[gst-devel] handling windows codecs in gstreamer?

[Osama Khan]

Hi Ronald,

Actually i am interested in basic wmv/wma stuff at the moment. So
ffmpeg seems sufficient for me as it supports both the codecs and the
ASF container format. This seems to be the most feasible way to
incorporate support for windows codecs in open source software. Lets
just hope the patent hawks keep away for as long as possible ;) ...

-Osama

On 6/21/05, Ronald S. Bultje <rbultje at ronald.bitfreak.net> wrote:
> 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>
> 
>