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• Warning "i686-mingw32-pkg-config not found, library detection may fail" while cross compiling ffmpeg

  12 octobre 2015, par S B

  I get the following warning while trying to cross compile ffmpeg as below

  $ ./configure --enable-gpl --enable-version3 --enable-libgsm --enable-libvorbis --enable-libtheora --enable-libspeex --enable-libmp3lame --enable-libopenjpeg --enable-libopencore_amrwb --enable-libopencore_amrnb --arch=x86 --enable-runtime-cpudetect --enable-static --disable-shared --enable-libxvid --enable-libx264 --target-os=mingw32 --enable-avisynth --enable-w32threads --cross-prefix=i686-mingw32- --cc='i686-mingw32-gcc' --enable-memalign-hack --disable-doc --enable-avfilter --disable-ffplay --disable-ffserver --disable-ffprobe

  Configure ran fine but with the following warning

  License: GPL version 3 or later
  
  Creating config.mak and config.h...
  
  libavutil/avconfig.h is unchanged
  
  
  
  WARNING: i686-mingw32-pkg-config not found, library detection may fail.

  How do I provide i686-mingw32-pkg-config to configure ?

• avcodec/videotoolboxenc : add rc_max_bitrate control into videotoolbox

  14 mars 2017, par Steven Liu

  avcodec/videotoolboxenc : add rc_max_bitrate control into videotoolbox
  add kVTCompressionPropertyKey_DataRateLimits support by rc_max_bitrate
  Reviewed-by : Rick Kern <kernrj@gmail.com>
  
  Signed-off-by : Steven Liu <lq@chinaffmpeg.org>
  

  • [DH] libavcodec/videotoolboxenc.c

• Video streaming- control frame rate x264

  3 mars 2017, par H.A

  I’m new to video coding, I found this https://github.com/RafaelPalomar/H264LiveStreamer application code very useful to my project. I want to live stream a webcam over RTP . However, I’m having problem selecting the Frame Per Seconds (FPS). below is the function that controls the encoding param.

  void x264Encoder::initilize()
  
  {
  
    x264_param_default_preset(&parameters, "veryfast", "zerolatency");
  
    parameters.i_log_level =  X264_LOG_DEBUG;
  
    parameters.i_threads = 1;
  
    parameters.i_width = 640;
  
    parameters.i_height = 480;
  
    parameters.i_fps_num = 25;
  
    parameters.i_fps_den = 1;
  
    parameters.i_keyint_max = 25;
  
    parameters.b_intra_refresh = 1;
  
    parameters.rc.i_rc_method = X264_RC_CRF;
  
    parameters.rc.i_vbv_buffer_size = 1000000;
  
    parameters.rc.i_vbv_max_bitrate = 90000;
  
    parameters.rc.f_rf_constant = 25;
  
    parameters.rc.f_rf_constant_max = 35;
  
    parameters.i_sps_id = 7;
  
    // the following two value you should keep 1
  
    parameters.b_repeat_headers = 1;    // to get header before every I-Frame
  
    parameters.b_annexb = 1; // put start code in front of nal. we will remove start code later
  
    x264_param_apply_profile(&parameters, "baseline");
  
  
  
    encoder = x264_encoder_open(&parameters);
  
    x264_picture_alloc(&picture_in, X264_CSP_I420, parameters.i_width, parameters.i_height);
  
    picture_in.i_type = X264_TYPE_AUTO;
  
    picture_in.img.i_csp = X264_CSP_I420;
  
    // i have initilized my color space converter for BGR24 to YUV420 because my opencv video capture gives BGR24 image. You can initilize according to your input pixelFormat
  
    convertContext = sws_getContext(parameters.i_width,parameters.i_height, PIX_FMT_BGR24, parameters.i_width,parameters.i_height,PIX_FMT_YUV420P, SWS_FAST_BILINEAR, NULL, NULL, NULL);
  
  }

  I’m using VLC as client whatever number i set i_fps_num to, I always get 12-14 FPS. fore example, in VLC Codec tab shows 25 FPS but in Stream statistics tab it shows it only display 13 FPS on average. here is the X264 encoder output

  x264 [debug]: frame=  72 QP=22.24 NAL=2 Slice:P Poc:144 I:97   P:116  SKIP:987  size=1464 bytes
  
  x264 [info]: frame I:1     Avg QP:20.06  size: 17848
  
  x264 [info]: frame P:72    Avg QP:22.12  size:  1337
  
  x264 [info]: mb I  I16..4: 40.2%  0.0% 59.8%
  
  x264 [info]: mb P  I16..4:  3.1%  0.0%  2.3%  P16..4:  8.3%  2.0%  0.6%  0.0%  0.0%    skip:83.7%
  
  x264 [info]: coded y,uvDC,uvAC intra: 53.6% 46.4% 7.4% inter: 3.0% 1.6% 0.0%
  
  x264 [info]: i16 v,h,dc,p: 11% 65% 12% 12%
  
  x264 [info]: i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 15% 46% 16%  3%  4%  3%  5%  3%  6%
  
  x264 [info]: i8c dc,h,v,p: 46% 42% 10%  2%
  
  x264 [info]: kb/s:312.60

  the last frame number that was encoded is 72 while in VLC stream statistics it shows that 133 frames are Displayed and 66 blocks are decoded for 10 seconds streaming in addition the video playback is bursty.

  my question is how to change the x264 parameters to get 25 FPS ?