L_GetExtensionAudio

#include "l_bitmap.h"

L_LTFIL_API L_INT L_GetExtensionAudio(pExtensionList, nStream, ppBuffer, puSize)

Gets the embedded audio data from the specified extension list.

Parameters

pEXTENSIONLIST pExtensionList

Pointer to the EXTENSIONLIST structure that contains the audio data to get.

L_INT nStream

Index of the audio stream to retrieve. The extensions may have more than one audio stream. This index is 0-based. Therefore, the first stream is stream 0, the second stream is stream 1, etc. To retrieve all the audio streams, retrieve the streams one by one until an error is returned.

L_UCHAR ** ppBuffer

Pointer to be updated with a pointer to the retrieved audio data. This pointer will point into the pExtensionList. Therefore, this pointer will be valid as long as pExtensionList is valid. The memory will be freed when L_FreeExtensions is called, so do not try to free this memory.

L_SIZE_T* puSize

Pointer to a variable to be updated with the size of the audio data.

Returns

Value Meaning
SUCCESS The function was successful.
< 1 An error occurred. Refer to Return Codes.

Comments

The audio data is stored inside extensions in the WAVE format. The audio data can be played directly from memory, or the data can be written to a disk file and played from the disk. When writing the audio data to a disk file, give the file a .WAV extension.

Required DLLs and Libraries

Platforms

Win32, x64, Linux.

See Also

Functions

Topics

Example

L_INT GetExtensionAudioExample(HWND          hWnd, 
                                               L_TCHAR     * pszName, 
                                               pBITMAPHANDLE pBitmap) 
{ 
   UNREFERENCED_PARAMETER(pBitmap); 
 
   pEXTENSIONLIST pExtensionList; 
   L_INT nRet; 
   L_TCHAR s[300]; 
 
   nRet = L_ReadFileExtensions(pszName, &pExtensionList, NULL); 
   if(nRet != SUCCESS) 
   { 
      wsprintf(s, TEXT("Error %d getting extensions!"), nRet); 
      MessageBox(hWnd, s, TEXT("ERROR"), MB_OK); 
      return nRet; 
   } 
 
   if(pExtensionList->uFlags & EXTENSION_AUDIO) 
   { 
      L_UCHAR *pAudioData; 
      L_SIZE_T  uSize; 
      FILE *fd; 
 
      nRet = L_GetExtensionAudio(pExtensionList, 0, &pAudioData, &uSize); 
      if(nRet != SUCCESS) 
      { 
      wsprintf(s, TEXT("Error %d getting the audio data"), nRet); 
      MessageBox(hWnd, s, TEXT("ERROR"), MB_OK); 
      } 
      else 
      { 
         
         _tfopen_s(&fd, MAKE_IMAGE_PATH(TEXT("exif.wav")), TEXT("wb")); 
         if(fd) 
         { 
            fwrite(pAudioData, uSize, 1, fd); 
            fclose(fd); 
         } 
      } 
   } 
 
   L_FreeExtensions(pExtensionList); 
   return SUCCESS; 
} 
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