[Gstreamer-openmax] Support for hardware codecs

[Felipe Contreras]

On Tue, Feb 23, 2010 at 4:45 PM, Stephen M. Webb <stephenw at xandros.com> wrote:
> On 22/02/10 12:05, Clark, Rob wrote:
>> On Feb 22, 2010, at 10:47 AM, Stephen M. Webb wrote:
>> >
>> > Another thing that came up recently was the ability to specify some
>> > OpenMAX parameters with default values on a per-plugin basis.  Even
>> > better, some way to specify rules for different parameters values to
>> > handle cases such as the WMVFileType setting for the TI video decoder.
>>
>> would it be sufficient to (a) expose more setting via properties, and (b)
>> have some generic (not specific to gst-openmax) way to config default
>> values for element's properties
>
> What I would want is some way to expose more properties via gst-openmax, at
> runtime.  I use gst-openmax to integrate various hardware codecs from
> different vendors, each one with a different set of properties that may need
> to be tweaked.  The more I can keep generic and as a single binary, the
> happier I am.  And the easier it will be to push everything upstream.

I'm not sure exactly what properties you might need. The only one I'm
aware of is TI's "OMX.TI.VideoDecode.Param.WMVFileType" which is
needed because the spec is missing something similar. And this one
cannot be properly set with a configuration file, it has to be set
programatically based on the fourcc/fomat caps.

Other than that it might make sense to add a quirks list that can be
configurable. I've tried to send patches to TI to fix their
implementation but I don't think that's ever going to happen. Other
implementations might make similar mistakes... not sure.

> Because of the need for compile-time differentiation, I currently end up
> building everything multiple times, once for each hardware platform.  That
> gives a fine end result but sure makes my life more difficult.

Yeah, that's definitely not ideal but it would be nice to know exactly
what are the differences each platform needs so that we know how to
build a binary that works on all those platforms with a proper
configuration file.

I'm only aware of bellagio (doesn't need any quirks), TI (needs quirks
at least for video components), and I know a bit about Android's
OpenCore, but haven't yet managed to get anything done with that.

Cheers.

-- 
Felipe Contreras