Artefacs on sandy bridge using vaapi driver

[max5962]

Hello,

I'm trying to make plex working with my i7 sandy bridge graphic hardware :

vainfo :

libva info: VA-API version 1.1.0
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_1_1
libva info: va_openDriver() returns 0
vainfo: VA-API version: 1.1 (libva 2.1.0)
vainfo: Driver version: Intel i965 driver for Intel(R) Sandybridge Mobile - 2.1.0
vainfo: Supported profile and entrypoints
      VAProfileMPEG2Simple            : VAEntrypointVLD
      VAProfileMPEG2Main              : VAEntrypointVLD
      VAProfileH264ConstrainedBaseline: VAEntrypointVLD
      VAProfileH264ConstrainedBaseline: VAEntrypointEncSlice
      VAProfileH264Main               : VAEntrypointVLD
      VAProfileH264Main               : VAEntrypointEncSlice
      VAProfileH264High               : VAEntrypointVLD
      VAProfileH264High               : VAEntrypointEncSlice
      VAProfileH264StereoHigh         : VAEntrypointVLD
      VAProfileVC1Simple              : VAEntrypointVLD
      VAProfileVC1Main                : VAEntrypointVLD
      VAProfileVC1Advanced            : VAEntrypointVLD
      VAProfileNone                   : VAEntrypointVideoProc

plex logs :

Jul 29, 2018 18:20:21.415 [0x7fe8bafff700] DEBUG - Codecs: hardware transcoding: testing API vaapi
Jul 29, 2018 18:20:21.415 [0x7fe8bafff700] VERBOSE - [FFMPEG] - Opened VA display via DRM device /dev/dr
i/renderD128.
Jul 29, 2018 18:20:21.415 [0x7fe8bafff700] VERBOSE - [FFMPEG] - libva: VA-API version 1.1.0
Jul 29, 2018 18:20:21.415 [0x7fe8bafff700] VERBOSE - [FFMPEG] - libva: va_getDriverName() returns 0
Jul 29, 2018 18:20:21.415 [0x7fe8bafff700] VERBOSE - [FFMPEG] - libva: Trying to open /usr/lib/plexmedia
server/dri/i965_drv_video.so
Jul 29, 2018 18:20:21.415 [0x7fe8bafff700] VERBOSE - [FFMPEG] - libva: Found init function __vaDriverIni
t_1_1
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] VERBOSE - [FFMPEG] - libva: va_openDriver() returns 0
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] VERBOSE - [FFMPEG] - Initialised VAAPI connection: version 1.
1
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] DEBUG - [FFMPEG] - Format 0x32315659 -> yuv420p.
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] DEBUG - [FFMPEG] - Format 0x30323449 -> yuv420p.
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] DEBUG - [FFMPEG] - Format 0x3231564e -> nv12.
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] DEBUG - [FFMPEG] - Format 0x32595559 -> yuyv422.
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] DEBUG - [FFMPEG] - Format 0x59565955 -> uyvy422.
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] DEBUG - [FFMPEG] - Format 0x48323234 -> yuv422p.
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] DEBUG - [FFMPEG] - Format 0x58424752 -> rgb0.
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] DEBUG - [FFMPEG] - Format 0x58524742 -> bgr0.
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] DEBUG - [FFMPEG] - Format 0x30313050 -> p010le.
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] VERBOSE - [FFMPEG] - Matched "Intel i965 driver for Intel(R) 
Sandybridge Mobile - 2.1.0" as known driver "Intel i965 (Quick Sync)".
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] DEBUG - [FFMPEG] - Created surface 0x4000000.
Jul 29, 2018 18:20:21.416 [0x7fe8bafff700] DEBUG - [FFMPEG] - Direct mapping possible.

Processus Transcode :

/usr/lib/plexmediaserver/Plex Transcoder -codec:0 h264 -hwaccel:0 vaapi -hwaccel_fallback_threshold:0 10 -hwaccel_output_format:0 vaapi -codec:1 ac3 -i /media/data/Video/FILE.mkv -filter_complex [0:0]hwupload[0];[0]scale_vaapi=w=720:h=406:format=nv12[1];[1]hwupload[2] -filter_complex [0:1] aresample=async=1:ocl='stereo':osr=48000[3] -map [2] -metadata:s:0 language=eng -codec:0 h264_vaapi -b:0 1293k -maxrate:0 1724k -bufsize:0 3448k -r:0 23.975999999999999 -force_key_frames:0 expr:gte(t,0+n_forced*8) -map [3] -metadata:s:1 language=fre -codec:1 aac -b:1 162k -f dash -min_seg_duration 8000000 -skip_to_segment 1 -time_delta 0.0625 -manifest_name http://127.0.0.1:32400/video/:/transcode/session/4d12gjs700eqw9wfj9bfdk8g/d2198c2d-2720-4d9d-90dd-e35bbf0e2a66/manifest -avoid_negative_ts disabled -map_metadata -1 -map_chapters -1 dash -start_at_zero -copyts -vsync cfr -y -vaapi_device /dev/dri/renderD128 -nostats -loglevel quiet -loglevel_plex error -progressurl http://127.0.0.1:32400/video/:/transcode/session/4d12gjs700eqw9wfj9bfdk8g/d2198c2d-2720-4d9d-90dd-e35bbf0e2a66/progress

Results :

According Plex engineer, artefact is due to bad optimisation for Sandy bridge hardware. So many people still using sandy bridge specialy for plex, so they don't want to help....

There is a way to improve the quality of the playback ?

Thanks in advance.
Maxime

[ValdikSS]

Here's a report from 2015, nothing changed since then.
https://bugs.freedesktop.org/show_bug.cgi?id=92075
And another one:
https://bugzilla.gnome.org/show_bug.cgi?id=751885

This looks like vaapi bug as there's no such problem on Windows with MediaCoder or Handbrake, both of which also use hardware encoding.

Here's what I get with Intel Sandy Bridge HD3000 and gstreamer when trying to encode H.264 3000 kbit/s, on Fedora 28, kernel 4.18.13-200.fc28.x86_64, libva-intel-driver-2.1.0-2.fc28.x86_64, libva-2.1.0-1.fc28.x86_64

ftp://serv.valdikss.org.ru/Downloads/Temp/bake-cbr-3000.mkv

gst-launch-1.0 -ve filesrc location=\[ANE\]\ Bakemonogatari\ -\ Ep03\ Creditless\ Opening\ \[BDRip\ 1080p\ x264\ FLAC\].mkv ! matroskademux ! avdec_h264 ! videoconvert ! video/x-raw,format=NV12 ! vaapih264enc rate-control=cbr bitrate=3000 ! h264parse ! matroskamux ! progressreport ! filesink location=bake-cbr-3000.mkv

Increasing bitrate up to 10 Mbit/s does not dramatically change the quality, there are still these strange stripes in the video.

[max5962]

UP :-)