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• How do I access the ipod-library for decoding ffmpeg in the xcode ?

  16 janvier 2014, par M_On

  Thank you to look at my question.

  There is a problem with too slow to access the music file using ffmpeg.

  Get the URL of the music that is in the ipod-library by using the 'valueForProperty:MPMediaItemPropertyAssetURL' method.

  Use the (AVAssetExportSession Class) TSLibraryImport.m, extract the music files from ipod-library.

  However, I took the extraction time is too long. (4 seconds of the 3GS iPhone, iPhone 5 is 1 second)

  It was not possible to be decoded using FFmpeg If you do not the Export.

  In order to use FFmpeg, it's AVPlayer can not be used.

  I will never forget the grace if you can answer if you folded to know how other maybe.

• Revision 92a29c157f : Change to prevent invalid memory access After change of MI context storage , mi

  24 septembre 2013, par Yaowu Xu

  Changed Paths :
   Modify /vp9/encoder/vp9_encodeframe.c

  
  
  Change to prevent invalid memory access

  After change of MI context storage , mi_8x8[] pointer may be null for
  a block outside of image border. The commit changes to access the data
  only after validation of mi_row and mi_col.

  Change-Id : I039c4eb486a228ea9d8e5f35ab9ae6717d718bf3

• Need help correcting Access Violation with FFmpeg DLL

  26 septembre 2012, par James

  I'm trying to use the FFmpeg dll's using Visual Studio 2012 and I'm getting a run time access violation when I call avcodec_find_encoder. Here is the code :

  // TestFFmpeg.cpp : Defines the entry point for the console application.
  
  //
  
  
  
  #include "stdafx.h"
  
  
  
  extern "C" {
  
  #include "libavcodec\avcodec.h"
  
  #include "libavformat\avformat.h"
  
  }
  
  
  
  #define INBUF_SIZE 4096
  
  
  
  int _tmain(int argc, _TCHAR* argv[])
  
  {
  
      AVCodec *codec;
  
  
  
      const char *videoFilename = "C:\\Users\\Public\\Videos\\Sample Videos\\Wildlife.wmv";
  
  
  
      av_register_all(); // This works; however, no parameters or return values.
  
  
  
      codec = avcodec_find_encoder(CODEC_ID_WMV3);  // Run time Access Violation HERE
  
      if (!codec) {
  
      fprintf(stderr, "Codec not found\n");
  
          exit(1);
  
      }
  
  
  
      return 0;
  
  }

  Here is the error message :

  Unhandled exception at 0x75C18B60 (msvcrt.dll) in TestFFmpeg.exe : 0xC0000005 : Access violation reading location 0x00000049.

  The stack trace is :

      msvcrt.dll!_strcmp()    Unknown
  
      avcodec-54.dll!6a56caac()   Unknown
  
      [Frames below may be incorrect and/or missing, no symbols loaded for avcodec-54.dll]    
  
  >   TestFFmpeg.exe!wmain(int argc, wchar_t * * argv) Line 23    C++
  
      TestFFmpeg.exe!__tmainCRTStartup() Line 533 C
  
      TestFFmpeg.exe!wmainCRTStartup() Line 377   C
  
      kernel32.dll!@BaseThreadInitThunk@12()  Unknown
  
      ntdll.dll!___RtlUserThreadStart@8() Unknown
  
      ntdll.dll!__RtlUserThreadStart@8()  Unknown

  I'm guessing there's a problem with returning the codec pointer, but I'm new to C++ and have no idea how to correct it. I tried the cdecl, stdcall, and fastcall calling conventions — none corrected the issue. I'm using the latest 32-bit DLL from Zeranoe. Any suggestions ?

  EDIT :
  I've called other functions in the DLL and they work. For example, avformat_open_input works properly. I can pass parameters and the function returns a successful return value (0) and populates the format context structure. av_find_stream_info works as well. I still can't figure out why avcodec_find_decoder creates an access violation.