Re: [PATCH 2/2] [media] v4l: Add 10-bits per channel YUV pixel formats

[ayaka <ayaka@soulik.info>]

On 01/02/2017 05:10 PM, Sakari Ailus wrote:
> Hi Randy,
>
> Thanks for the patch.
>
> On Mon, Jan 02, 2017 at 04:50:04PM +0800, Randy Li wrote:
>> The formats added by this patch are:
>> 	V4L2_PIX_FMT_P010
>> 	V4L2_PIX_FMT_P010M
>> Currently, none of driver uses those format, but some video device
>> has been confirmed with could as those format for video output.
>> The Rockchip's new decoder has supported those format for profile_10
>> HEVC/AVC video.
>>
>> Signed-off-by: Randy Li <ayaka@soulik.info>
> If the format resembles the existing formats but on a different bit depth,
> it should be named in similar fashion.
Do you mean it would be better if it is called as NV12_10?
>
> Could you also add ReST documentation for the format, please?
I will.
>
> The common requirement for merging patches that change interfaces has been
> that there's a user for that change. It'll still help you to get this
The kernel used in rockchip has supported that format in drm driver, but 
just we don't have a agreement about the pixel format. As the Gstreamer 
and some others would call it with a P010_ prefix, but Mark(rockchip's 
drm author) prefer the something like NV12_10, that is why I sent out 
those patches, I want the upstream decided its final name.
> reviewed now so the interface that the future hopefully-in-mainline driver
> provides will not change.
>
>> ---
>>   include/uapi/linux/videodev2.h | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
>> index 46e8a2e3..9e03f20 100644
>> --- a/include/uapi/linux/videodev2.h
>> +++ b/include/uapi/linux/videodev2.h
>> @@ -551,6 +551,7 @@ struct v4l2_pix_format {
>>   #define V4L2_PIX_FMT_NV61    v4l2_fourcc('N', 'V', '6', '1') /* 16  Y/CrCb 4:2:2  */
>>   #define V4L2_PIX_FMT_NV24    v4l2_fourcc('N', 'V', '2', '4') /* 24  Y/CbCr 4:4:4  */
>>   #define V4L2_PIX_FMT_NV42    v4l2_fourcc('N', 'V', '4', '2') /* 24  Y/CrCb 4:4:4  */
>> +#define V4L2_PIX_FMT_P010    v4l2_fourcc('P', '0', '1', '0') /* 15  Y/CbCr 4:2:0, 10 bits per channel */
>>   
>>   /* two non contiguous planes - one Y, one Cr + Cb interleaved  */
>>   #define V4L2_PIX_FMT_NV12M   v4l2_fourcc('N', 'M', '1', '2') /* 12  Y/CbCr 4:2:0  */
>> @@ -559,6 +560,7 @@ struct v4l2_pix_format {
>>   #define V4L2_PIX_FMT_NV61M   v4l2_fourcc('N', 'M', '6', '1') /* 16  Y/CrCb 4:2:2  */
>>   #define V4L2_PIX_FMT_NV12MT  v4l2_fourcc('T', 'M', '1', '2') /* 12  Y/CbCr 4:2:0 64x32 macroblocks */
>>   #define V4L2_PIX_FMT_NV12MT_16X16 v4l2_fourcc('V', 'M', '1', '2') /* 12  Y/CbCr 4:2:0 16x16 macroblocks */
>> +#define V4L2_PIX_FMT_P010M   v4l2_fourcc('P', 'M', '1', '0') /* 15  Y/CbCr 4:2:0, 10 bits per channel */
>>   
>>   /* three planes - Y Cb, Cr */
>>   #define V4L2_PIX_FMT_YUV410  v4l2_fourcc('Y', 'U', 'V', '9') /*  9  YUV 4:1:0     */