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• pgssubdec : fix subpicture output colorspace and range

  24 avril 2016, par Jan Ekström

  pgssubdec : fix subpicture output colorspace and range
  Functionality used before didn’t widen the values from limited to
  
  full range. Additionally, now the decoder uses BT.709 where it
  
  should be used according to the video resolution.
  Default for not yet set colorimetry is BT.709 due to most observed
  
  HDMV content being HD.
  BT.709 coefficients were gathered from the first two parts of BT.709
  
  to BT.2020 conversion guide in ARIB STD-B62 (Pt. 1, Chapter 6.2.2).
  
  They were additionally confirmed by manually calculating values.
  Fixes #4637
  

  • [DH] libavcodec/pgssubdec.c
  • [DH] libavutil/colorspace.h

• ffmpeg concat poduces DTS out of order errors

  2 juin 2016, par Andy

  I’m following the documentation on how to concatenate files with ffmpeg but during the process I’m seeing lots of warning and the output video stops after the first chunk but the audio keeps on playing.

  This is the command I’m using to concatenate the files :

  ffmpeg -f concat -i mylist.txt -c copy output.webm

  This are the warnings I’m seeing :

  [concat @ 0x7fee11822a00] DTS 0 < 2500 out of order
  
  [webm @ 0x7fee11011000] Non-monotonous DTS in output stream 0:0; previous: 2500, current: 0; changing to 2500. This may result in incorrect timestamps in the output file.

  The video files are coming from an external source. My current solution is to re-encode every file sepeatly to mp4 and then to concatenate them together and then to re-encode the complete file back to webm. That, of cause, that takes some significant time but I can’t find another solution.

• ffmpeg : getting video from http page streamed to youtube

  28 novembre 2014, par M-T-A

  I’m trying to configure ffmpeg to stream to youtube from ubuntu machine.

  I have my wifi camera streaming with format ’video/x-ms-asf’ on local http page.

  Then I use these commands in attempt to stream to youtube

  VBR="2500k" # Bitrate 
  
  FPS="20" # FPS 
  
  QUAL="medium" #ffmpeg quality
  
  YOUTUBE_URL="rtmp://a.rtmp.youtube.com/live2" # URL base
  
  
  
  SOURCE="http://192.168.9.XX/videostream.asf?user=admin&pwd=***" # Source of video
  
  KEY="KEY HERE" # youtube event key
  
  
  
  ffmpeg \
  
  -i "$SOURCE"  \
  
  -vcodec copy -pix_fmt yuv420p -preset $QUAL -r $FPS -g $(($FPS * 2)) -b:v $VBR \
  
   -ar 44100 -threads 6 -qscale 3 -b:a 712000 -bufsize 512k \
  
  -f flv "$YOUTUBE_URL/$KEY" 

  I get this output

  moha@moha:~/Desktop$ sh start_stream_xmas.sh 
  
  ffmpeg version git-2014-11-28-ea38e5a Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Nov 28 2014 11:06:47 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  
    configuration: --enable-gpl --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree --enable-version3
  
    libavutil      54. 15.100 / 54. 15.100
  
    libavcodec     56. 13.100 / 56. 13.100
  
    libavformat    56. 15.101 / 56. 15.101
  
    libavdevice    56.  3.100 / 56.  3.100
  
    libavfilter     5.  2.103 /  5.  2.103
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  [mjpeg @ 0xb0c0a60] ignoring invalid SAR: 0/0
  
  Guessed Channel Layout for  Input Stream #0.1 : mono
  
  Input #0, asf, from 'http://192.168.9.66/videostream.asf?user=admin&pwd=':
  
    Duration: N/A, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Video: mjpeg (MJPG / 0x47504A4D), yuvj422p(pc, bt470bg/unknown/unknown), 640x480, 25 tbr, 1k tbn, 1k tbc
  
      Stream #0:1: Audio: adpcm_ima_wav ([17][0][0][0] / 0x0011), 8000 Hz, 1 channels, s16p, 32 kb/s
  
  Please use -q:a or -q:v, -qscale is ambiguous
  
  Output #0, flv, to 'rtmp://a.rtmp.youtube.com/live2/createnetxmas.kpjg-5fdg-qp1c-4bvd':
  
    Metadata:
  
      encoder         : Lavf56.15.101
  
      Stream #0:0: Video: mjpeg (MJPG / 0x47504A4D), yuvj422p, 640x480, q=2-31, 2500 kb/s, 1k tbn, 20 tbc
  
      Stream #0:1: Audio: mp3 (libmp3lame) ([2][0][0][0] / 0x0002), 44100 Hz, mono, s16p, 712 kb/s
  
      Metadata:
  
        encoder         : Lavc56.13.100 libmp3lame
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
    Stream #0:1 -> #0:1 (adpcm_ima_wav (native) -> mp3 (libmp3lame))
  
  Press [q] to stop, [?] for help
  
  Multiple frames in a packet from stream 1
  
  frame=   12 fps=0.0 q=-1.0 size=     882kB time=00:00:06.34 bitrate=1138.6kbits/frame=   13 fps= 13 q=-1.0 size=     953kB time=00:00:06.83 bitrate=1142.0kbits/frame=   14 fps=9.1 q=-1.0 size=    1029kB time=00:00:07.30 bitrate=1153.5kbits/frame=   15 fps=7.3 q=-1.0 size=    1104kB time=00:00:07.77 bitrate=1162.7kbits/frame=   16 fps=6.1 q=-1.0 size=    1181kB time=00:00:08.42 bitrate=1148.4kbits/frame=   17 fps=5.3 q=-1.0 size=    1256kB time=00:00:09.07 bitrate=1133.4kbits/frame=   18 fps=4.8 q=-1.0 size=    1325kB time=00:00:09.70 bitrate=1119.0kbits/frame=   19 fps=4.4 q=-1.0 size=    1403kB time=00:00:10.19 bitrate=1127.3kbits/frame=   20 fps=4.1 q=-1.0 size=    1482kB time=00:00:10.66 bitrate=1138.3kbits/frame=   21 fps=3.9 q=-1.0 size=    1556kB time=00:00:11.31 bitrate=1126.0kbits/moha@moha:~/Desktop$ 

  Suddenly the streaming stops and the terminal hangs. I’m not sure why. Is it because the video has no audio in streaming ?