[PATCH 00/14] media: Add V4L2 H.264 stateless encode and VC8000E support

[Michael Nazzareno Trimarchi]

Hi

On Fri, May 22, 2026 at 4:55 PM Nicolas Dufresne
<nicolas.dufresne at collabora.com> wrote:
>
> Hi Paul,
>
> Le vendredi 22 mai 2026 à 12:16 +0200, Paul Kocialkowski a écrit :
> > This series introduces support for the V4L2 H.264 stateless encode uAPI,
> > core and support in the hantro driver for the Verisilicon VC8000E.
> >
> > While this is a first version that will likely need some level of rework,
> > it is already usable for most common use-cases and supports constant
> > bitrate rate-control.
> >
> > A GStreamer tree can be used to test the series at:
> > https://github.com/paulkocialkowski/gstreamer/tree/v4l2codecs/h264enc
> > And an example pipeline would look like:
> > gst-launch-1.0 videotestsrc pattern=smpte num-buffers=25 ! video/x-raw,width=640,height=480 ! v4l2slh264enc rate-control=cbr bitrate=8000000 qp-min=8 qp-max=42 ! h264parse ! matroskamux ! filesink location=encode.mkv
> >
> > Note that documentation for the new uAPI is intentionally left out of
> > this series since it has not yet received approval.
>
> The unfortunate part is that the spec is important for the actual review and
> interops analyses. That omission qualify this submission as RFC from my point of
> view. Any chances you can reply to this cover filling the blank for the few
> important bit (something similar but non spec style of:
>
> https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/dev-stateless-decoder.html#initialization
>
> - Querying capabilities
> - Initialization
> - Encoding
> - Dynamic Resolution Changes**
>
> The other sections are just going to be the same imho. The ** for the DRC is
> because H.264 is not that complicated, its intra only, so you can reset the
> encoder (use the drain flow). So that's probably something for future us
> (VP9/AV1). Adding your view on these topics (or just matching what you have
> implemented) will make review more constructive.
>
> cheers,
> Nicolas
>
> >
> > Marco Felsch (2):
> >   media: hantro: use hantro_decoded_buffer only for dst_vq
> >   arm64: dts: imx8mp: add VC8000E encoder node
> >
> > Paul Kocialkowski (12):
> >   media: h264: Add a more generic reflist builder init
> >   media: uapi: Add H.264 stateless encode support
> >   media: h264: Add SPS video definitions
> >   media: h264: Add stateless encode core
> >   media: h264: Add stateless encode rbsp
> >   media: h264: Add stateless encode reference management
> >   media: h264: Add stateless encode rate control
> >   media: verisilicon: Report default pixel coding for non-JPEG and fix JPEG case
> >   media: verisilicon: Cancel job with runtime pm put/clk disable on failure
> >   media: verisilicon: Add common encoder parm and frameintervals ioctls
> >   media: verisilicon: Add support for the VC8000E H.264 encoder
> >   media: verilisicon: imx8m: Add support for the VC8000E on i.MX8MP
> >
> >  arch/arm64/boot/dts/freescale/imx8mp.dtsi     |   11 +
> >  drivers/media/platform/verisilicon/Kconfig    |    1 +
> >  drivers/media/platform/verisilicon/Makefile   |    2 +
> >  drivers/media/platform/verisilicon/hantro.h   |   17 +
> >  .../media/platform/verisilicon/hantro_drv.c   |  180 +-
> >  .../media/platform/verisilicon/hantro_h264.c  |    6 +-
> >  .../media/platform/verisilicon/hantro_hw.h    |   28 +
> >  .../media/platform/verisilicon/hantro_v4l2.c  |  123 +-
> >  .../platform/verisilicon/hantro_vc8000e.c     |   68 +
> >  .../verisilicon/hantro_vc8000e_h264_enc.c     |  883 +++++++
> >  .../verisilicon/hantro_vc8000e_regs.h         | 2129 +++++++++++++++++
> >  .../media/platform/verisilicon/imx8m_vpu_hw.c |  113 +
> >  drivers/media/v4l2-core/Kconfig               |    4 +
> >  drivers/media/v4l2-core/Makefile              |    2 +
> >  drivers/media/v4l2-core/v4l2-ctrls-core.c     |   62 +
> >  drivers/media/v4l2-core/v4l2-ctrls-defs.c     |    4 +
> >  drivers/media/v4l2-core/v4l2-h264-enc-rbsp.c  | 1173 +++++++++
> >  drivers/media/v4l2-core/v4l2-h264-enc-rc.c    |  558 +++++
> >  drivers/media/v4l2-core/v4l2-h264-enc.c       | 1322 ++++++++++
> >  drivers/media/v4l2-core/v4l2-h264.c           |   69 +
> >  include/media/v4l2-ctrls.h                    |    2 +
> >  include/media/v4l2-h264-enc-rbsp.h            |   72 +
> >  include/media/v4l2-h264-enc-rc.h              |  108 +
> >  include/media/v4l2-h264-enc.h                 |  135 ++
> >  include/media/v4l2-h264.h                     |  146 ++
> >  include/uapi/linux/v4l2-controls.h            |   33 +
> >  include/uapi/linux/videodev2.h                |    1 +
> >  27 files changed, 7231 insertions(+), 21 deletions(-)
> >  create mode 100644 drivers/media/platform/verisilicon/hantro_vc8000e.c
> >  create mode 100644 drivers/media/platform/verisilicon/hantro_vc8000e_h264_enc.c
> >  create mode 100644 drivers/media/platform/verisilicon/hantro_vc8000e_regs.h
> >  create mode 100644 drivers/media/v4l2-core/v4l2-h264-enc-rbsp.c
> >  create mode 100644 drivers/media/v4l2-core/v4l2-h264-enc-rc.c
> >  create mode 100644 drivers/media/v4l2-core/v4l2-h264-enc.c
> >  create mode 100644 include/media/v4l2-h264-enc-rbsp.h
> >  create mode 100644 include/media/v4l2-h264-enc-rc.h
> >  create mode 100644 include/media/v4l2-h264-enc.h

I tested on px30 and achieved working H.264 encoding with some small changes

Michael