Recherche avancée

Sur d’autres sites (6046)

• 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 ?

• 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 ?

• Adjust MP3 Files Volume and save it to new file [duplicate]

  5 mai 2017, par Gio Vanno

  This question already has an answer here :

  • Mute specified sections of an audio file using ffmpeg
    
    1 answer
    

  I’m trying to make an audio-editing app here
  This program can adjust(increase and decrease) the mp3 file volume at the specific time(adjust start time and finish time, example : from 00:10 to 00:20) and we can save it to a new mp3 file.

  my questions is :

  -Does ffmpeg work for it ?

  -is there any alternative besides ffmpeg ?

  Thank you