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• FFMPEG with x264 encoding

  21 février 2014, par mmmaaak

  I'm trying ton encode video from set of jpeg images to h264, using ffmpeg + x264 for it. I init AVCodecContext in such way:

  _outputCodec = avcodec_find_encoder(AV_CODEC_ID_H264);
  _outputCodecContext = avcodec_alloc_context3(_outputCodec);
  avcodec_get_context_defaults3(_outputCodecContext, _outputCodec);
  _outputCodecContext->width                 = _currentWidth;
  _outputCodecContext->height                = _currentHeight;
  _outputCodecContext->pix_fmt               = AV_PIX_FMT_YUV420P;
  _outputCodecContext->time_base.num         = 1;
  _outputCodecContext->time_base.den         = 25;
  _outputCodecContext->profile =FF_PROFILE_H264_BASELINE;
  _outputCodecContext->level = 50;
  

  avcodec_open return no errors, anything is OK, but when I call avcodec_encode_video2() I get such messages (I think it's from x264):

  using mv_range_thread = %d
  
  %s
  
  profile %s, level %s
  

  And then app crashs. My be there are more neccessary settings for codec context, when use x264 &&

• How to reduce the quality of H264 Video

  20 février 2014, par user3239282

  How to reduce the quality of H264 video using libx264 library, for transmission over internet.

  I want to reduce the quality, so that the frame size will become small and decreases the network latency while transferring over internet.

• Reduce Bandwidth requirement for Video Streaming

  19 février 2014, par user3239282

  Please suggest some points on, how to reduce the bandwidth requirement for a video stream.

  We are actually streaming the desktop across internet, Remote Access Application.

  Encoder : libx264.lib

  Decoder : Ffmpeg

  Codec : H264

  Following is how am configuring h264 for encoding:

      x264_param_default_preset(&this->m_x264Settings, "veryfast", "zerolatency");
      this->m_x264Settings.i_threads = 1;
      this->m_x264Settings.i_width = width / 2;
      this->m_x264Settings.i_height = height / 2;
      this->m_x264Settings.i_keyint_max = 10;//fps;
      this->m_x264Settings.b_intra_refresh = 1;
      this->m_x264Settings.i_fps_num = 10;
      this->m_x264Settings.i_fps_den = 1;
      // Intra refres:
      this->m_x264Settings.i_keyint_max = 25;
      this->m_x264Settings.b_intra_refresh = 1;
      //Rate control:
      this->m_x264Settings.rc.i_rc_method = X264_RC_CRF;
      this->m_x264Settings.rc.f_rf_constant = 25;
      this->m_x264Settings.rc.f_rf_constant_max = 35;
  
      //For streaming:
      this->m_x264Settings.b_repeat_headers = 1;
      this->m_x264Settings.b_annexb = 1;
      x264_param_apply_profile(&this->m_x264Settings, "baseline");
  
      this->m_width = width;
      this->m_height = height;
      this->m_encoder = x264_encoder_open(&this->m_x264Settings);
      x264_picture_alloc(&this->m_picIn,X264_CSP_I420,(width / 2),(height / 2));
      int sws_flags = SWS_BICUBIC;
      m_imgConverCtx = sws_getContext(width, height, PIX_FMT_RGB32, (width/2), (height/2), PIX_FMT_YUV420P,sws_flags, NULL, NULL, NULL);
  

  Thanks in advance, Paul.

• Android link many static libraries into shared library

  3 février 2014, par nmxprime

  i have 4 static libraries libavcodec.a libavutil.a libswscale.a libx264.a

  I want to link it with libmytest.so

  I tried below Android.mk script

  LOCAL_PATH := $(call my-dir)
  INITIAL_PATH := $(LOCAL_PATH)
  
  include $(CLEAR_VARS)
  LOCAL_MODULE := mytest
  
  LOCAL_SRC_FILES := mytest.c
  
  LOCAL_LDLIBS += -llog
  LOCAL_WHOLE_STATIC_LIBRARIES := libavutil libavcodec libswscale libx264
  
  include $(BUILD_SHARED_LIBRARY)
  

  mytest.c calls many functions from those libraries. The 4 libraries are placed inside PROJECTPATH\jni\.

  But i get undefined reference to all functions from those libraries.

  I tried giving LOCAL_ALLOW_UNDEFINED_SYMBOLS := truewhich allowed me to create shared library, but when i launch the app, i get

  01-22 07:15:15.650: E/AndroidRuntime(9655): Caused by: java.lang.UnsatisfiedLinkError: Cannot load library: reloc_library[1285]:  1868 cannot locate 'avcodec_register_all'...
  01-22 07:15:15.650: E/AndroidRuntime(9655):     at java.lang.Runtime.loadLibrary(Runtime.java:370)
  01-22 07:15:15.650: E/AndroidRuntime(9655):     at java.lang.System.loadLibrary(System.java:535)
  

• Building ffmpeg for ubuntu No working C compiler found

  27 janvier 2014, par Whoami

  I am building ffmpeg on ubuntu. I could able to build yasm-1.2.0, and next i tried building x264. x264 requires minumum of yasm-1.2.0, Hence i tried the below command to build x264.

  ./configure --prefix= --bindir= --extracflgs= --extra-ldflags= 
  

  I got the below error:

  No working C compiler found.
  

  Not sure what error i commited. Could someone kindly tell me what do i have to do?