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

From: Hsia-Jun Li
Date: Thu Aug 18 2022 - 19:51:31 EST




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@xxxxxxxxxxxxx> wrote:

From: "Hsia-Jun(Randy) Li" <randy.li@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
---
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