[FFmpeg-user] MPEG OPTION CONFIGURATION

Cédric Cochennec cedric.cochennec at gmail.com
Thu Dec 8 22:50:30 EET 2022


Hey Guys

Maybe nobody have a clue or it is a too old subject, but any help would be
appreciated.
Any reading, blog, documentation, I searched all google (or near).

I tried this (changing all setting but bufsize and removing -f vcd). Seems
better, no underflow problems.
But having a warning which I can't understand and get read of.

[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255 speed=3.19x
    Last message repeated 3 times
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed=3.23x
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed=3.26x
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed=3.24x
    Last message repeated 1 times
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed=3.26x
    Last message repeated 2 times
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed=3.27x
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed=3.21x
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255 speed=3.21x
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed=3.22x
    Last message repeated 1 times
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255 speed=3.17x
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed=3.22x
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed=3.19x
    Last message repeated 4 times
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed=3.27x
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed= 3.2x
[mpeg1video @ 000001d4dd794940] warning, clipping 1 dct coefficients to
-255..255speed= 3.2x
frame=28625 fps= 78 q=2.5 Lsize=  320570kB time=00:19:04.98
bitrate=2293.6kbits/s speed=3.14x


Can anybody help me on this ?

here the full output os the shell:

ffmpeg version 5.0-full_build-www.gyan.dev Copyright (c) 2000-2022 the
FFmpeg developers
  built with gcc 11.2.0 (Rev5, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static
--disable-w32threads --disable-autodetect --enable-fontconfig
--enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-bzlib
--enable-lzma --enable-libsnappy --enable-zlib --enable-librist
--enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth
--enable-libbluray --enable-libcaca --enable-sdl2 --enable-libdav1d
--enable-libdavs2 --enable-libuavs3d --enable-libzvbi --enable-librav1e
--enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265
--enable-libxavs2 --enable-libxvid --enable-libaom --enable-libopenjpeg
--enable-libvpx --enable-mediafoundation --enable-libass --enable-frei0r
--enable-libfreetype --enable-libfribidi --enable-libvidstab
--enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm
--enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc
--enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libshaderc
--enable-vulkan --enable-libplacebo --enable-opencl --enable-libcdio
--enable-libgme --enable-libmodplug --enable-libopenmpt
--enable-libopencore-amrwb --enable-libmp3lame --enable-libshine
--enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc
--enable-libilbc --enable-libgsm --enable-libopencore-amrnb
--enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa
--enable-libbs2b --enable-libflite --enable-libmysofa
--enable-librubberband --enable-libsoxr --enable-chromaprint
  libavutil      57. 17.100 / 57. 17.100
  libavcodec     59. 18.100 / 59. 18.100
  libavformat    59. 16.100 / 59. 16.100
  libavdevice    59.  4.100 / 59.  4.100
  libavfilter     8. 24.100 /  8. 24.100
  libswscale      6.  4.100 /  6.  4.100
  libswresample   4.  3.100 /  4.  3.100
  libpostproc    56.  3.100 / 56.  3.100
Guessed Channel Layout for Input Stream #0.1 : stereo
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'T:\TEMP\0079\test_file.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isom
    creation_time   : 2022-11-02T15:43:01.000000Z
  Duration: 00:42:11.04, start: 0.000000, bitrate: 6114 kb/s
  Stream #0:0[0x1](eng): Video: h264 (Main) (avc1 / 0x31637661),
yuv420p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 4570 kb/s,
25 fps, 25 tbr, 24k tbn (default)
    Metadata:
      creation_time   : 2022-11-02T15:43:01.000000Z
      vendor_id       : TELE
      encoder         : AVC
  Stream #0:1[0x2](eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz,
stereo, s16, 1536 kb/s (default)
    Metadata:
      creation_time   : 2022-11-02T15:43:01.000000Z
      vendor_id       : [0][0][0][0]
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> mpeg1video (native))
  Stream #0:1 -> #0:1 (pcm_s16le (native) -> mp2 (native))
Press [q] to stop, [?] for help
Output #0, mpeg, to 'T:\TEMP\0079\test_file_31629.mpg':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isom
    encoder         : Lavf59.16.100
  Stream #0:0(eng): Video: mpeg1video, yuv420p(tv, bt709, progressive),
512x288 [SAR 1:1 DAR 16:9], q=2-31, 2123 kb/s, 25 fps, 90k tbn (default)
    Metadata:
      creation_time   : 2022-11-02T15:43:01.000000Z
      vendor_id       : TELE
      encoder         : Lavc59.18.100 mpeg1video
    Side data:
      cpb: bitrate max/min/avg: 2123200/2123200/2123200 buffer size: 327680
vbv_delay: N/A
  Stream #0:1(eng): Audio: mp2, 48000 Hz, stereo, s16, 160 kb/s (default)
    Metadata:
      creation_time   : 2022-11-02T15:43:01.000000Z
      vendor_id       : [0][0][0][0]
      encoder         : Lavc59.18.100 mp2
[mpeg1video @ 000001734eea26c0] warning, clipping 1 dct coefficients to
-255..255speed= 6.9x
    Last message repeated 1 times

Le ven. 2 déc. 2022 à 11:47, Cédric Cochennec <cedric.cochennec at gmail.com>
a écrit :

> Hi all
>
> I am trying to understand and set things up for mpeg streams options in
> ffmpeg.
> Let's do this with mpeg1video codec in mpg container.
>
> I peaked up this command line in ffmpeg documentation wich work perfectly
> well :
>
> -f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324
> -s 352x288 -r 25
> -codec:v mpeg1video -g 15 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680
> -ar 44100 -ac 2
> -codec:a mp2 -b:a 160k
>
>
> Now, I tried several changes to achieve bit_rate=2.123200 Mbit/s and
> overall bit_rate=2.332245 Mbit/s but with little success for readability,
> error buffer underflow etc...
>
> What would be the setup of these options :
>
>    - -muxrate
>    - -muxpreload
>    - -packetsize
>    - -b:v
>    - -maxrate:v
>    - -bufsize:v
>
> Many thanks for your help
>
> Cédric
>
>
>
>
>


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