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• Warning when streaming with vlc and x264 at a slow framerate

  24 octobre 2013, par jln611

  I am using libvlc and libx264 to stream images from a C++ program. It provides libvlc uncompressed images using the get and release callback. Everything seems to work ok at higher framerate (over 12 fps) but when I try slower framerates (from 1 to 10), I got the following warnings :

  [030d5c6c] mux_ts mux debug: adjusting rate at 0/500000 (3/0)
  [030d5c6c] main mux warning: late buffer for mux input (2127998)
  [030d5c6c] mux_ts mux debug: adjusting rate at 0/500000 (3/0)
  

  Over 4 fps, I am able to get the stream (for instance with vlc GUI) but under 4 fps, I got nothing, or sometimes a freeze image. The libvlc arguments are the following :

  --imem-get=15543672 --imem-release=15538482 --imem-data=0 --imem-codec=RV24 --imem-cookie=aCookie --imem-cat=2 --imem-height=960 --imem-width=1280 --verbose=2 --imem-id=1 --imem-group=1 --imem-fps=2.000000 -vvv --play-and-exit --no-audio --sout=#transcode{vcodec=h264, fps=2.000000, vb=200k,venc=x264{preset=ultrafast}}:standard{access=http,mux=ts,dst=0.0.0.0:8091/video}
  

  Any hints would be appreciated.

• "File for preset 'libx264-hq' not found" error in Eclipse (Windows)

  22 octobre 2013, par Rita

  When I use the command line to execute, f.e.,

  "ffmpeg -i input.avi -vcodec libx264 -vpre libx264-hq -b 1500k output.mp4"

  the .mp4 file with h264 is successfully created. However, if I try to execute the same command on Eclipse I get the "File for preset 'libx264-hq' not found" error even though I've already created the preset file and downloaded the library (because I used to have that same error in the command line).

  My question is: do I have to put the preset file anywhere else in order to make it function through Eclipse?

  Btw, I'm using Windows. There's a lack of information about ffmpeg for Windows.

• Streaming output of x264_encoder_encode

  11 octobre 2013, par user2660369

  how can I stream the output of x264_encoder_encode over UDP?

  This is my Init_x264-function:

  x264_param_t param;
  x264_param_default_preset(&param, "veryfast", "zerolatency");
  param.i_threads = 1;
  param.i_width = width;
  param.i_height = height;
  param.i_fps_num = 30;
  param.i_fps_den = 1;
  
  param.i_keyint_max = 30;
  param.b_intra_refresh = 1;
  
  param.rc.i_rc_method = X264_RC_CRF;
  param.rc.f_rf_constant = 25;
  param.rc.f_rf_constant_max = 35;
  
  param.b_annexb = 1;
  param.b_repeat_headers = 1;
  
  param.i_log_level = X264_LOG_DEBUG;
  
  x264_param_apply_profile(&param, "baseline");
  
  encoder = x264_encoder_open(&param);
  
  picIn = new x264_picture_t;
  picOut = new x264_picture_t;
  x264_picture_alloc(picIn, X264_CSP_I420, width, height);
  x264_encoder_parameters(encoder, &param);
  

  Now instead of saving the output of x264_encoder_encode to disk (using fwrite) I tried to just send it over UDP to my destination. I tried to play it with avplay, but it fails:

  [h264 @ 0x7f83f0012e80] non-existing PPS 0 referenced
  [h264 @ 0x7f83f0012e80] decode_slice_header error
  [h264 @ 0x7f83f0012e80] no frame!
  [h264 @ 0x7f83f0012e80] non-existing PPS 0 referenced
  [h264 @ 0x7f83f0012e80] decode_slice_header error
  [h264 @ 0x7f83f0012e80] no frame!
  

  With vlc I got different error messages, mostly about missing headers.

• Use ActionScript and Lib Flash to Record h.264 Webcam In Browser w/o Media Server ?

  10 octobre 2013, par Jake Steele

  Was wondering if its possible to use ActionScript and maybe wrap libx264 to record and encode a video inside the browser in h.264 format for playback.

  If anyone has any examples of something close to this please hook me up!

• libx264 - Setting up AVCodecContext for HD & SD capturing

  8 octobre 2013, par moose

  I'm trying to configure the AVCodecContext properly in order to capture HD in real-time (1080i) and SD (720 x 576) - also interlaced. I'm using libx264 with the ffmpeg static lib on Windows OS. If anybody can help with flags, gop_size, max_b_frames and all other AVCodecContext's members...

  For example, I guess I should have CODEC_FLAG_INTERLACED_ME | CODEC_FLAG_INTERLACED_DCT flags set. However, what I need is the whole story on how to set all this up.