Re: [PATCH 2/2] [WIP]: media: Add Synaptics compressed tiled format

[Hsia-Jun Li <Randy.Li@synaptics.com>]

On 8/19/22 07:13, Laurent Pinchart wrote:
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> 
> 
> On Thu, Aug 18, 2022 at 02:33:42PM +0800, Hsia-Jun Li wrote:
>> On 8/18/22 14:06, Tomasz Figa wrote:
>>> On Tue, Aug 9, 2022 at 1:28 AM Hsia-Jun Li <randy.li@synaptics.com> wrote:
>>>>
>>>> From: "Hsia-Jun(Randy) Li" <randy.li@synaptics.com>
>>>>
>>>> The most of detail has been written in the drm.
> 
> This patch still needs a description of the format, which should go to
> Documentation/userspace-api/media/v4l/.

I just want t tell people we need an extra plane for MVTP and I don't 
have enough space here to place all the pixel formats.

Besides, I was thinking a modifer in v4l2_ext_pix_format is not enough.
Let's take a compression NV12 tile format as an example, we need
1. luma planes
2. chroma planes
3. compression meta data for luma
4. compression meta data for chroma
5. mvtp
and a single data planer version would be
1. luma and chroma data
2. compression meta data
3. mvtp

You see, we actually have 3 kind of data here(not including the 
compression options that I am thinking of storing them somewhere else).
> 
>>>> Please notice that the tiled formats here request
>>>> one more plane for storing the motion vector metadata.
>>>> This buffer won't be compressed, so you can't append
>>>> it to luma or chroma plane.
>>>
>>> Does the motion vector buffer need to be exposed to userspace? Is the
>>> decoder stateless (requires userspace to specify the reference frames)
>>> or stateful (manages the entire decoding process internally)?
>>
>> No, users don't need to access them at all. Just they need a different
>> dma-heap.
>>
>> You would only get the stateful version of both encoder and decoder.
> 
> Shouldn't the motion vectors be stored in a separate V4L2 buffer,
> submitted through a different queue then ?
Yes, I like that.
Proposal: A third buffer type for the reconstruction buffers in V4L2 M2M 
encoder
https://www.spinics.net/lists/linux-media/msg214565.html

Although the major usage for the decoder here is producing the non-tile 
buffers, the decoder of us could product the NV12 or the pixel formats 
that GPU likes, but it must happen at the same time a frame is decoded.
Still the reference buffer or we call them the real decoded frame would 
stay in a tiled format. More than one queue would be need here.
> 
>>>> Signed-off-by: Hsia-Jun(Randy) Li <randy.li@synaptics.com>
>>>> ---
>>>>    drivers/media/v4l2-core/v4l2-common.c | 1 +
>>>>    drivers/media/v4l2-core/v4l2-ioctl.c  | 2 ++
>>>>    include/uapi/linux/videodev2.h        | 2 ++
>>>>    3 files changed, 5 insertions(+)
>>>>
>>>> diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
>>>> index e0fbe6ba4b6c..f645278b3055 100644
>>>> --- a/drivers/media/v4l2-core/v4l2-common.c
>>>> +++ b/drivers/media/v4l2-core/v4l2-common.c
>>>> @@ -314,6 +314,7 @@ const struct v4l2_format_info *v4l2_format_info(u32 format)
>>>>                   { .format = V4L2_PIX_FMT_SGBRG12,       .pixel_enc = V4L2_PIXEL_ENC_BAYER, .mem_planes = 1, .comp_planes = 1, .bpp = { 2, 0, 0, 0 }, .hdiv = 1, .vdiv = 1 },
>>>>                   { .format = V4L2_PIX_FMT_SGRBG12,       .pixel_enc = V4L2_PIXEL_ENC_BAYER, .mem_planes = 1, .comp_planes = 1, .bpp = { 2, 0, 0, 0 }, .hdiv = 1, .vdiv = 1 },
>>>>                   { .format = V4L2_PIX_FMT_SRGGB12,       .pixel_enc = V4L2_PIXEL_ENC_BAYER, .mem_planes = 1, .comp_planes = 1, .bpp = { 2, 0, 0, 0 }, .hdiv = 1, .vdiv = 1 },
>>>> +               { .format = V4L2_PIX_FMT_NV12M_V4H1C, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 5, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 2, .vdiv = 2, .block_w = { 128, 128 }, .block_h = { 128, 128 } },
>>>>           };
>>>>           unsigned int i;
>>>>
>>>> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
>>>> index e6fd355a2e92..8f65964aff08 100644
>>>> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
>>>> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
>>>> @@ -1497,6 +1497,8 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
>>>>                   case V4L2_PIX_FMT_MT21C:        descr = "Mediatek Compressed Format"; break;
>>>>                   case V4L2_PIX_FMT_QC08C:        descr = "QCOM Compressed 8-bit Format"; break;
>>>>                   case V4L2_PIX_FMT_QC10C:        descr = "QCOM Compressed 10-bit Format"; break;
>>>> +               case V4L2_PIX_FMT_NV12M_V4H1C:  descr = "Synaptics Compressed 8-bit tiled Format";break;
>>>> +               case V4L2_PIX_FMT_NV12M_10_V4H3P8C:     descr = "Synaptics Compressed 10-bit tiled Format";break;
>>>>                   default:
>>>>                           if (fmt->description[0])
>>>>                                   return;
>>>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
>>>> index 01e630f2ec78..7e928cb69e7c 100644
>>>> --- a/include/uapi/linux/videodev2.h
>>>> +++ b/include/uapi/linux/videodev2.h
>>>> @@ -661,6 +661,8 @@ struct v4l2_pix_format {
>>>>    #define V4L2_PIX_FMT_NV12MT_16X16 v4l2_fourcc('V', 'M', '1', '2') /* 12  Y/CbCr 4:2:0 16x16 tiles */
>>>>    #define V4L2_PIX_FMT_NV12M_8L128      v4l2_fourcc('N', 'A', '1', '2') /* Y/CbCr 4:2:0 8x128 tiles */
>>>>    #define V4L2_PIX_FMT_NV12M_10BE_8L128 v4l2_fourcc_be('N', 'T', '1', '2') /* Y/CbCr 4:2:0 10-bit 8x128 tiles */
>>>> +#define V4L2_PIX_FMT_NV12M_V4H1C v4l2_fourcc('S', 'Y', '1', '2')   /* 12  Y/CbCr 4:2:0 tiles */
>>>> +#define V4L2_PIX_FMT_NV12M_10_V4H3P8C v4l2_fourcc('S', 'Y', '1', '0')   /* 12  Y/CbCr 4:2:0 10-bits tiles */
>>>>
>>>>    /* Bayer formats - see https://urldefense.proofpoint.com/v2/url?u=http-3A__www.siliconimaging.com_RGB-2520Bayer.htm&d=DwIBaQ&c=7dfBJ8cXbWjhc0BhImu8wVIoUFmBzj1s88r8EGyM0UY&r=P4xb2_7biqBxD4LGGPrSV6j-jf3C3xlR7PXU-mLTeZE&m=87M5Aa5fG3kdTTjlJrLIgv0E7O10QAj_4RqDlVsCAFdbfJzJ_P0s8wkBqaR0VBUO&s=8AsoiLPt9hQnn4ta51tT-RUXRLoKKYrePdAwtdvxuDo&e=   */
>>>>    #define V4L2_PIX_FMT_SBGGR8  v4l2_fourcc('B', 'A', '8', '1') /*  8  BGBG.. GRGR.. */
> 
> --
> Regards,
> 
> Laurent Pinchart

-- 
Hsia-Jun(Randy) Li