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• 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.

• C++, FFMpeg : Unable to find any decoder or encoder

  14 juillet 2016, par AmN

  I have been using this sample https://ffmpeg.org/doxygen/trunk/decoding__encoding_8c.html as reference for my C++ application. I have used the same code as in the given page. I have linked the libraries, placed the dlls and compiled with no errors. Everything works except that it always throws : Codec not found error.

  /* find the MPEG-1 video decoder */
  
  codec = avcodec_find_decoder(AV_CODEC_ID_MP2);
  
  if (!codec) {
  
      fprintf(stderr, "Codec not found\n");
  
      exit(1);
  
  }

  I have changed the line to AV_CODEC_ID_MP2 in this, just to test if only the MPEG codex was missing but seems like all are missing. I have tried changing this to multiple codecs as defined in avcodec.h file (enum AVCodecID, line 189), but all return "Codec not found".

  Am I missing something ?

  Compiler : Microsoft Visual Studio 2015 Community Edition
  Project Type : QTProject

  Oh and I am trying to make a Video Player just to enhance my c++ skills during these holidays. First I was trying QTMediaPlayer Widget, but it was throwing crazy errors on "DirectShowPlay::doRender" or something like that. So I switched to FFMpeg, but this too doesn’t work.

  Thank you for reading my question.

• Wave Goodbye ; What About VP8/WebM ?

  7 août 2010, par Multimedia Mike — Multimedia PressWatch

  Some big news in the geek community this past week came in the form of Google’s announcement that it would no longer be caring about its vaunted Wave technology. I was mildly heartbroken by this since I had honestly wanted to try Google Wave. Then I remembered why I never got a chance to try it : they made it an exclusive club at the beginning. I really did try to glean some utility out of the concept by reading documentation and watching videos and I had some ideas about how I might apply it. Then again, I try to think of a use for nearly any technology that crosses my path.

  It still struck me as odd : Why would Google claim that no one was interested in their platform when they wouldn’t give anyone a chance to try it out ? A little digging reveals that Google did open it for general use back around May 18. That date sounds familiar... oh yeah, VP8 was open sourced right around the same time. Maybe that’s why I don’t remember hearing anything about Wave at the time.

  But now I’m wondering about VP8 and WebM. How long do you think it might be before Google loses interest in these initiatives as well and reassigns their engineering resources ? Fortunately, if they did do that, the technology would live on thanks to the efforts of FFmpeg developers. A multimedia format has a far more clear-cut use case than Google Wave.