiple projects.  If you need step by step instructions, I would be happy to assist once I'm sitting in front of a machine with Motion on it.

best, Jason.


How to prevent lossy re-encode of low-bitrate videos uploaded to YouTube I have a huge number of low-res Flash videos (480x270, 30 fps, 800 Kbps) and I want to resample all those videos in 1280x720 with some added spatial sharpening and lomo filters to make them look nicer. I intend to store these larger videos on a HDD and also upload them on YouTube.

The total running time of the videos is around 50 days, so I'm not going to use a lossless codec. I experimented a bit and found that anything over 2 Mbps (H.264) didn't result in a noticeable increase in visual quality, which isn't surprising considering the tiny original resolution. 50 days at 2 Mbps is about 1 TB which would be great.

The problem is that YouTube seems hell-bent on re-encoding anything that is being uploaded regardless of the actual bitrate, so even though the local 1280x720 videos look great the uploaded 1280x720 videos look awful. I found some official recommended upload encoding settings but using those settings still results in compression artefacts.

How can I avoid the artefacts from YouTube's lossy re-encode without uploading videos of a significantly higher bitrate?

(I'm currently using Avidemux for resampling/re-encoding but from what I've read most people use Handbrake or MeGUI; should I switch or is Avidemux fine for my purposes?)

Youtube applies different maximum bitrates to different HD formats. A lot of people these days upscale their original 1080p HD content to 4k, since youtube allows higher datarate for 4k. Probably the same applies to 720p vs. 1080p, you should check. In general, you can optimize a video a lot so the same bitrate encoding will result in better quality, mainly by denoising it beforehand - or in you case, deblocking. I don't know if you are aquainted with AviSynth etc. but there are a couple of deblocking filters for it which might come in handy. From my experience there is no big difference if uploading a h264 with a high bitrate (like 25Mbps) or a ProRes file, after Youtube recompression quality is the same.


Color shift FFmpeg raw RGBA images to YUV format I have a list of raw bitmap in rgba format, captured with an openGL frameBuffer.
I want to export them in a video, currently i am using the following command:

ffmpeg -f rawvideo -r 30 -pix_fmt rgba -s 1920x1018 -i - -threads 0 -y -c:v libx264 -pix_fmt yuv420p -b:v 8000K -vf vflip,drawbox=10:20:200:60:red@1:t=fill result.mp4

When I open the output video in different viewers (vlc, windows media player), the resulting color are shifted and appears more green.

For example I draw a solid red rectangle (255, 0, 0) got translated to (255, 24, 0)

I have played with pix_fmt and the format filter with no result.

In the end I add to use the following options and tell ffmpeg wich colorSpace i am using and how to decode it to display on screen.

ffmpeg -f rawvideo -r 30 -pix_fmt rgba -s 1920x1017 -i - -threads 0 -y -c:v libopenh264 -pix_fmt yuv444p -b:v 8000K -vf vflip,scale=out_color_matrix=bt709 -color_primaries bt709 -color_trc bt709 -colorspace bt709 output.mp4


Is it possible to search all markers in Premiere? If I have added markers to multiple clips, how do I search for those markers using the text within the markers, if they're not already in a sequence?

For example: I have a clip that it playing, I hit M to mark.  I type "good" into the marker description.  I now want to find that marker globally in my whole project.  The clip isn't in a sequence yet.  Can I?

You can use the Project panel search box to find your specific markers, and even save your search as a Search Bin by clicking the folder icon with the magnifying glass.

You can then search within each matching clip for the specific marker by first selecting that clip in the Project panel, then using the search in the Markers panel which you can open by going to Windows > Markers

You can find additional information about searching your project in Adobe's help documentation on finding assets.


Getting audio components from two audio streams to remove noise As a computer scientist, I know that it is possible to decompose two signal streams (such as audio) using the SVD (Singular Value Decomposition), to get the most natural bases for the signals.

This is very useful because you could, in theory, record with two microphones to remove background noise. For example, one microphone near the speaker, and another far from the speaker. The one that is near the speaker will have a stronger speech and weaker noise, on the other hand, the far microphone will record stronger noise and weaker speech.

The problem is that I don't know of tools to accomplish this. Also I don't have a clue of what to look for, since I am not a professional in video editing. All I can find is tools to remove noise based on one audio only.

So, you'd be inverting the phase of the noise signal, adjusting its amplification to match the level of the noise in the other clip, and then summing the two to obtain speech minus noise. You might find that adding EQ. to the noise signal as well as amplification might also help.

Any audio app that can mix two signals could do this, if you want a good free one Audacity is the most widely used.

This technique is used in a electomechanical sense in a lip-ribbon microphone, commonly used in sports commentary.


How can I edit in FCPX like I would for a live event when I have multiple sync'd tracks of the same event? I have layered up multiple clips of the same event in FCPX on the same timeline and synced the audio between clips.

I would like to view a certain layer at a certain point in the clip and select a few seconds of that clip to be visible, then switch to another layer, find another clip segment and make that visible. It would be very much like broadcasting live video where the director can select one or another camera and switch to that camera for broadcast.

Multicam clips do exactly what you're asking.  There's a good tutorial on how to use them here.


Technical Term for "side by side scene editing"? I am looking for video editing software that has a feature, but I don't know the name of it. It was a feature I had in EditDV around 2000, but I have not found it since.

Essentially, setting the END FRAME of one scene while "simultaneously" setting the START FRAME of the NEXT scene. You had side-by-side, frame-by-frame control over the end and start points of 2 different scenes, at the same time. There was also a 5-second preview button that showed you just the video around your edit, which was really nice.

Does anyone know what this is called? And more to the point, a reasonable ($50~) video editing software package (for windows) that has this?

What you are describing is called a "ripple edit" (because the adjustment you make to the clip ripples through the rest of the timeline that comes after it).  It may also be called something like "ripple trim" as a more specific term for the precise type of ripple edit.  It is a feature available in any decent professional editing package.  Depending on your other needs, it's probably worth taking a look at DaVinci Resolve as Resolve is a high end professional product which also offers a completely free version with about 90-95% of its features included.  It's out of your price range for the full version (at $299 for a license that they haven't charged for an upgrade in the last 3-4 versions) but there is a decent possibility it will cover your needs in the free version.

There is lots of other software with Ripple Edit capabilities, but Resolve is the cheapest one I personally work with enough to be able to recommend.  I've been out of the consumer market for a very long time, so I'm not sure what products would be current there.


Is there still a reason to buy camcorders? My main goals are family events.
So I would like a nice zoom & 1080/60p and a a wifi connection would be nice too.
and I am not comparing camcorders vs dslr (too bulky) only vs point & shoot.

At first I thought of buying panasonic v720.
Then I saw that many Point and shoots have my desired requirements.
Do I really need a camcorder or will a good Point and shoot will do?

It sounds like that the one intended to be a video camera will be better but how?

It depends on the type of camcorder you get.  Most point and shoots use a cheap CMOS sensor.  The problem with this is that CMOS is read sequentially by line and results in an effect called screen tearing.

Basically, as you pan quickly, the lines at the top of the frame are in a different position than in the bottom so that you end up with a jello like effect where vertical lines become diagonal.  A decent camcorder should use a CCD sensor which can capture an entire image at the same time and thus you get smooth panning.

While high end DSLRs have done a pretty good job at accounting for this issue by reading their sensor very quickly, low end consumer models, particularly of point and shoots, will have a substantial issue with this.  If money is tight and you can only get one, then, yes, a Point and Shoot should do a passable job for home video, but there is certainly a lot to be gained by using a camcorder of similar quality.

Another factor to consider is that there are often time limits on how long of videos can be captured without stopping on still cameras.  You can thank the European Union for this fantastic bit of idiocy because they decided to charge a significant tax on video cameras and defined them as anything that can shoot 30 minutes of video or more at a time.  Due to this, most camera manufacturers place a completely artificial limit of 29 minutes, 59 seconds on continuous recording from any still camera.  Some do make different versions outside of the EU, but others seem to be worried that it will make the EU come down on them if they only do it for the one model for the EU.


Digital video cameras optical zoom vs lenses If you read at digital video cameras specifications, you will probably read that camera has 20x optical zoom or even greater.

If you compare this camera with my Nikor 18-200 lens, the lens itself is much bigger then digital video camera, but digital video camera has bigger optical zoom. How this is made, and why my lenses are so big in compare with digital video cameras?

Term digital video camera is referencing to devices which is used for recording video in first place.

Your facts mislead you. Lens magnification and size have nothing to do with video or stills. They have to do with sensor-size.

Your DSLR has a large sensor and requires a large lens. The digital video camera you refer to has a small sensor and requires a small lens. You can very easily pick some random examples to show the opposite! Take a Canon Powershot SX50 HS, for example, which has a 50X optical zoom and a Sony NEX FS100U which has a sensor larger than your Nikon and will require an even larger lens to achieve the same magnification. This makes it impossible to get the kinds of zoom seen on small cameras without the lens requiring its own transport mechanism!


Audio cd ripping with AccurateRip Does anyone know why are there different results in accuraterip database? For example:

When finish with ripping an audio CD, the results might look like:

Track 1 (98/120) Accurately ripped
Track 2 (98/120) Accurately ripped
Track 3 (98/120) Accurately ripped
Track 4 (98/120) Accurately ripped
Track 5 (98/120) Accurately ripped
Track 6 (98/120) Accurately ripped

Offsetted by -6
Track 1 (22/120) Accurately ripped
Track 2 (22/120) Accurately ripped
Track 3 (22/120) Accurately ripped
Track 4 (22/120) Accurately ripped
Track 5 (22/120) Accurately ripped
Track 6 (22/120) Accurately ripped

What is the offset? are they both correct?

I'm quoting this from here:
Drive read offsets
Very few CD drives actually start reading data from audio CDs exactly at the sector requested by DAE software. There are drives that are off by over 1 sector (1/75th of a second), but most are off by much less (1/250 to 1/350 second). Most modern CD drives have "Accurate Stream" technology, so there's no "jitter", meaning in this case that the variance is consistent from read to read, and will tend to be the same for all drives of a certain make & model.
The AccurateRip database allows one to find out the read offset, which is normally constant for given make & model of CD drive. This number can then be used by DAE software to ensure that each track is ripped from its exact start to its exact finish.
The offset is given in samples. One "sample" on an audio CD is 4 bytes, consisting of a 2-byte left-channel value and a 2-byte right-channel value. There are 2352 bytes, or 588 samples, in each sector of an audio CD, corresponding to 1/75th of a second of sound. Therefore, an AccurateRip offset of +134 means the drive consistently delivers data from 536 bytes behind (earlier than) where it was asked to read from, so the DAE software needs to look that far ahead (hence the positive offset) in order to get the right data.
When offsets are taken into account, the DAE software might have to ask the drive to "overread" into the lead-in or lead-out portions of the disc, where there's no audio data. Some drives can't be asked to do it, some drives will try to do it and fail, and some will just return null samples (a stream of "0" bytes, a.k.a. digital silence).
If the drive can't overread, then there will be samples missing from the extracted track. The DAE software can correct for this by padding the track with digital silence so it's the correct length.
Soooooooooooooooooooooooooooooooooo...
Basically both rips are accurate, since the DAE software should correct the situation


Strange gaps in teleprompter pricing I need a teleprompter for my video production.

A fast googling gives me teleprompters of very diverse prices.

How can one product have that huge price span?

Which should I use as a "normal" youtuber with only the aim of looking into the camera all the time?

scandinavian photo

https://www.scandinavianphoto.se/video-dronare/tvvideoproduktion/teleprompter

3 products: 7590, 5750 and 42490 SEK (10 SEK is approx 1 USD)

film city

https://www.proaim.be/products/filmcity-easy-teleprompter?variant=22880703512657&gclid=CjwKCAiAsIDxBRAsEiwAV76N88GatMOINnM6lHLp99MTZMQLusZXdG-5Z4t2ZHftsB4SNzWD_5X1KxoCV-UQAvD_BwE

1 product: 182 euro, is almost like USD

leeventi

http://leeventi-teleprompter.com/product/teleprompter-by-leeventi

1 product: 49 euro, like USD

Like many products, teleprompters vary in price for a number of reasons. First, it helps to understand how a prompter works. A beam splitter, basically a two way mirror, is positioned between the camera lens and the speaker. It allows the light from the scene to reach the camera while the reflection of the display device, positioned below the beam splitter, is seen by the speaker.

In no particular order, some of the factors that influence the price are:

The quality of the beam splitter. Higher quality glass means less light loss to the camera.
The size of the beam splitter. Bigger glass equals bigger text.
The mounting system. How do the glass, camera, and display all attach to each other. Is it flimsy and the speaker will see the text bounce around with the slightest movement of the system? Will a light breeze shake the camera?
The display device. Do you have to supply your own tablet? Is it a high quality display to connect to a computer?
Software. Is prompter software included or do you need to supply your own?
Accessories. Tally and cue lights, confidence/feedback monitors, playback controllers are all options for various situations.


How can I swap a Motion Graphic Template (mogrt) in Adobe Premiere? How can I swap a motion graphic template (essential graphics) with another one within Adobe Premiere ?

Thanks !

If Mogrt are built similarly (same text layers etc.) drag and drop new mogrt on old holding ‘alt’.

I hope that it is what you were looking for.


How do I convert a series of PNGs into an AVI using Avidemux? I'd like to convert a series of PNGs (in this case 180 in total) into an AVI movie using Avidemux. I've tried opening the first of these numbered PNGs (starting at 1I090001.png ending at 1I090180.png) in Avidemux and then clicking File→Save and typing the AVIs name with the .avi extension at the end, but this created an unreadable avi (VLC gave an "No suitable decoder modulate" error).

Use ffmpeg instead, e.g.

ffmpeg audio.mp4 -framerate 50 -pattern_type glob -i 3_DucksTakeOff_720p50_CgrLevels_SINC_FILTER_SVTdec05_/'*'.sgi -sws_flags lanczos+print_info -c:a copy -c:v libx264 -preset slow -crf 22 -pix_fmt yuv420p output.mkv

adjust the input file naming as necessary.  ffmpeg can read png just fine.  If there are other PNGs in the same dir that you don't want to include, use
-start_number 090001 -i dir/1I%06d.png  -frames 180.  (Note that it matters what goes before -i input, and what goes after.  Stuff before is input options, stuff after is output options.)

leave out the audio file if you don't have an audio track to mux.

Decrease the CRF to get higher quality at higher bitrate.

Increase the preset to slower or veryslow to get higher quality at similar bitrate but slower encode time.

Leave out the -pix_fmt yuv420p to not force ffmpeg to subsample the chroma after converting from RGB (PNG's color format) to YUV.  (Most hardware players will only have hardware decoding for 8-bit 4:2:0 h.264, unfortunately.  Same for GPU-accelerated decoding on PCs.)

Hmm, I'm not sure whether ffmpeg defaults to the bt.709 or bt.601 color matrix for RGB -> YUV conversion.

If you really need to make an AVI (with a DIVX / MPEG4-ASP video stream, I assume) for compatibility with an old hardware player, then see the guide.  With avidemux, did you make a non-standard AVI, like h.264 in AVI?

I highly recommend against avidemux for video encoding.  Its x264 options dialog is ancient and terrible.


Does Vegas allow for rendering in frame rate different than source frame rate? I filmed my short video in 60p, yes not 60i. I set the project in Vegas Pro 11 to 30 frame per second, but the only thing that seemed to get rid of scan line was to change the project to 30 frames per second interlaced (lower field first).

However, Now Vegas will not allow me to render to match the project settings. It simply returns an error that prevented it from starting the render. Is Vegas capable of rendering in a format differing from the source media?

Software: Vegas pro 11.0 (up to date)
Hardware/OS: Windows 7 and NVIDIA GTX 560 Ti (both up to date).

Thank you

Yes, it does allow rendering in a format different from source media. Vegas works well with projects containing mixed media formats.

More likely, this may be an interpretation problem. In the Project Media window, right-click on the input video and select Properties (at the bottom). Check that the field order is set to Progressive (since your footage is 60p). Same for your project, and render settings.


Use ffprobe or ffmpeg to list ony english tracks as the title suggests I need command for ffmpeg or ffprobe to list only english sub and audio tracks in a media file;I suspect this may involve using sed, awk, or exiftool--if anyone can explain I would appreciate it. TIA

The command will show entries for those English tracks which have been assigned a language tag of eng:

ffprobe -show_entries stream=index,codec_type:stream_tags=language -of compact video.mp4 -v 0 | grep eng

Output e.g.

stream|index=1|codec_type=audio|tag:language=eng

(On Windows, use findstr eng in place of grep eng)


Open source video editing software compatible with Linux I've been looking around for open source software I can use to quickly edit some of my projects when I'm away from home on my Linux laptop and the best I've found so far is Blender.

Does anyone else have any recommendations for open source software? FX software recommendations would also be welcome.

Light Works is supposed to be pretty good. It's been used on some pretty big budget projects so it's definitely worth a look. I have tried it myself though.

https://www.lwks.com/

EDIT
This is not open source software but it is freely available.


Vegas pro will not show video for avi with mp4v fourcc codec? I have a few avi videos that are encoded with the mp4v fourcc codec. I have Sony Vegas Pro 8 and it will not open the video part. It will bring the files into the file manager, but when I drag them into the project timeline they only show the audio track as if there is no video track at all. There is no error message at all.

I would like to be able to resolve this without converting the files.

I resolved this issue by installing VLC. Apparently VLC has some necessary codecs that Vegas Pro uses.

After installing VLC I was able to import the video and use it normally with no hindrances.

After some time, this issue cropped up on a different computer. Installing/reinstalling VLC did not work.

I installed AVI Codec Pack Pro v2.4.0 from Softpedia and the issue was resolved.

If Softpedia no longer has the file available by the time you are reading this, the file was titled "avi.codec.pack.pro.v2.4.0.setup.exe" and was 16.7MB (17,538,685 bytes). A google search at the time of update yields other sources for download, but some are concerned with malware imbedded in it. I haven't noticed any malware with the softpedia download.


ffmpeg copy highest quality audio track of a specific language Say you input has 2 english audio tracks, 7.1 and 2.0.

You want to copy the audio track of highest quality (number of channels) to audio.ext

If I use -map 0:m:language:eng it selects all english audio tracks where I thought by default it would only copy the highest channel audio track.

Example:

ffmpeg -i *mkv -map 0:m:language:eng -vn -acodec copy output.flac

A map option will select all streams matched by the specification. The 'best' stream is only selected in the absence of any map options.

So, you'll need a two-stage process to do this:

ffmpeg -i in.mkv -map 0:a:m:language:eng -vn -acodec copy -f nut - | ffmpeg -f nut -i - -c copy output.flac

The first ffmpeg process sends all English language audio streams to the 2nd ffmpeg process, which will select only the 'best' among the received streams for output.

If you want to keep metadata, and not worry about the codec of the input file, you can change your output to .mkv


Is there any way to record external audio from a Canon Rebel R6? I am looking at buying a Canon Rebel T6 to record video, but would like to have better audio than the built in microphone. Is there any way, with an adapter or otherwise, that I can use this camera to record video with externally supplied audio?

Welcome to Video Production Stack Exchange!

Bad news first-

Unfortunately, you are stuck with the in-camera mic with the T6. The T6i has a microphone jack for mounting an external microphone. If you want to mount an external mic to a Canon Rebel T6 body and record that audio stream to the same SD card, that's really your only option.

However

Can you elaborate a little on what your uses for the video are and what your workflow is?

I have shot on a T6 and T6i extensively and I eventually determined the workflow that was best for me was to use a Zoom H4N as my primary sound recorder (placed somewhere out of sight in the shot) and synced the audio streams together in Adobe Premiere during post production.


how to detect empty wav files There are some wav files that are empty (though their size is not 0 bytes). Their duration is also 00:00.

When you open these files, nothing happens even if you hit the play button again and again.

Is there a way to filter all such files from a collection of (say 10000) .wav files?

Equivalently, could you help me in filtering all .wav files of duration less than or equal to 2 seconds from a huge collection of files?

If the files have no content then it's enough to key on size. A totally "empty" WAV file will have just a header and will almost certainly be less than 200 bytes. So it's probably enough to delete any files smaller than that. I would sort the folder by increasing size. You will probably see a sharp change from very low values to a series of much larger files. Bulk delete above that point (shift-select, delete).

If the files have some length but contain only silence, you need a more rigorous test. But from your question it doesn't sound like that's the case.


Premier Elements "Time Slider" in Premier Pro I have just upgraded from Premier Elements to Premier Pr CC.

Premier Elements had a slider under the video playback area that allowed you to playback the video at different speeds or backwards. I found this really useful for looking for a certain bit in the video. It allowed you to quickly zoom to roughly the right bit of the video and then find the specific frame.

Does such a thing exist in Premier Pro? I've not been able to find it anywhere.

Thanks

The UI part you are looking for is called (depending on your locale, and local film industry) the shuttle, or jogger.

I don't know if Premiere supports the exact same graphical control.

However using the [J] [K] and [L] keys on your keyboard lets you:

[J] / [L] move backward / forward (moves fast for each press of the same button; moves slower in the same direction when pressing the opposite)

[K] Stops playback

Using these keys, you can shuttle around footage in the same manner as you previously used your mouse the the GUI interface.


Mac Pro audio for FCPX I have been using an elderly iMac for FCPX and finally made the move to the new Mac Pro. However, the Mac Pro has pretty lame audio output, so I'm looking for a relatively inexpensive solution that can give me equal or better audio compared to the iMac.

I have two fairly decent unpowered 8ohm speakers that I could add a subwoofer to for 2.1 audio monitoring.  Does anyone have suggestions for an amplifier that might take mini toslink jack input? I would like to keep the budget as low as possible.

Since the speakers are un-powered you will certainly need either an amplifier or a receiver that can handle the Toslink.  Honestly, if you are trying to keep the cost as low as possible, you may have more luck buying new speakers that take digital input.

Toslink input on a receiver is a mid-range feature if not a high end one, so you probably aren't going to find a lot of cheap amps with it and depending on how good the speakers are, it might not cost that much to replace them with a purpose built system. (For example, Behringer makes this set.)

Alternately, you could go with a simple analog amp.  Toslink itself is more consumer targeted and probably isn't going to give you that huge of an advantage over an analog output unless the DAC in the MacPro is really poor, though even if it is, when you are working on a budget, you probably aren't going to get a substantially better DAC, so investing instead in a basic clean analog amp might get better overall results.


How to dynamically add texture to an object in a video and get a new video? I have a video in which there appears a wall at some point. Having that video as input and a photo (that could be new in each interation), I want to get a new video in which the texture of that wall would be changed with the photo.

I mean, my program must get as input the same base video every time, and a new photo.  It should generate the new video with my photo as the wall texture. Of course, I could prepare/mangle the video before the process, get whatever info I need to do that texture change dynamically, etc.

My questions is, what technique/software do you recommend to accomplish this? I'm a newbie in the field and want some direction/light from some experts so I can then dig deeper.

If I understand you correctly, this is traditionally done by compositing programs such as Adobe After Effects.  You could track the wall and then replace the wall with an image but it's going to be a lot trickier if anything is moving in front of the wall.  (You would need to make a rotoscope mask to tell it where not to render the image.)  You could then simply change out the image that is being applied to the wall.


Working on audio effects for multiple clips at once My problem is that I have many clips with audio and I need to remove, modify and apply audio effects to all of them at once.
Initially, I added an audio effect to a long clip and then I split it in many smaller clips. My problem is that now I want to remove all audio effects so I can start again from scratch. I can select multiple audios but the options available to be changed at once are only the standard options (volume, etc), not the effects, even though the selected audios have the same effects applied.
I can use the Edit Index to select Audio tracks and then Audio with effects. But apparently this only identifies the offensive tracks, I can't select them all at once:

I have checked Resolve manual and I couldn't find anything.
How can I remove the applied effects from the multiple tracks at once?
After that, I will need to apply some effects to multiple tracks at once, but I believe this can be done by selecting all tracks and dragging and dropping the effect on them.

You can lasso them on the timeline, right-click and choose "remove attributes..."  Then, make sure "plugins" is checked, and click "apply."

After that, I will need to apply some effects to multiple tracks at once, but I believe this can be done by selecting all tracks and dragging and dropping the effect on them.

Yes, you can do that.  You can also apply effects to a whole track, which often saves a lot of mouse clicks, and helps you stay consistent.  There's a row of tiny plus signs on the mixer channel strips labeled "effects" where you go to do that.  It's also possible to group multiple tracks together, send that through a submix, and apply effects to the whole group at once.  So you could affect dialogue uniformly, for instance.


severe artifacts pixelation when using cuda rendering premiere pro In premiere pro when I set the renderer to GPU Acceleration (CUDA), for the timeline and on media encoder export, half the video is completely messed up with lots of pixelation artifacts when I switch on any effect or make a change in the lumetri colour panel. Any solutions?
I'm running premiere pro 2020 v14.3.0 and have the GTX 1060 3GB GPU with Nvidia drivers 451.48.
I have also tried reinstalling both and deleting all the cache to no effect.

Rolled back the Nvidia driver to the version before and it seems to have fixed it. Might be a bug. Typical!


.SRT File Import Problem on Premiere Pro CC 2017 1.2 I'm having some really strange behaviour of an .srt file when I import into a Premiere project.

First off, the .srt file defaults to 720 x 480 in size and 1000 fps. My project video settings are 23.976 fps. My sequence lasts 3:30:00 in duration but when I drag the .srt file over it only lasts 1:30:00. The timing info for all the subtitles are out of whack. When I modify the settings of the .srt file to 23.976 fps, the subtitles then extend to over 5 minutes.

To me, it's as if Premiere is not reading the data in the .srt file properly. Do I need to export it differently than just using Notepad (or similar), changing to unicode and saving the text as a .srt file? I really thought this would be a simple import functionality on Premiere but it's not.

Thanks for your help!

It's a Premiere bug. Try Subtitle Edit 3.5.5, which is free, insert the .srt, export as EBU STL file (25 fps works fine, it's time coded not frame coded).

Import to Premiere, interpret as open Captions, set the adequate resolution and..way you go. For problems with position of the titles and rows, play with 9 position squares in matrix (3 X 3), it will correct the position of both rows.


How can I replicate C-LOG in a Canon DSLR? I shoot almost all my video footage on Canon DSLRs (APS-C sensors if this makes any difference). I know that true C-LOG isn't available on DSLRs and I've seen many sites that claim to sell "C-LOG" profiles however my understanding is that these are just custom presets.

So:

a) Is there actually any difference between these "C-LOG" profiles online and me just changing the settings in-camera?

b) Is this actually the best way to get the most amount of data out of my Canon DSLRs?

I know about "Exposing to the right" for example, but should this be used in conjunction with other settings?

The Magic Lantern firmware transforms Canon DSLR cameras into RAW-capable video cameras that are not half bad.  The native Canon video codecs are universally among the worst of any current DSLR, not only because of their weak codecs, but because their line-skipping algorithms really destroy the image quality from the start.  If you are shooting RAW video, then RAW->C-LOG is a valid transformation and one that will make your videos very easy to edit in most NLEs.  If your are shooting a native Canon profile, you've already lost resolution, bit-depth, and color gamut.  Any profile that reads a native Canon video file and converts it to C-LOG is merely memorializing all the bad that has been done to the image and offers none of the good that could have come from using RAW data to begin with.

TL;DR To get the most amount of data from your Canon DLSRs, use Magic Lantern firmware and scrap the Canon codecs.


Example of film/tv scene where visual triggers audio only flashback? I am planning a scene where the lead character sees a mother and child, it triggers a memory from his childhood. Instead of flashing back showing him as a child with his mum, we thought just have the audio over the top would work with an echo or other effect etc.  Does anyone know of any examples of this in other movies, as our DOP is
struggling to visualise how the final would work? I am sure I have seen it in other movies.

I can't think of specific examples, but what I can "see and hear in my mind" is:

a single shot of the character who's having the flashback
the actor's face is reacting to the audio in the flashback
the camera slowly zooms or trucks in on the actor's face
sounds in the present-time scene have become quieter and/or muffled
the audio flashback may have an echo or reverb added to it
there may be visual flashbacks subtly transposed over the present-time shot


Is there any format for videos like RAW format for photos? Like the RAW format for photos which stores the exact image information that is of great use for post processing, are there any similar formats for video?

Yes there is but if you have to ask, you probably can't afford it :)

Digital video cameras for professional use can shoot in a RAW format with one file for each frame. The bandwidth required is enormous and requires fast hard drives or an output over a fiber-optic link. Pricing is several times that of a full-frame


DaVinci Resolve Python 3.6 not found I'm trying to run some basic scripts on Linux (Debian), however no python can be found.

Both Python 2 and 3 are present on the system.
$ python -V
Python 2.7.18

$ python3 -V
Python 3.8.5

Based on strace is seems that fuscript binary searches for libpython2.7.so and libpython3.6.so
$ /opt/resolve/libs/Fusion/fuscript -l py3

DaVinci Resolve Script Interpreter
Copyright (C) 2005 - 2020 Blackmagic Design Pty. Ltd.

ERROR: Language 'py3' is not available.

E.g. on Debian based systems this could be installed, if you're lucky and the exact version is available for your distribution.
sudo apt install libpython3.6

The binary looks into several paths one of them is /usr/local/lib/libpython3.6.so. According to documentation this could be configured by PYTHONPATH env variable. However it doesn't seem to have any effect.
Using pyenv any Python version can be installed (we need shared libraries - *.so files):
env PYTHON_CONFIGURE_OPTS="--enable-shared" pyenv install 3.6.11

then create a symlink:
sudo ln -s $HOME/.pyenv/versions/3.6.11/lib/python3.6 /usr/local/lib/python3.6
sudo ln -s $HOME/.pyenv/versions/3.6.11/lib/libpython3.so /usr/local/lib/libpython3.6.so

Finally console should be working (Resolve will need a restart):
$ /opt/resolve/libs/Fusion/fuscript -l py3 -i

DaVinci Resolve Script Interpreter
Copyright (C) 2005 - 2020 Blackmagic Design Pty. Ltd.

Cannot read termcap database;
using dumb terminal settings.
Py3>


Add black (or other color) padding when doing vstack (or hstack) I am using the following filter_complex to put 2 videos of resolution 320 x 240, one right next to the other:

-filter_complex "[v1][v2]hstack=inputs=2[videoout]"

This works great, but now I was wondering how could I do it, so that I could add a small padding between them. Let's say for instance 5 black pixels (even though I would love to be able to customize the color or at least the distance).

How could I do that?

First, setup a color filter of the same height, and then add it to the hstack

-filter_complex "color=black:5x240[c];[v1][c][v2]hstack=inputs=3:shortest=1[videoout]"

See the options for the color filter here.

Alternate method is

-filter_complex "[0]pad=iw+5:ih:color=black[0v];[0v][v2]hstack[videoout]"


Adobe Premiere is slow. Please recommend My Adobe premiere is slow running on my pc. Playing video slow, edit text slow.
Below is my computer spec. What else can I upgrade so my Premiere can running fast.

You seem to have a low-end $50 GPU on a low-to-mid range Windows PC (Core i5) with the bare minimum of RAM (24 GB). I'm betting you're using a "spinning rust" drive instead of an SSD as well.

If you're serious about video editing, you should START with the recommended requirements described at this link: https://helpx.adobe.com/premiere-pro/system-requirements.html

A "decent" system for Premiere will typically have an nVidia Quadro GPU, possibly 2 of them.

Premiere will take all the hardware you can give it and still come back for more. Adobe gives short shrift to non-CUDA GPU. Plan on buying at least an $800 GPU for serious editing work.

Please describe the type of video work you want to do. Premiere requires a serious investment to get real work done, but you may be able to use a lesser tool for what you need to do. Nowadays I tell a lot of beginners to get an iPad Pro and use iMovie or LumaFusion, or on Windows - Camtasia/Vegas.


Adding many sounds to a video file at specific frames I have a video of a TAS I've created that unfortunately does not contain sound. I would like to add sound to the video before releasing it, but I obviously don't want to have to go through and place hundreds or thousands of sounds manually.

An example of a finished product, with all sounds that are present having been added manually, can be seen here:

I can modify the source code of the game, so a list of exact frames that sounds are played on is trivial to create. I'm currently using Adobe Premiere Pro CC 2015, but I'm happy to switch to different software if it provides the functionality I want.

FFmpeg looks like it might be able to do what I want, but I don't know enough about using it and haven't been able to find any examples of using it for what I want to do. I'd also rather not create a plugin (and haven't been able to find any information on scripting) for Premiere or anything like that, though I'd prefer that to doing it manually.

Thanks in advance!

Alright, more googling found that ffmpeg is definitely the solution to my issue!

ffmpeg -i inputvideo.mp4 -i inputsound.wav -filter_complex "[1:0]adelay=leftchanneldelay|rightchanneldelay[delayed];[0:1][delayed]amix[mixout]" -map 0:v -map [mixout] -c:v copy -c:a aac outputvideo.mp4

This line allows me to easily determine where in the video (down to the millisecond, which is more than precise enough with each frame equaling 20 milliseconds) I wish to place the sound; wrap it in a loop inside a batch file (or whichever method you prefer) and off you go!

Edit: A more fully-featured solution written in Java, which only creates the audio file (to allow you to add it manually):

package javaapplication4;

import java.io.IOException;

public class JavaApplication4 {
static String delay;

public static void main(String[] args) throws IOException, InterruptedException {
    String a = "0";
    String c = "1";
    String temp = "";
    String basePath = "C:\\Users\\Desktop\\Stuff\\FFMpeg\\";
    String fileIn = "blockbreak";
    int[] delays = {2740,5760,51381,61040,84520,109600,113660,156640,311260,312820,314100,443800,735120,740540};
    Runtime.getRuntime().exec(basePath + "ffmpeg.exe -y -i " + basePath + fileIn +".flac -filter_complex \"[0:0]adelay=" + delays[0] + "[mixout]\" -map [mixout] -c:a flac " + basePath + "output0.flac").waitFor();
    for (int i = 1; i <= delays.length - 1; i++) {
        delay = "" + delays[i];
        System.out.println("" + (i) + "/" + (delays.length - 1));
        Runtime.getRuntime().exec(basePath + "ffmpeg.exe -y -i " + basePath + "output" + a + ".flac -i " + basePath + fileIn +".flac -filter_complex \"[1:0]adelay=" + delay + "[delayed];[delayed][0:0]amix=inputs=2:duration=longest[mixin];[mixin]volume=6.0201dB[mixout]\" -map [mixout] -c:a flac " + basePath + "output" + c + ".flac").waitFor();
        temp = a;
        a = c;
        c = temp;
    }

}

}

I increase the volume of the sound by 6.021db each time as ffmpeg seems to lower the volume when encoding; this isn't a perfect number, but it's close enough that the difference in volume between the first and last sounds in a file that's a few thousand sounds long ends up being around 1 db.


Is it right time to buy 4K video camera? I want to casual shooting (family, travels etc.), but I do not want to sacrifice the quality.

Should I buy a camera equipped with 4K shooting? Is it the right time to buy a 4K camera or should I buy a 1080p now and may be after 2-3 years I will buy 4K.

From my perspective, 4K is still not evolved, it will take another 3-4 years to reach its peak and that's when I think more and more cameras will be available with affordable price.

You will pay substantially more for a good 4k camera right now than you would for a good 1080p camera. Quality =/= resolution, there are phones that can shoot in 4k but the videos will look a lot worse than a 1080p video from a dedicated 1080p camcorder/dslr, the image quality depends on a lot of factors.
A bigger sensor for example has the ability to capture a lot more light and have much more accurate colors than a tiny sensor that only captures very few photons per pixel.
The video compression used by the camera is also a big factor, even with h264 there can be huge quality differences between cameras depending on the encoding settings of the camera.

The question you should also ask yourself, what do you get from a 4k resolution when you mostly shoot things that are meant to be memories that you don't already get with 1080p.

My advise would be to not think about 4k and look for a nice 1080p camera. Even in commercial video there is not that much to gain with 4k video right now and probably not even in the future, we are reaching resolutions that don't necessarily improve the image quality for every content. It really depends on what you shoot and most importantly how big your screen is and how far you sit away from it. Right now there are quite a few living room configurations where its already hard for a lot of people to tell the difference between 1080p and 720p.


Recommended Encoding for VHS to Digital to be Followed by Post Processing I have VHS tapes that I want to digitize. I started this using something like Pinnacle's Dazzle. I notice that the only encoding options were for compressed video, which could lead to quality degradation, especially in reprocessing to improve the image quality (such as adjusting colors and contrast, noise reduction, and de-interlacing).

I was concerned whether I should continue such a time consuming process without first choosing an encoding wouldn't lead to unwanted limitations (e.g., as described here) in the final product.

I would guess that I have on the order of 100 hours of video. In the past, cost of disk storage was a concern, hence encoding with compression was the norm. But I don't feel constrained that way anymore.

Can I get some recommendations on a range of consumer hardware and encoding choices and some ideas of what the benefits and limitations are?

(Sorry if this has already been answered, but I didn't see anything in the list of related questions. This one touches on the subject, but doesn't go into much detail.)

VHS is already highly 'compressed', so capturing to an uncompressed format is likely overkill. For your purposes MJPEG with a reasonably high quality setting will preserve all your options and shouldn't degrade the images any further than VHS already has.

MJPEG goes by other names -- the idea is that it's all "I-frames". It is a lossy codec, but there are no interframe artifacts since each video frame is encoded separately.


Camcorder pass-through or stand alone capture box for VHS source What would yield better quality: camcorder pass-through or buying a more recent dedicated capture box?

I have a Canon Elura 65 that I've used in the past to capture video from VHS sources. It produces 480i AVI files. However, I lost the AV cable.

So, should I get a new cable from EBay or buy a dedicated capture box?

This is really going to depend on the quality of your camera and the quality of your VCR.  In general, the circuitry that is used to digitize an analog signal has grown by leaps and bounds in the past 10 to 15 years, but also VHS tapes and VCRs produce limited quality to begin with.   For maximum quality you will certainly want something with an S-Video input and a VCR deck with an S-video output to maximize quality.

As far as the line input goes, I'd probably favor the line input on a high quality camera from the end of the DV era over a cheap USB capture device, but a modern moderate or high quality capture device is going to do much better than even a high end in-camera analog to digital converter.  Even cheap USB devices now are most likely better than cheap camcorders or early camcorders in the DV era, but millage will vary depending on the specific device.


After Effects Circular Image Repeater Hi I'm trying to create something like this with motion in after effects but I'm unable to find a way to do so. (basically what exists with the shape layer but for images) Any ideas?

You definitely need the plug-in from Red Giant Trapcode Echospace, I don't know if it's enough for your project but for sure it will help you to make most of the work.


How to stop and start a key frame on a specific time on After Effects? I am new to After Effects. When I set my first key frame on my image, it would move to that specific co-ordinates. Now I want it to stay there and then move again to the next. What I did was create a new key frame for that. Problem is, it goes to the first then straight away to the next. I want it to stay put on the first key frame for about 5 seconds then start moving on the next. How can I do that?

I understand your problem as follows:

There are three timepoints: T0, T1 and T2.

At T0 you place the image in an initial position.
At T1 you place the first keyframe (position: x1, y1).
And at T2 you have the second keyframe (position: x2,y2).

You want it to stay at T1 for several seconds before moving on to T2. The easiest way to achieve this is to make a new keyframe at a timepoint several seconds after T1, but before T2. Let's name it T1a.
Now the image will move to x1,y1, stay there until keyframe T1a and then move to position x2,y2.


ffmpeg vertical pan over an image (top to bottom scrolling effect) I have a UHD wide image (3840px) which is very tall (11568px). I'd like to make a video like this:

3840 x 2160 resolution, mp4 output file
starts and ends black
image takes up full width of the UHD frame
top of the image appears at the bottom of the video frame and "scrolls up" until the bottom of the image disappears past the top of the video frame

It would be ideal if each step of the scroll shifted the image up 48px. But if it goes up 1 pixel every step because that's easier to script I can live with that. I'm trying to emulate something like an ANSI scroller where each line would present itself one at a time over a 28.8kbps modem after logging into a BBS
I have found some similar questions asked but haven't figured out what parameters to tweak for the particular effect I've described. Horizontal scroll question on reddit. Ken Burns Effect Slideshows with FFMPeg blog post.
Thanks in advance for any help/direction

Create a canvas of output size and use an animated overlay to simulate a scroll.
ffmpeg -f lavfi -i color=s=3840x2160 -i UHDimage -filter_complex "[0][1]overlay=x=0:y=H-48*n" -vframes 242 out.mp4
Output duration is clamped to 242 frames = (11568/48)+1.


adobe premiere playback lag Having some trouble with video playback. Was wondering if anyone has settings suggestions to help solve the problem. Just trying to play the project in premiere lags even with the resolution downgraded. Any suggestions would be great.

Computer specs:

Intel Core i7-5820K running @ 4,124 MHz, logical processors 12
2x GeForce GTX 980 cards 4,096 MB in SLI
Memory 32,768 MB @ 2,332 MHz
64-bit Windows 10
M.2 512GB

Video files: 60 fps @ 4096x2048 uncompressed

Nothing spikes, memory runs low and has about 28.9 gigs allocated, processors run low, video cards run low in mem and processors, using mercury. I'm guessing it's some settings that are causing it. I know I'm not using a quarto card which has better drivers for this type if thing ( video drivers are updated ).

Any advice is appreciated,
Thanks!

Uncompressed 4K video at 60fps requires your playback system to deliver approximately 2GB/sec (or more than 15 Gbps).  You can use Blackmagic Design's Disk Speed Test (part of the Desktop Video bundle you can find here) to see whether your system meets this criteria.  If it does not, then you'll need to compress your video until you have a bitrate that your IO system can actually support.


Rendered two videos from Adobe Premiere with the same settings but different resolution and they're the same file size I exported two videos from Adobe Premiere. Same length, same quality settings, but one was 4K (the original footage was 4k) and one was 1080p. I was trying to put these on Facebook so I was trying to crunch file size.

But with the exact same settings they were both 24.4MB. How can this be? The 4K one should be much much larger. Quality stayed the same so when the resolution changed file size should have changed, but it didn't.

Why?

Side note: This was done with variable bitrate, might that have been the reason?

Well you've kinda answered your own question: Both videos have the same size because you used the same settings, specifically the settings for target bitrate and maximum bitrate (assuming you're using the H264 codec, other codecs might only have an average bitrate setting available). If you use identical bitrate settings, videos of the same length will always have the same size, regardless of it's resolution and framerate. This is because the bitrate is exactly that: The (average) amount of bits per second. If you have a 10 second video with a bitrate of 10 Mbit/s, it's size will be about 100 Mbit, simple math.

To elaborate on how this is possible with videos with different resolutions: Most commonly used video codecs (as well as image formats) use highly efficient compressing algorithms that can use different levels of compression, where a higher compression level yields smaller video files at the cost of some video quality loss. For example, a JPG image will combine nearly monochrome chunks of the image to one block of information. The higher the compression, the higher the tolerance for similar pixels, resulting in compression artifacts:

(Source)

So what does that mean for your video? To accommodate for the higher resolution of your 4k video, you will need to use a higher bitrate in order to yield better quality, as there is much more information in a 4k video. If you use the same bitrate, the 4k video might actually look worse because there are more compression artifacts.