[VDPAU] [PATCH] Enable Lossless Decode Capabilities via VDPAU API

[Rémi Denis-Courmont]

Le 2014-12-04 01:44, Karthikeyan Sreenivasan a écrit :
>> Extending the existing VdpPictureInfoH264 structure will perturb its 
>> ABI.
>> If different software in the system uses the structure in a way that
>> relies on its size (e.g., an array of VdpPictureInfoH264s, or a 
>> structure
>> with a VdpPictureInfoH264 member and other members afterwards), and
>> those are passed between software components that were compiled with
>> different VdpPictureInfoH264 definitions, bad things will happen.

Fair enough. Lets not change the existing structure then.

>> For name: I'd recommend a name that describes the usage of the 
>> profile.
>> E.g., VdpPictureInfoH264Predictive.  If we expect the structure to
>> be useful for other profiles, then maybe a little more general; 
>> e.g.,
>> VdpPictureInfoH264TransformBypass ?  But really, the bikeshed can be
>> any color.
>
> The names correspond to the structure as such:
>
> 1. VdpPictureInfoH264Extended, Will contain the current 
> transform_bypass
> field and a struct_version so as to add more fields in the future if
> need arises.

Adding a version number does not solve this the binary compatibility 
issue above. I would leave versioning out and rely on the decoder 
profile - effectively treating lossy H.264 and lossless H.264 as two 
different codecs.

> 2. VdpPictureInfoH264Predictive, will contain all the fields 
> necessary for
> VDP_DECODER_PROFILE_H264_HIGH_444_PREDICTIVE and the structure will 
> not
> change and will be used exclusively for Hi444PP [w/ or w/o lossless 
> decode].

Yes.

-- 
Rémi Denis-Courmont