[gst-devel] handling windows codecs in gstreamer?

[Ronald S. Bultje]

Hi Osama,

On Sat, 2005-06-18 at 22:10, Osama Khan wrote:
> I was just wondering how does gstreamer handle windows codecs (wmv, wma
> etc.) from a programmer's point of view? Does it use a wrapper for the
> original windows codec DLLs or does it use reverse engineered codecs.
> Any comments (advantages/disadvantages, ease of implementation) on
> either of these or any other approach will be highly welcome. I tried
> searching the archives but didnt find anything covering this question
> in a reasonable manner.

Depends which one you mean. There's multiple WMA versions. WMAv7 and v8
have been fully reverse engineered by the excellent ffmpeg project
(http://ffmpeg.org/), so we use their code in our gst-ffmpeg package
(available from the gstreamer website). The same goes for WMVv7 and v8.
WMA/WMAv9 have not been reverse engineered. We support WMVv9 via binary
DLLs in the pitfdll package (http://ronald.bitfreak.net/). I've tried to
get WMAv9 to work, but that's currently unfinished. Those obviously only
work under IA32.
Specs for VC1 (WMVv9) are publically available via MPEG-LA, btw, but
they are incomplete (i.e. media files you'll find online don't match the
specs).

HTH,

Ronald

-- 
Ronald S. Bultje <rbultje at ronald.bitfreak.net>