SOLVED: Bad transcoding performance using Intel UHD 770

[fl0wfr]

What is the output of this command?

Code:

sudo dmesg | grep i915

Unrelated, you should check "Enable tone mapping" and uncheck VPP tone mapping.  The OpenCL based tone mapping produces better results than VPP tone mapping.

Hi, there it is:

Code:

[    1.425485] i915 0000:00:02.0: [drm] VT-d active for gfx access
[    1.425543] i915 0000:00:02.0: vgaarb: deactivate vga console
[    1.425582] i915 0000:00:02.0: [drm] Using Transparent Hugepages
[    1.426222] i915 0000:00:02.0: vgaarb: VGA decodes changed: olddecodes=io+mem,decodes=io+mem:owns=io+mem
[    1.427763] i915 0000:00:02.0: [drm] Finished loading DMC firmware i915/adls_dmc_ver2_01.bin (v2.1)
[    2.384219] i915 0000:00:02.0: [drm] [ENCODER:235:DDI A/PHY A] failed to retrieve link info, disabling eDP
[    2.558032] i915 0000:00:02.0: [drm] GT0: GuC firmware i915/tgl_guc_70.bin version 70.36.0
[    2.558035] i915 0000:00:02.0: [drm] GT0: HuC firmware i915/tgl_huc.bin version 7.9.3
[    2.561053] i915 0000:00:02.0: [drm] GT0: HuC: authenticated for all workloads
[    2.561804] i915 0000:00:02.0: [drm] GT0: GUC: submission enabled
[    2.561805] i915 0000:00:02.0: [drm] GT0: GUC: SLPC enabled
[    2.562241] i915 0000:00:02.0: [drm] GT0: GUC: RC enabled
[    2.594121] [drm] Initialized i915 1.6.0 20230929 for 0000:00:02.0 on minor 0
[    2.658459] fbcon: i915drmfb (fb0) is primary device
[    2.728794] i915 0000:00:02.0: [drm] fb0: i915drmfb frame buffer device
[    5.210384] snd_hda_intel 0000:00:1f.3: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915])

This appears to be a slowdown caused by I/O. You can try the following command to rule out the problem.

Test QSV decoder:

Code:

/usr/lib/jellyfin-ffmpeg/ffmpeg -init_hw_device vaapi=va:/dev/dri/renderD128,driver=iHD -init_hw_device qsv=qs@va -filter_hw_device qs -hwaccel qsv -hwaccel_output_format qsv -noautorotate -c:v hevc_qsv -i file:"/media/data/Series/episode.mkv" -an -sn -f null -

Test QSV encoder:

Code:

/usr/lib/jellyfin-ffmpeg/ffmpeg -init_hw_device vaapi=va:/dev/dri/renderD128,driver=iHD -init_hw_device qsv=qs@va -filter_hw_device qs -f lavfi -i nullsrc=s=3840x1606,format=nv12 -c:v hevc_qsv -low_power 1 -preset veryfast -b:v 14616000 -maxrate 14616000 -bufsize 29232000 -profile:v main -level 50 -g:v 72 -keyint_min:v 72 -f null -

I don't see any bottleneck:

Code:

Linux 5.14.0-503.31.1.el9_5.x86_64 (bunker.fl0w.lan)    03/19/2025      _x86_64_        (32 CPU)

avg-cpu:  %user  %nice %system %iowait  %steal  %idle
          5.05    0.31    2.47    1.35    0.00  90.80

Device            tps    kB_read/s    kB_wrtn/s    kB_dscd/s    kB_read    kB_wrtn    kB_dscd
dm-0              6.42      296.53        21.10        0.00    350512      24945          0
dm-1              5.33      113.72        59.84        0.00    134418      70737          0
dm-2            386.78      9975.27      2180.59        0.00  11791366    2577590          0
md125            0.40        4.84        0.00        0.00      5716          0          0
md126          371.50    10387.48      2261.54        0.00  12278624    2673273          0
md127            0.20        3.71        0.01        0.00      4383        14          0
nvme0n1        340.35      7197.99      2275.79        0.00    8508459    2690122          0
nvme1n1        196.54      3200.39      2275.79        0.00    3783051    2690122          0
sda              0.62        9.24        1.73        0.00      10920      2048          0
sdb              1.61      519.25        1.73        0.00    613784      2048          0
sdc              1.85      563.72        1.73        0.00    666356      2048          0
sdd              3.01      1848.08        1.73        0.00    2184536      2048          0
sde              1.97      714.93        1.81        0.00    845084      2136          0
sdf              2.17      1269.86        1.73        0.00    1501052      2048          0
sdg              0.71        15.63        1.86        0.00      18472      2204          0
sdh              0.74        10.28        1.73        0.00      12156      2048          0
sdi              0.64        38.01        1.86        0.00      44928      2204          0
sdj              1.26      252.45        2.14        0.00    298408      2532          0

But yeah, not very quick...

Code:

frame= 5386 fps= 86 q=-0.0 Lsize=N/A time=00:03:44.68 bitrate=N/A speed=3.58x

Code:

frame=  650 fps= 27 q=-0.0 size=N/A time=00:00:25.84 bitrate=N/A speed=1.08x