What is the best video format for audio quality?

[Anonymous20]

Hello,

avi vs mov vs mkv

Which format has the best audio quality please ?

Some people say avi is the best for that, and others say it's mov

Thank you

PS : it's for youtube, i want the best quality

[johnmeyer]

Video container (AVI, MOV, etc.) has nothing to do with audio quality. Audio quality is determined by bits per second in the audio portion of the video file. That audio portion is multiplexed with the video to create the video file.

Also, YouTube re-encodes, so you don't have any control over the audio quality. If you want the best audio quality, you should host the video file yourself and let your subscribers download the file.

[Anonymous20]

Ok johnmeyer

Another question : do the video framerate affect the audio quality ?

What is the best FPS for audio quality (1 or 30fps ?)

Thank you

[Anonymous20]

Thank you!

But then why when I change the video fps, the audio signal seems out of sync

Original

[Attachment 49125 - Click to enlarge]

30fps

[Attachment 49126 - Click to enlarge]


[Attachment 49127 - Click to enlarge]

[Cornucopia]

Those are spectrographs! There's NO way to tell if they are in-sync or out-of-sync. They show Intensity (color/brightness) varying on frequency & time axis, but they never show how that compares against video, which would be required when concerning sync.

BTW, if you change your 29.97 video to 23.976 (via ITVC I would hope) it doesn't change the duration of the video at all, so there should be no difference in sync.
If you are going 29.97 <-> 30.00, or other stuff, it's very likely you are either speeding up/slowing down or are interpolating new frames, and those usually would affect duration, and duration would affect sync unless you ALSO change the accompanying duration of the audio.

Scott

[johnmeyer]

Another question : do the video framerate affect the audio quality ?

Nope. They are completely independent. You could have a 1 fps video or a 120 fps video, and then multiplex the audio into each of them. When played, the audio would be 100.00% the same.

What is the best FPS for audio quality (1 or 30fps ?)

Based on what I just wrote, there is no "best" video frame rate for audio because the audio is not affected, at all, by the video frame rate.

The reason your audio changes when you change the frame rate of video is that you are not first demultiplexing (removing) the audio from the video. However, if you change the frame rate of the video so that it plays in more, or in less time than the original, then if you want the audio to sync up, the audio must be changed, and the audio quality will suffer when it is resampled to match the new playing time of the video. That is simply an unavoidable law of physics.