Huge file after WMV to AVI conversion

[windranger]

Hello,

I'm trying to reencode a WMV file to AVI. The WMV file is about 100Mb, has 29.97 fps.

I'm using AviSynth command DirectShowSource("file.wmv", fps=29.97) to open the file with VirtualDub.
I make the following settings in VirtualDub:
- Video -> Direct Stream Copy
- Audio -> Source Audio, Direct Stream Copy

When I choose to Save the file as AVI, I get a final file of 7GB (!) and that is my problem.
I wonder where so much redundant information comes from...

I only need a final file of same size as the original, 100Mb or a little bit less.

If anybody knows where the problem may be, please advise.

Thanks!

[Midzuki]

You must use the latest stable version of VirtualDub plus
the WMV input plugin. Avisynth scripts always output
uncompressed video and uncompressed audio, which are not
very suitable for "Direct Stream Copy".

http://home.comcast.net/~fcchandler/Plugins/WMV/index.html

[windranger]

Thanks for the tip but I actually did that at the beginning. I'm using VirtualDub 1.7.8 with the wmv plugin and when I load any WMV file, it sais "Missing Codec", and just can't load wmv files.

I think DirectShowSource() is OK but I think I'm missing the proper settings in VirtualDub....

[Midzuki]

Try installing the WMV9 Video Compression Manager.
You may also need the ffdshow plugin for the proper decoding of VC-1 streams.

http://download.microsoft.com/download/9/8/a/98a6cb2d-6659-485e-b1f9-2c0d9bf6c328/wmv9VCMsetup.exe

[jagabo]

Sure DirectShowSource() is OK. But it gives you uncompressed video. You will have to use VirtualDub in Fast Recompress mode (at least), select a compression codec, select the compression parameters, and then save.

If you want to put the WMV video into an AVI file without conversion you will need a VFW based WMV codec. This, I think:

http://www.microsoft.com/windows/windowsmedia/forpros/format/codecdownload.aspx

[windranger]

OK, now I have the WMV9 Codec installed on my PC (ffdshow was from before, as part of a mega codec pack), but same result:

can't load the wmv file directly into VirtualDub ("Missing Codec"), and
can't get a same size AVI file by reencoding with DirectShowSource().
If I choose Fast Recompress mode in VD, the file gets even bigger than 7Gb!

No matter how RAW the video is, one thing is for sure: if you get a bigger size file after any kind of processing, reencoding, etc, than that extra information in the new file is redundant.

Very strange piece of software..

[Midzuki]

Are you sure you're not dealing with an "Advanced Profile"
Windows Media Video 9 File (also known as "VC-1")

[jagabo]

OK, now I have the WMV9 Codec installed on my PC (ffdshow was from before, as part of a mega codec pack), but same result:

can't load the wmv file directly into VirtualDub ("Missing Codec")

Did you enable the VFW WMV (and VC-1) decoders in ffdshow? VirtualDub uses VFW not DirectShow. Start -> All Programs -> ffdshow -> VFW Configuration.

can't get a same size AVI file by reencoding with DirectShowSource().
If I choose Fast Recompress mode in VD, the file gets even bigger than 7Gb!

You didn't select a video codec to compress the video. Video -> Compression...

Note that AVI is a container -- a box you put video and audio in. That box can contain video and audio compressed (or not) with any of a zillion different codecs.

[guns1inger]

Fast Recompress simply passes the video through to the codec you choose without affecting the colour space. The normal behaviour of virtualdub in full processing mode is to convert the colourspace to RGB, which is slow to process. Fast Recompress simply bypasses this stage (and means no filtering), but you still have to chose a compression method (codec).