How To Fix Gradual Sync Problems
How To Fix Gradual Sync Problems
this is how to fix sync problems in mpeg videos where the audio
starts out being in sync and becomes off sync later
u need:
- sound forge www.sonicfoundry.com
- tmpgenc, or any other video software that can demux and mux the
video and audio streams
- virtualdub
1. first watch your video and go to a
part near the end where it is off sync, the nearer the end the
better
watch for a event that will allow u to determine how it is off
sync, like a door slamming or a person clapping
2. open your video in virtualdub and seek
to that part and note the exact time where the event happened
(the door slamming, person clapping, etc) write down this
time
3. use tmpgenc or a similar program to
seperate the audio and video streams into a video file and a mp2
audio file
information on how to do that is at the beginning of the other
audio sync guide, www.vcdhelp.com/sync.htm
4. open the mp2 file in sound forge and
find the sound that was the event that u used to determine the
off-syncness of the video (the sound of the door slamming, etc)
note the time where this event begins and write down this
time
5. subtract the numbers from the video
and audio and find a difference, that number is what u will
stretch or compress the mp2 file by in sound forge
-example (does not apply to the pictures on this guide):
video time: 00:21:04.53
audio time: 00:21:03.27
00:21:04.53 - 00:21:03.27 = 1.26 seconds
therefore the sync is off by approximately 1.26 seconds
- if the video time is larger then the audio time, then u will
stretch (make longer) the audio by the difference
- if the video time is shorter then the audio time, then u will
compress (make shorter) the audio by the difference
here is how to do this in sound forge:
1. choose "A01: Music 1" ive never had any problems
with it
2. take the initial time and:
- add the difference you got in step 5 to the initial time if the
video comes before the audio.
- subtract the difference you got in step 5 from the initial time
if the audio comes before the video.
take this number and enter it as the Final Time.
3. hit OK
6. then save it as a wav file with
these settings:
7. then convert the wav file back to mp2,
using tmpgenc or a similar program, with the settings 224kb/s,
stereo, 44100hz.
remux the video with the new audio stream with tmpgenc and the
video and audio should be in sync.
-Phat J-
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