[PATCH v5 0/2] media: cedrus: Add H264 decoding support

From: Maxime Ripard
Date: Thu Mar 07 2019 - 08:20:11 EST


Here is a new version of the H264 decoding support in the cedrus

As you might already know, the cedrus driver relies on the Request
API, and is a reverse engineered driver for the video decoding engine
found on the Allwinner SoCs.

This work has been possible thanks to the work done by the people
behind libvdpau-sunxi found here:

I've tested the various ABI using this gdb script:

And this test script:

The application compiled is quite trivial:

The output is:
arm: builds/arm-test-v4l2-h264-structures
SHA1: fd15b30328765c2caac877e8ea8452c829b2b1d8
x86: builds/x86-test-v4l2-h264-structures
SHA1: fd15b30328765c2caac877e8ea8452c829b2b1d8
x64: builds/x64-test-v4l2-h264-structures
SHA1: fd15b30328765c2caac877e8ea8452c829b2b1d8
arm64: builds/arm64-test-v4l2-h264-structures
SHA1: fd15b30328765c2caac877e8ea8452c829b2b1d8

Let me know if there's any flaw using that test setup, or if you have
any comments on the patches.


Changes from v4:
- Changed the luma and chroma weight and offset from s8 to s16
- Adjusted chroma and luma denominators masks in the driver
- Casted the luma and chroma offset to prevent an overflow
- ALways write the interrupt status register
- Fix a bug in the sram write routine that would write something even if
the length was 0
- Make the scaling lists mandatory
- Made the reference list order explicit in the documentation
- Made the fact that the slice structure can be an array
- Renamed the slice format to V4L2_PIX_FMT_H264_SLICE_RAW
- Rebased on Hans' tag br-v5.1s

Changes from v3:
- Reintroduced long term reference flag and documented it
- Reintroduced ref_pic_list_p0/b0/b1 and documented it
- Documented the DPB flags
- Treat the scaling matrix as optional in the driver, as documented
- Free the neighbor buffer
- Increase the control IDs by a large margin to be safe of collisions
- Reorder the fields documentation according to the structure layout
- Change the tag documentation by the timestamp
- Convert the sram array to size_t
- Simplify the buffer retrieval from timestamp
- Rebase

Changes from v2:
- Simplified _cedrus_write_ref_list as suggested by Jernej
- Set whether the frame is used as reference using nal_ref_idc
- Respect chroma_format_idc
- Fixes for the scaling list and prediction tables
- Wrote the documentation for the flags
- Added a bunch of defines to the driver bit fields
- Reworded the controls and data format descriptions as suggested
by Hans
- Reworked the controls' structure field size to avoid padding
- Removed the long term reference flag
- Reintroduced the neighbor info buffer
- Removed the ref_pic_list_p0/b0/b1 arrays that are redundant with the
one in the DPB
- used the timestamps instead of tags
- Rebased on 5.0-rc1

Changes from v1:
- Rebased on 4.20
- Did the documentation for the userspace API
- Used the tags instead of buffer IDs
- Added a comment to explain why we still needed the swdec trigger
- Reworked the MV col buffer in order to have one slot per frame
- Removed the unused neighbor info buffer
- Made sure to have the same structure offset and alignments across
32 bits and 64 bits architecture

Maxime Ripard (1):
media: cedrus: Add H264 decoding support

Pawel Osciak (1):
media: uapi: Add H264 low-level decoder API compound controls.

Documentation/media/uapi/v4l/biblio.rst | 9 +-
Documentation/media/uapi/v4l/ext-ctrls-codec.rst | 549 +++++++++++++-
Documentation/media/uapi/v4l/pixfmt-compressed.rst | 19 +-
Documentation/media/uapi/v4l/vidioc-queryctrl.rst | 30 +-
Documentation/media/videodev2.h.rst.exceptions | 5 +-
drivers/media/v4l2-core/v4l2-ctrls.c | 42 +-
drivers/media/v4l2-core/v4l2-ioctl.c | 1 +-
drivers/staging/media/sunxi/cedrus/Makefile | 3 +-
drivers/staging/media/sunxi/cedrus/cedrus.c | 31 +-
drivers/staging/media/sunxi/cedrus/cedrus.h | 38 +-
drivers/staging/media/sunxi/cedrus/cedrus_dec.c | 13 +-
drivers/staging/media/sunxi/cedrus/cedrus_h264.c | 577 ++++++++++++++-
drivers/staging/media/sunxi/cedrus/cedrus_hw.c | 4 +-
drivers/staging/media/sunxi/cedrus/cedrus_regs.h | 91 ++-
drivers/staging/media/sunxi/cedrus/cedrus_video.c | 9 +-
include/media/h264-ctrls.h | 190 +++++-
include/media/v4l2-ctrls.h | 13 +-
include/uapi/linux/videodev2.h | 1 +-
18 files changed, 1622 insertions(+), 3 deletions(-)
create mode 100644 drivers/staging/media/sunxi/cedrus/cedrus_h264.c
create mode 100644 include/media/h264-ctrls.h

base-commit: ae95367b7a685b0b8659494dabb4b494e87b467d
git-series 0.9.1