Vertigo1
12th November 2003, 21:56
Hi,
I have an xvid avi, which I'm trying to convert to mpeg2 to burn as a dvd. I've done this before without problems, but this time I found that the resultant video and audio files had slightly different durations (about 1.7seconds out).
When I mux them together and author a DVD, sure enough the audio is running ahead of the video, but this didn't happen on the original xvid.
On closer inspection of the xvid, I notice that the video actually starts without any sound at all, then the sound cuts in a second or two later, and both then run in sync.
Now when I extract the audio as a WAV using VirtualDub, there is no silence at the start of the file, it cuts straight in, so there must be something in the xvid file which tells it to start playing the video, then start the sound a bit later.
This is a new one on me! If I'm right and there is such a built-in delay/offset, can someone please tell me how I find out exactly what it is, so I can add that much silence to the beginning of the extracted WAV.
If I'm completely wrong about this, then can anyone please help me out here as I'm totally confused.
Many thanks.
I have an xvid avi, which I'm trying to convert to mpeg2 to burn as a dvd. I've done this before without problems, but this time I found that the resultant video and audio files had slightly different durations (about 1.7seconds out).
When I mux them together and author a DVD, sure enough the audio is running ahead of the video, but this didn't happen on the original xvid.
On closer inspection of the xvid, I notice that the video actually starts without any sound at all, then the sound cuts in a second or two later, and both then run in sync.
Now when I extract the audio as a WAV using VirtualDub, there is no silence at the start of the file, it cuts straight in, so there must be something in the xvid file which tells it to start playing the video, then start the sound a bit later.
This is a new one on me! If I'm right and there is such a built-in delay/offset, can someone please tell me how I find out exactly what it is, so I can add that much silence to the beginning of the extracted WAV.
If I'm completely wrong about this, then can anyone please help me out here as I'm totally confused.
Many thanks.