Re: [PATCH v2 0/4] media: HEVC: RPS clean up

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Le 15/10/2021 à 16:14, Alex Bee a écrit :

Am 15.10.21 um 16:06 schrieb Benjamin Gaignard:

Le 15/10/2021 à 12:33, Alex Bee a écrit :
Hi Benjamin, Jernej
Am 12.10.21 um 18:08 schrieb Jernej Škrabec:
CC: Alex Bee

Alex, please take a look to these patches too.
These patches don't remove anything that would be need for rkvdec hevc - but indeed - we need some more: https://github.com/LibreELEC/LibreELEC.tv/blob/master/projects/Rockchip/patches/linux/default/linux-2001-v4l-wip-rkvdec-hevc.patch#L242-L305

v4l2_ctrl_hevc_sps:
__u8    video_parameter_set_id
__u8    seq_parameter_set_id

v4l2_ctrl_hevc_pps:
__u8    pic_parameter_set_id
__u16    short_term_ref_pic_set_size
__u16    long_term_ref_pic_set_size

As far as I can see, they are all part of the spec and should be therefore good to go in the uapi.

Do you have any plan to upstream these fields in HEVC uAPI ?

I might be upstreaming them at some point, yes.

With this I just wanted to underline Jernej said: HEVC uapi is NOT ready
to get unstaged yet.

Ok but the question is how to get it unstaged ?
Should we continue to do changes in staged uAPI ?
or send a RFC to move it to stable and review all the missing parts at that time ?

Regards,
Benjamin



Regards,
Benjamin


As you might now, even rkvdec is a frame-based decoder, it doesn't fully parse slice headers in HW for HEVC and we need to set references in SW which requires looping over the slices. Downstream we have a hack to give num_slices in v4l2_ctrl_hevc_sps for doing that. That could fully go away, if V4L2_CID_MPEG_VIDEO_HEVC_SLICE_PARAMS could get dynamic array control support and would make upstreaming this a lot easier - as far as I'm concered this would be required for RPi HEVC decoder as well.
As a last resort we could also implement a HW specifc control à la
V4L2_CID_HANTRO_HEVC_SLICE_HEADER_SKIP - but I'd like to avoid that, knowing it would certainly be better from performance pov.

Alex.

Dne torek, 12. oktober 2021 ob 17:57:50 CEST je Benjamin Gaignard napisal(a):

Le 12/10/2021 à 17:34, Jernej Škrabec a écrit :
Hi Benjamin!

Dne torek, 12. oktober 2021 ob 16:35:48 CEST je Benjamin Gaignard
napisal(a):
This series aims to clean up Reference Picture Set usage and flags.

Long term flag was named with RPS prefix while it is not used for RPS but for mark long term references in DBP. Remane it and remove the two
other useless RPS flags.

Clarify documentation about RPS lists content and make sure that Hantro
driver use them correctly (i.e without look up in DBP).

These patches are the last in my backlog impacting HEVC uAPI.
  From my point of view, once they get merged, you could start talking
about how move HEVC uAPI to stable.
With your changes, HEVC uAPI controls still won't be complete. Cedrus
needs
entry point control, which in turn needs dynamic array support. I'm a bit
lazy
implementing that control, but I guess I can take a look in a month or so.
rkvdec also needs more fields for HEVC. With patches collected here:
https://github.com/LibreELEC/LibreELEC.tv/blob/master/projects/Rockchip/
patches/linux/default/linux-2001-v4l-wip-rkvdec-hevc.patch
fluster HEVC test score is reportedly 121/135 (8-bit tests only).

Hi Jernej,

Thanks for your feedback, getting a list of missing items in HEVC uAPI
will definitively help to fill the hope.
The patch you mention for rkvdec are already merged in mainline kernel (at
least for uAPI part).

Are they? What about:
video_parameter_set_id
seq_parameter_set_id
pic_parameter_set_id
short_term_ref_pic_set_size
long_term_ref_pic_set_size

At least I don't see them in linux-next. Maybe that information can be
obtained in some other way?

Cedrus needs are about num_entry_point_offsets, offset_len_minus1 and
entry_point_offset_minus1[ i ]
in HEVC specifications ?

Yes, Cedrus needs to know whole list of entry points. I don't think we need to worry about offset_len_minus1, list could be pre-processed - just number of
entry points and their values.

Best regards,
Jernej


Regards,
Benjamin


I would certainly wait with moving HEVC uAPI to stable.

Best regards,
Jernej

version 2:
- change DPB field name from rps to flags

Please note that the only purpose of commits 3 and 4 is to allow to test G2 hardware block for IMX8MQ until a proper solution isuing power domain
can be found. Do not merge them.

GStreamer HEVC plugin merge request can be found here:
https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1079

With those piece of code fluster score is 77/147.

Benjamin

Benjamin Gaignard (4):
    media: hevc: Remove RPS named flags
    media: hevc: Embedded indexes in RPS
    media: hantro: Use syscon instead of 'ctrl' register
    arm64: dts: imx8mq: Add node to G2 hardware

   .../media/v4l/ext-ctrls-codec.rst             | 14 +++---
   arch/arm64/boot/dts/freescale/imx8mq.dtsi     | 43 +++++++++++++----
   drivers/staging/media/hantro/hantro.h         |  5 +-
   .../staging/media/hantro/hantro_g2_hevc_dec.c | 27 +++--------
   drivers/staging/media/hantro/imx8m_vpu_hw.c   | 48 ++++++++++++-------
   .../staging/media/sunxi/cedrus/cedrus_h265.c  |  2 +-
   include/media/hevc-ctrls.h                    |  6 +--
   7 files changed, 84 insertions(+), 61 deletions(-)

--
2.30.2










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