On 6/2/21 12:56 PM, Hans Verkuil wrote:

On 29/04/2021 12:58, Stanimir Varbanov wrote:

quoted

Here we add custom Qualcomm raw compressed pixel formats. They are
used in Qualcomm SoCs to optimaize the interconnect bandwidth.

optimize

quoted

Signed-off-by: Stanimir Varbanov <redacted>
---
 .../userspace-api/media/v4l/pixfmt-reserved.rst      | 12 ++++++++++++
 drivers/media/v4l2-core/v4l2-ioctl.c                 |  2 ++
 include/uapi/linux/videodev2.h                       |  2 ++
 3 files changed, 16 insertions(+)

diff --git a/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst b/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst
index 0b879c0da713..30b9cef4cbf0 100644
--- a/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst
+++ b/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst

@@ -260,6 +260,18 @@ please make a proposal on the linux-media mailing list.
 	of tiles, resulting in 32-aligned resolutions for the luminance plane
 	and 16-aligned resolutions for the chrominance plane (with 2x2
 	subsampling).
+    * .. _V4L2-PIX-FMT-QC8C:
+
+      - ``V4L2_PIX_FMT_QC8C``
+      - 'QC8C'
+      - Compressed Macro-tile 8Bit YUV420 format used by Qualcomm platforms.

8Bit -> 8-bit

quoted

+	The compression is lossless. It contains four planes.
+    * .. _V4L2-PIX-FMT-QC10C:
+
+      - ``V4L2_PIX_FMT_QC10C``
+      - 'QC10C'
+      - Compressed Macro-tile 10Bit YUV420 format used by Qualcomm platforms.

10Bit -> 10-bit

quoted

+	The compression is lossless. It contains four planes.

What is not clear from this description is if these formats are opaque, i.e. the
only way to decompress is through hardware, or if they can be decompressed in
software. If so, a reference to Qualcomm documentation would be useful. See e.g.
the V4L2_PIX_FMT_MT21C description (that's an opaque format).

Yes, the formats are opaque and can be decompressed by hardware blocks
only. I'll clear that in v2. Thanks for the review.

-- 
regards,
Stan