Hi Jonas,

On Tue Aug 12, 2025 at 7:11 PM CEST, Jonas Karlman wrote:

On 8/12/2025 2:11 PM, Diederik de Haas wrote:

quoted

On Sun Aug 10, 2025 at 11:24 PM CEST, Jonas Karlman wrote:

quoted

This series add a HEVC backend to the Rockchip Video Decoder driver.

With the dependent H.264 High 10 and 4:2:2 profile support series
finally merged there is finally time to send a v2 with minor changes and
a suggested code style fix of this series. v1 of this series has been
fully functional up until recent unstaging of the rkvdec driver.

Patch 1 add the new HEVC backend.
Patch 2-3 add variants support to the driver.
Patch 4 add support for a rk3288 variant.
Patch 5 add a rk3328 variant to work around hw quirks.
Patch 6-7 add device tree node for rk3288.

It looks like I had a previous version of linuxtv-rkvdec-hevc-v2 branch
locally and that also had this commit:
- media: rkvdec: Keep decoder clocks gated

Is that one no longer needed/useful/etc ?

I do not think it is, could possible be to keep power consumption at
minimum while decoding. Some parts enable auto gating and then we
disable it when decoding is complete. With auto-suspend the entire block
is disabled anyway so this probably did not make any noticeable
difference and could instead introduce new possible issues.

Makes sense, thanks.
 

quoted

And 'chewitt' also had a commit to fix 8/10-bit selection:
https://github.com/chewitt/linux/commit/4b93b05d2ca608bc23f1d52bcc32df926d435c7c
"WIP: media: rkvdec: fix 8-bit/10-bit format selection"

I haven't tried that one (yet), but did  try an other variant with
changing the ordering in rkvdec_hevc_decoded_fmts but that didn't work
in my tests. (Can ofc be PEBKAC)

The format selection in kernel for this series should be correct,
however to ensure 10-bit works you need following for ffmpeg-v4l2request
to select and use 10-bit pixel formats:

libdrm 2.4.104+ (NV15) / 2.4.118+ (NV20)
- 10-bit drm formats, ffmpeg v4l2request test with a #ifdef

linux headers v6.16-rc1+ (NV15/NV20)
- 10-bit v4l2 pix fmt, ffmpeg v4l2request test with a #ifdef

FFmpeg v4l2request will not negotiate use of 10-bit formats without
DRM_FORMAT_NV15/NV20 and V4L2_PIX_FMT_NV15/NV20 defined when ffmpeg was
compiled.

That would be the most likely issue if only 8-bit formats is working.

Thanks so much for the detailed explanation with which I can check where
my stack wasn't doing what I hoped it would :-)

quoted

Would that be useful? I do/did have consistent problems with playing
10-bit encoded video files.

Looking quickly at the 'fix 8/10-bit selection' commit the issue is that
rkvdec_hevc_get_image_fmt() was incomplete to begin with. The
rkvdec_hevc_get_image_fmt() in this series has been correct since v1.

Thanks :)

Cheers,
  Diederik