Synchronisation Problem

andy

Hi, I encoded a video Real Player (.rm) into a .avi with Boilsoft, the only soft that worked with me to do this

But my new video has a big synchronisation problem.
The more the video goes on, the more the sound is desynchronised with the video.

I tried to change the frames with quot;So video and sound matchesquot; but it didn't work, and I tried to change the frame but although I'm able to synchronise the beggining of the vidéo the 3 first minutes, it starts to goes wrong after !! And I can't find a ramerate that make the sound and audio match for all the movie !

How can I do, it's very important.

Thank you for helping me !

Please open your avi in VirtualDub, then from the menu bar select
File gt; File Information.

In the video stream section, what is the FPS?

In the audio stream Section, what is the Sampling Rate?

You might be able to run it through AviSynth to resample the audio, or you might need a program such as CoolEdit or Sound Forge to quot;shrinkquot;
it.

The fps is 10.853 and the Sampling Rate is 22050Hz.

I got Sound Forge but what do you want me to do ? Because even if the vidéo goes wrong, the sound is good

open the audio file and look at the time lenght. Do the same using virtualdub(move the slider to the end) again you are looking for the time lenght. these two times need to match. Use your audio apps time stretching function/plugin to correct the audio if needed. You also may want to resample the audio to either 44,100 or 48,000 depending on your desired end result

Originally posted by echooff
open the audio file and look at the time lenght. Do the same using virtualdub(move the slider to the end) again you are looking for the time lenght.

huh? what about just checking the file info in VDub? wouldnt that be easier?

and what do sampling rates have to do with A/V synch?

@kryn, if you used the 'change frame rate so that audio and video durations match' in VDM and save that with direct stream copy, can you confirm that both audio and video lengths are the same?

otherwise, just post the file info from VDub...

Well, I made a .wav with Virtual Dub and the audio only lasts 39'57'' but the video (with the sound) on Virtual Dub lasts 44'01''

The File info for the Video is :Video Stream :

fps : 320*240, 10.853fps
# of frames (time) : 28669 (44:01)
Decompressor : Divx Pro 5.05 Codec
Number of Key Frames : 2077
Min/avg/max/total key frame size : 906/8339/29429 (16916K)
Min/avg/max/total delta frame size : 1/3549/40874 (92188K)

Audio Stream :

Sampling Rate : 22050Hz
Chanels : 1 (Mono)
Sample Precision : 16-Bit
Compression : PCM (uncompressed)
Preload Skew : 0 samples (0.00s)
# of frames : 26477
min/avg/max /total frame size : 4400/4400/4400 (113769K)So how can I synchronise Audio with Video ?
And by the way, is there a way to move the sound to Stereo with a frequence 44100Hz ? (But for now I only want to synchronise it would be great)

well, if setting the frame rate so that audio and video durations match (about 10.57 fps?) doesnt work. something else might be going wrong. RM files can have (or usually has) a variable frame rate so this might be what is causing you trouble. it would cause the audio to go in and out synch again and again.

you could try to convert to avi with TMPGEnc though. you probably need the the realmedia splitter from gabest for it, but it should work.

With Sound Forge you would use quotrocess gt; Resamplequot; on the wav to reset the sample rate, then adjust the lenght using quotrocess gt; Time Compress/Expandquot; to be the same lenght as the video.

However, I think that there is a better way.

Use this AviSynth script and open it in VirtualDub, then save the wav.

#
Avisource(quot;my.aviquot;).ConvertToYUY2().AssumeFPS(10.853,True)
#

This will reset the audio sample rate so that the wav is synced.

Now open the saved wave with BeSweet and use the Ssrc application to Convert WAV to 22050 Hz.  Then remux the new wav with your avi using another AviSynth script:

#
video = Avisource(quot;my.aviquot;)
audio = Wavsource(quot;new.wavquot;)
Audiodub(video,audio)
#

Woops, I just noticed that your audio is shorter than the video.

Oh, boy.

I think that this is the best way, but may not sync at the end because
Sound Forge quot;incrementsquot; will not let you get it exact.

I believe that if you do the above scripts, the audio rate will be less than 22050 Hz.  You can still do the above and resample it in
Sound Forge.  Ssrc will not upsample ( I could not make it do it).

Please let us know your results.Now open the saved wave with BeSweet and use the Ssrc application to Convert WAV to 22050 Hz.  Then remux the new wav with your avi using another AviSynth script:

#
video = Avisource(quot;my.aviquot;)
audio = Wavsource(quot;new.wavquot;)
Audiodub(video,audio)
#
don't let him remux with avisynth, but with virtualdub(mod). otherwise he'd have to re-encode the video again.

Thank you all for your answer ! But you've said a lot of things and I don't understand everything.
What are the softwares I gotta download ? Can you list it please ? Because one time you tell me to use one, then someone else says not to use it.
And by the way hartford, when you say : quot;Woops, I just noticed that your audio is shorter than the videoquot; does it mean that I'm not to do what you said above this sentence ?

Thanx for your answer, I would be glad !

Well, infact I think the sound is OK but it's definitivly the vidéo that is wrong, so what are the program I could use ? Because you've said me a lot

huh? what about just checking the file info in VDub? wouldnt that be easier?

It would be if the info gave you quot;timequot; lenght. But it does not. hartford gave him a workable response.

uhm
then what would those numbers mean

@krynn:

i would use TMPGEnc, but like i said you would need to download the RealMedia splitter from gabest for that.

TMPGEnc
RealMedia splitter

- install the realmedia splitter by extracting it to a directory (e.g. c:\realmediasplitter)
- then go to start--gt;run and type: regsvr32 c:\realmediasplitter\release\realmediasplitter.ax (or use the path where the file is in)

- open TMPGEnc and open your file
- press the 'load' button, in the quot;TMPGEncquot;-directory, go into the quot;templatequot;-dir and then in the quot;ëxtraquot;-dir and load the unlock-template

- press the 'settings' button and set your video to correct size (320x240)
- the framerate is a bit more difficult but i would suggest you use 10 fps. do it by clicking on the 'setting'-button right to the frame rate and select 30 fps and devide that by 3
- close the settings window by pressing 'OK'
- then go to file --gt; quot;output to avifilequot; and make your codec settings and save the file

if you have a lot of diskspcae i would save in lossless format first (huffyuv + pcm) and compress for example with VDub later.

if this all doesnt work, i might even have another method but well see that later