Author Topic: Please help explain audio synch (shift)  (Read 174 times)

aussie43

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Please help explain audio synch (shift)
« on: November 30, 2018, 12:54:33 AM »
Hi,

I have two files where the audio needed 500 ms delay (two parts of the same movie). I worked it out using VLC player.
I also needed to convert the video from MPEG2 to H264, and audio from AC3 to AAC.  Avidemux did all this relatively fast.  I ticked "shift" and put 500 in the box in the audio section.

The audio is now in synch with video as far as I can say, playing the files with VLC.  But strangely, when I look at the files in MediaInfo, one file has  "delay relative to video:-26ms", the other -82ms.

How should I understand this?   

eumagga0x2a

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Re: Please help explain audio synch (shift)
« Reply #1 on: November 30, 2018, 12:48:29 PM »
Difficult to tell with the information available. Please open Avidemux (I would strongly suggest using the latest nightly vs the last release or even older versions), load the first source video, copy admlog.txt from %localappdata%\avidemux to another location, rename it e.g. admlog-source-1.txt, close Avidemux. Repeat these steps with the second source video and with both processed videos, renaming admlog.txt to admlog-source-2.txt, admlog-processed-1.txt and admlog-processed-2.txt correspondingly. Compress and attach the logs to your reply.

aussie43

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Re: Please help explain audio synch (shift)
« Reply #2 on: November 30, 2018, 10:33:31 PM »
I found that when I do just audio shift, MediaInfo shows the correct delay.
But when I also do conversions at the same time, then it shows wrong information. 
Doesn't matter, the main thing is that it is in synch as far as I can observe.