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• ffmpeg library performance for decoding h.264 for embedded device

  2 avril 2015, par pasifus

  I have some confuse when tried to compile and run decode h.264 on ARM and MIPS architecture.

  I have two embedded devices. I tired to run simple code that read h264 format from file and decode it to h264 in loop in maximum speed (without sleep between frames)

  I found that it too slow in there devices.
  I tested HD video (720p/25fps)

  1. MIPS32® 1004K (700MHz) it was 4 fps average.
  2. Raspberry Pi Model B (700MHz) it also was 4 fps average. (i know that raspberry have GPU to decoding/encoding)

  A also check it on my virtual machine on ubuntu i686 (1300MHz) and it was 200 fps average.

  The question : why it so different preference ? Somebody know how to increase decoding preference on MIPS32® 1004K architecture ?

  #include 
  
  #include 
  
  #include 
  
  #include 
  
  
  
  #include <sys></sys>time.h>
  
  #include 
  
  
  
  #include "libavcodec/avcodec.h"
  
  #include "libavutil/mathematics.h"
  
  
  
  #define INBUF_SIZE 80000
  
  
  
  
  
  static long get_time_diff(struct timeval time_now) {
  
     struct timeval time_now2;
  
     gettimeofday(&amp;time_now2,0);
  
     return time_now2.tv_sec*1.e6 - time_now.tv_sec*1.e6 + time_now2.tv_usec - time_now.tv_usec;
  
  }
  
  
  
  int main(int argc, char **argv)
  
  {
  
      AVCodec *codec;
  
      AVCodecContext *c= NULL;
  
      AVCodecParserContext *parser = NULL;
  
      int frame, got_picture, len2, len;
  
      const char *filename;
  
      FILE *f;
  
      AVFrame *picture;
  
      char *arghwtf = malloc(INBUF_SIZE);
  
      uint64_t in_len;
  
      int pts, dts;
  
      struct timeval t,t2;
  
      float inv_fps = 1e6/23.98;
  
      AVPacket avpkt;
  
  
  
      // register all the codecs
  
      avcodec_register_all();
  
  
  
      // log level
  
      av_log_set_level(AV_LOG_PANIC|AV_LOG_FATAL|AV_LOG_ERROR|AV_LOG_WARNING);
  
  
  
      filename = argv[1];
  
  
  
      av_init_packet(&amp;avpkt);
  
  
  
      printf("Decoding file %s...\n", filename);
  
  
  
      // find the H.264 video decoder
  
      codec = avcodec_find_decoder(CODEC_ID_H264);
  
      if (!codec)
  
      {
  
          fprintf(stderr, "codec not found\n");
  
          exit(1);
  
      }
  
  
  
      c = avcodec_alloc_context3(codec);
  
      picture = avcodec_alloc_frame();
  
  
  
      // skiploopfilter=all
  
      c->skip_loop_filter = 48;
  
  
  
      AVDictionary* dictionary = NULL;
  
      if (avcodec_open2(c, codec, &amp;dictionary) &lt; 0)
  
      {
  
          fprintf(stderr, "could not open codec\n");
  
          exit(1);
  
      }
  
  
  
      // the codec gives us the frame size, in samples
  
      parser = av_parser_init(c->codec_id);
  
      parser->flags |= PARSER_FLAG_ONCE;
  
  
  
      f = fopen(filename, "rb");
  
      if (!f)
  
      {
  
          fprintf(stderr, "could not open %s\n", filename);
  
          exit(1);
  
      }
  
  
  
      frame = 0;
  
      gettimeofday(&amp;t, 0);
  
      if(fread(arghwtf, 1, INBUF_SIZE, f) == 0)
  
      {
  
          exit(1);
  
      }
  
  
  
      in_len = 80000;
  
      gettimeofday(&amp;t2, 0);
  
      while (in_len > 0 &amp;&amp; !feof(f))
  
      {
  
          len = av_parser_parse2(parser, c, &amp;avpkt.data, &amp;avpkt.size, arghwtf, in_len, pts, dts, AV_NOPTS_VALUE);
  
  
  
          len2 = avcodec_decode_video2(c, picture, &amp;got_picture, &amp;avpkt);
  
          if (len2 &lt; 0) {
  
              fprintf(stderr, "Error while decoding frame %d\n", frame);
  
              exit(1);
  
          }
  
  
  
          if (got_picture)
  
          {
  
              fprintf(stderr, "\rDisplaying %c %dx%d :frame %3d (%02d:%03d)...", av_get_picture_type_char(picture->pict_type), c->width, c->height, frame, (int)(get_time_diff(t)/1000000), (int)((get_time_diff(t)/1000)%1000));
  
              fflush(stderr);
  
  
  
              frame++;
  
          }
  
  
  
          memcpy(arghwtf, arghwtf + len, 80000-len);
  
          fread(arghwtf + 80000 - len, 1, len, f);
  
      }
  
  
  
      fclose(f);
  
      avcodec_close(c);
  
      av_free(c);
  
      av_free(picture);
  
      printf("\n");
  
      printf("Avarage fps: %d\n", (int)(((double)frame)/(double)(get_time_diff(t)/1000)*1000));
  
  
  
      return 0;
  
  }

• Including ffmpeg in C program

  20 mars 2015, par Nick

  I’m using dranger’s ffmpeg tutorial :

  http://dranger.com/ffmpeg/tutorial01.html

  I’m stuck trying to compile the first tutorial. I downloaded ffmpeg using homebrew, but the compile command provided in the tutorial did not work :

  gcc -o tutorial01 tutorial01.c -lavutil -lavformat -lavcodec -lz -lavutil -lm

  Based on my experience with SDL, I made a separate file that simply included one of the ffmpeg headers, and changed the compile command to :

  gcc main.c -I/usr/local/Cellar/ffmpeg/2.6.1/include

  It was actually able to compile. But when I tried this with the tutorial file using this command :

  gcc tutorial01.c -I/usr/local/Cellar/ffmpeg/2.6.1/include

  I got these errors :

  Undefined symbols for architecture x86_64:
  
    "_av_dump_format", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_av_frame_alloc", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_av_frame_free", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_av_free", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_av_free_packet", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_av_malloc", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_av_read_frame", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_av_register_all", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_avcodec_alloc_context3", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_avcodec_close", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_avcodec_copy_context", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_avcodec_decode_video2", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_avcodec_find_decoder", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_avcodec_open2", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_avformat_close_input", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_avformat_find_stream_info", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_avformat_open_input", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_avpicture_fill", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_avpicture_get_size", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_sws_getContext", referenced from:
  
        _main in tutorial01-9cd32b.o
  
    "_sws_scale", referenced from:
  
        _main in tutorial01-9cd32b.o

  I figured I had to add the extra things from the tutorial, so I did

  gcc tutorial01.c -I/usr/local/Cellar/ffmpeg/2.6.1/include -lavutil -lavformat -lavcodec -lz -lavutil -lm

  But then I got this error

  ld: library not found for -lavutil
  
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  
  make: *** [all] Error 1

  I feel like the directory /usr/local/Cellar/ffmpeg/2.6.1/lib might be relevant, it includes the files :

  libavcodec.56.26.100.dylib  libavresample.dylib
  
  libavcodec.56.dylib         libavutil.54.20.100.dylib
  
  libavcodec.a                libavutil.54.dylib
  
  libavcodec.dylib            libavutil.a
  
  libavdevice.56.4.100.dylib  libavutil.dylib
  
  libavdevice.56.dylib        libpostproc.53.3.100.dylib
  
  libavdevice.a               libpostproc.53.dylib
  
  libavdevice.dylib           libpostproc.a
  
  libavfilter.5.11.102.dylib  libpostproc.dylib
  
  libavfilter.5.dylib         libswresample.1.1.100.dylib
  
  libavfilter.a               libswresample.1.dylib
  
  libavfilter.dylib           libswresample.a
  
  libavformat.56.25.101.dylib libswresample.dylib
  
  libavformat.56.dylib        libswscale.3.1.101.dylib
  
  libavformat.a               libswscale.3.dylib
  
  libavformat.dylib           libswscale.a
  
  libavresample.2.1.0.dylib   libswscale.dylib
  
  libavresample.2.dylib       pkgconfig
  
  libavresample.a

  I’m often really lost trying to compile downloaded libraries (it took me a long time to get SDL to compile, and when I finally got it to work I still didn’t completely understand why).

  If anyone could help me understand how these things work, and specifically help me compile this first tutorial, I would be extremely grateful.

  Thank you for your time.

• avcodec/vc1_mc : move median4() to mathops.h

  14 février 2015, par zhaoxiu.zeng

  avcodec/vc1_mc : move median4() to mathops.h
  Needed for architecture specific optimizations
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavcodec/mathops.h
  • [DH] libavcodec/vc1_mc.c