Re: [PATCH v8 09/13] media: uapi: Add a control for HANTRO driver
From: Ezequiel Garcia <hidden>
Date: 2021-04-02 12:27:45
Also in:
linux-arm-kernel, linux-media, linux-rockchip, lkml
Hi Benjamin, Thanks for the patch. On Thu, 2021-04-01 at 17:59 +0200, Benjamin Gaignard wrote:
quoted hunk ↗ jump to hunk
The HEVC HANTRO driver needs to know the number of bits to skip at the beginning of the slice header. That is a hardware specific requirement so create a dedicated control that this purpose. Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com> --- version 5: - Be even more verbose in control documentation. - Do not create class for the control. version 4: - The control is now an integer which is enough to provide the numbers of bits to skip. version 3: - Fix typo in field name .../userspace-api/media/drivers/hantro.rst | 14 ++++++++++++++ .../userspace-api/media/drivers/index.rst | 1 + include/uapi/linux/v4l2-controls.h | 13 +++++++++++++ 3 files changed, 28 insertions(+) create mode 100644 Documentation/userspace-api/media/drivers/hantro.rstdiff --git a/Documentation/userspace-api/media/drivers/hantro.rst b/Documentation/userspace-api/media/drivers/hantro.rst new file mode 100644 index 000000000000..78dcd2a44a03 --- /dev/null +++ b/Documentation/userspace-api/media/drivers/hantro.rst@@ -0,0 +1,14 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Hantro video decoder driver +=========================== + +The Hantro video decoder driver implements the following driver-specific controls: + +``V4L2_CID_HANTRO_HEVC_SLICE_HEADER_SKIP (integer)`` + Specifies to Hantro HEVC video decoder driver the number of data (in bits) to + skip in the slice segment header. + If non-IDR, the bits to be skipped go from syntax element "pic_output_flag" + to before syntax element "slice_temporal_mvp_enabled_flag". + If IDR, the skipped bits are just "pic_output_flag" + (separate_colour_plane_flag is not supported).diff --git a/Documentation/userspace-api/media/drivers/index.rst b/Documentation/userspace-api/media/drivers/index.rst index 1a9038f5f9fa..12e3c512d718 100644 --- a/Documentation/userspace-api/media/drivers/index.rst +++ b/Documentation/userspace-api/media/drivers/index.rst@@ -33,6 +33,7 @@ For more details see the file COPYING in the source distribution of Linux.ccs cx2341x-uapi + hantro imx-uapi max2175 meye-uapidiff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h index f3376aafea65..1dfb874b6272 100644 --- a/include/uapi/linux/v4l2-controls.h +++ b/include/uapi/linux/v4l2-controls.h@@ -869,6 +869,19 @@ enum v4l2_mpeg_mfc51_video_force_frame_type {#define V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_STATIC (V4L2_CID_CODEC_MFC51_BASE+53) #define V4L2_CID_MPEG_MFC51_VIDEO_H264_NUM_REF_PIC_FOR_P (V4L2_CID_CODEC_MFC51_BASE+54) +/* MPEG-class control IDs specific to the Hantro driver as defined by V4L2 */
We are moving away from "MPEG" terminology for codecs.
+#define V4L2_CID_CODEC_HANTRO_BASE (V4L2_CTRL_CLASS_CODEC | 0x1200)
Using V4L2_CTRL_CLASS_CODEC_STATELESS is IMO better, since this belongs to a stateless decoder. And also, since we are still a bit unsure about the syntax of this parameter (given it's not documented): how about keeping the V4L2_CID_HANTRO_HEVC_SLICE_HEADER_SKIP definition in drivers/staging/media/hantro/hantro.h ? This would be a hint for applications that this control is a quirk. Hans, Philipp, any thoughts on this? Regards, Ezequiel