Recherche avancée

Sur d’autres sites (8141)

• Révision 92681 : Suppression des barres verticales entre les boutons, maintenant qu’ils sont bien ...

  6 novembre 2015, par nicolas.dorigny@gmail.com

• Decoding with FFMPEG on Visual Studio 2010

  6 juin 2013, par user2439801

  I just started using FFMPEG with C++ and try to code an audio decoder then write the decoded audio into a file.

  However i'm not sure about which data to write to the output file. As far as i know from looking at the sample codes it seems to be the AVFrame -> data[0].
  But when i try to print it on the consoles, i get some random numbers that are different each time i run the program. And when i try to write this AVFrame->data[0] into a file i keep getting an error.

  So my question is how can i write the decoded audio after i call the function av_codec_decode_audio4 ?

  Below i attached my code and i pass the argument "C :\02.mp3" which is a path for a valid mp3 file on my PC.

  Thank you for your help.

  // TestFFMPEG.cpp : Audio Decoder
  
  //
  
  
  
  #include "stdafx.h"
  
  
  
  #include <iostream>
  
  #include <fstream>
  
  #include <sstream>
  
  
  
  extern "C" {
  
      #include 
  
      #include 
  
      #include 
  
  
  
  }
  
  
  
  using namespace std;
  
  
  
  
  
  int main(int argc, char* argv[])
  
  {
  
  int audioStream = -1;
  
  
  
  AVCodec         *aCodec;
  
  AVPacket        avPkt;
  
  AVFrame         *decode_frame = avcodec_alloc_frame();
  
  
  
  AVCodecContext  *aCodecCtxt;
  
  AVFormatContext *pFormatCtxt = NULL;
  
  
  
  if(argc != 2) {     // Checking  whether there is enough argument
  
      return -1; 
  
  }
  
  
  
  av_register_all();  //Initialize CODEC
  
  avformat_network_init();
  
  av_init_packet (&amp;avPkt);
  
  
  
  
  
   if (avformat_open_input (&amp;pFormatCtxt, argv[1],NULL,NULL)!= 0 ){ //Opening File
  
       return -2;
  
   }
  
  
  
   if(avformat_find_stream_info (pFormatCtxt,NULL) &lt; 0){ //Get Streams Info 
  
       return -3; 
  
   }
  
  
  
   AVStream *stream = NULL;
  
   //av_read_play (pFormatCtxt); //open streams
  
  
  
  
  
   for (int i = 0;  i &lt; pFormatCtxt->nb_streams ; i++) { //Find Audio Stream
  
       if (pFormatCtxt->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO){
  
           audioStream =i;
  
       }
  
   }
  
  
  
   aCodecCtxt = pFormatCtxt ->streams [audioStream]->codec; // opening decoder   
  
   aCodec = avcodec_find_decoder( pFormatCtxt->streams [audioStream] ->codec->codec_id);
  
  
  
   if (!aCodec) {
  
       return -8;
  
   }
  
  
  
   if (avcodec_open2(aCodecCtxt,aCodec,NULL)!=0) {
  
       return -9; 
  
   } 
  
  
  
  int cnt = 0;
  
  
  
  while(av_read_frame(pFormatCtxt,&amp;avPkt) >= 0 ){
  
  
  
      if (avPkt.stream_index == audioStream){
  
          int check = 0; 
  
          int result = avcodec_decode_audio4 (aCodecCtxt,decode_frame,&amp;check, &amp;avPkt);
  
          cout &lt;&lt; "Decoded : "&lt;&lt; (int) decode_frame->data[0] &lt;&lt;", "&lt;&lt; "Check : " &lt;&lt; check &lt;&lt; ", Format :" &lt;&lt; decode_frame->format &lt;&lt;" " &lt;&lt; decode_frame->linesize[0]&lt;&lt; " "&lt;<cnt return="return" acodec="acodec">id;  
  
  } 
  
  </cnt></sstream></fstream></iostream>

• Using ffmpeg static libraries in an visual studio explress C++ 2010 project

  29 octobre 2015, par Yvo Götz

  As the title says, I have been trying to get ffmpeg/libav libraries to work in MSVC++ 2010.
  However, I keep running in the following error while coding on debug mode.

  code :

  extern "C" 
  
  {
  
      #ifndef __STDC_CONSTANT_MACROS
  
      #define __STDC_CONSTANT_MACROS
  
      #endif
  
      #include 
  
      #include 
  
      #include 
  
      #include 
  
  }
  
  int main( int argc, char* argv[] ) 
  
  {
  
      av_register_all();
  
      return 0;
  
  }

  console :

  1>------ Build started: Project: ffmpeg, Configuration: Debug Win32 ------
  
  1>ffmpeg.obj : error LNK2019: unresolved external symbol _av_register_all referenced in       function _main
  
  1>C:\Users\okki\documents\visual studio 2010\Projects\ffmpeg\Debug\ffmpeg.exe : fatal    error LNK1120: 1 unresolved externals
  
  ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

  I used zeranoe’s latest build git-56ba331 (2013-05-14).

  And I have tried the following to fix this :

  • configuring the project to look for both the x64 and x86 libraries.
  • Add the DLLs from the ’shared’ package to both library folders.
  • Add the library directory to both the linker options and VC++ Directories.

  I have been stuck on this for a while, and any suggestion can help.
  If any extra info is needed I will happily provide.