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• Recommendations for real-time pixel-level analysis of television (TV) video

  6 décembre 2011, par Randall Cook

  [Note : This is a rewrite of an earlier question that was considered inappropriate and closed.]

  I need to do some pixel-level analysis of television (TV) video. The exact nature of this analysis is not pertinent, but it basically involves looking at every pixel of every frame of TV video, starting from an MPEG-2 transport stream. The host platform will be server-class, multiprocessor 64-bit Linux machines.

  I need a library that can handle the decoding of the transport stream and present me with the image data in real-time. OpenCV and ffmpeg are two libraries that I am considering for this work. OpenCV is appealing because I have heard it has easy to use APIs and rich image analysis support, but I have no experience using it. I have used ffmpeg in the past for extracting video frame data from files for analysis, but it lacks image analysis support (though Intel's IPP can supplement).

  In addition to general recommendations for approaches to this problem (excluding the actual image analysis), I have some more specific questions that would help me get started :

  1. Are ffmpeg or OpenCV commonly used in industry as a foundation for real-time
     video analysis, or is there something else I should be looking at ?
  2. Can OpenCV decode video frames in real time, and still leave enough
     CPU left over to do nontrivial image analysis, also in real-time ?
  3. Is sufficient to use ffpmeg for MPEG-2 transport stream decoding, or
     is it preferable to just use an MPEG-2 decoding library directly (and if so, which one) ?
  4. Are there particular pixel formats for the output frames that ffmpeg
     or OpenCV is particularly efficient at producing (like RGB, YUV, or YUV422, etc) ?

• libvpx : check if CQ level is in correct bounds

  25 février 2013, par slhck

  libvpx : check if CQ level is in correct bounds

• Trying to determine h.264 profile & level pragmatically

  23 juin 2012, par kryptobs2000

  Ideally the solution would be in python and cross platform, but that's probably not too likely, so all I require is it work in linux, and I can use a c extension to interface w/python if necessary. I see there is a python binding for ffmpeg which I was thinking about using, however I can't figure out how to determine the profile and level as it is, with fmmpeg or anything else, much less do it pragmatically. Google is not much help on the matter either.

  I've been able to determine what features I'd be looking for if I needed to determine the profile and levels manually then I can do that, but then that leads to the question, can ffmpeg then determine if the video was encoded with that feature set ? I guess what I'm wondering to that effect is, is it perhaps not possible to fully determine the level and specific profile after encoding ? I would think you'd have to know in order to decode it, but maybe not ; that would explain why I can't find any information on it. I've been toying with this on and off for awhile, but recently decided to consider a project I'd been thinking about, but this is one of this big things holding me back.