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• Encoded images into H264 video are skipped and/or missing ?

  25 juillet 2013, par Jona

  I'm trying to encode images into an H264 MP4 video. The issues I'm having is that some of the images are skipped or at the end of the video simply missing. I need the video to play every single image I encode since it is an animation.

  Any help setting the encoder properly would be greatly appreciated !

  Encoder settings :

  AVCodecContext *c;
  
  ...
  
  c->codec_id = AV_CODEC_ID_H264;
  
  c->bit_rate = mOutputWidth*mOutputHeight*4;//400000;
  
  /* Resolution must be a multiple of two. */
  
  c->width    = mOutputWidth;
  
  c->height   = mOutputHeight;
  
      /* timebase: This is the fundamental unit of time (in seconds) in terms
  
       * of which frame timestamps are represented. For fixed-fps content,
  
       * timebase should be 1/framerate and timestamp increments should be
  
       * identical to 1. */
  
  c->time_base.den = mFps;
  
  c->time_base.num = 1;
  
  c->gop_size      = 12; /* emit one intra frame every twelve frames at most */
  
  c->pix_fmt       = AV_PIX_FMT_YUV420P;
  
  ...
  
  av_dict_set(&pOptions, "preset", "medium", 0);
  
  av_dict_set(&pOptions, "tune", "animation", 0);
  
  
  
  /* open the codec */
  
  ret = avcodec_open2(c, codec, &pOptions);
  
  if (ret < 0) {
  
      LOGE("Could not open video codec: %s", av_err2str(ret));
  
      return -1;
  
  }

  Update 07/24/13 :
  I was able to achieve a better video by setting the gop_size=FPS and writing the last video frame repeatedly FPS+1 times seemed to resolve all issues. To me it seems odd to do that but might be something standard in the video encoding world ? Any tips feedback about this ?

• Troll spirit

  15 juin 2013, par Mans — Law and liberty

  Last week’s announcements from the White House of steps being taken to begin fighting back against patent trolls, along with legislation passed in Vermont for the same purpose, are worthy of praise. Whether they prove effective or not, they are a sign of the problem finally having been recognised by the highest authorities. That said, only one aspect of the issue is addressed, that of non-practising entities or trolls. Little effort is being made to stymie troll-like behaviour from otherwise legitimate actors. While a stake is driven through the heart of the troll, its spirit remains free to roam the corporate world, and like a demon of darkness it possesses companies, compelling them to engage in the very practices we seek to eradicate.

  The demon

  The most damaging, when wielded by a troll, are those patents with vague or overly broad claims. These can easily be asserted against large numbers of alleged infringers, many of which likely choose to settle out of court rather than risk an expensive litigation process with uncertain outcome. Such negotiations are frequently subject to non-disclosure agreements prohibiting publication of details in any deals, or even the existence thereof. As a result, an accused has no way of assessing a fair price for a licence (assuming the patent is in fact valid), and the patent holder can thus extract from each would-be infringer precisely as much as they are willing or able to pay to avoid a lawsuit.

  At the root of this problem is the ease with which applications for the patents in question are granted. Given the volume of patent applications, it is hardly reasonable to demand a hugely more extensive examination process than currently takes place (although some improvements here are no doubt possible) ; after all, a speedy decision is in the best interest of all parties. The solution must evidently be found elsewhere.

  The exorcism

  An obvious cure to the problem is the abolishment of the patent system. As this is clearly not feasible today, more practical, albeit less effective, remedies must be sought. A few ideas follow.

  Make patent validity all or nothing

  Change the rules such that any claim being found invalid cancels the patent its entirety. With the full patent at stake in this manner, companies would be discouraged from gambling on frivolous claims and encouraged to conduct a more thorough background investigation before filing.

  Maintain a registry of licences

  Require that all patent licence agreements be filed in an open, easily searchable registry. This would hopefully increase fairness in licensing deals.

  Mandate reimbursement of licence fees for invalidated patents

  If a patent is challenged and found invalid, require that the owner reimburse any licence fees previously collected for the patent in question. Apart from being morally right, this could act as a deterrent to over-charging. The amount requested for a licence would likely be balanced against the risk of being made to pay it all back later, resulting in lower licence fees for low-confidence patents.

  These suggestions, alone or together, will not completely eradicate the problems of patent abuse. They are but small steps towards a more thorough overhaul of a system increasingly ill-suited to the nature and pace of modern technological development.

• ffmpeg watermarking processing is very slow

  25 février 2014, par Hitesh Rohilla

  I am working on a video processing project and using ffmpeg for watermarking. I achieve exactly what i want but the problem is that the process is very very slow.

  I am using a Intel Smart 2nd gen family Core-i5 Processor with 4GB RAM on a 32 bit operating system Microsoft Windows-8 on a 64-bit CPU.

  I tried watermarking a video [mp4] of length 1:30 Min. size of file is 1.5GB

  Whole process accomplish in 3 Hrs to watermark my video file and what i noticed while process is that ffmpeg was processing 28 frames per sec first and then later it slow down up to 20 frames per second. a normal human watch video with frame rate of 30 frame per second and process was even slower then this that's why it took more time [3 Hrs] then the actual length of video itself [1:33]

  What i think to make process efficient is to use ffmpeg Watermarking Source Code and modify it somewhat...

  I want to ask if someone have achieve fast watermarking before by any other way or have modified this code to achieve faster process in order to save my time...