[FFmpeg-trac] #9377(undetermined:new): QSV MPEG2 => H264 transcode PSNR dropped by 32%

[FFmpeg]

#9377: QSV MPEG2 => H264 transcode PSNR dropped by 32%
-------------------------------------+-------------------------------------
             Reporter:  eero-t       |                    Owner:  (none)
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  git-master   |               Resolution:
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Comment (by eero-t):

 Full FFmpeg output for the PSNR calculation:
 {{{
 ffmpeg version N-103273-g51a80aacce Copyright (c) 2000-2021 the FFmpeg
 developers
   built with gcc 9 (Ubuntu 9.3.0-17ubuntu1~20.04)
   configuration: --prefix=/opt/install/Nightly_2581 --enable-libmfx
 --enable-vaapi --enable-sdl2 --disable-libx265 --disable-libx264
 --disable-libvpx --enable-libvorbis --enable-libopus --disable-libmp3lame
 --disable-libass --disable-sndio --enable-libfreetype --enable-gpl
 --disable-doc
   libavutil      57.  4.100 / 57.  4.100
   libavcodec     59.  4.101 / 59.  4.101
   libavformat    59.  4.101 / 59.  4.101
   libavdevice    59.  0.101 / 59.  0.101
   libavfilter     8.  2.100 /  8.  2.100
   libswscale      6.  0.100 /  6.  0.100
   libswresample   4.  0.100 /  4.  0.100
   libpostproc    56.  0.100 / 56.  0.100
 [mpegvideo @ 0x55f44e597180] Estimating duration from bitrate, this may be
 inaccurate
 Input #0, mpegvideo, from '1920x1080i_29.97_20mb_mpeg2_high.mpv':
   Duration: 00:01:59.91, bitrate: 20000 kb/s
   Stream #0:0: Video: mpeg2video (Main), yuv420p(tv, bottom first),
 1920x1080 [SAR 1:1 DAR 16:9], 20000 kb/s, 29.97 fps, 29.97 tbr, 1200k tbn
     Side data:
       cpb: bitrate max/min/avg: 20000000/0/0 buffer size: 9781248
 vbv_delay: N/A
 Input #1, h264, from '0024_HD17i7_1.0.h264':
   Duration: N/A, bitrate: N/A
   Stream #1:0: Video: h264 (High), yuv420p(progressive), 1920x1080 [SAR
 1:1 DAR 16:9], 29.97 fps, 29.97 tbr, 1200k tbn
 Stream mapping:
   Stream #0:0 (mpeg2video) -> psnr:main
   Stream #1:0 (h264) -> psnr:reference
   psnr -> Stream #0:0 (wrapped_avframe)
 Press [q] to stop, [?] for help
 [Parsed_psnr_0 @ 0x55f4509aeb00] not matching timebases found between
 first input: 1/1200000 and second input 1/1200000, results may be
 incorrect!
 Output #0, null, to 'pipe:':
   Metadata:
     encoder         : Lavf59.4.101
   Stream #0:0: Video: wrapped_avframe, yuv420p(tv, bottom coded first
 (swapped)), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 29.97 fps,
 29.97 tbn (default)
     Metadata:
       encoder         : Lavc59.4.101 wrapped_avframe
 frame=    1 fps=0.0 q=-0.0 size=N/A time=00:00:00.06 bitrate=N/A
 speed=2.09x
 frame=  218 fps=0.0 q=-0.0 size=N/A time=00:00:07.30 bitrate=N/A
 speed=13.7x
 frame=  441 fps=427 q=-0.0 size=N/A time=00:00:14.74 bitrate=N/A
 speed=14.3x
 frame=  662 fps=432 q=-0.0 size=N/A time=00:00:22.12 bitrate=N/A
 speed=14.4x
 frame=  886 fps=436 q=-0.0 size=N/A time=00:00:29.59 bitrate=N/A
 speed=14.5x
 frame= 1110 fps=438 q=-0.0 size=N/A time=00:00:37.07 bitrate=N/A
 speed=14.6x
 frame= 1199 fps=436 q=-0.0 Lsize=N/A time=00:00:40.04 bitrate=N/A
 speed=14.6x
 video:515kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: unknown
 [Parsed_psnr_0 @ 0x55f4509aeb00] PSNR y:27.630109 u:42.264918 v:39.133647
 average:29.278348 min:15.279748 max:49.989809
 }}}
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9377#comment:2>
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