[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <50dd9b7a-8f48-0799-57f6-048d20de8dcc@synaptics.com>
Date: Fri, 19 Aug 2022 23:44:33 +0800
From: Hsia-Jun Li <Randy.Li@...aptics.com>
To: Nicolas Dufresne <nicolas@...fresne.ca>
Cc: Tomasz Figa <tfiga@...omium.org>, dri-devel@...ts.freedesktop.org,
maarten.lankhorst@...ux.intel.com, mripard@...nel.org,
tzimmermann@...e.de, airlied@...ux.ie, daniel@...ll.ch,
mchehab@...nel.org, hverkuil-cisco@...all.nl,
ezequiel@...guardiasur.com.ar, sakari.ailus@...ux.intel.com,
ribalda@...omium.org,
Laurent Pinchart <laurent.pinchart@...asonboard.com>,
linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
sebastian.hesselbarth@...il.com, jszhang@...nel.org,
linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH 2/2] [WIP]: media: Add Synaptics compressed tiled format
On 8/19/22 23:28, Nicolas Dufresne wrote:
> CAUTION: Email originated externally, do not click links or open attachments unless you recognize the sender and know the content is safe.
>
>
> Le vendredi 19 août 2022 à 02:13 +0300, Laurent Pinchart a écrit :
>> 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@...aptics.com> wrote:
>>>>>
>>>>> From: "Hsia-Jun(Randy) Li" <randy.li@...aptics.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/.
>>
>>>>> 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 ?
>
> Imho, I believe these should be invisible to users and pooled separately to
> reduce the overhead. The number of reference is usually lower then the number of
> allocated display buffers.
>
You can't. The motion vector buffer can't share with the luma and chroma
data planes, nor the data plane for the compression meta data.
You could consider this as a security requirement(the memory region for
the MV could only be accessed by the decoder) or hardware limitation.
It is also not very easy to manage such a large buffer that would change
when the resolution changed.
>>
>>>>> Signed-off-by: Hsia-Jun(Randy) Li <randy.li@...aptics.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=DwIFaQ&c=7dfBJ8cXbWjhc0BhImu8wVIoUFmBzj1s88r8EGyM0UY&r=P4xb2_7biqBxD4LGGPrSV6j-jf3C3xlR7PXU-mLTeZE&m=lkQiuhx0yMAYHGcW-0WaHlF3e2etMHsu-FoNIBdZILGH6FPigwSAmel2vAdcVLkp&s=JKsBzpb_3u9xv52MaMuT4U3T1pPqcObYkpHDBxvcx_4&e= */
>>>>> #define V4L2_PIX_FMT_SBGGR8 v4l2_fourcc('B', 'A', '8', '1') /* 8 BGBG.. GRGR.. */
>>
>
--
Hsia-Jun(Randy) Li
Powered by blists - more mailing lists