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• ffmpeg - duration usage in input text file

  12 May 2018, by Voicu

  I am trying to use ffmpeg to concatenate video segments with some black screen. To do that I’ve first generated a blank 10-second video (no audio track) with:

  $ ffmpeg -f lavfi -i color=black:s=320x240:r=1 -f lavfi -i anullsrc -t 10 -vcodec libvpx -an blank.mkv

  I then created the simplest possible scenario within input.txt file (contents below) in order to have three seconds of black screen followed by some video (no audio track):

  file 'blank.mkv'
  
  duration 3
  
  file 'video_example.mkv'

  And, finally, ran the following ffmpeg command to concat the contents of that input file:

  $ ffmpeg -f concat -i input.txt -codec:v copy -codec:a copy output.mkv

  The issue that I have is that the duration 3 is not considered, so the final video still has ten seconds of black frames (instead of three) followed by my video. And also "Non-monotonous DTS in output stream 0:0 ..." message is shown when using duration x in the file. If I remove duration the warnings are gone and getting the 10-second black screen first output as well.

  Full output of the ffmpeg concat command:

  $ ffmpeg -hide_banner -f concat -i input.txt -codec:v copy -codec:a copy output.mkv
  
  Input #0, concat, from 'input.txt':
  
    Duration: N/A, start: 0.000000, bitrate: N/A
  
      Stream #0:0: Video: vp8, yuv420p(progressive), 320x240, SAR 1:1 DAR 4:3, 1 fps, 1 tbr, 1k tbn, 1k tbc
  
      Metadata:
  
        ENCODER         : Lavc57.107.100 libvpx
  
        DURATION        : 00:00:10.000000000
  
  File 'output.mkv' already exists. Overwrite ? [y/N] y
  
  Output #0, matroska, to 'output.mkv':
  
    Metadata:
  
      encoder         : Lavf57.83.100
  
      Stream #0:0: Video: vp8 (VP80 / 0x30385056), yuv420p(progressive), 320x240 [SAR 1:1 DAR 4:3], q=2-31, 1 fps, 1 tbr, 1k tbn, 1k tbc
  
      Metadata:
  
        ENCODER         : Lavc57.107.100 libvpx
  
        DURATION        : 00:00:10.000000000
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
  Press [q] to stop, [?] for help
  
  [concat @ 000000000031a440] DTS 3000 < 9000 out of order
  
  [matroska @ 0000000000328420] Non-monotonous DTS in output stream 0:0; previous: 9000, current: 3000; changing to 9000. This may result in incorrect timestamps in the output file.
  
  [matroska @ 0000000000328420] Non-monotonous DTS in output stream 0:0; previous: 9000, current: 4001; changing to 9000. This may result in incorrect timestamps in the output file.
  
  [matroska @ 0000000000328420] Non-monotonous DTS in output stream 0:0; previous: 9000, current: 4998; changing to 9000. This may result in incorrect timestamps in the output file.
  
  [matroska @ 0000000000328420] Non-monotonous DTS in output stream 0:0; previous: 9000, current: 6004; changing to 9000. This may result in incorrect timestamps in the output file.
  
  [matroska @ 0000000000328420] Non-monotonous DTS in output stream 0:0; previous: 9000, current: 7002; changing to 9000. This may result in incorrect timestamps in the output file.
  
  [matroska @ 0000000000328420] Non-monotonous DTS in output stream 0:0; previous: 9000, current: 8005; changing to 9000. This may result in incorrect timestamps in the output file.
  
  frame= 5794 fps=0.0 q=-1.0 Lsize=    7109kB time=01:37:09.70 bitrate=  10.0kbits/s speed=5.16e+004x
  
  video:7043kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.926229%

  Any idea what am I doing wrong? The warning seems to hint towards the issue here.

  Other possibly useful info:

  $ ffprobe -hide_banner blank.mkv
  
  Input #0, matroska,webm, from 'blank.mkv':
  
    Metadata:
  
      ENCODER         : Lavf57.83.100
  
    Duration: 00:00:10.00, start: 0.000000, bitrate: 1 kb/s
  
      Stream #0:0: Video: vp8, yuv420p(progressive), 320x240, SAR 1:1 DAR 4:3, 1 fps, 1 tbr, 1k tbn, 1k tbc (default)
  
      Metadata:
  
        ENCODER         : Lavc57.107.100 libvpx
  
        DURATION        : 00:00:10.000000000
  
  
  
  $ ffprobe -hide_banner video_example.mkv
  
  Input #0, matroska,webm, from 'video_example.mkv':
  
    Metadata:
  
      encoder         : GStreamer matroskamux version 1.8.1.1
  
      creation_time   : 2018-05-04T17:57:04.000000Z
  
    Duration: 01:37:08.70, start: 15434.269000, bitrate: 9 kb/s
  
      Stream #0:0(eng): Video: vp8, yuv420p(progressive), 320x240, SAR 1:1 DAR 4:3, 1 fps, 1 tbr, 1k tbn, 1k tbc (default)
  
      Metadata:
  
        title           : Video
  
  
  
  $ ffmpeg -v
  
  ffmpeg version 3.4.2 Copyright (c) 2000-2018 the FFmpeg developers
  
    built with gcc 7.3.0 (GCC)

• Ffmpeg concatenate video file with hw acceleration using cuvid

  9 March 2023, by Jack Kwakman

  I am trying to use Nvidia hardware acceleration for FFmpeg using cuvid. I want to merge multiple h264 / mp4 files using a complex filter (simplified example):

  



  ffmpeg -hwaccel cuvid -c:v h264_cuvid -i input.ts -y -fflags +genpts -filter_complex "[0:v:0][0:a:0]concat=n=1:v=1:a=1[outv][outa]" -map "[outv]" -map "[outa]" output.mp4


  



  I use the following version FFmpeg and Ubuntu 16.04:

  



  version 3.4.2-1~16.04.york0.2 Copyright (c) 2000-2018 the FFmpeg developers built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.9) 20160609


  



  If i run the command i get the following error:

  



  Impossible to convert between the formats supported by the filter 'Parsed_concat_0' and the filter 'auto_scaler_0'
Error reinitializing filters!
Failed to inject frame into filter network: Function not implemented


  



  When i remove the hwaccel flag the command runs but i get a massive CPU load. How can i use a concat complex_filter in combination with cuvid hw acceleration?

  



  SOLUTION

  



  The concat demuxing worked. The output of the encoder is now in h264. I group the files in a list.txt:

  



  file '/path/to/file1'
file '/path/to/file2'
file '/path/to/file3'


  



  Then run ffmpeg:

  



  ffmpeg -y -f concat -safe 0 -i list.txt -c copy result.mp4


  


• ffmpeg: Cannot open libx265 encoder. Error initializing output stream 0:0 — Error while opening encoder for output stream #0:0

  16 May 2018, by bnge

  Sorry for my bad English. I am trying to use ffmpeg to convert some image to heic format. Most of them were succeeded, but some large jpeg (seems only jpeg, png will be okay) files not.

  How can I improve my command to compatible all my images, so I can convert them automatically?

  ➜  ~ ffmpeg -i sample.jpg -crf 12 -preset placebo -pix_fmt yuv420p -f hevc bitstream.265
  
  ffmpeg version 4.0 Copyright (c) 2000-2018 the FFmpeg developers
  
    built with Apple LLVM version 9.1.0 (clang-902.0.39.1)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/4.0 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-libmp3lame --enable-libx264 --enable-libx265 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
  
    libavutil      56. 14.100 / 56. 14.100
  
    libavcodec     58. 18.100 / 58. 18.100
  
    libavformat    58. 12.100 / 58. 12.100
  
    libavdevice    58.  3.100 / 58.  3.100
  
    libavfilter     7. 16.100 /  7. 16.100
  
    libavresample   4.  0.  0 /  4.  0.  0
  
    libswscale      5.  1.100 /  5.  1.100
  
    libswresample   3.  1.100 /  3.  1.100
  
    libpostproc    55.  1.100 / 55.  1.100
  
  Input #0, image2, from 'sample.jpg':
  
    Duration: 00:00:00.04, start: 0.000000, bitrate: 5226869 kb/s
  
      Stream #0:0: Video: mjpeg, yuvj444p(pc, bt470bg/unknown/unknown), 13333x4200, 25 tbr, 25 tbn, 25 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (mjpeg (native) -> hevc (libx265))
  
  Press [q] to stop, [?] for help
  
  [swscaler @ 0x7fd2e3006000] deprecated pixel format used, make sure you did set range correctly
  
  x265 [info]: HEVC encoder version 2.7
  
  x265 [info]: build info [Mac OS X][clang 9.0.0][64 bit] 8bit+10bit+12bit
  
  x265 [info]: using cpu capabilities: MMX2 SSE2Fast LZCNT SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
  
  x265 [error]: Picture width must be an integer multiple of the specified chroma subsampling
  
  [libx265 @ 0x7fd2e2802a00] Cannot open libx265 encoder.
  
  Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
  
  Conversion failed!