remux mp4 question: PLEASE HELP

[maverickluke]

Ok. I realize mkv files are much easier to deal with and mp4 files are a royal pain in the ass even though they can be played on the ATV. I took the original .mp4 file with the 5.1 ac3 and the aac that the ATV is not recognizing the ac3 (This mp4 is the one I used your script a couple weeks ago to create the second aac) and demuxed the .h264 and .ac3 and then remuxed them with mymp4box gui. The resulting new mp4 has the audio and video out of sync. I then used mkvtoolonix to mux the .h264 and .ac3. The resulting mkv did not even play in vlc. I THEN LOADED THE ORIGINAL MP4 WITH MKVTOOLNIX, ONLY SELECTED THE VIDEO AND AC3 AUDIO TO CREATE A NEW MKV FILE. THE NEW MKV FILE PLAYED FLAWLESSLY WITHT THE VIDEO AND AUDIO PERFECTLY IN SYNC.

[sneaker]

Yes, the containers hold valuable information about syncing. When demuxing these can get lost.

[maverickluke]

A long time ago I realized at times there is an easy path and a difficult one. Manipulating mkv files is easy. If I have an mp4 I need to manipulate, I will stick to my original method using mkvtoolnix and if need be I will reencode the mkv back to mp4 with Vidcoder using high quality settings. Life is good this way