Re: [PATCH 1/2] drm: drm_fourcc: add NV20 YUV format【请注意，邮件由linux-rockchip-bounces+sandy.huang=rock-chips.com@lists.infradead.org代发】

[Huang Jiachai <hjc@rock-chips.com>]

Hi Jonas Karlman,

在 2020/6/26 22:19, Jonas Karlman 写道:
> On 2020-06-17 14:07, Huang Jiachai wrote:
>> Hi Jonas Karlman,
>>
>>       Is there an another yuv 10bit format with 4:4:4 sub-simpling but
>> has no padding?
>>
>>    Maybe we can call it DRM_FORMAT_NV30:
>>
>> { .format = DRM_FORMAT_NV30,		.depth = 0,
>>     .num_planes = 2, .char_per_block = { 5, 5, 0 },
>>     .block_w = { 4, 2, 0 }, .block_h = { 1, 1, 0 }, .hsub = 1,
>>     .vsub = 1, .is_yuv = true },
>>
>> this format can supported by rockchip rk3288/rk3399... platform, can you
>> add this format at this series patches?
> I will send a v2 including this 4:4:4 format later this weekend.
>
> Is there any hw block on rk3288/rk3399 that can produce a buffer in such format?
> If I am not mistaken rkvdec only support 10-bit h264 in 4:2:0/4:2:2 and
> hevc 4:2:0 10-bit, those are the formats I have been able to test so far.
>
> Regards,
> Jonas

yes,rockchip platform hw video decoder 10-bit yuv format only can 
support 4:2:0/4:2:2 so far, but the software decoder path maybe output 
4:4:4-10 format to VOP.

>
>> 在 2020/6/8 4:25, Jonas Karlman 写道:
>>> DRM_FORMAT_NV20 is a 2 plane format suitable for linear memory layout.
>>> The format is similar to P210 with 4:2:2 sub-sampling but has no padding
>>> between components. Instead, luminance and chrominance samples are grouped
>>> into 4s so that each group is packed into an integer number of bytes:
>>>
>>> YYYY = UVUV = 4 * 10 bits = 40 bits = 5 bytes
>>>
>>> The '20' suffix refers to the optimum effective bits per pixel which is
>>> achieved when the total number of luminance samples is a multiple of 4.
>>>
>>> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
>>> ---
>>>    drivers/gpu/drm/drm_fourcc.c  | 4 ++++
>>>    include/uapi/drm/drm_fourcc.h | 1 +
>>>    2 files changed, 5 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
>>> index 722c7ebe4e88..2a9c8ae719ed 100644
>>> --- a/drivers/gpu/drm/drm_fourcc.c
>>> +++ b/drivers/gpu/drm/drm_fourcc.c
>>> @@ -278,6 +278,10 @@ const struct drm_format_info *__drm_format_info(u32 format)
>>>    		  .num_planes = 2, .char_per_block = { 5, 5, 0 },
>>>    		  .block_w = { 4, 2, 0 }, .block_h = { 1, 1, 0 }, .hsub = 2,
>>>    		  .vsub = 2, .is_yuv = true },
>>> +		{ .format = DRM_FORMAT_NV20,		.depth = 0,
>>> +		  .num_planes = 2, .char_per_block = { 5, 5, 0 },
>>> +		  .block_w = { 4, 2, 0 }, .block_h = { 1, 1, 0 }, .hsub = 2,
>>> +		  .vsub = 1, .is_yuv = true },
>>>    		{ .format = DRM_FORMAT_Q410,		.depth = 0,
>>>    		  .num_planes = 3, .char_per_block = { 2, 2, 2 },
>>>    		  .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 }, .hsub = 0,
>>> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
>>> index b5bf1c0e630e..244d32433a67 100644
>>> --- a/include/uapi/drm/drm_fourcc.h
>>> +++ b/include/uapi/drm/drm_fourcc.h
>>> @@ -242,6 +242,7 @@ extern "C" {
>>>     * index 1 = Cr:Cb plane, [39:0] Cr1:Cb1:Cr0:Cb0 little endian
>>>     */
>>>    #define DRM_FORMAT_NV15		fourcc_code('N', 'V', '1', '5') /* 2x2 subsampled Cr:Cb plane */
>>> +#define DRM_FORMAT_NV20		fourcc_code('N', 'V', '2', '0') /* 2x1 subsampled Cr:Cb plane */
>>>    
>>>    /*
>>>     * 2 plane YCbCr MSB aligned
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-- 
Best Regard

黄家钗
Sandy Huang
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