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• Stream OpenGL framebuffer over HTTP (via FFmpeg)

  17 juin 2016, par mOfl

  I have an OpenGL application of which rendered images need to be streamed over internet to mobile clients. Previously, it sufficed to simply record the rendering into a video file, which is already working, and now this should be extended to subsequent streaming.

  What is working right now :

  • Render a scene to an OpenGL framebuffer object
  • Capture the FBO content using NvIFR
  • Encode it to H.264 using NvENC (no CPU round trip required)
  • Download the encoded frame to host memory as a byte array
  • Append this frame to a video file

  None of this steps involves FFmpeg or any other library so far. I now want to replace the last step with "Stream the current frame’s byte array over internet" and I assume that using FFmpeg and FFserver would be a reasonable choice for this. Am I correct ? If not, what would be the proper way ?

  If so, how do I approach this within my C++ code ? As pointed out, the frame is already encoded. Also, there is no sound or other stuff, simply a H.264 encoded frame as byte array that is updated irregularly and should be converted into a steady video stream. I assume that this would be FFmpeg’s job and that the subsequent streaming via FFserver would be simple from there. What I don’t know is how to feed my data to FFmpeg in the first place, as all FFmpeg tutorials I found (in a non-exhaustive search) work on a file or webcam/capture device as data source, not volatile data in main memory.

  The file mentioned above that I am already able to create is a C++ file stream to which I append each single frame, meaning that different framerates of video and rendering are not treated correctly. This also needs to be taken care of at some point.

  Can somebody point me in the right direction ? Can I forward data from my application to FFmpeg to build a proper video feed without writing to the hard disk ? Tutorials are greatly appreciated. By the way FFmpeg/FFserver is not mandatory. If you have a better idea for streaming of OpenGL framebuffer contents, I’m eager to know.

• avcodec/vc1dec : Remove AVCodec.pix_fmts arrays

  5 février 2024, par Andreas Rheinhardt

  avcodec/vc1dec : Remove AVCodec.pix_fmts arrays
  They are not intended for decoders (for which there is the get_format
  
  callback in case the user has a choice).
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavcodec/vc1dec.c

• lavu : Adding ARIB STD-B67 (hybrid log-gamma) enum value and transfer function.

  21 avril 2016, par Neil Birkbeck

  lavu : Adding ARIB STD-B67 (hybrid log-gamma) enum value and transfer function.
  Adding hybrid log-gamma (https://en.wikipedia.org/wiki/Hybrid_Log-Gamma)
  
  based on the standardization in ARIB STD-B67 :
  
  http://www.arib.or.jp/english/html/overview/doc/2-STD-B67v1_0.pdf
  The choice of enum value of 18 is consistent with HEVC :
  
  http://phenix.it-sudparis.eu/jct/doc_end_user/current_document.php?id=10481
  And also with latest proposal for color format in mkv :
  
  https://mailarchive.ietf.org/arch/search/?email_list=cellar&gbt=1&q=Colour+Format+proposal
  The implementation assumes a nominal input range of [0, 1], which is
  
  consistent with HEVC.
  Signed-off-by : Neil Birkbeck <neil.birkbeck@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavutil/color_utils.c
  • [DH] libavutil/pixdesc.c
  • [DH] libavutil/pixfmt.h
  • [DH] tests/ref/fate/color_utils