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• Converting series of images with ffmpeg results in black video [migrated]

  27 avril 2013, par Marco Gagliardi

  I've just downloaded ffmpeg since it seems to perfectly match my needs (make a video from a set of pictures). I'm currently playing around with some examples just to get started and there's something weird happening that I can't explain.
  I'm trying this command (provided in the official documentation) :

  ffmpeg -f image2 -pattern_type glob -i 'foo-*.jpeg' -r 12 -s WxH foo.avi

  on a data set of 10 jpg pictures (of course I changed the pattern with '*.jpg'). The video seems to be encoded correctly but it's simply too fast to be sure about that (anyway it stops on the last frame that corresponds to the last picture). In order to get a longer video i thought to low the frame rate from 12 to 1 (one sec each picture) or 0.5 (2 sec each one) and so on.. no way ! with low rate values even if the video is played the pictures are simply not displayed. The player (VLC in my case) just shows a blank/empty video for a few seconds.

  Am I making something wrong or have I misunderstood the -r parameter ? Is it something related to codecs involved ? Finally.. How can i get each picture displayed for 1 or 2 seconds ?

  Here's the output :

  MacBook-Pro$ ffmpeg -f image2 -pattern_type glob -i '*.jpg' -r 1 -s 200x300 foo.avi
  
  ffmpeg version N-52517-g1e4f75d Copyright (c) 2000-2013 the FFmpeg developers
  
    built on Apr 27 2013 19:41:11 with llvm-gcc 4.2.1 (LLVM build 2336.11.00)
  
    configuration: --disable-yasm
  
    libavutil      52. 27.101 / 52. 27.101
  
    libavcodec     55.  6.100 / 55.  6.100
  
    libavformat    55.  3.100 / 55.  3.100
  
    libavdevice    55.  0.100 / 55.  0.100
  
    libavfilter     3. 61.100 /  3. 61.100
  
    libswscale      2.  2.100 /  2.  2.100
  
    libswresample   0. 17.102 /  0. 17.102
  
  Input #0, image2, from '*.jpg':
  
    Duration: 00:00:00.40, start: 0.000000, bitrate: N/A
  
      Stream #0:0: Video: mjpeg, yuvj422p, 2560x1920 [SAR 1:1 DAR 4:3], 25 fps, 25 tbr, 25 tbn, 25 tbc
  
  File 'foo.avi' already exists. Overwrite ? [y/N] y
  
  Output #0, avi, to 'foo.avi':
  
    Metadata:
  
      ISFT            : Lavf55.3.100
  
      Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 200x300 [SAR 2:1 DAR 4:3], q=2-31, 200 kb/s, 1 tbn, 1 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (mjpeg -> mpeg4)
  
  Press [q] to stop, [?] for help
  
  frame=    2 fps=0.0 q=2.0 Lsize=      43kB time=00:00:02.00 bitrate= 177.1kbits/s dup=0 drop=8    
  
  video:38kB audio:0kB subtitle:0 global headers:0kB muxing overhead 15.099197%
  
  MacBook-Pro$ 

• FFmpeg -filter_complex_script crop & blurbox with time based values

  6 juin 2021, par user1503606

  I am trying to create a script that will move a blur boxed across a video based on x and y cords in a text script.

  


  I can easily create a blur box with the following ffmpeg command.

  


  ffmpeg -y -i pex.mp4 -filter_complex_script cropblur.txt -map "[v]" out_crop.mp4


  


  The cropblur.txt has the following.

  


  [0:v]crop=400:400:300:350,boxblur=10[fg]; [0:v][fg]overlay=300:350:enable='between(t\,0\,5)'[v]


  


  This creates this.

  


  

  


  What I want is the blur box to move across where the lady is running.

  


  

  


  She obviously runs out from where the box is positioned.

  


  I can create a script where I can track the correct x and y positions for the blox using jquery ui or something I just dont understand how to implement this in a filter_complex_script.

  


  I thought it would be a simple as just appending to the script something like this.

  


  [0:v]crop=400:400:300:350,boxblur=10[fg]; [0:v][fg]overlay=300:350:enable='between(t\,0\,2)'[v]
[0:v]crop=200:200:200:360,boxblur=10[fg]; [0:v][fg]overlay=300:350:enable='between(t\,2\,3)'[v]
[0:v]crop=200:200:200:370,boxblur=10[fg]; [0:v][fg]overlay=300:350:enable='between(t\,3\,4)'[v]
[0:v]crop=200:200:200:380,boxblur=10[fg]; [0:v][fg]overlay=300:350:enable='between(t\,4\,5)'[v]


  


  Changing the time and the x position based on the incremented time.

  


  If I run this script I get this error.

  


  No output pad can be associated to link label '0:v'


  


  Obviously I am doing something wrong but I cannot find any documentation that really helps me understand how to do this https://ffmpeg.org/ffmpeg.html the official docs dont really help.

  


  I could do it by running multiple passes like this.

  


  ffmpeg -y -i pex.mp4 -filter_complex "[0:v]crop=400:400:300:350,boxblur=10[fg]; [0:v][fg]overlay=300:350:enable='between(t\,0\,2)'[v]" -map "[v]" out_crop.mp4 && ffmpeg -y -i out_crop.mp4 -filter_complex "[0:v]crop=200:200:200:360,boxblur=10[fg]; [0:v][fg]overlay=300:350:enable='between(t\,2\,3)'[v]" -map "[v]" out_crop2.mp4


  


  I Would just really like to understand how to use the filter complex scripts in this way ?

  


  Any help would be great.

  


  Thanks

  


• rtmp : Rename packet types to closer match the spec

  31 janvier 2017, par Martin Storsjö

  rtmp : Rename packet types to closer match the spec
  Also rename comments and log messages accordingly,
  
  and add clarifying comments for some hardcoded values.
  The previous names were taken from older, reverse engineered
  
  references.
  These names match the official public rtmp specification, and
  
  matches the names used by wirecast in annotating captured
  
  streams. These names also avoid hardcoding the roles of server
  
  and client, since the handling of them is irrelevant of whether
  
  we act as server or client.
  The RTMP_PT_PING type maps to RTMP_PT_USER_CONTROL.
  The SERVER_BW and CLIENT_BW types are a bit more intertwined ;
  
  RTMP_PT_SERVER_BW maps to RTMP_PT_WINDOW_ACK_SIZE and
  
  RTMP_PT_CLIENT_BW maps to RTMP_PT_SET_PEER_BW.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DBH] libavformat/rtmppkt.c
  • [DBH] libavformat/rtmppkt.h
  • [DBH] libavformat/rtmpproto.c