Le vendredi 26 juillet 2019 à 12:02 +0200, Hans Verkuil a écrit : > On 7/26/19 11:56 AM, Chen-Yu Tsai wrote: > > On Fri, Jul 26, 2019 at 5:50 PM Maxime Jourdan <mjourdan@xxxxxxxxxxxx> wrote: > > > On Wed, Jul 24, 2019 at 1:27 PM Hans Verkuil <hverkuil-cisco@xxxxxxxxx> wrote: > > > > (There were too many recipients for my provider, so resending > > > > again without the zillion CCs, and in batches of 5 patches. Stupid > > > > spammer detection...) > > > > > > > > This series consolidates various patches/patch series that add > > > > features or document memory-to-memory video codec interfaces. > > > > > > > > This includes patches adding V4L2_FMT_FLAG_DYN_RESOLUTION, > > > > new code adding V4L2_FMT_FLAG_HAS_BITSTREAM_PARSER, new code > > > > adding V4L2_DEC_CMD_FLUSH, patches adding V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF > > > > (now with documentation) and patches documenting the stateful > > > > encoder/decoder and stateless decoder. > > > > > > > > The stateful encoder documentation is still RFC quality (there are > > > > open TODOs, see https://patchwork.kernel.org/cover/10972783/). > > > > > > > > The stateless decoder documentation is the same as the v5 posted > > > > by Alexandre, but with my comments incorporated. > > > > > > > > Also added are updated pixelformat descriptions. Please review this! > > > > I didn't update the MPEG4 format since I'm not sure what to put there. > > > > > > > > If anyone has access to recent codec standards, then I would really > > > > like to have the right references to 'MPEG Picture' and 'Access Unit'. > > > > It would be good to just refer to the definition of what a Picture > > > > or Access Unit is in the right standards. > > > > > > > > Changes for the stateful decoder documentation since v4: > > > > > > > > - In the Decoding section change "multiple ``OUTPUT`` buffers generate > > > > one ``CAPTURE`` buffer: timestamp of the ``OUTPUT`` buffer queued last > > > > will be copied." to "queued first" since this corresponds to > > > > existing implementations. > > > > > > > > - Document that width and height are required fields in step 4 of the > > > > Capture Setup. > > > > > > > > - Mention the new ENUM_FMT flags. > > > > > > > > Changes for the stateless decoder documentation since v5: > > > > > > > > - Document that width and height are required fields in step 4 of the > > > > Capture Setup. > > > > > > > > - Mention the new V4L2_DEC_CMD_FLUSH command to flush the last held > > > > capture buffer. This replaces the 'queue an empty buffer' solution. > > > > > > > > In my view this series is ready to go in, except for the last patch > > > > (stateful encoder). > > > > > > > > Maxime, I didn't add the proposed V4L2_FMT_FLAG_MANUAL_RESOLUTION > > > > flag since I think that can go in separately. I also am not 100% > > > > happy with that name, although I can't think of a better one. > > > > > > > > > > Sure! I can prepare an RFC once this series lands if you wish. > > > > > > > Regards, > > > > > > > > Hans > > > > > > > > Alexandre Courbot (1): > > > > media: docs-rst: Document m2m stateless video decoder interface > > > > > > > > Hans Verkuil (6): > > > > v4l2-ioctl.c: OR flags in v4l_fill_fmtdesc(), not don't overwrite > > > > videodev2.h: add V4L2_FMT_FLAG_HAS_BITSTREAM_PARSER > > > > videodev2.h.rst.exceptions: tymecode -> timecode > > > > vb2: add V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF > > > > videodev2.h: add V4L2_DEC_CMD_FLUSH > > > > pixfmt-compressed.rst: improve H264/HEVC/MPEG1+2/VP8+9 documentation > > > > > > > > Maxime Jourdan (5): > > > > videodev2.h: add V4L2_FMT_FLAG_DYN_RESOLUTION > > > > media: venus: vdec: flag OUTPUT formats with > > > > V4L2_FMT_FLAG_DYN_RESOLUTION > > > > media: s5p_mfc_dec: set flags for OUTPUT coded formats > > > > media: mtk-vcodec: flag OUTPUT formats with > > > > V4L2_FMT_FLAG_DYN_RESOLUTION > > > > media: vicodec: set flags for vdec/stateful OUTPUT coded formats > > > > > > > > Tomasz Figa (2): > > > > media: docs-rst: Document memory-to-memory video decoder interface > > > > media: docs-rst: Document memory-to-memory video encoder interface > > > > > > > > Documentation/media/uapi/v4l/buffer.rst | 13 + > > > > Documentation/media/uapi/v4l/dev-decoder.rst | 1101 +++++++++++++++++ > > > > Documentation/media/uapi/v4l/dev-encoder.rst | 608 +++++++++ > > > > Documentation/media/uapi/v4l/dev-mem2mem.rst | 10 +- > > > > .../media/uapi/v4l/dev-stateless-decoder.rst | 424 +++++++ > > > > .../media/uapi/v4l/pixfmt-compressed.rst | 36 +- > > > > Documentation/media/uapi/v4l/pixfmt-v4l2.rst | 10 + > > > > Documentation/media/uapi/v4l/v4l2.rst | 12 +- > > > > .../media/uapi/v4l/vidioc-decoder-cmd.rst | 52 +- > > > > .../media/uapi/v4l/vidioc-dqevent.rst | 11 +- > > > > .../media/uapi/v4l/vidioc-encoder-cmd.rst | 51 +- > > > > .../media/uapi/v4l/vidioc-enum-fmt.rst | 16 + > > > > .../media/uapi/v4l/vidioc-reqbufs.rst | 6 + > > > > .../media/videodev2.h.rst.exceptions | 7 +- > > > > .../media/common/videobuf2/videobuf2-v4l2.c | 8 +- > > > > .../platform/mtk-vcodec/mtk_vcodec_dec.c | 4 + > > > > .../platform/mtk-vcodec/mtk_vcodec_drv.h | 1 + > > > > drivers/media/platform/qcom/venus/core.h | 1 + > > > > drivers/media/platform/qcom/venus/vdec.c | 11 + > > > > .../media/platform/s5p-mfc/s5p_mfc_common.h | 1 + > > > > drivers/media/platform/s5p-mfc/s5p_mfc_dec.c | 18 + > > > > drivers/media/platform/vicodec/vicodec-core.c | 3 + > > > > drivers/media/v4l2-core/v4l2-ioctl.c | 2 +- > > > > include/media/v4l2-mem2mem.h | 42 + > > > > include/media/videobuf2-core.h | 3 + > > > > include/media/videobuf2-v4l2.h | 5 + > > > > include/uapi/linux/videodev2.h | 20 +- > > > > 27 files changed, 2419 insertions(+), 57 deletions(-) > > > > create mode 100644 Documentation/media/uapi/v4l/dev-decoder.rst > > > > create mode 100644 Documentation/media/uapi/v4l/dev-encoder.rst > > > > create mode 100644 Documentation/media/uapi/v4l/dev-stateless-decoder.rst > > > > > > > > -- > > > > 2.20.1 > > > > > > > > > > Thank you for including my series with your modifications on top. > > > > > > The patches regarding stateful decoders are fine by me. To nitpick, I > > > would maybe rename V4L2_FMT_FLAG_HAS_BITSTREAM_PARSER to something > > > such as: > > > - V4L2_FMT_FLAG_FLEXIBLE_BITSTREAM_PARSER > > > - V4L2_FMT_FLAG_PERMISSIVE_BITSTREAM_PARSER > > > > > > Since by definition a stateful decoder is able to parse the bitstream, > > > it could be a bit confusing to see a format without > > > V4L2_FMT_FLAG_HAS_BITSTREAM_PARSER, something actually quite common. > > > But it is all well explained in the format documentation (patch 11/14) > > > and is of low-ish importance, so I don't really mind either. > > > > Out of curiosity, would the new flags mean people have to update > > userspace applications to check for them? I mean, stateful decoders > > already "just work" right now, don't they? At least that was my > > impression playing with the out-of-tree bcm2835-codec. > > Kind of. Some stateful codecs still require userspace to do some > preparsing and give them buffers containing the Access Unit (H264). > This is what e.g. gstreamer and ffmpeg do, and so that works. But such > drivers can't handle the case where you just feed them a raw bitstream, > and that was never documented. > > So we're tightening the spec reflecting what is actually used. And adding > a new flag to tell userspace that there is a full parser so you don't > have to split up the bitstream. On top of this, V4L2_FMT_FLAG_DYN_RESOLUTION is what will allow adding support for CODEC driven resolution change, and CODEC driven sync detection. This should make things a little more robust and eventually should also allow gapless resolution changes. At the moment, in GStreamer we completely drain and stop the decoder whenever a resolution change is detected which introduce a long delay. With V4L2_FMT_FLAG_DYN_RESOLUTION enabled drivers, we'll be able to start queuing the encoded data for the new resolution in before the capture buffers are re-allocated. > > Regards, > > Hans
Attachment:
signature.asc
Description: This is a digitally signed message part
