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• lavf : ignore attachment streams for interleaving purposes

  20 janvier 2014, par Anton Khirnov

  lavf : ignore attachment streams for interleaving purposes
  Those streams should never get any packets by definition.
  

  • [DH] libavformat/avformat.h
  • [DH] libavformat/internal.h
  • [DH] libavformat/mux.c
  • [DH] libavformat/options.c
  • [DH] libavformat/utils.c

• Streaming desktop screen over the internet using ffmpeg

  22 janvier 2014, par user2944822

  I am a newbie in ffmpeg. I am trying to stream my Desktop screen over the internet using ffmpeg. This is the server configuration.

  Port 8090                      # Port to bind the server to
  
  BindAddress 0.0.0.0
  
  MaxHTTPConnections 2000
  
  MaxClients 1000
  
  MaxBandwidth 10000             # Maximum bandwidth per client
  
                             # set this high enough to exceed stream bitrate
  
  CustomLog -
  
  NoDaemon                       # Remove this if you want FFserver to daemonize after start
  
  
  
  <feed>               # This is the input feed where FFmpeg will send
  
     File ./feed1.ffm            # video stream.
  
     FileMaxSize 1G              # Maximum file size for buffering video
  
     ACL allow 127.0.0.1         
  
  </feed>
  
  
  
  <stream>              # Output stream URL definition
  
     Feed feed1.ffm              # Feed from which to receive video
  
     Format webm
  
  
  
     # Audio settings
  
     NoAudio
  
     #AudioCodec vorbis
  
     #AudioBitRate 64             # Audio bitrate
  
  
  
     # Video settings
  
     VideoCodec libvpx
  
     VideoSize 720x576           # Video resolution
  
     VideoFrameRate 25           # Video FPS
  
     AVOptionVideo flags +global_header  # Parameters passed to encoder
  
                                     # (same as ffmpeg command-line parameters)
  
     AVOptionVideo cpu-used 0
  
     AVOptionVideo qmin 10
  
     AVOptionVideo qmax 42
  
     AVOptionVideo quality good
  
     AVOptionAudio flags +global_header
  
     PreRoll 15
  
     StartSendOnKey
  
     VideoBitRate 400            # Video bitrate
  
  </stream>
  
  
  
  <stream>            # Server status URL
  
     Format status
  
     # Only allow local people to get the status
  
     ACL allow localhost
  
     ACL allow 192.168.0.0 192.168.255.255
  
  </stream>
  
  
  
  <redirect>    # Just an URL redirect for index
  
     # Redirect index.html to the appropriate site
  
     URL http://www.ffmpeg.org/
  
  </redirect>

  Server starts without showing any problem.

  Input stream is as follows :
  ffmpeg -f x11grab -r 25 -s 1366x768 -i :0.0 http://xxx.xxx.xxx.xxx:8090/feed1.ffm

  I get always core dumped. Please help me out or point me to any tutorial which can help me in this context.

  Regards
  Dheeraj

• What makes the bitrate of dash stream output low as compared to bitrate of input mp4 video

  7 janvier 2021, par Chinmaey Shende

  I used ffmpeg to convert bbb.mp4 to dash stream. I used the ffprobe to get the bitrates of input and output (shown below)
For the same resolution video 1920x1080 input has bit rate 2998 kb/s where as output has bitate of 20 kb/s.
My profile is set to "-b:v:0 200K -s:v:0 640x360 -b:v:1 600K -s:v:1 852x480 -b:v:2 4000K -s:v:2 1920x1080".
I am trying to understand what determines the output bit rate for the dash stream ?
Why does my output different from the input profile set in ffmpeg command

  



  Input video stream - bbb.mp4

  



  '''  Duration: 00:10:34.53, start: 0.000000, bitrate: 3481 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 2998 kb/s, 30 fps, 30 tbr, 30k tbn, 60 tbc (default)'''


  



  Output :

  



  '''  Duration: 00:10:34.60, start: 630.000000, bitrate: 20 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 20 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)

    major_brand     : iso5
    minor_version   : 512
    compatible_brands: iso5iso6mp41
    encoder         : Lavf58.42.100
  Duration: 00:10:34.60, start: 630.000000, bitrate: 4 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 852x480 [SAR 640:639 DAR 16:9], 4 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)

    major_brand     : iso5
    minor_version   : 512
    compatible_brands: iso5iso6mp41
    encoder         : Lavf58.42.100
  Duration: 00:10:34.60, start: 630.000000, bitrate: 1 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 640x360 [SAR 1:1 DAR 16:9], 1 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
'''


  



  I tried to look in ffprobe documentation I could not find the definition of the bit_rate field output in ffprobe.

  



  Can you please help me to understand this ?