muxing AVI together, synchronising

[mortee]

Well, I'm not sure this is the right category for my question, but please don't blame me for this.

So, my problem is the following. I got a movie in QuickTime .mov format. QT for PC can't play the video, but it could tell it was in 'DIV3' format. The audio is in VBR MP3.

So, I went and extracted the audio in a separate file, this is now a .mov with only the audio (~1 MB). I have this in various formats since (AIFF (270 MB), MP3 (210 MB), AVI/WMAv2 (100 MB)).

I used GraphEdit to re-encapsulate the encoded video stream into an AVI container. Now it can be played with any regular movie player under windows.

The last step would be to mux the two files together, but anything I tried so far failed to estabilish the synch between the audio track and the video. What software is recommended for this task, and where could I get them? I'd prefer to perform this task without re-encoding the video part.

A minor problem is that any format I re-encoded the audio to yielded in gigantic file size expansion (1 MB -> 100 MB or more, see above). What is recommended to use in such a situation to keep the audio track small?

thx
mortee

[setarip]

"I got a movie in QuickTime .mov format. QT for PC can't play the video, but it could tell it was in 'DIV3' format"

It appears, then, that this is actually a DivX-compressed .AVI file. Just change the extension to .AVI and you should be able to play it under Windows Media Player or virtually any othe .AVI player around...

[mortee]

No, it IS a QuickTime movie. QuickTime could open it, play the audio, give info on the trackes, even extract tracks to separate QuickTime files (see above the case with the audio track).

It just couldn't handle the DIV3 video. That's why I wanna make a _real_ AVI out of it.

[setarip]

"QT for PC can't play the video, but it could tell it was in 'DIV3' format."

Once again, "DIV3" is DivX-compressed .AVI. Load the file into VirtualDub. From under the "File" dropdown menu, select "File Information". Post here a screen capture of that information box. If you're unable to do that, post here EVERYTHING listed in the box (both video and audio information)...

[mortee]

I don't doubt DIV3 stands for that. Anyway, if I open it the way it is, neither QuickTime can play the video part, neither MediaPlayer (I'm sure it tries to use the QT engine for it, because it is a real QT formatted file).

When I extracted the encoded video data with GraphEdit, and directed it into an AVI container, MediaPlayer and any AVI-capable player could plat it (just the video).

Anyway, I did what you said, here's what VirtualDub says when I try to open it. The same goes when it's renamed to .avi.

What about simply giving a hint on how I can synch the video to the audio? Is that some big secret I can't ever discover?

[setarip]

"A minor problem is that any format I re-encoded the audio to yielded in gigantic file size expansion (1 MB -> 100 MB or more, see above). What is recommended to use in such a situation to keep the audio track small?"

You can use a program such as GoldWave or CoolEdit to convert the audio file to .MP3 (which is a compressed audio format) format.

Or, since you also need to synchronize the audio with the video (assuming you've already got an .MP3 codec, such as the Radium .MP3 codec or LAME installed on you system), you can use VirtualDub to both convert the audiostream and synchronize it to the video.

Just as an aside, it's baffling as to why your video contains a "DIV3" header...

[mortee]

"You can use a program such as GoldWave or CoolEdit to convert the audio file to .MP3 (which is a compressed audio format) format"

As you can read above, I already converted the audio into several formats, including MP3. 90 minutes of uncompressed 48 kHz 16 bit stereo raw audio would take a "bit" more than 100-200 MB. Anyway, the one who created the QuickTime file, somehow managed to have the VBR MP3 sound track only take 1 MB. That's what I want to reproduce, having recompressing the audio myself.

I also already tried VirtualDub. Actually, I used NanDub, a VD derivative. I had it to raw copy the video stream from the video-only AVI file, and recompress the audio taken from the MP3 file I created with another program into MP3 format, on its own. I set ND to synchronize the audio and the video tracks. I also set it to interleave audio and video data.

When opening the resulting AVI file, either in MediaPlayer 8 or PowerDVD, the video starts, the audio starts too with some delay (bad synchronization already at the start), then it starts to crackle, and audio is gone. Should I seek to any further point in the movie, it has no sound anymore.

Anyway, I have attached the screenshot of the AVI info window of NanDub, regarding the video-only AVI file.