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• armv6 : Accelerate ff_fft_calc for general case (nbits != 4)

  16 juillet 2014, par Ben Avison

  armv6 : Accelerate ff_fft_calc for general case (nbits != 4)
  The previous implementation targeted DTS Coherent Acoustics, which only
  
  requires nbits == 4 (fft16()). This case was (and still is) linked directly
  
  rather than being indirected through ff_fft_calc_vfp(), but now the full
  
  range from radix-4 up to radix-65536 is available. This benefits other codecs
  
  such as AAC and AC3.
  The implementaion is based upon the C version, with each routine larger than
  
  radix-16 calling a hierarchy of smaller FFT functions, then performing a
  
  post-processing pass. This pass benefits a lot from loop unrolling to
  
  counter the long pipelines in the VFP. A relaxed calling standard also
  
  reduces the overhead of the call hierarchy, and avoiding the excessive
  
  inlining performed by GCC probably helps with I-cache utilisation too.
  I benchmarked the result by measuring the number of gperftools samples that
  
  hit anywhere in the AAC decoder (starting from aac_decode_frame()) or
  
  specifically in the FFT routines (fft4() to fft512() and pass()) for the
  
  same sample AAC stream :
                Before          After
  
                Mean   StdDev   Mean   StdDev  Confidence  Change
  
  Audio decode  2245.5 53.1     1599.6 43.8    100.0%      +40.4%
  
  FFT routines  940.6  22.0     348.1  20.8    100.0%      +170.2%
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DBH] libavcodec/arm/fft_init_arm.c
  • [DBH] libavcodec/arm/fft_vfp.S

• In using FFmpeg SDK, the mp4 file encoded with HEVC(x265) codec not playing in general player

  26 octobre 2016, par Wiktor Kostus

  Everyone !

  I am going to encode mp4 file (x264 codec) to HEVC(x265) codec using FFmpeg SDK.
  Also, I am going to write the encoded file into .mp4 file container.

  The problem I am facing is that the encoded file is played well in FFplay and VLC player but it isn’t played in general HEVC player.

  I used the general method to encode the codec in FFmpeg SDK. I think I have a mistake to use the avformat_write_header() function. It seems that some parameters to pass AVFormatContext, AVOutputFormat or AVCodecContext for HEVC codec are missing.

  Finally, I would like to know the way to write the HEVC codec into mp4 container. I also would like to know the right parameters related to Context instances for HEVC codec.

  Below is my tiny demo code. (I have skipped the code related to InputStream since I think I have a mistake in OutputStream)

  AVFormatContext* pFormatCtx;
  
  AVOutputFormat* fmt;
  
  AVStream* video_st;
  
  AVCodecContext* pCodecCtx;
  
  
  
  const char* out_file = "output.mp4";
  
  
  
  pFormatCtx = avformat_alloc_context();
  
  fmt = av_guess_format(NULL, out_file, NULL);
  
  pFormatCtx->oformat = fmt;
  
  
  
  if (avio_open(&pFormatCtx->pb, out_file, AVIO_FLAG_READ_WRITE) < 0){
  
      printf("Failed to open output file! \n");
  
      return -1;
  
  }
  
  
  
  video_st = avformat_new_stream(pFormatCtx, 0);
  
  video_st->time_base.num = 1; 
  
  video_st->time_base.den = 25;  
  
  
  
  if (video_st==NULL){
  
      return -1;
  
  }
  
  //Param that must set
  
  pCodecCtx = video_st->codec;
  
  pCodecCtx->codec_id =AV_CODEC_ID_HEVC;
  
  pCodecCtx->codec_id = fmt->video_codec;
  
  pCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
  
  pCodecCtx->pix_fmt = PIX_FMT_YUV420P;
  
  pCodecCtx->width = in_w;  
  
  pCodecCtx->height = in_h;
  
  pCodecCtx->time_base.num = 1;  
  
  pCodecCtx->time_base.den = 25;  
  
  pCodecCtx->bit_rate = 400000;  
  
  pCodecCtx->gop_size=250;
  
  pCodecCtx->qmin = 10;
  
  pCodecCtx->qmax = 51;
  
  pCodecCtx->max_b_frames = 1;
  
  
  
  // Set Option
  
  AVDictionary *param = 0;
  
  av_dict_set(&param, "preset", "ultrafast", 0);
  
  av_dict_set(&param, "tune", "zero-latency", 0);
  
  av_dict_set(&param, "x265-params", "crf=25", 0);
  
  
  
  pCodec = avcodec_find_encoder(pCodecCtx->codec_id);
  
  if (!pCodec){
  
      printf("Can not find encoder! \n");
  
      return -1;
  
  }
  
  if (avcodec_open2(pCodecCtx, pCodec,&param) < 0){
  
      printf("Failed to open encoder! \n");
  
      return -1;
  
  }
  
  
  
  //Write File Header
  
  avformat_write_header(pFormatCtx, NULL); <------ I think it takes any error in here.

  Help me what I am doing wrong.

  Thank you for your consider.

• Revision b62ddd5f8b : General code cleanup. Switching from mi_{width, height}_log2 and b_{width, heig

  28 août 2013, par Dmitry Kovalev

  Changed Paths :
   Modify /vp9/decoder/vp9_decodframe.c

  
   Modify /vp9/encoder/vp9_bitstream.c

  
   Modify /vp9/encoder/vp9_encodeframe.c

  
   Modify /vp9/encoder/vp9_rdopt.c

  
  
  General code cleanup.

  Switching from mi_width, height_log2 and b_width, height_log2 to
  num_8x8_blocks_wide, high and num_4x4_blocks_wide, high. Removing
  redundant code, adding const.

  Change-Id : Iaab2207590fd24d0b76999071778d1395dc5cd5d