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• Change file format from flv to anything android will play

  19 octobre 2011, par Bilthon

  I need to take this file which encoded is in h264 but in a flv container and just put it in a mp4, 3gp or whatever file format the android MediaPlayer will understand.

  I want to do this natively. As I will not be decoding nor encoding anything I think I will not be wasting a lot of power (am I wrong ?)

  I followed the instructions from here http://www.roman10.net/?p=394 and could sucessfully compile and use ffmpeg and use it with mp4 and 3gp files.

  But when it comes to flv files it fails. I understand there is no format definition for flv files in that specific port of ffmpeg for android.

  There is no libavformat/flv.h header file for instance.

  Maybe that's why this works :

  extern AVInputFormat ff_mov_demuxer ;
  av_register_input_format(&ff_mov_demuxer) ;

  While this fails :

  extern AVInputFormat ff_flv_demuxer;
  
  av_register_input_format(&ff_flv_demuxer);

  Question is, is there a light at the end of the tunnel ? has someone done something similar ? is it useful ? I mean, I can always just throw the flv media file into a flash player and voila.. the thing is that this would be a parcial solution, as it will not work for all those folks running slower devices that can't yet run Flash.

  Nelson

  PS. Just in case. Here's some info about the file I'm talking about :

  ffmpeg -i rio.flv 
  
  ffmpeg version N-32624-gea8de10, Copyright (c) 2000-2011 the FFmpeg developers
  
    built on Sep 15 2011 23:31:42 with gcc 4.5.2
  
    configuration: --enable-libfaac --enable-libmp3lame --enable-librtmp --enable-libtheora --enable-libx264 --enable-libxvid --enable-gpl --enable-nonfree
  
    libavutil    51. 16. 0 / 51. 16. 0
  
    libavcodec   53. 15. 0 / 53. 15. 0
  
    libavformat  53. 12. 0 / 53. 12. 0
  
    libavdevice  53.  3. 0 / 53.  3. 0
  
    libavfilter   2. 42. 0 /  2. 42. 0
  
    libswscale    2.  1. 0 /  2.  1. 0
  
    libpostproc  51.  2. 0 / 51.  2. 0
  
  
  
  Seems stream 0 codec frame rate differs from container frame rate: 2000.00 (2000/1) -> 14.99 (15000/1001)
  
  Input #0, flv, from 'rio.flv':
  
    Duration: 00:01:00.06, start: 0.000000, bitrate: 783 kb/s
  
      Stream #0.0: Video: h264 (Main), yuv420p, 704x480 [SAR 10:11 DAR 4:3], 14.99 tbr, 1k tbn, 2k tbc

• Python/FFMPEG command line issues

  5 octobre 2011, par 12hys

  I have a problem with running an FFMPEG command from within a Python script. When I run the following command from the terminal, I can stream video and audio from my attached webcam (Logitech C310) and output to file "out.avi" without any errors.

  ffmpeg -f alsa -i default -itsoffset 00:00:00 -f video4linux2 -s 1280x720 -r 25 -i /dev/video0 out.avi

  When I run the same command in a Python script below,

  def call_command(command):
  
      subprocess.Popen(command.split(' '))
  
  
  
  call_command("ffmpeg -f alsa -i default -itsoffset 00:00:00 -f video4linux2 -s 1280x720 -r 25 -i /dev/video0 out.avi")

  it gives me the error :

  Input #0, alsa, from 'default':
  
    Duration: N/A, start: 1317762562.695397, bitrate: N/A
  
    Stream #0.0: Audio: pcm_s16le, 44100 Hz, 1 channels, s16, 705 kb/s
  
  [video4linux2 @ 0x165eb10]Cannot find a proper format for codec_id 0, pix_fmt -1.
  
  /dev/video0: Input/output error

  Could anyone shed some light on what could be going on here ? I've tried using os.system() as well as subprocess.call() and it gives me the same errors. I'm not sure where to start on what could be going wrong here. I tried searching for the "video4linux2 Cannot find a proper format for codec_id 0, pix_fmt -1" error, but couldn't find anything consistent.

  I've also tried putting the "ffmpeg -f..." command in a shell script "test.sh", and giving it executable permissions. I then open terminal, and run "./test.sh", and it works. When I try calling the command "./test.sh" from within my Python script, I'm left with the original error as before. This is the Python command I tried with the test.sh script :

  subprocess.call(["./test.sh"])

• Command-line streaming webcam with audio from Ubuntu server in WebM format

  28 avril 2017, par mjtb

  I am trying to stream video and audio from my webcam connected to my headless Ubuntu server (running Maverick 10.10). I want to be able to stream in WebM format (VP8 video + OGG). Bandwidth is limited, and so the stream must be below 1Mbps.

  I have tried using FFmpeg. I am able to record WebM video from the webcam with the following :

  ffmpeg -s 640x360 \
  
  -f video4linux2 -i /dev/video0 -isync -vcodec libvpx -vb 768000 -r 10 -vsync 1 \
  
  -f alsa -ac 1 -i hw:1,0 -acodec libvorbis -ab 32000 -ar 11025 \
  
  -f webm /var/www/telemed/test.webm 

  However despite experimenting with all manner of vsync and async options, I can either get out of sync audio, or Benny Hill style fast-forward video with matching fast audio. I have also been unable to get this actually working with ffserver (by replacing the test.webm path and filename with the relevant feed filename).

  The objective is to get a live, audio + video feed which is viewable in a modern browser, in a tight bandwidth, using only open-source components. (None of that MP3 format legal chaff)

  My questions are therefore :
  How would you go about streaming webm from a webcam via Linux with in-sync audio ? What software you use ?

  Have you succeeded in encoding webm from a webcam with in-sync audio via FFmpeg ? If so, what command did you issue ?

  Is it worth persevering with FFmpeg + FFserver, or are there other more suitable command-line tools around (e.g. VLC which doesn’t seem too well built for encoding) ?

  Is something like Gstreamer + flumotion configurable from the command line ? If so, where do I find command line documentation because flumotion doc is rather light on command line details ?

  Thanks in advance !