Author Topic: Phase lag between vieo and audio in Avidemux but not in other players  (Read 3346 times)

txema57

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Hello,
I have some mpeg2-PS files that play fine in "Media player clasic" and "Windos Media Player V11". i open them in Avidemux whithout problem, but when I play them in Avidemux (before converting) I notice that there is a phase lag between video and audio. I tried with both Avidemux V 2.5 and V 2.6 with the same result. I noticed this problem in several mpeg2-PS files recorded from Cable TV with a Woxter recorder. ¿Anybody knows why the phase lag appears in Avidemux and not in WMplayer? ¿Any idea to resolve the problem?.
Any help will be appreciated;
Regards;

Jan Gruuthuse

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Re: Phase lag between vieo and audio in Avidemux but not in other players
« Reply #1 on: November 01, 2012, 09:03:48 AM »
Try to change in Preferences: [Video]: Video display, if you have a choice. Video needs a lot of processing power, of loading from cpu to gpu could help.
If this does not helps. Provide a recording 5 seonds or 20 MB in size and upload to rapidshare or similar website and provide a link to it.
Could be an audio issue to if multichannel, ... play with settings in  Preferences: [Audio]:
Local playback downmixing
AudioDivice: ....

txema57

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Re: Phase lag between vieo and audio in Avidemux but not in other players
« Reply #2 on: November 05, 2012, 10:17:49 AM »
Hy Jan,
I tried changes in settings but it did not solve the problem. My PC is an intel i5 with Windows 7, i think it has power proccesing enough.
This is the link to a video sample (5 seconds) in rapidshare:
https://rapidshare.com/files/627006389/5seconds_sample.mpg

Thank you in advance;
« Last Edit: November 06, 2012, 06:59:30 AM by txema57 »

styrol

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Re: Phase lag between vieo and audio in Avidemux but not in other players
« Reply #3 on: November 05, 2012, 08:42:48 PM »
Interesting issue: QuickTime Player 7 also fails, other programs on OS X (QuickTime Player X, MPEG Streamclip, MPlayer, VLC) can handle the file correctly.
Remuxing with ffmpeg to no avail. ffmpeg complains about missing header:
Code: [Select]
[mp2 @ 0x102033c00] Header missingAvidemux 2.6 do not even starts at the beginning:
Quote
[updateRefVideo]  Updating firstFramePTS, The first frame has a PTS >0, adjusting to 4512 ms
Maybe a header issue, where some software do guess missing information correctly, other software like Avidemux does not.

txema57

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Re: Phase lag between vieo and audio in Avidemux but not in other players
« Reply #4 on: November 06, 2012, 01:18:57 PM »
Maybe a header issue, where some software do guess missing information correctly, other software like Avidemux does not.
From that i deduce the video has a problem itself and there is no way to solve it, simply some software are not able to handle it correctly. ¿isn't that so?
Thank you;