HydrogenAudio

Digital Audio/Video => General A/V => Topic started by: nickreserved on 2022-09-26 22:24:19

Title: Streching an audio stream with mkvmerge leads to (un)expected results
Post by: nickreserved on 2022-09-26 22:24:19
I use mkvmerge to mux a video and an audio stream.
Audio stream is not synced with video.
So, I choose on mkvtoonix a delay of 1000ms and a stretch by 1.123456 for the audio stream (this does not reencode audio stream).

Media Player Classic play the product very well - as expected.

VLC for PC or android play the product for a few seconds, then sound starts to crank and then stops. It seems that VLC does not stretch the audio stream. If I seek elsewere in the container sound play restores for a few seconds and again it cranks and stops.

MX Player for android, does not crank the audio stream. It play the audio stream continuously but it does not stretch it, so after a few seconds audio stream looses its sychronization with video stream.

So:
- What is the correct behavior between 3 different programs? I believe MPC.
- Must I bug report the behavior of VLC and MX Player?
Title: Re: Streching an audio stream with mkvmerge leads to (un)expected results
Post by: Octocontrabass on 2022-09-26 23:39:58
Why does the audio not match the video in the first place?

I think MPC's behavior is correct, but I'm not surprised that it doesn't work in other players. Try stretching the video track instead - players tend to handle that more gracefully.
Title: Re: Streching an audio stream with mkvmerge leads to (un)expected results
Post by: nickreserved on 2022-09-29 20:15:32
Why does the audio not match the video in the first place?

I think MPC's behavior is correct, but I'm not surprised that it doesn't work in other players. Try stretching the video track instead - players tend to handle that more gracefully.

Thanks but I avoid to bloat my question.
I have an audio/video/english subtitles correct and I am trying to mux secondary language with secondary subtitles, both desynced (from another video).
So, it is more complicated.

But thanks.
Also I think MPC handle it correct.