Poway said:
When I save my movies to cd's. My audio is out of sync
with my movie. Its about a second behind the scene.
Does anyone know what causes this???? Thanks
Some speculate it is a problem with frames, others are blaming the sound or
video card, others blame the processor speed, and another group blames the
software. Who knows?
One theory is if the sound card is not really at 44,100 Hz and is actually
at 44,109, then the audio could be off several seconds at the end of the
movie sort of a compression or expansion of the audio file. This one might
explain why a ripped movie is different when played on various players or
computers.
I did one tonight where the audio and video synch was off a few seconds on a
DivX AVI movie rip I did to put it in my portable player. The thing was off
a little at the beginning and a bunch at the end.
A couple of pieces of software can help: VirtualDub and SoundForge
(VirtualDub is free, other is trial I believe but I bought SF as I like it).
Here is the outline as I wrote it down:
Open the AVI file in VirtualDub and make note of the frame counter time
(bottom of screen) for a sound near the beginning and one near the end. I
used someone banging a hammer for one and shouting at the end.
In VirtualDub, you can rip a WAV file out of the AVI file. Using
SoundForge, load the large WAV file and scan to the two "approximate" times
noted above and listen for the sounds you are using to mark the file (i.e.
the hammer and shout noise in mine). Make an exact note of the "real
occurring time" of the two noises at the bottom of the screen in SoundForge.
Add or subtract the two times in SoundForge from the frame video times in
VirtualDub. The object is to get the two times to agree with each other as
close as you can.
You can shift the WAV file time ahead or back using either a Insert Time at
the beginning of the WAV file or subtract it to match the above video frame
times. No doubt they "both" will not match doing so.
Now come the little trick. You can use Resample in SoundForge and shift the
audio (either compress or expand the length of the track). Open Resample
(leave anti-alias off), check the box regarding "Sample Only" so you do not
save it yet, and change the Sample Rate from 44,100 Hz to say 44,110 and see
where the new audio times are in comparison to the frame times earlier done.
You can increment or decrement the 44,100 number and watch the audio times
change. The idea is to change it and get it to closely match the video
frames. You cannot get it exact but close.
Once done, set the Resample back to 44,100, uncheck the Sample only box, and
save it. You can then set both the video and audio pulldowns in VirtualDub
to Streaming and load the AVI file. Under the Audio select your new WAV,
Press F7 (or Save AVI), and let it rip. It's pretty fast here (4-5
minutes).
However, now you have a DivX AVI with a WAV file and it's pretty large. Run
it back through VirtualDub. Turn on Full Processing Mode in both Video and
Audio pulldowns. Set the video Compression codecs for DivX; the audio
Compression for LAME Mp3 (set to around 44,100 Hz, 128 Constant Bit Rate
(CBR - not variable or average), Stereo. You can also alter the Video
filter with a bit of Brightness and Contrast (mine always seems so dark in
Windows Media Player). This run will take longer (30 mins) and the file
will be much smaller.
That's as much as I remember.....whew!
Good luck.
B~
