//-----------------------------------------------------------------------------
// Purpose: reads the actual sample data and parses it
// Input : &walk - RIFF file
//-----------------------------------------------------------------------------
void CAudioSourceMemWave::ParseDataChunk( IterateRIFF &walk )
{
int size = walk.ChunkSize();
// create a buffer for the samples
m_pData = new char[size];
// load them into memory
walk.ChunkRead( m_pData );
if ( m_format == WAVE_FORMAT_PCM )
{
// number of samples loaded
m_sampleCount = size / m_sampleSize;
// some samples need to be converted
ConvertSamples( m_pData, m_sampleCount );
}
else if ( m_format == WAVE_FORMAT_ADPCM )
{
// The ADPCM mixers treat the wave source as a flat file of bytes.
m_sampleSize = 1;
// Since each "sample" is a byte (this is a flat file), the number of samples is the file size
m_sampleCount = size;
// file says 4, output is 16
m_bits = 16;
}
}
//-----------------------------------------------------------------------------
// Purpose:
// Input : &walk -
//-----------------------------------------------------------------------------
void CSoundCombiner::ParseSentence( CSentence& sentence, IterateRIFF &walk )
{
CUtlBuffer buf( 0, 0, CUtlBuffer::TEXT_BUFFER );
buf.EnsureCapacity( walk.ChunkSize() );
walk.ChunkRead( buf.Base() );
buf.SeekPut( CUtlBuffer::SEEK_HEAD, walk.ChunkSize() );
sentence.InitFromDataChunk( buf.Base(), buf.TellPut() );
}
//-----------------------------------------------------------------------------
// Purpose: Bastardized construction routine. This is just to avoid complex
// constructor functions so code can be shared more easily by sub-classes
// Input : *pFormatBuffer - RIFF header
// formatSize - header size
// &walk - RIFF file
//-----------------------------------------------------------------------------
void CAudioSourceWave::Setup( const char *pFormatBuffer, int formatSize, IterateRIFF &walk )
{
Init( pFormatBuffer, formatSize );
while ( walk.ChunkAvailable() )
{
ParseChunk( walk, walk.ChunkName() );
walk.ChunkNext();
}
}
//-----------------------------------------------------------------------------
// Purpose:
// Input : &walk -
//-----------------------------------------------------------------------------
void CAudioSourceWave::ParseSentence( IterateRIFF &walk )
{
CUtlBuffer buf( 0, 0, true );
buf.EnsureCapacity( walk.ChunkSize() );
walk.ChunkRead( buf.Base() );
buf.SeekPut( CUtlBuffer::SEEK_HEAD, walk.ChunkSize() );
m_Sentence.InitFromDataChunk( buf.Base(), buf.TellPut() );
}
//-----------------------------------------------------------------------------
// Purpose: parses loop information from a cue chunk
// Input : &walk - RIFF iterator
// Output : int loop start position
//-----------------------------------------------------------------------------
int CAudioSourceWave::ParseCueChunk( IterateRIFF &walk )
{
// Cue chunk as specified by RIFF format
// see $/research/jay/sound/riffnew.htm
struct
{
unsigned int dwName;
unsigned int dwPosition;
unsigned int fccChunk;
unsigned int dwChunkStart;
unsigned int dwBlockStart;
unsigned int dwSampleOffset;
} cue_chunk;
int cueCount;
// assume that the cue chunk stored in the wave is the start of the loop
// assume only one cue chunk, UNDONE: Test this assumption here?
cueCount = walk.ChunkReadInt();
walk.ChunkReadPartial( &cue_chunk, sizeof(cue_chunk) );
return cue_chunk.dwSampleOffset;
}
//-----------------------------------------------------------------------------
// Purpose: Parse base chunks
// Input : &walk - riff file to parse
// : chunkName - name of the chunk to parse
//-----------------------------------------------------------------------------
// UNDONE: Move parsing loop here and drop each chunk into a virtual function
// instead of this being virtual.
void CAudioSourceWave::ParseChunk( IterateRIFF &walk, int chunkName )
{
switch( chunkName )
{
case WAVE_CUE:
{
m_loopStart = ParseCueChunk( walk );
}
break;
case WAVE_VALVEDATA:
{
ParseSentence( walk );
}
break;
// unknown/don't care
default:
{
ChunkError( walk.ChunkName() );
}
break;
}
}
//-----------------------------------------------------------------------------
// Purpose: Set up a sub-chunk iterator
// Input : &parent - parent iterator
//-----------------------------------------------------------------------------
IterateRIFF::IterateRIFF( IterateRIFF &parent )
: m_riff(parent.m_riff), m_size(parent.ChunkSize())
{
m_start = parent.ChunkFilePosition();
ChunkSetup();
}
