[FFmpeg-devel] Patch: CrystalHD decoder support

Michael Niedermayer michaelni
Thu Dec 30 23:56:08 CET 2010

On Mon, Dec 27, 2010 at 10:38:52PM -0800, Philip Langdale wrote:
> Hi all,
> This is an update of my previously posted diff against mplayer
> for a native mplayer codec implementation. I've ported it to work
> directly against ffmpeg and improved its behaviour significantly
> in the interim period.
> The Broadcom CrystalHD chips are standalone video decoders that
> decode video frames to system memory. As such, they are independent
> of the GPU and usually appear as mini-card addons to laptops and
> small form factor desktops. There are fully open-source drivers and
> userspace libraries for Linux and OSX (and I guess windows too).
> The main challenge when working with the hardware is keeping it happily
> fed with frames - it is pipelined, so multiple frames are being
> processed at the same time, and the lag between a frame being submitted
> and the decoded frame being returned is significant - so the user
> application needs to be capable of handling this characteristic. Under
> normal conditions, there could be up to 20 frames in flight at once.
> Empirically, I arrived at a 50ms delay between frame submissions during
> the intial pipeline fill.

Our API doesnt support this thus this cannot be done without a small API
extension (that is to keep the dts at the decoder input useable)
The multithreading code needs a similar/same API extension to allow decoders to
work on multiple frames at the same time.

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Freedom in capitalist society always remains about the same as it was in
ancient Greek republics: Freedom for slave owners. -- Vladimir Lenin
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