[PATCH] drm: drm_fourcc: add 10/12bit software decoder YCbCr formats
Robert Mader
robert.mader at collabora.com
Thu May 1 09:25:42 UTC 2025
Hi Tomi
On 24.04.25 18:49, Tomi Valkeinen wrote:
> Hi,
>
> On 24/04/2025 16:31, Laurent Pinchart wrote:
>> On Thu, Apr 24, 2025 at 02:53:18PM +0200, Robert Mader wrote:
>>> Chris, Javier, Laurent - sorry for the noise, but given you reviewed
>>> changes in the respective files before, maybe you can help me moving
>>> this forward? I'd be very happy for any feedback to get this landed,
>>> thanks! :)
>>
>> I don't have spare bandwidth at the moment, sorry :-( One comment below
>> though.
>>
>> Tomi, can you check if there's any overlap with the formats you're
>> adding for the Xilinx FPGA drivers ?
>
> No overlap, they are quite different.
>
>>> On 07.04.25 21:13, Robert Mader wrote:
>>>> This adds FOURCCs for 10/12bit YCbCr formats used by software decoders
>>>> like ffmpeg, dav1d and libvpx. The intended use-case is buffer sharing
>>>> between SW-decoders and GPUs by allocating buffers with udmabuf or
>>>> dma-heaps, avoiding unnecessary copies or format conversions.
>>>>
>>>> Unlike formats typically used by hardware decoders these formats
>>>> use a LSB alignment. In order to allow fast implementations in GL
>>>> and Vulkan the padding must contain only zeros, so the float
>>>> representation can calculated by simple multiplicating with 2^6=64
>
> "can be"
>
>>>> or 2^4=16.
>>
>> This needs to be documented somewhere.
>
> Reviewed-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
Thanks a lot! I just send out a v2 - the changes I made were IMO
slightly too big to carry that r-b over - I'd be very thankful if you
could have another look / renew your r-b :)
>
> Tomi
Cheers,
Robert
>
>>>>
>>>> WIP MRs for Mesa, Vulkan and Gstreamer can be found at:
>>>> - https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34303
>>>> -
>>>> https://github.com/rmader/Vulkan-Docs/commits/ycbcr-16bit-lsb-formats/
>>>> -
>>>> https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8540
>>>>
>>>>
>>>> The values where inspired by the corresponding VA_FOURCC_I010, however
>>>> suggestions are very welcome.
>>>>
>>>> Signed-off-by: Robert Mader <robert.mader at collabora.com>
>>>> ---
>>>> drivers/gpu/drm/drm_fourcc.c | 18 ++++++++++++++++++
>>>> include/uapi/drm/drm_fourcc.h | 20 ++++++++++++++++++++
>>>> 2 files changed, 38 insertions(+)
>>>>
>>>> diff --git a/drivers/gpu/drm/drm_fourcc.c
>>>> b/drivers/gpu/drm/drm_fourcc.c
>>>> index 3a94ca211f9c..917f77703645 100644
>>>> --- a/drivers/gpu/drm/drm_fourcc.c
>>>> +++ b/drivers/gpu/drm/drm_fourcc.c
>>>> @@ -346,6 +346,24 @@ const struct drm_format_info
>>>> *__drm_format_info(u32 format)
>>>> { .format = DRM_FORMAT_P030, .depth = 0,
>>>> .num_planes = 2,
>>>> .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 },
>>>> .block_h = { 1, 1, 0 },
>>>> .hsub = 2, .vsub = 2, .is_yuv = true},
>>>> + { .format = DRM_FORMAT_I010, .depth = 0,
>>>> .num_planes = 3,
>>>> + .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 },
>>>> .block_h = { 1, 1, 1 },
>>>> + .hsub = 2, .vsub = 2, .is_yuv = true},
>>>> + { .format = DRM_FORMAT_I210, .depth = 0,
>>>> .num_planes = 3,
>>>> + .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 },
>>>> .block_h = { 1, 1, 1 },
>>>> + .hsub = 2, .vsub = 1, .is_yuv = true},
>>>> + { .format = DRM_FORMAT_I410, .depth = 0,
>>>> .num_planes = 3,
>>>> + .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 },
>>>> .block_h = { 1, 1, 1 },
>>>> + .hsub = 1, .vsub = 1, .is_yuv = true},
>>>> + { .format = DRM_FORMAT_I012, .depth = 0,
>>>> .num_planes = 3,
>>>> + .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 },
>>>> .block_h = { 1, 1, 1 },
>>>> + .hsub = 2, .vsub = 2, .is_yuv = true},
>>>> + { .format = DRM_FORMAT_I212, .depth = 0,
>>>> .num_planes = 3,
>>>> + .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 },
>>>> .block_h = { 1, 1, 1 },
>>>> + .hsub = 2, .vsub = 1, .is_yuv = true},
>>>> + { .format = DRM_FORMAT_I412, .depth = 0,
>>>> .num_planes = 3,
>>>> + .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 },
>>>> .block_h = { 1, 1, 1 },
>>>> + .hsub = 1, .vsub = 1, .is_yuv = true},
>>>> };
>>>> unsigned int i;
>>>> diff --git a/include/uapi/drm/drm_fourcc.h
>>>> b/include/uapi/drm/drm_fourcc.h
>>>> index e41a3cec6a9e..f22c80031595 100644
>>>> --- a/include/uapi/drm/drm_fourcc.h
>>>> +++ b/include/uapi/drm/drm_fourcc.h
>>>> @@ -397,6 +397,26 @@ extern "C" {
>>>> #define DRM_FORMAT_YUV444 fourcc_code('Y', 'U', '2', '4') /*
>>>> non-subsampled Cb (1) and Cr (2) planes */
>>>> #define DRM_FORMAT_YVU444 fourcc_code('Y', 'V', '2', '4') /*
>>>> non-subsampled Cr (1) and Cb (2) planes */
>>>> +/*
>>>> + * 3 plane YCbCr LSB aligned
>>>> + * index 0 = Y plane, [15:0] x:Y [6:10] little endian
>>>> + * index 1 = Cr plane, [15:0] x:Cr [6:10] little endian
>>>> + * index 2 = Cb plane, [15:0] x:Cb [6:10] little endian
>>>> + */
>>>> +#define DRM_FORMAT_I010 fourcc_code('I', '0', '1', '0') /* 2x2
>>>> subsampled Cb (1) and Cr (2) planes 10 bits per channel */
>>>> +#define DRM_FORMAT_I210 fourcc_code('I', '2', '1', '0') /* 2x1
>>>> subsampled Cb (1) and Cr (2) planes 10 bits per channel */
>>>> +#define DRM_FORMAT_I410 fourcc_code('I', '4', '1', '0') /*
>>>> non-subsampled Cb (1) and Cr (2) planes 10 bits per channel */
>>>> +
>>>> +/*
>>>> + * 3 plane YCbCr LSB aligned
>>>> + * index 0 = Y plane, [15:0] x:Y [4:12] little endian
>>>> + * index 1 = Cr plane, [15:0] x:Cr [4:12] little endian
>>>> + * index 2 = Cb plane, [15:0] x:Cb [4:12] little endian
>>>> + */
>>>> +#define DRM_FORMAT_I012 fourcc_code('I', '0', '1', '2') /* 2x2
>>>> subsampled Cb (1) and Cr (2) planes 12 bits per channel */
>>>> +#define DRM_FORMAT_I212 fourcc_code('I', '2', '1', '2') /* 2x1
>>>> subsampled Cb (1) and Cr (2) planes 12 bits per channel */
>>>> +#define DRM_FORMAT_I412 fourcc_code('I', '4', '1', '2') /*
>>>> non-subsampled Cb (1) and Cr (2) planes 12 bits per channel */
>>>> +
>>>> /*
>>>> * Format Modifiers:
>>
>
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