bbobbo
11th February 2006, 08:40
i've been recording late night with conan o'brien off of comcast using a myhd mdp-130. i wanted to convert the shows to xvid using autogk but ran into the dreaded audio sync problem.
after trying a lot of different methods, i found that demuxing the audio and video with projectx and remuxing using mpeg multiplexer (mplex) kept the audio in sync. the only problem is that projectx for some reason skips a bunch of frames during the intro (the animated sequence when the guests for the show are announced).
at first i thought there were some "hidden" recording errors in the file i was converting, because the intro played back fine from the original .tp file. but then i tried converting some other files, and i realized that the intro to conan was always getting messed up in the same way when i demuxed it--the pattern of skipped frames always seems the same (a couple of short skips, a longer skip, then maybe a couple more short skips).
anyway, i had to resort to splitting each program into two files: a 30-second intro which i encoded directly with autogk, then the rest of the show which i ran through projectx and mplex first, and then through autogk. then i joined the two xvid avi's with avimerge (part of the transcode package in linux).
this solutions works, except that there is a noticeable skip between the two joined segments, plus a change in the audio volume. not that big a deal, but it is kind of a pain to do it this way. i have to go with this method for now so i can clear some storage space (hours of olympics hd coming!).
anyway, i was wondering if anyone had any ideas why projectx is causing the glitch. is there something strange about how the animated sequence is encoded?
here is a small clip of the original file--the last few seconds of leno and then the intro to conan. if you play it back directly, it should be fine. then demux it in projectx and remux into an mpeg2 file with mplex, and you should see the intro skipping.
see below for correct link
after trying a lot of different methods, i found that demuxing the audio and video with projectx and remuxing using mpeg multiplexer (mplex) kept the audio in sync. the only problem is that projectx for some reason skips a bunch of frames during the intro (the animated sequence when the guests for the show are announced).
at first i thought there were some "hidden" recording errors in the file i was converting, because the intro played back fine from the original .tp file. but then i tried converting some other files, and i realized that the intro to conan was always getting messed up in the same way when i demuxed it--the pattern of skipped frames always seems the same (a couple of short skips, a longer skip, then maybe a couple more short skips).
anyway, i had to resort to splitting each program into two files: a 30-second intro which i encoded directly with autogk, then the rest of the show which i ran through projectx and mplex first, and then through autogk. then i joined the two xvid avi's with avimerge (part of the transcode package in linux).
this solutions works, except that there is a noticeable skip between the two joined segments, plus a change in the audio volume. not that big a deal, but it is kind of a pain to do it this way. i have to go with this method for now so i can clear some storage space (hours of olympics hd coming!).
anyway, i was wondering if anyone had any ideas why projectx is causing the glitch. is there something strange about how the animated sequence is encoded?
here is a small clip of the original file--the last few seconds of leno and then the intro to conan. if you play it back directly, it should be fine. then demux it in projectx and remux into an mpeg2 file with mplex, and you should see the intro skipping.
see below for correct link