[SOLVED] Jumps in movies with external audio track.
 

Greetings...

I have some movies (.m2v) with external audio tracks (.ac3). I easily can "attach" them to movie and hear them correctly (in the right time). But when I'm jumping in those movies -- sound became incorrect: there is gap (large gap) between video and audio.

Best regards...

Re: Jumps in movies with external audio track.
 

MPEG-1 and MPEG-2 streams are generally not seekable. Seeking works only in constant bitrate files. I think DirectShow jumps to a given % of file size (which happens to match time in CBR).

In your case I would mux both m2v and ac3 into Matroska container.

If you need compatibility with standalones or whatever, do a MPEG-2 Program Stream instead. There is a good tool for this called ImagoMPEG-Muxer. MPEG-2 PS on the other hand are seekable with proper demultiplexer installed, because they have Presentation Time Stamps for each frame. So the system can seek by these values without indexing the whole stream first.

Anyway if you still want to watch your videos before you convert them, you can fix the audio gap by using BSplayer adjust audio time feature (default keyboard shortcut is SHIFT+CTRL+LEFT or RIGHT, you can change these shortcuts in BSplayer preferences window, WinLIRC and Keydefinitions, search for Decrease/Increase audio delay)

In case someone is not familiar with terms "multiplexing" and "container", I will add that the described process is relatively fast and absolutely no quality is lost.

Wrong audio delay is an enirely different beast. If delay indeed had to be corrected, then the person performing it would have lost any interest in watching the given video(s) by the time the value is gotten about right. It's a tedious process.