Support for WMV-VCM codec in AutoGK?

[Yo]

A suggestion to add support for the WMV9-VCM codec in AutoGK and GK.

With the installation of that codec (one can find it at microsoft.com), one can use WMV9 compression without the WMV container, and in any encoding program. In other words, one can make an .AVI, .OGM, or Matroska video in VirtualDubMod using WMV9 compression.

Some tests I have seen show the WMV9 compression to be superior to DIVX and XVID at lower bit rates. As my only reason for compressing a video (other than DVDShrink, which remains in MPEG-2) is to make small lower bit rate videos for my Pocket PC, that makes it a good choice. I have tried encoding a couple videos in VDubMod using the WMV-VCM codec, with good results.

It would be nice to be able to choose that codec in AutoGK too, to be able to choose WMV-VCM as well as DIVX or XVID.

Any chance that support can be added?

[len0x]

Having political reasons of including/not including a certain codec and the fact that AutoGK mostly designed for codecs that can be played on standalones (although sigma 62xx chip is supposed to decode wmv9 in a few months) aside - there is a technical problem of codec settings: only those codecs that are storing its settings in registry/files in a plain text form can be supported. Afaik WMV doesn't have that.

[Yo]

Originally posted by len0x
Having political reasons of including/not including a certain codec and the fact that AutoGK mostly designed for codecs that can be played on standalones (although sigma 62xx chip is supposed to decode wmv9 in a few months) aside - there is a technical problem of codec settings: only those codecs that are storing its settings in registry/files in a plain text form can be supported. Afaik WMV doesn't have that.

I don't know about the registry settings for WMV-VCM. Have you taken a look at it? In VDub it works just like any other codec. (Therefore it must be a VFW codec, but I don't know about its registry settings.) I'd suggest you take a look at it. It's a nice codec.

I believe I have read about more hardware support coming out for WMV in the next months, more than one device.

I don't know that political feelings should be involved. I know many people don't like Microsoft, for some good reasons. (However, most of those people still use Windows, rather than switching to a Mac or using Linux.) But in choosing something like a codec, I think people should choose which works best for them, for what they want to do with it, rather than like or dislike of the company from which it originated.

[len0x]

Originally posted by Yo
I don't know about the registry settings for WMV-VCM. Have you taken a look at it?

yes, my "afaik" means I had a look and it didn't have readable registry settings. VFW support is only half of the job...

[Sharktooth]

...and about VP6?

[len0x]

Originally posted by Sharktooth
...and about VP6?

actually I did try to work with vp62 and found out that they store codec settings in registry but only as a binary stream... I have very little desire of hacking binary data :)

[Yo]

Originally posted by len0x
Having political reasons of including/not including a certain codec and the fact that AutoGK mostly designed for codecs that can be played on standalones (although sigma 62xx chip is supposed to decode wmv9 in a few months) aside - there is a technical problem of codec settings: only those codecs that are storing its settings in registry/files in a plain text form can be supported. Afaik WMV doesn't have that.

Well, I think I found the registry settings for it. I was looking at the help file, and came across the following:

--quote from WMV-VCM9 Help File----

Why does my video look soft or fuzzy?
The Windows Media Video 9 decoder is designed to use postprocessing filters to smooth the decompressed video frames. This processing is intended to correct the blocky appearance that is often a byproduct of the type of compression used by the Windows Media Video codecs.

If you prefer a crisper image, at the risk of more compression artifacts, you can change the registry setting that controls the type of postprocessing that the decoder performs.

The registry key is HKEY_CURRENT_USER\Software\Microsoft\Scrunch\Force Post Process Mode. Set it to one of the following values.

Registry value Description
0 The decoder performs no postprocessing.
1 The decoder performs deblocking.
2 The decoder performs strong deblocking.
3 The decoder performs deblocking and deringing.
4 The decoder performs strong deblocking and deringing.


If the registry key is not present, or is set to 0xFFFFFFFF, then the decoder automatically selects the type of postprocessing to use.

To get the best results, use no postprocessing for very high-quality (high bit-rate) content, and use increasingly higher postprocessing values for lower-quality (low bit-rate) content.

Note Changing the registry setting for postprocessing does not work in either the Microsoft Windows 98 Second Edition or Microsoft Windows Millennium Edition (Me) operating systems.

----end of quote----

Perhaps why you didn't find the settings before is the unexpected place they put them in--a key called "Scrunch". (I wonder who dreamed that up? Why not in a key called "WMV9-VCM"?

I looked there, and there are also settings for bit rate and resoloution there. So, I would suggest that you might want to take another look at the current release of this codec.

[len0x]

those are just decoder settings - they have nothing to do with encoding.

[Yo]

Originally posted by len0x
those are just decoder settings - they have nothing to do with encoding.

The setting that the help file was discussing (quoted in my previous post) certainly had to do with encoding, a registry key to add if the default setting results in too much softening.

[manono]

I don't think so. It's talking about postprocessing. Those things kick in at playback, I think. Those settings are used by the decoder.

[Yo]

Originally posted by manono
I don't think so. It's talking about postprocessing. Those things kick in at playback, I think. Those settings are used by the decoder.

I don't think so. These are settings for encoding a video. By postprocessing I think they mean that the softening is done after the compression, but still a part of the encoding process.

As I said, there are also settings in that key for resolution and bit rate. A decoder would not be setting resolution and bit rate, no? Setting that is part of the encoding process.

I don't think the WMV9-VCM codec has anything to do with decoding. Any computer that has WM9 on it should be able to decode it, right. If I make a movie with this codec and give it to someone else who does not have the VCM codec installed, as long as they are running a recent version of Windows they should be able to play it, no? The VCM codec is just a way to use WMV9 compression in containers other than .WMV. It wouldn't involve a different decoder than wmv9.

[len0x]

No offence Yo, but what you're saying is a complete nonsense. But be more on the subject - try comparing options from registry with options available in VCM gui. As soos as you find _all_ of them in registry let me know and I'll have a closer look.

[stephanV]

uhm Yo...

read what you posted yourself:


Posted by Yo, 17th August 2004 20:14
If you prefer a crisper image, at the risk of more compression artifacts, you can change the registry setting that controls the type of postprocessing that the decoder performs.

these are really decoder options. :rolleyes:

[manono]

I don't think the WMV9-VCM codec has anything to do with decoding.

Sure it does. The word "codec" is short for compressor/decompressor. The deblocking and deringing are decoder settings.

[stephanV]

im guessing it is actually the WMVideo decoder DMO that you are setting there, not the VCM codec. i have the key too and i dont recall installing WM9 VCM.

[len0x]

Originally posted by stephanV
im guessing it is actually the WMVideo decoder DMO that you are setting there, not the VCM codec. i have the key too and i dont recall installing WM9 VCM.

second that

[Yo]

Originally posted by stephanV
im guessing it is actually the WMVideo decoder DMO that you are setting there, not the VCM codec. i have the key too and i dont recall installing WM9 VCM.

Do you mean that if I use the WM9VCM codec in VDub to encode a video, and I find too much softening in the result, and I make the quoted registry change specified in the help file, and encode it again, that if I send the file to someone else, to look at on another computer, that my having made the change in the registry before re-encoding won't have made any difference, because that setting only affects the playback on my computer, doesn't affect the file being encoded itself?

If so then, why are there settings for Bit Rate and Resolution there? Why would playback settings have keys for bit rate and resolution? (I notice there are more than one "Scrunch" key in the registry. Make sure you look at the exact one specified in the help file-- HKEY_CURRENT_USER\Software\Microsoft\Scrunch

[Yo]

Originally posted by manono
I don't think the WMV9-VCM codec has anything to do with decoding.

Sure it does. The word "codec" is short for compressor/decompressor. The deblocking and deringing are decoder settings.

Yes, of course a codec is usually for both coding and decoding. What I meant was--the decoding capability is already present on all computers running a recent version of Windows, i.e any that have WM9 codecs installed. Files created with WMV-VCM do not require that WMV-VCM be installed on the playback computer, but only WM9.

Therefore, my point was, the only point of WMV-VCM is to add encoding capability (to be able to use WMV9 compression in containers other than WMV and ASF, and with encoding programs that do not support WMV or ASF), not to add decoding capability, as the decoding capability is already present on the computer.

[Yo]

Originally posted by Yo
Do you mean that if I use the WM9VCM codec in VDub to encode a video, and I find too much softening in the result, and I make the quoted registry change specified in the help file, and encode it again, that if I send the file to someone else, to look at on another computer, that my having made the change in the registry before re-encoding won't have made any difference, because that setting only affects the playback on my computer, doesn't affect the file being encoded itself?

If so then, why are there settings for Bit Rate and Resolution there? Why would playback settings have keys for bit rate and resolution? (I notice there are more than one "Scrunch" key in the registry. Make sure you look at the exact one specified in the help file-- HKEY_CURRENT_USER\Software\Microsoft\Scrunch

Actually, I did that, re-did an encoding after making the suggested registry change, after changing that "Force Post-Process Mode" key to 0.

It encoded faster after making that change, and the resulting file size was smaller. If those keys only affected playback, how could a change in the key could affect encoding speed and file size?

[stephanV]

ive got no idea how those settings would affect the codec... i havent got it installed and still have the key... its really just post-processing options. so it could get into play with re-encoding. but really, this codec doesnt seem to be configurable from the registry... no one stops you from using it though.

[musicnyman]

just got the buffalo linktheater and it supports wmv9 and wmvhd so wmv addition to auto gk would be nice to try...