Re: [PATCH v2 01/12] media: v4l2: Add NV15 pixel format

From: Hsia-Jun Li
Date: Thu Feb 16 2023 - 03:58:11 EST




On 1/12/23 20:56, Sebastian Fricke wrote:
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From: Jonas Karlman <jonas@xxxxxxxxx>

Add the NV15 pixel format used by the Rockchip Video Decoder for 10-bit buffers.

I think this pixel format in the Rockchip platform supports multiple planes buffers. It is all right not to add more variant until the ext pixel format and buffer APIs are merged.

I just want to mention the need of this.
NV15 is a packed 10-bit 4:2:0 Y/CbCr format similar to P010 and P210 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 '15' suffix refers to the optimum effective bits per pixel
which is achieved when the total number of luminance samples is a multiple
of 8 for NV15.

Signed-off-by: Jonas Karlman <jonas@xxxxxxxxx>
Signed-off-by: Sebastian Fricke <sebastian.fricke@xxxxxxxxxxxxx>
---
.../userspace-api/media/v4l/pixfmt-yuv-planar.rst | 75 ++++++++++++++++++++++
drivers/media/v4l2-core/v4l2-common.c | 2 +
drivers/media/v4l2-core/v4l2-ioctl.c | 1 +
include/uapi/linux/videodev2.h | 1 +
4 files changed, 79 insertions(+)

diff --git a/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst b/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst
index f1d5bb7b806d..7d8d228f8063 100644
--- a/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst
+++ b/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst
@@ -79,6 +79,13 @@ All components are stored with the same number of bits per component.
- Cr, Cb
- Yes
- Linear
+ * - V4L2_PIX_FMT_NV15
+ - 'NV15'
+ - 15
+ - 4:2:0
+ - Cb, Cr
+ - Yes
+ - Linear
* - V4L2_PIX_FMT_NV12M
- 'NM12'
- 8
@@ -183,6 +190,7 @@ horizontally.

.. _V4L2-PIX-FMT-NV12:
.. _V4L2-PIX-FMT-NV21:
+.. _V4L2-PIX-FMT-NV15:
.. _V4L2-PIX-FMT-NV12M:
.. _V4L2-PIX-FMT-NV21M:
.. _V4L2-PIX-FMT-P010:
@@ -586,6 +594,73 @@ Data in the 10 high bits, zeros in the 6 low bits, arranged in little endian ord
- Cb\ :sub:`11`
- Cr\ :sub:`11`

+.. _V4L2_PIX_FMT_NV15:
+
+NV15
+----
+
+Similar to P010, a semi-planar 10-bit Y/CbCr format, but all components are
+packed without any padding between each other. As a side-effect, each group of
+4 components are stored over 5 bytes (YYYY or UVUV = 4 * 10 bits = 40 bits = 5
+bytes).
+
+.. flat-table:: Sample 4x4 NV15 Image
+ :header-rows: 0
+ :stub-columns: 0
+
+ * - start + 0:
+ - Y'\ :sub:`00`
+ - Y'\ :sub:`01`
+ - Y'\ :sub:`02`
+ - Y'\ :sub:`03`
+ * - start + 8:
+ - Y'\ :sub:`04`
+ - Y'\ :sub:`10`
+ - Y'\ :sub:`11`
+ - Y'\ :sub:`12`
+ * - start + 16:
+ - Y'\ :sub:`13`
+ - Y'\ :sub:`14`
+ - Y'\ :sub:`20`
+ - Y'\ :sub:`21`
+ * - start + 24:
+ - Y'\ :sub:`22`
+ - Y'\ :sub:`23`
+ - Y'\ :sub:`24`
+ - Y'\ :sub:`30`
+ * - start + 32:
+ - Y'\ :sub:`31`
+ - Y'\ :sub:`32`
+ - Y'\ :sub:`33`
+ - Y'\ :sub:`34`
+
+ * - start + 0:
+ - Cb\ :sub:`00`
+ - Cr\ :sub:`00`
+ - Cb\ :sub:`01`
+ - Cr\ :sub:`01`
+ * - start + 8:
+ - Cb\ :sub:`02`
+ - Cr\ :sub:`02`
+ - Cb\ :sub:`03`
+ - Cr\ :sub:`03`
+ * - start + 16:
+ - Cb\ :sub:`04`
+ - Cr\ :sub:`04`
+ - Cb\ :sub:`10`
+ - Cr\ :sub:`10`
+ * - start + 24:
+ - Cb\ :sub:`11`
+ - Cr\ :sub:`11`
+ - Cb\ :sub:`12`
+ - Cr\ :sub:`12`
+ * - start + 32:
+ - Cb\ :sub:`13`
+ - Cr\ :sub:`13`
+ - Cb\ :sub:`14`
+ - Cr\ :sub:`14`
+
+.. raw:: latex

Fully Planar YUV Formats
========================
diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index 40f56e044640..be23e319fb3a 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -262,6 +262,8 @@ const struct v4l2_format_info *v4l2_format_info(u32 format)
/* YUV planar formats */
{ .format = V4L2_PIX_FMT_NV12, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 2, .vdiv = 2 },
{ .format = V4L2_PIX_FMT_NV21, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 2, .vdiv = 2 },
+ { .format = V4L2_PIX_FMT_NV15, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 5, 5, 0, 0 }, .hdiv = 2, .vdiv = 2,
+ .block_w = { 4, 2, 0, 0 }, .block_h = { 1, 1, 0, 0 } },
{ .format = V4L2_PIX_FMT_NV16, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 2, .vdiv = 1 },
{ .format = V4L2_PIX_FMT_NV61, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 2, .vdiv = 1 },
{ .format = V4L2_PIX_FMT_NV24, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 1, .vdiv = 1 },
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 8e0a0ff62a70..1c80ad78ef00 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1343,6 +1343,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
case V4L2_PIX_FMT_M420: descr = "YUV 4:2:0 (M420)"; break;
case V4L2_PIX_FMT_NV12: descr = "Y/UV 4:2:0"; break;
case V4L2_PIX_FMT_NV21: descr = "Y/VU 4:2:0"; break;
+ case V4L2_PIX_FMT_NV15: descr = "10-bit Y/UV 4:2:0 (Packed)"; break;
case V4L2_PIX_FMT_NV16: descr = "Y/UV 4:2:2"; break;
case V4L2_PIX_FMT_NV61: descr = "Y/VU 4:2:2"; break;
case V4L2_PIX_FMT_NV24: descr = "Y/UV 4:4:4"; break;
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 1befd181a4cc..e9731286dc77 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -621,6 +621,7 @@ struct v4l2_pix_format {
/* two planes -- one Y, one Cr + Cb interleaved */
#define V4L2_PIX_FMT_NV12 v4l2_fourcc('N', 'V', '1', '2') /* 12 Y/CbCr 4:2:0 */
#define V4L2_PIX_FMT_NV21 v4l2_fourcc('N', 'V', '2', '1') /* 12 Y/CrCb 4:2:0 */
+#define V4L2_PIX_FMT_NV15 v4l2_fourcc('N', 'V', '1', '5') /* 15 Y/CbCr 4:2:0 10-bit packed */
#define V4L2_PIX_FMT_NV16 v4l2_fourcc('N', 'V', '1', '6') /* 16 Y/CbCr 4:2:2 */
#define V4L2_PIX_FMT_NV61 v4l2_fourcc('N', 'V', '6', '1') /* 16 Y/CrCb 4:2:2 */
#define V4L2_PIX_FMT_NV24 v4l2_fourcc('N', 'V', '2', '4') /* 24 Y/CbCr 4:4:4 */

--
2.25.1

--
Hsia-Jun(Randy) Li