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• how to allow a worker to run a ffmpeg command on heroku for my python/django app ?

  10 mars 2013, par GetItDone

  I've been stuck trying to figure this out for weeks. I previously asked a similar question found here but I never got any replies. I really cannot find any good documentation anywhere. All I need to do is use a worker (don't care what worker have django-celery and rq installed) to convert a file to flv when it is uploaded from a form. I was able to get this done easily locally, but after over a week I haven't been able to get it to work no matter what I have tried. I tried adding a tasks.py file for celery, or a worker.py file for rq, and I have no idea what else (if anything) needs to be done, such as in my settings.py or Procfile. My procfile looks like :

  web: gunicorn lftv.wsgi -b 0.0.0.0:$PORT
  
  celeryd: celery -A tasks worker --loglevel=info
  
  worker: python worker.py

  My requirements.txt showing what I have installed looks like this :

  Django==1.4.3
  
  Logbook==0.4.1
  
  amqp==1.0.6
  
  anyjson==0.3.3
  
  billiard==2.7.3.19
  
  boto==2.6.0
  
  celery==3.0.13
  
  celery-with-redis==3.0
  
  distribute==0.6.31
  
  dj-database-url==0.2.1
  
  django-celery==3.0.11
  
  django-s3-folder-storage==0.1
  
  django-storages==1.1.6
  
  gunicorn==0.16.1
  
  kombu==2.5.4
  
  pil==1.1.7
  
  psycopg2==2.4.5
  
  python-dateutil==1.5
  
  pytz==2012j
  
  redis==2.7.2
  
  requests==1.1.0
  
  rq==0.3.2
  
  six==1.2.0
  
  times==0.6

  The only thing relevant in my settings.py are as follows :

  BROKER_BACKEND = 'django'
  
  BROKER_URL = #For this I copy/pasted the code from my redistogo add-on from heroku. Not sure if correct
  
  BROKER_TRANSPORT_OPTIONS = {'visibility_timeout': 1800}

  Without trying to take up too much more space, my tasks.py looks like this :

  import subprocess
  
  
  
  @task
  
  def ffmpeg_conversion(input_file):
  
      converted_file = subprocess.call(input_file)
  
      return converted_file

  I use S3 to store my static and media files, and the upload works (adding uploads to my bucket), however no matter what I try the conversion never will. Is there a good tutorial for absolute beginners ? I followed the heroku redis tutorial, celery docs, rq docs, and whatever else I can find, and got the examples to work, but the worker will not execute the command from my view. For example one of the many things I tried :

  ...
  
  ffmpeg = "ffmpeg -i %s -acodec mp3 -ar 22050 -f flv -s 320x240 %s" % (sourcefile, targetfile)
  
  ffmpegresult = ffmpeg_conversion.delay(ffmpeg)
  
  ...

  or using rq

  ...
  
  q = Queue(connection=conn)
  
  result = q.enqueue(ffmpeg_conversion, ffmpeg)
  
  ...

  I seems like it should be simple, however I am completely self-taught and have never deployed a project whatsoever, and there just doesn't seem to be any good documentation or tutorial available for what I am trying to do. I can't judge whether I am completely off and completely missing something significant or relatively close to getting this to work. I really do appreciate any input whatsoever, this is driving me nuts. Thanks in advance.

• lavf/qtpalette : Ignore greyscale bit in certain cases

  2 janvier 2016, par Mats Peterson

  lavf/qtpalette : Ignore greyscale bit in certain cases
  The QuickTime File Format Specification states the following :
  "Depth : A 16-bit integer that indicates the pixel depth of the
  
  compressed image. Values of 1, 2, 4, 8 ,16, 24, and 32 indicate the
  
  depth of color images. The value 32 should be used only if the image
  
  contains an alpha channel. Values of 34, 36, and 40 indicate 2-, 4-, and
  
  8-bit grayscale, respectively, for grayscale images."
  There is no mention of value 33, i.e. 1-bit video (0x01) with the
  
  greyscale bit (0x20) set. I therefore suggest that we ignore the
  
  greyscale bit when processing 1-bit video. Another reason to do this is
  
  that the first 1-bit sample file below will be displayed properly with
  
  blue colors in QuickTime in Windows or Mac *in spite of* the greyscale
  
  bit being set.
  Also, QuickTime in Windows or Mac ignores the greyscale bit if the
  
  video sample description contains a palette, regardless of bit depth.
  
  This is undocumented behaviour, but I think we should do the same, and
  
  it seems pretty logical after all, since one wouldn’t really bother
  
  putting a customized palette into a grayscale file anyway. See the
  
  second 8-bit sample file below, which has the greyscale bit set, and
  
  which contains a palette in the video sample description. In Windows or
  
  Mac, it will be displayed with the palette in the sample description, in
  
  spite of the greyscale bit being set.
  Sample file 1 (1-bit QuickTime Animation) :
  
  https://drive.google.com/open?id=0B3_pEBoLs0faTThSek1EeXQ0ZHM
  
  Earth Spin 1-bit qtrle orig.mov
  Sample file 2 (8-bit QuickTime Animation) :
  
  https://drive.google.com/open?id=0B3_pEBoLs0fad2s0V1YzUWo5aDA
  
  quiz-palette+gs.mov
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavformat/qtpalette.c

• FFmpeg + RTSP + JSMpeg : Stream randomly rotates in browser

  27 mai, par Lais Lemos

  I'm streaming an RTSP camera to a web page using FFmpeg as the encoder and JSMpeg as the web player. The stream generally works fine, but sometimes — completely at random — the video rotates (usually 45 or 225 degrees) without any change in the code, camera settings, or stream configuration.

  


  This issue usually occurs after the server has been running for a while (one or two weeks). Currently, the only way to solve it is by restarting the Docker container that runs the server.

  


  Setup

  


  

  • Source : IP camera via RTSP

  


  • Streaming : FFmpeg reads the RTSP stream and sends it to a WebSocket server

  


  • Player : JSMpeg in the browser receives the WebSocket stream and plays the video in a canvas.

  


  


  FFmpeg options used

  


  ffmpegOptions: {  
          '-loglevel': 'error',  
          '-r': 30,  
          '-b:v': '5000k',  
          '-s': '1920x1080',  
          '-maxrate': '8000k',  
          '-max_delay': '500000',  
          '-bufsize': '16000k',  
          '-sc_threshold': 0,  
          '-metadata:s:v:0': 'rotate=0',  
          '-vf': 'rotate=0'  
        }


  


  What I've Checked

  


  

  • Verified that the camera itself does not send incorrect rotation metadata — seems fine.

  


  • It doesn't appear that JSMpeg is causing the issue either.

  


  • The problem appears to be on FFmpeg's side.

  


  


  Screenshots of the issue

  


  The blue edges shows the stream orientation during the bug and the red ones, how it was supposed to be.

  


  

  


  Questions

  


  

  • Has anyone experienced this behavior ?

  


  • Any suggestions on how to debug or fix this ?

  


  


  

  


  Any help or guidance would be greatly appreciated !