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• FFMPEG : While decoding video, is possible to generate result to user's provided buffer ?

  26 octobre 2023, par cbel

  In ffmpeg decoding video scenario, H264 for example, typically we allocate an AVFrame and decode the compressed data, then we get the result from the member data and linesize of AVFrame. As following code :

  



  // input setting: data and size are a H264 data.
AVPacket avpkt;
av_init_packet(&avpkt);
avpkt.data = const_cast(data);
avpkt.size = size;

// decode video: H264 ---> YUV420
AVFrame *picture = avcodec_alloc_frame();
int len = avcodec_decode_video2(context, picture, &got_picture, &avpkt);


  



  We may use the result to do something other tasks, for example, using DirectX9 to render. That is, to prepare buffers(DirectX9 Textures), and copy from the result of decoding.

  



  D3DLOCKED_RECT lrY;
D3DLOCKED_RECT lrU;
D3DLOCKED_RECT lrV;
textureY->LockRect(0, &lrY, NULL, 0);
textureU->LockRect(0, &lrU, NULL, 0);
textureV->LockRect(0, &lrV, NULL, 0);

// copy YUV420: picture->data ---> lr.pBits.
my_copy_image_function(picture->data[0], picture->linesize[0], lrY.pBits, lrY.Pitch, width, height);
my_copy_image_function(picture->data[1], picture->linesize[1], lrU.pBits, lrU.Pitch, width / 2, height / 2);
my_copy_image_function(picture->data[2], picture->linesize[2], lrV.pBits, lrV.Pitch, width / 2, height / 2);


  



  This process is considered that 2 copy happens(ffmpeg copy result to picture->data, and then copy picture->data to DirectX9 Texture).

  



  My question is : is it possible to improve the process to only 1 copy ? On the other hand, can we provide buffers(pBits, the buffer of DirectX9 textures) to ffmpeg, and decode function results to buffer of DirectX9 texture, not to buffers of AVFrame ?

  


• We are hiring engineers to build an awesome product and platform used by millions of people

  16 février 2016, par Piwik Core Team — Uncategorized

  Are you ready for a new challenge ? Or maybe you know someone who is looking for a change ? We have some exciting problems to solve and are looking for senior developers to work with us and our community on our open source Piwik Analytics platform. Piwik is used by more than one million websites all over the world. It is deployed on more than 300.000 servers and some users track more than 1 billion actions per month.

  What is it like to work on Piwik ?

  We develop this software using modern PHP, MySQL, Redis, AngularJS and more. We provide several kind of APIs and a plugin architecture to allow developers to extend and change Piwik to their needs. However, we would not be Piwik if we stopped at this point ! We want to turn Piwik into an even more awesome product and platform.
  You can imagine there is a lot to do and many challenges to face !

  While one part is to always make Piwik scale better and to improve UI and UX, we also want to provide simple APIs to make the life of developers as pleasant as possible. We aim to solve things the right way and our thousands of unit, integration, system, JavaScript and screenshot tests help us to innovate and to not be afraid of change. We like clean code and constant improvements.

  The Piwik team lives in New Zealand and Europe (Germany). We do the vast majority of our collaboration online. Our values include being open, transparent and sharing knowledge. For this we use tools like GitHub and Slack to communicate and Quake servers to take our minds off complex challenges. We are a small, flexible team, so when you come aboard, you will play an integral part in engineering and have a big impact on the product loved by so many people. You’ll help to create a welcoming environment for new contributors and set an example with your development practices and communications skills.

  Apply now, or spread the word !

  If you have strong skills in PHP send us an email with your CV and tell us a little about yourself and your experience in engineering complex applications.

  Apply for a job here http://piwik.org/jobs/ and if you’re maybe not the right candidate, contribute to the project by sharing this blog post and by sending it to your friends !

• lavc : deprecate AV_CODEC_FLAG_DROPCHANGED

  9 juillet 2023, par Anton Khirnov

  lavc : deprecate AV_CODEC_FLAG_DROPCHANGED
  This decoding flag makes decoders drop all frames after a parameter
  
  change, but what exactly constitutes a parameter change is not well
  
  defined and will typically depend on the exact use case.
  
  This functionality then does not belong in libavcodec, but rather in
  
  user code
  

  • [DH] doc/APIchanges
  • [DH] libavcodec/avcodec.c
  • [DH] libavcodec/avcodec.h
  • [DH] libavcodec/decode.c
  • [DH] libavcodec/internal.h
  • [DH] libavcodec/options_table.h
  • [DH] libavcodec/version_major.h