/*
* Wave file structure: Riff header + Wave format chunk + Wave data chunk
*
* Riff header:
* ==================================================
* Offset Size Description Value
* 0x00 4 Chunk ID "RIFF"
* 0x04 4 Chunk Data Size ( file size ) - 8
* 0x08 4 RIFF Type "WAVE"
* 0x0c * Wave chunks *
*
* Wave Format Chunk:
* ==================================================
* Offset Size Description Value
* 0x00 4 Chunk ID "fmt "
* 0x04 4 Chunk Data Size 16 + extra format bytes ( 0 for normal wav files)
* 0x08 2 Compression code 1...65535 ( 1 for PCM uncompressed)
* 0x0a 2 Nbr of channels 1...65535
* 0x0c 4 Sample rate 1...0xFFFFFFFF
* 0x10 4 Average bytes per sec
* 0x14 2 block align
* 0x16 2 siginificant bits per sample
* 0x18 2 extra format bytes 0...65535
* 0x1a * extra format bytes, if any *
*
* Wave Data Chunk:
* ==================================================
* Offset Size Description Value
* 0x00 4 Chunk ID "data"
* 0x04 4 Chunk data size
* 0x08 * sample data *
*
*/
void CTactileAudioPlayer::ReadSampleL( RFile& aFile,
HBufC8*& aDes,
TUint& aChannels,
TUint& aSampleRate )
{
TRACE("CTactileAudioPlayer::ReadSampleL - Start");
const TInt fmtOffset = 0x0c;
const TInt dataOffset = fmtOffset + 0x18;
TBuf8<KRiffHeaderSize> header;
TInt err = aFile.Read( header, KRiffHeaderSize );
if ( err )
{
TRACE("CTactileAudioPlayer::ReadSampleL: reading from file failed, aborting");
User::Leave( err );
}
TPtr8 p = header.LeftTPtr( 4 );
if ( p.Compare( KRiff ) )
{
TRACE("CTactileAudioPlayer::ReadSampleL: no RIFF header found, aborting" );
User::Leave( KErrCorrupt );
}
p = header.MidTPtr( 0x08, 4 );
if ( p.Compare( KWave ) )
{
TRACE("CTactileAudioPlayer::ReadSampleL: not a WAVE file, aborting" );
User::Leave( KErrCorrupt );
}
p = header.MidTPtr( fmtOffset + 0x00, 4 );
if ( p.Compare( KFmt ) )
{
TRACE("CTactileAudioPlayer::ReadSampleL: no 'fmt ' chunk found, aborting" );
User::Leave( KErrCorrupt );
}
p = header.MidTPtr( dataOffset, 4 );
if ( p.Compare( KData ) )
{
TRACE("CTactileAudioPlayer::ReadSampleL: no 'data' chunk found, aborting" );
User::Leave( KErrCorrupt );
}
TUint8 lo = header[ fmtOffset + 0x08 ];
TUint8 hi = header[ fmtOffset + 0x08 + 1 ];
if ( !( lo == 1 && hi == 0) )
{
TRACE("CTactileAudioPlayer::ReadSampleL: non PCM wav not supported, aborting" );
User::Leave( KErrNotSupported );
}
lo = header[ fmtOffset + 0x0a ];
hi = header[ fmtOffset + 0x0a + 1 ];
aChannels = lo;
if ( !(aChannels == 1 || aChannels == 2 && hi == 0) )
{
TRACE2("CTactileAudioPlayer::ReadSampleL: unsupported number of channels ( %d ), aborting", aChannels );
User::Leave( KErrNotSupported );
}
aSampleRate = 0;
for ( TInt i = 0; i < 4; i++ )
{
lo = header[ fmtOffset + 0x0c + i ];
TUint32 tmp = lo;
tmp = tmp << i * 8;
aSampleRate = aSampleRate | tmp;
}
lo = header[ fmtOffset + 0x16 ];
hi = header[ fmtOffset + 0x16 + 1 ];
TUint16 bitsPerSample = hi;
bitsPerSample = bitsPerSample << 8;
bitsPerSample = bitsPerSample | lo;
if ( bitsPerSample != 16 )
{
TRACE2("CTactileAudioPlayer::ReadSampleL: %d bits per sample not supported", bitsPerSample );
User::Leave( KErrNotSupported );
}
TUint32 bytesPerSample = bitsPerSample / 8;
// how many bytes for 6 ms
TUint bytesNeeded = ( aSampleRate * aChannels * bytesPerSample * 6 ) / 1000;
TInt fsize( 0 );
if ( aFile.Size( fsize ) == KErrNone && fsize >= bytesNeeded + KRiffHeaderSize )
{
aDes = HBufC8::NewL( bytesNeeded );
TPtr8 des = aDes->Des();
aFile.Read( des, bytesNeeded );
}
else
{
TRACE("CTactileAudioPlayer::ReadSampleL: Less than 6ms content in file, aborting" );
User::Leave( KErrNotSupported );
}
TRACE3("CTactileAudioPlayer::ReadSampleL %dHz %dchannel sample read successfully - End",
iSampleRate, iChannels);
}
