void SndBuffer::_WriteSamples(StereoOut32 *bData, int nSamples)
{
m_predictData = 0;
// Problem:
// If the SPU2 gets out of sync with the SndOut device, the writepos of the
// circular buffer will overtake the readpos, leading to a prolonged period
// of hopscotching read/write accesses (ie, lots of staticy crap sound for
// several seconds).
//
// Compromise:
// When an overrun occurs, we adapt by discarding a portion of the buffer.
// The older portion of the buffer is discarded rather than incoming data,
// so that the overall audio synchronization is better.
int free = m_size - _GetApproximateDataInBuffer(); // -1, but the <= handles that
if( free <= nSamples )
{
// Disabled since the lock-free queue can't handle changing the read end from the write thread
#if 0
// Buffer overrun!
// Dump samples from the read portion of the buffer instead of dropping
// the newly written stuff.
s32 comp;
if( SynchMode == 0 ) // TimeStrech on
{
comp = timeStretchOverrun();
}
else
{
// Toss half the buffer plus whatever's being written anew:
comp = GetAlignedBufferSize( (m_size + nSamples ) / 16 );
if( comp > (m_size-SndOutPacketSize) ) comp = m_size-SndOutPacketSize;
}
_DropSamples_Internal(comp);
if( MsgOverruns() )
ConLog(" * SPU2 > Overrun Compensation (%d packets tossed)\n", comp / SndOutPacketSize );
lastPct = 0.0; // normalize the timestretcher
#else
if( MsgOverruns() )
ConLog(" * SPU2 > Overrun! 1 packet tossed)\n");
lastPct = 0.0; // normalize the timestretcher
return;
#endif
}
_WriteSamples_Safe(bData, nSamples);
}
void SndBuffer::Init()
{
//if( mods[OutputModule] == NULL )
//{
// _InitFail();
// return;
//}
// initialize sound buffer
// Buffer actually attempts to run ~50%, so allocate near double what
// the requested latency is:
m_rpos = 0;
m_wpos = 0;
m_data = 0;
try
{
const float latencyMS = SndOutLatencyMS * (timeStretchDisabled ? 1.5f : 2.0f );
m_size = GetAlignedBufferSize( (int)(latencyMS * SampleRate / 1000.0f ) );
m_buffer = new StereoOut32[m_size];
m_underrun_freeze = false;
sndTempBuffer = new StereoOut32[SndOutPacketSize];
sndTempBuffer16 = new StereoOut16[SndOutPacketSize];
}
catch( std::bad_alloc& )
{
// out of memory exception (most likely)
printf( "Out of memory error occurred while initializing SPU2." );
_InitFail();
return;
}
// clear buffers!
// Fixes loopy sounds on emu resets.
memset( sndTempBuffer, 0, sizeof(StereoOut32) * SndOutPacketSize );
memset( sndTempBuffer16, 0, sizeof(StereoOut16) * SndOutPacketSize );
sndTempProgress = 0;
soundtouchInit(); // initializes the timestretching
// some crap
//spdif_set51(mods[OutputModule]->Is51Out());
// initialize module
//if( mods[OutputModule]->Init() == -1 ) _InitFail();
}
// Returns TRUE if there is data to be output, or false if no data
// is available to be copied.
bool SndBuffer::CheckUnderrunStatus( int& nSamples, int& quietSampleCount )
{
quietSampleCount = 0;
int data = _GetApproximateDataInBuffer();
if( m_underrun_freeze )
{
int toFill = m_size / ( (SynchMode == 2) ? 32 : 400); // TimeStretch and Async off?
toFill = GetAlignedBufferSize( toFill );
// toFill is now aligned to a SndOutPacket
if( data < toFill )
{
quietSampleCount = nSamples;
return false;
}
m_underrun_freeze = false;
if( MsgOverruns() )
ConLog(" * SPU2 > Underrun compensation (%d packets buffered)\n", toFill / SndOutPacketSize );
lastPct = 0.0; // normalize timestretcher
}
else if( data < nSamples )
{
nSamples = data;
quietSampleCount = SndOutPacketSize - data;
m_underrun_freeze = true;
if( SynchMode == 0 ) // TimeStrech on
timeStretchUnderrun();
return nSamples != 0;
}
return true;
}
// Returns TRUE if there is data to be output, or false if no data
// is available to be copied.
bool SndBuffer::CheckUnderrunStatus( int& nSamples, int& quietSampleCount )
{
quietSampleCount = 0;
if( m_underrun_freeze )
{
int toFill = (int)(m_size * ( timeStretchDisabled ? 0.50f : 0.1f ) );
toFill = GetAlignedBufferSize( toFill );
// toFill is now aligned to a SndOutPacket
if( m_data < toFill )
{
quietSampleCount = nSamples;
return false;
}
m_underrun_freeze = false;
//TODO
//if( MsgOverruns() )
printf(" * SPU2 > Underrun compensation (%d packets buffered)\n", toFill / SndOutPacketSize );
lastPct = 0.0; // normalize timestretcher
}
else if( m_data < nSamples )
{
nSamples = m_data;
quietSampleCount = SndOutPacketSize - m_data;
m_underrun_freeze = true;
if( !timeStretchDisabled )
timeStretchUnderrun();
return nSamples != 0;
}
return true;
}
void SndBuffer::_WriteSamples(StereoOut32 *bData, int nSamples)
{
int free = m_size-m_data;
m_predictData = 0;
assert( m_data <= m_size );
// Problem:
// If the SPU2 gets out of sync with the SndOut device, the writepos of the
// circular buffer will overtake the readpos, leading to a prolonged period
// of hopscotching read/write accesses (ie, lots of staticy crap sound for
// several seconds).
//
// Compromise:
// When an overrun occurs, we adapt by discarding a portion of the buffer.
// The older portion of the buffer is discarded rather than incoming data,
// so that the overall audio synchronization is better.
if( free < nSamples )
{
// Buffer overrun!
// Dump samples from the read portion of the buffer instead of dropping
// the newly written stuff.
s32 comp;
if( !timeStretchDisabled )
{
comp = timeStretchOverrun();
}
else
{
// Toss half the buffer plus whatever's being written anew:
comp = GetAlignedBufferSize( (m_size + nSamples ) / 2 );
if( comp > (m_size-SndOutPacketSize) ) comp = m_size-SndOutPacketSize;
}
m_data -= comp;
m_rpos = (m_rpos+comp) % m_size;
//TODO
//if( MsgOverruns() )
printf(" * SPU2 > Overrun Compensation (%d packets tossed)\n", comp / SndOutPacketSize );
lastPct = 0.0; // normalize the timestretcher
}
// copy in two phases, since there's a chance the packet
// wraps around the buffer (it'd be nice to deal in packets only, but
// the timestretcher and DSP options require flexibility).
const int endPos = m_wpos + nSamples;
const int secondCopyLen = endPos - m_size;
StereoOut32* wposbuffer = &m_buffer[m_wpos];
m_data += nSamples;
if( secondCopyLen > 0 )
{
nSamples -= secondCopyLen;
memcpy( m_buffer, &bData[nSamples], secondCopyLen * sizeof( *bData ) );
m_wpos = secondCopyLen;
}
else
m_wpos += nSamples;
memcpy( wposbuffer, bData, nSamples * sizeof( *bData ) );
}