[MPlayer-dev-eng] Open Source Video 1 Decoder

Arpi arpi at thot.banki.hu
Sun Nov 11 14:50:42 CET 2001


Hi,

> Hi there,
> 	I'm pleased to contribute an open source decoder for
> Microsoft Video 1 data. This is data that corresponds to the CRAM, WHAM,
> and MSVC fourccs, and is normally handled by the msvidc32.dll codec. The
> 16-bit variant works just fine, but the 8-bit variant is still slightly
> off. If anyone has some more 8-bit Video 1 files, or 16-bit ones that
> don't work, send them my way.

JAF has lots of CRAM files :)

> 	Please note that this is my first attempt at making a patch
ok, applied with some modifications:
driver renamed video1->msvidc  (video1 may cause some confusion)
decoder moved to msvidc.c

> 	You'll probably want to move the decoder into a separate file so
> it doesn't clutter up dec_video.c. And you may want to fix up the
> little-endian reader/converters as well; I just used my own since I didn't
> know what to use from the MPlayer codebase. Oh, and I was also lazy to the
> point of only implementing BGR888 output data.
I'll add 15/16/32 bpp too.

> 	I was able to implement this by studying the XAnim source
> code. For those who may be worried about code origin issues, I didn't
> copy this code directly from XAnim. I reverse engineered a high-level
> description of the algorithm that you can read here:
>   http://www.pcisys.net/~melanson/video1.txt
should i put this link or the file itself to docs?

> 	Hopefully, this code will eliminate the need for at least one
> binary-only codec. It's a start.
yes, thanks.


A'rpi / Astral & ESP-team

--
mailto:arpi at thot.banki.hu
http://esp-team.scene.hu



More information about the MPlayer-dev-eng mailing list