may24
18th May 2012, 17:24
Hi all, I encountered the following problem:
I extracted some AVC video from a matroska container and re-encoded it with avisynth/x264.
Then remuxed the audio/video with Yamb (+ mp4box 0.4.6 rev2735 - March 02, 2011) into a new .mp4.
I played the file with VLC and MPC (+ CoreAVC) and always got a huge out-of-sync between audio and video.
A quick check with mediainfo revealed that the fps had been set to 23.97 instead of 25.
When using x264 I created raw streams and in Yamb I specified explicitly 25fps in the settings. I also tried the CLI way. But whatever you try the fps always remain 23.97 inastead of 25.
And I need .mp4 (PS3 doesn't accept .mkv) ;)
However, I could either encode the whole thing again and tell avisynth that the assumed fps are 25 or slowdown the audio.
But I think the issue can be solved way faster by modifying the SPS of the AVC raw stream.
So this is my question: What bytes I've to modify in order to change the framrate ?
I extracted some AVC video from a matroska container and re-encoded it with avisynth/x264.
Then remuxed the audio/video with Yamb (+ mp4box 0.4.6 rev2735 - March 02, 2011) into a new .mp4.
I played the file with VLC and MPC (+ CoreAVC) and always got a huge out-of-sync between audio and video.
A quick check with mediainfo revealed that the fps had been set to 23.97 instead of 25.
When using x264 I created raw streams and in Yamb I specified explicitly 25fps in the settings. I also tried the CLI way. But whatever you try the fps always remain 23.97 inastead of 25.
And I need .mp4 (PS3 doesn't accept .mkv) ;)
However, I could either encode the whole thing again and tell avisynth that the assumed fps are 25 or slowdown the audio.
But I think the issue can be solved way faster by modifying the SPS of the AVC raw stream.
So this is my question: What bytes I've to modify in order to change the framrate ?