[FFmpeg-user] I am unable to get ffmpeg to calculate PSNR for any video files.

[Gyan Doshi]

On 19-01-2021 05:49 am, Reed Crowe wrote:
> I have tried this test with three different versions of ffmpeg (4.3.1,
> 3.4.8 and N-100671-gc48110a4a4  on 2 different OSes (Ubuntu 18.04, Fedora
> 33).
>
> Here is the command I am using:
> ffmpeg -i 17647_20210118_195325.mp4 -i test.mp4 -filter_complex psnr -f
> null -
> These are the same file (one just renamed). But I have tried it with
> different files as well with the same error. I'm not totally sure what the
> error means.
>
> Error: Application provided invalid, non monotonically increasing dts to
> muxer in stream 0: 748 >= 748

The output (encoding) time base is, by default, set to the reciprocal of 
the frame rate.  When converting from a finer input time base, 90000 in 
this case, may produce collisions. So let's keep the input tie base. Add 
-enc_time_base -1

However, this does not interfere with PSNR calculation. See below.

> Output with errors:
>
> ffmpeg version 4.3.1 Copyright (c) 2000-2020 the FFmpeg developers
>    built with gcc 10 (GCC)
>    configuration: --prefix=/usr --bindir=/usr/bin
> --datadir=/usr/share/ffmpeg --docdir=/usr/share/doc/ffmpeg
> --incdir=/usr/include/ffmpeg --libdir=/usr/lib64 --mandir=/usr/share/man
> --arch=x86_64 --optflags='-O2 -flto=auto -ffat-lto-objects -fexceptions -g
> -grecord-gcc-switches -pipe -Wall -Werror=format-security
> -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS
> -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -fstack-protector-strong
> -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic
> -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection'
> --extra-ldflags='-Wl,-z,relro -Wl,--as-needed -Wl,-z,now
> -specs=/usr/lib/rpm/redhat/redhat-hardened-ld ' --extra-cflags='
> -I/usr/include/rav1e' --enable-libopencore-amrnb --enable-libopencore-amrwb
> --enable-libvo-amrwbenc --enable-version3 --enable-bzlib
> --disable-crystalhd --enable-fontconfig --enable-frei0r --enable-gcrypt
> --enable-gnutls --enable-ladspa --enable-libaom --enable-libdav1d
> --enable-libass --enable-libbluray --enable-libcdio --enable-libdrm
> --enable-libjack --enable-libfreetype --enable-libfribidi --enable-libgsm
> --enable-liblensfun --enable-libmp3lame --enable-libmysofa --enable-nvenc
> --enable-openal --enable-opencl --enable-opengl --enable-libopenjpeg
> --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg
> --enable-librav1e --enable-libsoxr --enable-libspeex --enable-libssh
> --enable-libtheora --enable-libvorbis --enable-libv4l2 --enable-libvidstab
> --enable-libvmaf --enable-version3 --enable-vapoursynth --enable-libvpx
> --enable-vulkan --enable-libglslang --enable-libx264 --enable-libx265
> --enable-libxvid --enable-libxml2 --enable-libzimg --enable-libzvbi
> --enable-lv2 --enable-avfilter --enable-avresample --enable-libmodplug
> --enable-postproc --enable-pthreads --disable-static --enable-shared
> --enable-gpl --disable-debug --disable-stripping --shlibdir=/usr/lib64
> --enable-lto --enable-libmfx --enable-runtime-cpudetect
>    libavutil      56. 51.100 / 56. 51.100
>    libavcodec     58. 91.100 / 58. 91.100
>    libavformat    58. 45.100 / 58. 45.100
>    libavdevice    58. 10.100 / 58. 10.100
>    libavfilter     7. 85.100 /  7. 85.100
>    libavresample   4.  0.  0 /  4.  0.  0
>    libswscale      5.  7.100 /  5.  7.100
>    libswresample   3.  7.100 /  3.  7.100
>    libpostproc    55.  7.100 / 55.  7.100
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '17647_20210118_195325.mp4':
>    Metadata:
>      major_brand     : isom
>      minor_version   : 512
>      compatible_brands: isomiso2avc1mp41
>      title           : 'LVT17647'
>      encoder         : Lavf58.20.100
>    Duration: 00:00:59.87, start: 0.000000, bitrate: 67 kb/s
>      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuvj420p(pc,
> bt470bg/bt470bg/bt709), 704x480, 66 kb/s, 15.03 fps, 15 tbr, 90k tbn, 180k
> tbc (default)
>      Metadata:
>        handler_name    : VideoHandler
> Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'test.mp4':
>    Metadata:
>      major_brand     : isom
>      minor_version   : 512
>      compatible_brands: isomiso2avc1mp41
>      title           : 'LVT17647'
>      encoder         : Lavf58.20.100
>    Duration: 00:00:59.87, start: 0.000000, bitrate: 67 kb/s
>      Stream #1:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuvj420p(pc,
> bt470bg/bt470bg/bt709), 704x480, 66 kb/s, 15.03 fps, 15 tbr, 90k tbn, 180k
> tbc (default)
>      Metadata:
>        handler_name    : VideoHandler
> Stream mapping:
>    Stream #0:0 (h264) -> settb
>    Stream #1:0 (h264) -> settb
>    psnr -> Stream #0:0 (wrapped_avframe)
> Press [q] to stop, [?] for help
> Output #0, null, to 'pipe:':
>    Metadata:
>      major_brand     : isom
>      minor_version   : 512
>      compatible_brands: isomiso2avc1mp41
>      title           : 'LVT17647'
>      encoder         : Lavf58.45.100
>      Stream #0:0: Video: wrapped_avframe, yuvj420p, 704x480, q=2-31, 200
> kb/s, 15 fps, 15 tbn, 15 tbc (default)
>      Metadata:
>        encoder         : Lavc58.91.100 wrapped_avframe
> *[null @ 0x55e31e9a0240] Application provided invalid, non monotonically
> increasing dts to muxer in stream 0: 748 >= 748*
> frame=  899 fps=0.0 q=-0.0 Lsize=N/A time=00:00:59.86 bitrate=N/A speed=
> 150x
> video:471kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
> muxing overhead: unknown
> [Parsed_psnr_4 @ 0x55e31edfa580] PSNR y:inf u:inf v:inf average:inf min:inf
> max:inf

PSNR is calculated and printed on the last line above.

Regards,
Gyan