Regressed deinterlacing support as compared to i965-va-driver

[mamarley]

I have tried out media-driver 19.3.x on a few systems with Broadwell and Skylake CPUs (Specifically, HD Graphics 5500 and Iris 540) (reproduced with Linux 5.3, 5.4, and 5.5-rc) and have found that the hardware deinterlacing support doesn't work as well compared to the i965-va-driver. Here's what I have found:

1. If ENABLE_NONFREE_KERNELS=OFF is set, double-frame-rate deinterlacing doesn't work at all, resulting in 1080i30 content created from a 60FPS source playing jerkily at 30FPS instead of 60FPS as it did with the i965-va-driver. (The previous driver supported double-frame-rate even when the non-free features were disabled.) This is important for many news and sports broadcasts on 1080i ATSC channels.
2. If ENABLE_NONFREE_KERNELS=ON is set, double-frame-rate deinterlacing works only sometimes and with reduced quality compared to i965-va-driver. In VLC, the frame rate is always doubled, but the video seems subjectively fuzzier than with i965-va-driver and horizontal lines seem to "shimmer" up and down. In Kodi, it seems to alternate between no frame rate doubling (resulting in 30FPS) and the degraded frame rate doubling as I saw in VLC every few seconds at random intervals.

I apologize for not including any more information with this report, but there doesn't seem to be anything relevant in the logging output from either application and I'm not sure what else would be helpful. I will certainly provide any requested information though. Thanks!

[XinfengZhang]

thanks reporting, one question: are you using Bob DI or some advance DI?

[mamarley]

VLC doesn't seem to give me an option, but with Kodi I have tried both Bob and Motion-Adaptive and I see the same results with both.

[XinfengZhang]

@FurongZhang , @Jister could you help to check it

[yasij]

I noticed the same issue. I just tested 19.4.0r on Coffee Lake with ENABLE_NONFREE_KERNELS=ON . Motion Adaptive deinterlace looks exactly the same as Bob in Kodi. I notice the flickering line at the top of the screen. Motion-Compensated deinterlacing is not available. i965-va-driver presents Bob, Motion-Adaptive and Motion-Compensated. Motion-Adaptive and Motion-Compensated look much better, and don't have he characteristic Bob artifacts that intel-media-driver does.

[Jister]

Hi, @mamarley @yasij , could you please provide your test clip and reproducing steps so that we can reproduce the issue

[mamarley]

I have an example file, but it is too large to upload here. Is there any place you would prefer me to put it?

[yasij]

Here's a clip from a recording that shows the issue. I just took the first 6 MiB of the TS file:
sampledeint.ts.gz

Reproduction steps:
gunzip sampledeint.ts.gz
env LIBVA_DRIVER_NAME=iHD mpv --fs --hwdec=vaapi --vf=vavpp:deint=motion-adaptive sampledeint.ts

Look at the text. Notice that it bobs up and down like bob deinterlace
Now play it with the i965 driver:
mpv --fs --hwdec=vaapi --vf=vavpp:deint=motion-adaptive sampledeint.ts
The text doesn't not bob with i965.

i965 with the VAAPI bob deinterlacer
mpv --fs --hwdec=vaapi --vf=vavpp:deint=bob sampledeint.ts
The text bobs like iHD with the motion-adaptive filter.

The hardware is Intel Core i7-8700K UHD Graphics 630.

[yasij]

This might be the same issue as #640 . However, that one mentions that the reference frames aren't passed in VAProcPipelineParameterBuffer. I checked mpv, kodi and gstreamer. All of them are passing reference frames in VAProcPipelineParameterBuffer.

[yasij]

media_libva.h#L82

The driver defines DDI_CODEC_NUM_BK_REF and DDI_CODEC_NUM_FWD_REF as 0. That's why the reference frames aren't passed. The driver reports that max number of FWD and BK references as 0 in DdiMedia_QueryVideoProcPipelineCaps.

[Jister]

Hi, @yasij , I add the correct reference number in #820 , could you help to try the patch? Thanks

[mamarley]

This doesn't seem to have any effect for me. I still get 60fps with shimmering in VLC and alternating between 30fps and 60fps with no option for motion-compensated deinterlacing in Kodi.

[Jister]

Hi, @mamarley , I update #820 , could you help to have a try again? Thanks.