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• Posthoc connect FFMPEG to opencv-python binary for Google Cloud Dataflow job

  16 juillet 2017, par bw4sz

  I would like to run some video processing jobs on linux based compute engines on Google Cloud DataFlow. Cloud DataFlow requires you to build a setup.py file, or supply dependencies in a requirements.txt.

  https://cloud.google.com/dataflow/pipelines/dependencies-python

  My video process requires opencv in python with FFMPEG support. I would like to avoid building opencv from source, as this takes nearly 35 minutes for each worker to git clone/make/make install.

  There is a linux python binary .whl that works great. But its specifically compiled without FFMPEG.

  From https://pypi.python.org/pypi/opencv-python

  "IMPORTANT NOTE

  MacOS and Linux wheels have currently some limitations :

  video related functionality is not supported (not compiled with FFmpeg)"

  Is it possible to post-hoc connect FFMPEG to the binary ? That is download FFMPEG and its libraries separately and still read video ? I know this is contrived, but are are there any options here besides building opencv from source for every new worker ?

• ffmpeg not finding audio streams ?

  24 septembre 2013, par Jim Miller

  I'm doing some video conversion with ffmpeg v. N-54271-g7f866c1 (a fresh pull from the git sources in late June 2013) on Fedora 19. One of the things I want to do is to concatenate two videos and then convert the result to an mp4. The following code is working well for me :

  ffmpeg -i video_a.mov -i video_b.mov -acodec libfaac -vcodec libx264 
  
       -preset fast -crf 22  -s 940x528 -pix_fmt yuv420p 
  
       -filter_complex '[0:1] [0:0] [1:1] [1:0]  concat=n=2:v=1:a=1 [v] [a]' 
  
       -map '[v]' -map '[a]' output.mp4

  except for a couple of older hunks of test video I've been using. On those, ffmpeg isn't finding the audio stream, and so the above call dies with ffmpeg complaining that Stream specifier ':1' in filtergraph description [0:1][0:0][1:1][1:0] concat=n=2:v=1:a=1 [v] [a] matches no streams. The catch, of course, is that there is an audio stream in the video ; it's just not getting found.

  When ffmpeg starts, I get a description of the input like so :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/var/www/priv/videorising7/raw_take_video/v2261-MTQxMzgwMDM4NzAx.mov':
  
    Metadata:
  
      major_brand     : qt  
  
      minor_version   : 537199360
  
      compatible_brands: qt  
  
      creation_time   : 2011-10-13 16:08:18
  
    Duration: 00:00:25.52, start: 0.000000, bitrate: 49 kb/s
  
      Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 608x342, 47 kb/s, 10.03 fps, 10 tbr, 1k tbn, 2k tbc
  
      Metadata:
  
        creation_time   : 2011-10-13 16:08:18
  
        handler_name    : Apple Alias Data Handler

  I suppose the video might just be so old (2006 ?) that I should be lucky that it plays at all. However, I'm able to run these videos through some other ffmpeg jobs (converting from .mov to .mp4, for instance), but those don't require explicitly referencing the audio and video tracks. Any insights out there ?

• Marketing Analytics in Banking : How to Be Effective and Compliant

  17 septembre 2024, par Daniel Crough — Banking and Financial Services, Marketing, Privacy, banks, finserv, fintech, marketing analytics

  Marketing analytics is reshaping decision-making in the financial sector, with recent studies showing it influences over half of all marketing strategies. However, marketers surveyed by MarketingWeek identify data and analytics as the biggest skill gap in their department.

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