Re: [PATCH libdrm] libdrm: update drm/drm_fourcc.h from kernel to add multi plane formats

[Sylwester Nawrocki <snjw23@gmail.com>]

On 03/30/2012 01:09 PM, Marcus Lorentzon wrote:
> On 03/30/2012 12:12 PM, Ville Syrjälä wrote:
>>> +#define DRM_FORMAT_NV12MT fourcc_code('T', 'M', '1', '2') /* 2x2
>>> subsampled Cr:Cb plane 64x32 macroblocks */
>> This one is more difficult. Until now tiling was always handled in
>> driver specific manner. OTOH if this format is really supported by
>> different devices from multiple vendors, then it would probably
>> make sense to add it as a standard format.
>>
> What about adding a DRM_FORMAT_PRIV_NV12MT and force vendor to add
> detailed documentation about this new format. Because if the format is
> not defined and documented, how will we ever discover if vendors have
> similar formats? And if we document all these MB formats "everyone"
> uses, then maybe we can get HW vendors to unify on a de facto standard.
> It would be nice to have an efficient format supported by everyone,
> instead of having to fallback to old linear formats every time you
> interact with another device.

Just for the record, documentation of this tiled macro-block format
can be found here:

http://linuxtv.org/downloads/v4l-dvb-apis/re27.html

--
Regards,
Sylwester