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• How to control specific frame size ?

  11 avril 2020, par he852100

  Picture example

  



  Enlarge the bit rate of a specific key frame or specific paragraph

  



  Goal : The key frame in a specific area becomes the largest key frame in the video

  


• FFMPEG : Redirecting MP4 muxed data to socket using movflags resets timestamp

  1er septembre 2014, par Parth Shah

  I am using FFMPEG library to mux H.264 and AAC frames to MP4 file. I do that C program.
  I store H.264 and AAC frame’s timestamp in epoch format.

  I use ffprobe to check timestamps that stored in the MP4 file, ffprobe confirms that file is in MP4 format and timestamps are stored correctly. below is the output of ffprobe.

  ffprobe -show_packets 20140805095931.mp4

      Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '20140805095931.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf54.29.104
  
    Duration: 00:01:39.70, start: 1407232771.984000, bitrate: 1063 kb/s
  
      Stream #0.0(und): Video: h264 (High), yuv420p, 960x540, 999 kb/s, 30 fps, 59.94 tbr, 1k tbn, 60 tbc
  
      Stream #0.1(und): Audio: aac, 48000 Hz, mono, s16, 53 kb/s
  
  [PACKET]
  
  codec_type=video
  
  stream_index=0
  
  pts=1407232771984
  
  pts_time=1407232771.984000 
  
  dts=1407232771984
  
  dts_time=1407232771.984000 
  
  duration=34
  
  duration_time=0.034000 
  
  size=24556.000000 
  
  pos=48
  
  flags=K
  
  [/PACKET]
  
  [PACKET]
  
  codec_type=video
  
  stream_index=0
  
  pts=1407232772018
  
  pts_time=1407232772.018000 
  
  dts=1407232772018
  
  dts_time=1407232772.018000 
  
  duration=33
  
  duration_time=0.033000 
  
  size=3180.000000 
  
  pos=24604
  
  flags=_
  
  [/PACKET]
  
  [PACKET]
  
  codec_type=video
  
  stream_index=0
  
  pts=1407232772051
  
  pts_time=1407232772.051000 
  
  dts=1407232772051
  
  dts_time=1407232772.051000 
  
  duration=33
  
  duration_time=0.033000 
  
  size=3209.000000 
  
  pos=27784
  
  flags=_
  
  [/PACKET]

  My goal is reading this muxed MP4 data from MP4 file and send this muxed mp4 data to the client over socket without creating any temporary file. My actual goal is to write a C program though.

  I tried using protocols tcp and udp but they are not working with Mp4 format and gives error as below.

  ffmpeg -i 20140805095931.mp4 -f mp4 -vcodec copy tcp ://10.99.19.163:8888

  [mp4 @ 0xb1e1920] muxer does not support non seekable output
  Could not write header for output file #0 (incorrect codec parameters ?) : Invalid argument

  So, I read somewhere about moov atom and tried it with following command

  ffmpeg -i 20140805095931.mp4 -movflags isml+frag_keyframe -f mp4 -vcodec copy tcp ://10.99.19.163:8888

  using above commandline I am able to send mp4 file to the client using tcp protocol that ffmpeg supports.

  But when I apply ffprobe on the MP4 file timestamp resets to 0 , even starttime becomes 0.0000. Below is the output of ffmpeg.

  ffprobe -show_packets out.mp4

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'out.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf55.48.100
  
    Duration: 00:01:39.71, start: 0.000000, bitrate: 1059 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 960x540, 999 kb/s, 30 fps, 30 tbr, 16k tbn, 60 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, mono, fltp, 53 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  [PACKET]
  
  codec_type=video
  
  stream_index=0
  
  pts=0
  
  pts_time=0.000000
  
  dts=0
  
  dts_time=0.000000
  
  duration=533
  
  duration_time=0.033313
  
  convergence_duration=N/A
  
  convergence_duration_time=N/A
  
  size=24556
  
  pos=3853
  
  flags=K
  
  [/PACKET]
  
  [PACKET]
  
  codec_type=video
  
  stream_index=0
  
  pts=544
  
  pts_time=0.034000
  
  dts=544
  
  dts_time=0.034000
  
  duration=533
  
  duration_time=0.033313
  
  convergence_duration=N/A
  
  convergence_duration_time=N/A
  
  size=3180
  
  pos=28409
  
  flags=_
  
  [/PACKET]
  
  [PACKET]
  
  codec_type=video
  
  stream_index=0
  
  pts=1072
  
  pts_time=0.067000
  
  dts=1072
  
  dts_time=0.067000
  
  duration=533
  
  duration_time=0.033313
  
  convergence_duration=N/A
  
  convergence_duration_time=N/A
  
  size=3209
  
  pos=31589
  
  flags=_
  
  [/PACKET]

  Any help or advice ? Thank you in advance.

• How take a screenshoot using FFMpeg-bundle

  4 septembre 2014, par PokeRwOw

  I realize a upload video with Symfony and ffmpeg bundle (https://github.com/pulse00/ffmpeg-bundle). The goal it’s a website with a upload video and convert behind for return video in mp4
  So now, the convert in mp4 works fine but i want to take a screenshoot in video (the mmpeg library permit this) but with this bundle he returned me an error :

  Attempted to load class "TimeCode" from namespace "FFMpeg\FFMpeg\Coordinate" in /var/www/src/VD/VideoGalleryBundle/Controller/AdminController.php line 62. Do you need to "use" it from another namespace ? Perhaps you need to add a use statement for one of the following : FFMpeg\Coordinate\TimeCode.

  Use statement is in the controller in the beggining but he don’t want loaded this.

  Thanks per advance !

  PokeR