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• Revision 5c05fbf6bb : Merge "Refactor 4x4 block level rd loop" into experimental

  30 mai 2013, par Jingning Han

  Changed Paths :
   Modify /vp9/encoder/vp9_rdopt.c

  
  
  Merge "Refactor 4x4 block level rd loop" into experimental

• avformat/matroskaenc : Remove unnecessary avio_tell(), avio_seek()

  22 janvier 2020, par Andreas Rheinhardt

  avformat/matroskaenc : Remove unnecessary avio_tell(), avio_seek()
  avio_close_dyn_buf() has a bug : When the write pointer does not point to
  
  the end of the written data when calling it (i.e. when one has performed
  
  a seek back to update already written data), it would not add padding to
  
  the end of the buffer, but to the current position, overwriting other
  
  data ; furthermore the reported size would be wrong (off by the amount of
  
  data it has overwritten with padding).
  In order not to run into this when updating already written elements or
  
  elements for which size has only been reserved, the Matroska muxer would
  
  first record the current position of the dynamic buffer, then seek to
  
  the desired position, perform the update and seek back to the earlier
  
  position.
  But now that end_ebml_master_crc32() does not make use of
  
  avio_close_dyn_buf() any more, this is no longer necessary.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  

  • [DH] libavformat/matroskaenc.c

• Encode buffer captured by OpenGL in C

  4 janvier 2020, par M. Ying

  I am trying to use OpenGL to capture the back buffer of my computer’s screen, and then H.264 encode the buffer using FFMPEG’s libavcodec library. The issue I’m having is that I would like to encode the video in AV_PIX_FMT_420P, but the back buffer capture function provided by OpenGL, glReadPixels(), only supports formats like GL_RGB. As you can see below, I try to use FFMPEG’s swscale() function to convert from RGB to YUV, but the following code crashes at the swscale() line. Any ideas on how I can encode the OpenGL backbuffer ?

  // CAPTURE BACK BUFFER USING OPENGL
  
      int width = 1280, height = 720;
  
      BYTE* pixels = (BYTE *) malloc(sizeof(BYTE));
  
      glReadPixels(0, 720, width, height, GL_RGB, GL_UNSIGNED_BYTE, pixels);
  
  
  
  //CREATE FFMPEG VARIABLES
  
      avcodec_register_all();
  
  
  
      AVCodec *codec;
  
      AVCodecContext *context;
  
      struct SwsContext *sws;
  
      AVPacket packet;
  
      AVFrame *frame;
  
  
  
      codec = avcodec_find_encoder(AV_CODEC_ID_H264);
  
      context = avcodec_alloc_context3(encoder->codec);
  
      context->dct_algo = FF_DCT_FASTINT;
  
      context->bit_rate = 400000;
  
      context->width = width;
  
      context->height = height;
  
      context->time_base.num = 1;
  
      context->time_base.den = 30;
  
      context->gop_size = 1;
  
      context->max_b_frames = 1;
  
      context->pix_fmt = AV_PIX_FMT_YUV420P;
  
  
  
      avcodec_open2(context, codec, NULL);
  
  
  
  // CONVERT TO YUV AND ENCODE
  
      int frame_size = avpicture_get_size(AV_PIX_FMT_YUV420P, out_width, out_height);
  
      encoder->frame_buffer = malloc(frame_size);
  
      avpicture_fill((AVPicture *) encoder->frame, (uint8_t *) encoder->frame_buffer, AV_PIX_FMT_YUV420P, out_width, out_height);
  
      sws = sws_getContext(in_width, in_height, AV_PIX_FMT_RGB32, out_width, out_height, AV_PIX_FMT_YUV420P, SWS_FAST_BILINEAR, 0, 0, 0);
  
  
  
      uint8_t *in_data[1] = {(uint8_t *) pixels};
  
      int in_linesize[1] = {width * 4};
  
  
  
  
  
  // PROGRAM CRASHES HERE
  
  
  
  
  
      sws_scale(encoder->sws, in_data, in_linesize, 0, encoder->in_height, encoder->frame->data, encoder->frame->linesize);
  
  
  
      av_free_packet(&packet);
  
      av_init_packet(&packet);
  
      int success;
  
  
  
      avcodec_encode_video2(context, &packet, frame, &success);