int PreCacheFrameOffsets(MFMADDecoder *pDecoder)
{
MP3Header header;
unsigned char headerBuffer[10];
int sampleRate = 0;
uint32 filePos = MFFile_Tell(pDecoder->pFile);
while(MFFile_Read(pDecoder->pFile, headerBuffer, 4))
{
int validHeader = ReadMP3Header(&header, headerBuffer);
sampleRate = header.samplerate;
if(validHeader != 1)
{
if(pDecoder->frameCount >= pDecoder->numFrameOffsetsAllocated)
{
pDecoder->numFrameOffsetsAllocated *= 2;
pDecoder->pFrameOffsets = (uint32*)MFHeap_Realloc(pDecoder->pFrameOffsets, sizeof(uint32) * pDecoder->numFrameOffsetsAllocated);
}
pDecoder->pFrameOffsets[pDecoder->frameOffsetCount++] = filePos;
++pDecoder->frameCount;
MFFile_Seek(pDecoder->pFile, header.frameSize-4, MFSeek_Current);
}
else
{
// check if we have some other header.. ID3?
if(!MFString_CaseCmpN((char*)headerBuffer, "TAG", 3))
{
// read ID3 v1? ...
// skip past it for now...
MFFile_Seek(pDecoder->pFile, 128-4, MFSeek_Current);
}
else if(!MFString_CaseCmpN((char*)headerBuffer, "ID3", 3))
{
// ID3 v2...
MFFile_Read(pDecoder->pFile, headerBuffer + 4, 6);
uint32 size = GetSynchSafeInt(headerBuffer + 6);
// skip ID3 v2 data
MFFile_Seek(pDecoder->pFile, size, MFSeek_Current);
}
else
{
// lost sync? :/
return 0;
}
}
filePos = MFFile_Tell(pDecoder->pFile);
}
return sampleRate;
}
long ztell_file_func(voidpf opaque, voidpf stream)
{
return MFFile_Tell((MFFile*)stream);
}
MF_API long MFFile_StdTell(void* fileHandle)
{
return (long)MFFile_Tell((MFFile*)fileHandle);
}
void CreateWAVStream(MFAudioStream *pStream, const char *pFilename)
{
MFCALLSTACK;
// open wav file
MFFile* hFile = MFFileSystem_Open(pFilename);
if(!hFile)
return;
// attempt to cache the vorbis stream
MFOpenDataCachedFile cachedOpen;
cachedOpen.cbSize = sizeof(MFOpenDataCachedFile);
cachedOpen.openFlags = MFOF_Read | MFOF_Binary | MFOF_Cached_CleanupBaseFile;
cachedOpen.maxCacheSize = 256*1024; // 256k cache for wav stream should be heaps!!
cachedOpen.pBaseFile = hFile;
MFFile *pCachedFile = MFFile_Open(MFFileSystem_GetInternalFileSystemHandle(MFFSH_CachedFileSystem), &cachedOpen);
if(pCachedFile)
hFile = pCachedFile;
RIFFHeader header;
MFFile_Read(hFile, &header, sizeof(header));
if(header.RIFF != MFMAKEFOURCC('R', 'I', 'F', 'F') || header.WAVE != MFMAKEFOURCC('W', 'A', 'V', 'E'))
return; // not a .wav file...
// if everything's good, and it appears to be a valid wav file
MFWAVStream *pWS = (MFWAVStream*)MFHeap_AllocAndZero(sizeof(MFWAVStream));
pStream->pStreamData = pWS;
pWS->pStream = hFile;
size_t read;
size_t fptr = sizeof(header);
do
{
MFFile_Seek(hFile, fptr, MFSeek_Begin);
WAVChunk dataChunk;
MFZeroMemory(&dataChunk, sizeof(dataChunk));
read = MFFile_Read(hFile, &dataChunk, sizeof(dataChunk));
fptr += sizeof(dataChunk) + dataChunk.size;
if(dataChunk.id == MFMAKEFOURCC('f', 'm', 't', ' '))
{
read = MFFile_Read(hFile, &pWS->format, dataChunk.size);
if(pWS->format.cbSize)
read = (size_t)MFFile_Seek(hFile, pWS->format.cbSize, MFSeek_Current);
}
else if(dataChunk.id == MFMAKEFOURCC('d', 'a', 't', 'a'))
{
pWS->dataOffset = (size_t)MFFile_Tell(hFile);
pWS->dataSize = dataChunk.size;
}
}
while(read);
// return to the start of the audio data
MFFile_Seek(pWS->pStream, (int)pWS->dataOffset, MFSeek_Begin);
// calculate the track length
pWS->sampleSize = (pWS->format.nChannels * pWS->format.wBitsPerSample) >> 3;
pStream->trackLength = (float)(pWS->dataSize / pWS->sampleSize) / (float)pWS->format.nSamplesPerSec;
// fill out the stream info
pStream->streamInfo.sampleRate = pWS->format.nSamplesPerSec;
pStream->streamInfo.channels = pWS->format.nChannels;
pStream->streamInfo.bitsPerSample = pWS->format.wBitsPerSample;
pStream->streamInfo.bufferLength = pWS->format.nSamplesPerSec;
}
