Recherche avancée

Sur d’autres sites (10149)

• Moov atom in android MeidaRecorder recorded data

  11 mars 2013, par mmmaaak

  I have a problem :

  I record data from camera using MediaRecorder in my Android app. I save it in socket, not in file. This data's length may be different. At the other side of socket connection, I save it in file. Connection may be interrupted at any unexpected moment. So after android socket disconnection I try to decode received data using ffmpeg. But as I understood, it cant find moov atom in this file. I've read some info about moov, so I think that MediaRecorder puts moov atom in the end of file. But if recording was interrupted, writing moov atom was skipped.

  I also have read that for data with unknown length (progressive loading, streaming) it is possible to write moov atom at the begining of the file.

  How to write my own moov data into the stream ? May I use MediaRecorder for this ? Or it is neccessary to do it manualy ? How to generate valid moov data ? If anybody has already solved this problem, please give me advice..

• ffmpeg - Extract Video filesize from virtual data

  18 décembre 2015, par Youssef El Gharbaoui

  I am trying to calculate a video filesize from its data using FFMPEG.

  Assuming that I have the following data in my disposal :

  • vcodec => mp4a.40.2
  • acodec => avc1.64001F
  • format_note => hd720
  • height => 720
  • width => 1280
  • ext => mp4
  • duration => 56 (seconds)

  Questions :

  1. Is there any mathematical formula that can extract the video
     filesize using the data above
  2. Is it possible to simulate and extract the filesize of a
     non-existing file using the data above
  3. If FFMPEG cannot accomplish what Im asking, what do you suggest ?

  Please let me know if you need any additional information.

  Thanks for your help.

• Feed raw data to ffmpeg from python

  27 octobre 2020, par eri

  I want to wrap h264 stream to mp4 container on fly. But ffmpeg exits after first buffer

  


  ffmpeg = subprocess.Popen("ffmpeg -f h264 -i pipe: -c copy -f mp4 -movflags frag_keyframe+empty_moov+faststart pipe:".split(), stdout=subprocess.PIPE, stdin=subprocess.PIPE)

fd = ffmpeg.stdout.fileno()
fl = fcntl.fcntl(fd, fcntl.F_GETFL)
fcntl.fcntl(fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)

while True:
    data = infile.read(32768)
    ffmpeg.stdin.write(data)
    data = ffmpeg.stdout.read()
    outfile.write(data)