Hi guys,
I was trying to downsize a mkv file by re-enconding it using "ffmpeg -i file_video.mkv -c:v libx264 -b:v 1000k -c:a aac -b:a 128k output.mp4" but after running that the audio is out of synch (sometimes just stops for a few frames.). Is there anything I can do to fix the mp4?
Thanks guys.
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You should add the video framerate with -vf fps=24000/1001 (for 23.976, as example).
Code:ffmpeg -i file_video.mkv -vf fps=24000/1001 -c:v libx264 -b:v 1000k -c:a aac -b:a 128k output.mp4
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You might try inserting one of these:
-c:a aac copy
-c:a aac -b:a 128k -strict -2
-c:a aac -b:a 128k -strict experimental
If that fails you could try :
-vsync -1
or
-async 1
Depending on which way the audio is out of sync.
Using ProWo's code with -vsync -1 &
Code:ffmpeg -vsync -1 -i file_video.mkv -vf fps=24000/1001 -c:v libx264 -b:v 1000k -c:a aac copy output.mp4
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