Author Topic: All Videos' Audio Out Of Sync With Avidemux  (Read 353 times)

ball2hi

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All Videos' Audio Out Of Sync With Avidemux
« on: January 07, 2018, 06:40:21 AM »
Version : Avidemux v2.7.0 (180101_e0faefd0595
No preferences changed.

Never had this issue before. I livestream a lot and locally record in higher quality using Intel's QuickSync(H.264). Initial output is .mkv and then I use FFMPEG to remux to .mp4. All audio in the original .mkv (and in the .mp4) are 100% in sync however when I open the video in Avidemux the videos' audio is out of sync by almost 1100ms. Sure, I can shift audio but I'd prefer to not have to do that for every single new video I'm going to be throwing on here.

Jan Gruuthuse

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Re: All Videos' Audio Out Of Sync With Avidemux
« Reply #1 on: January 07, 2018, 07:46:08 AM »
Avidemux should not be used as media player.
You do use latest avidemux 2.7 from here: http://avidemux.org/nightly/ ? If not wait for one released on or after 2018/jan/06
- Audio delay can have several causes: like AC3 or DTS is hardware demanding (processing power)
- What happens when you remux the recorded video with avidemux?
« Last Edit: January 07, 2018, 07:48:42 AM by Jan Gruuthuse »

eumagga0x2a

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Re: All Videos' Audio Out Of Sync With Avidemux
« Reply #2 on: January 07, 2018, 01:59:22 PM »
Version : Avidemux v2.7.0 (180101_e0faefd0595
No preferences changed.

Never had this issue before.

Does it mean that the issue doesn't exist in the 2.7.0 release? Unfortunately, there is no public nightly archive to do easy regression testing.

Anyway, please provide a sample.

ball2hi

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Re: All Videos' Audio Out Of Sync With Avidemux
« Reply #3 on: January 07, 2018, 02:21:34 PM »
Avidemux should not be used as media player.
Having a media-player function is pretty important for a media-editing program... regardless whatever desync Avidemux does in playback applies to the final product if I save it.

You do use latest avidemux 2.7 from here: http://avidemux.org/nightly/ ? If not wait for one released on or after 2018/jan/06
- Audio delay can have several causes: like AC3 or DTS is hardware demanding (processing power)
- What happens when you remux the recorded video with avidemux?
I'm already using the nightly builds. I've also never tried to remux the recording in Avidemux.


Does it mean that the issue doesn't exist in the 2.7.0 release? Unfortunately, there is no public nightly archive to do easy regression testing.

Anyway, please provide a sample.
I'm not sure. I'll have to check it later today. Also I'll record something short to provide a sample. I'm usually taking clips out of 3 - 4 hour recordings.

Jan Gruuthuse

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Re: All Videos' Audio Out Of Sync With Avidemux
« Reply #4 on: January 07, 2018, 06:00:11 PM »
load mkv video, leave [copy] for audio & video, set Output Format to
MP4 or MP4v2 Muxer and see what works best for you.

You should test audio delay on real hardware media player like stand alone DVD or Blu-ray player or Smart TV.

Depending on what is going on (probably your computer) you can change settings accordingly in avidemux to see what works best for you.
Avidemux Menu: Edit: Preferences: [Audio]
Local playback downmixing: [Stereo] <- dropdown list
AudioDevice: [PulseAudio] <- dropdown list

see if this removes audio delay in Avidemux.
« Last Edit: January 07, 2018, 06:05:10 PM by Jan Gruuthuse »

ball2hi

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Re: All Videos' Audio Out Of Sync With Avidemux
« Reply #5 on: January 14, 2018, 06:23:25 PM »
load mkv video, leave [copy] for audio & video, set Output Format to
MP4 or MP4v2 Muxer and see what works best for you.
This wont' work because Avidemux wont' work the entire .mkv which is why I have to remux it to .mp4 using ffmpeg.

You should test audio delay on real hardware media player like stand alone DVD or Blu-ray player or Smart TV.
I mean, this doesn't really matter when the final output has audio delay in VLC Media Player and it's going to upload to YouTube like that.

Depending on what is going on (probably your computer) you can change settings accordingly in avidemux to see what works best for you.
Avidemux Menu: Edit: Preferences: [Audio]
Local playback downmixing: [Stereo] <- dropdown list
AudioDevice: [PulseAudio] <- dropdown list

see if this removes audio delay in Avidemux.
I'll see what I can do with this.
EDIT: Don't have PulseAudio, only Win32 & DUmmy.
« Last Edit: January 14, 2018, 06:26:02 PM by ball2hi »

eumagga0x2a

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Re: All Videos' Audio Out Of Sync With Avidemux
« Reply #6 on: January 14, 2018, 07:52:46 PM »
This wont' work because Avidemux wont' work the entire .mkv which is why I have to remux it to .mp4 using ffmpeg.

Please explain what "won't work the entire .mkv" means.

Quote
EDIT: Don't have PulseAudio, only Win32 & DUmmy.

PulseAudio audio output is Linux/Unix-only.

GeoSlv

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Re: All Videos' Audio Out Of Sync With Avidemux
« Reply #7 on: January 28, 2018, 09:53:51 PM »
Likely VBR which avidemux doesn't handle right.
I'm also working with live captures and a related question is that the recorded streams don't seem to start with a keyframe. Is that right?

bernd_b

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Re: All Videos' Audio Out Of Sync With Avidemux
« Reply #8 on: February 08, 2018, 07:41:26 PM »
My humble knowledge says to me that a video that doesn't start(!) with a keyframe doesn't make sense when dealing with compressed video formats. Why would a cut in copy mode have to be at a keyframe otherwise?

And you are referring to audio when saying that VBR isn't likely to be treated correctly?