1 files changed, 171 insertions, 0 deletions
diff --git a/plugins/gme/Game_Music_Emu-0.5.2/gme/Fir_Resampler.h b/plugins/gme/Game_Music_Emu-0.5.2/gme/Fir_Resampler.h
new file mode 100644
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--- /dev/null
+++ b/plugins/gme/Game_Music_Emu-0.5.2/gme/Fir_Resampler.h
@@ -0,0 +1,171 @@
+// Finite impulse response (FIR) resampler with adjustable FIR size
+
+// Game_Music_Emu 0.5.2
+#ifndef FIR_RESAMPLER_H
+#define FIR_RESAMPLER_H
+
+#include "blargg_common.h"
+#include <string.h>
+
+class Fir_Resampler_ {
+public:
+	
+	// Use Fir_Resampler<width> (below)
+	
+	// Set input/output resampling ratio and optionally low-pass rolloff and gain.
+	// Returns actual ratio used (rounded to internal precision).
+	double time_ratio( double factor, double rolloff = 0.999, double gain = 1.0 );
+	
+	// Current input/output ratio
+	double ratio() const { return ratio_; }
+	
+// Input
+	
+	typedef short sample_t;
+	
+	// Resize and clear input buffer
+	blargg_err_t buffer_size( int );
+	
+	// Clear input buffer. At least two output samples will be available after
+	// two input samples are written.
+	void clear();
+	
+	// Number of input samples that can be written
+	int max_write() const { return buf.end() - write_pos; }
+	
+	// Pointer to place to write input samples
+	sample_t* buffer() { return write_pos; }
+	
+	// Notify resampler that 'count' input samples have been written
+	void write( long count );
+	
+	// Number of input samples in buffer
+	int written() const { return write_pos - &buf [write_offset]; }
+	
+	// Skip 'count' input samples. Returns number of samples actually skipped.
+	int skip_input( long count );
+	
+// Output
+	
+	// Number of extra input samples needed until 'count' output samples are available
+	int input_needed( blargg_long count ) const;
+	
+	// Number of output samples available
+	int avail() const { return avail_( write_pos - &buf [width_ * stereo] ); }
+	
+public:
+	~Fir_Resampler_();
+protected:
+	enum { stereo = 2 };
+	enum { max_res = 32 };
+	blargg_vector<sample_t> buf;
+	sample_t* write_pos;
+	int res;
+	int imp_phase;
+	int const width_;
+	int const write_offset;
+	blargg_ulong skip_bits;
+	int step;
+	int input_per_cycle;
+	double ratio_;
+	sample_t* impulses;
+	
+	Fir_Resampler_( int width, sample_t* );
+	int avail_( blargg_long input_count ) const;
+};
+
+// Width is number of points in FIR. Must be even and 4 or more. More points give
+// better quality and rolloff effectiveness, and take longer to calculate.
+template<int width>
+class Fir_Resampler : public Fir_Resampler_ {
+	BOOST_STATIC_ASSERT( width >= 4 && width % 2 == 0 );
+	short impulses [max_res] [width];
+public:
+	Fir_Resampler() : Fir_Resampler_( width, impulses [0] ) { }
+	
+	// Read at most 'count' samples. Returns number of samples actually read.
+	typedef short sample_t;
+	int read( sample_t* out, blargg_long count );
+};
+
+// End of public interface
+
+inline void Fir_Resampler_::write( long count )
+{
+	write_pos += count;
+	assert( write_pos <= buf.end() );
+}
+
+template<int width>
+int Fir_Resampler<width>::read( sample_t* out_begin, blargg_long count )
+{
+	sample_t* out = out_begin;
+	const sample_t* in = buf.begin();
+	sample_t* end_pos = write_pos;
+	blargg_ulong skip = skip_bits >> imp_phase;
+	sample_t const* imp = impulses [imp_phase];
+	int remain = res - imp_phase;
+	int const step = this->step;
+	
+	count >>= 1;
+	
+	if ( end_pos - in >= width * stereo )
+	{
+		end_pos -= width * stereo;
+		do
+		{
+			count--;
+			
+			// accumulate in extended precision
+			blargg_long l = 0;
+			blargg_long r = 0;
+			
+			const sample_t* i = in;
+			if ( count < 0 )
+				break;
+			
+			for ( int n = width / 2; n; --n )
+			{
+				int pt0 = imp [0];
+				l += pt0 * i [0];
+				r += pt0 * i [1];
+				int pt1 = imp [1];
+				imp += 2;
+				l += pt1 * i [2];
+				r += pt1 * i [3];
+				i += 4;
+			}
+			
+			remain--;
+			
+			l >>= 15;
+			r >>= 15;
+			
+			in += (skip * stereo) & stereo;
+			skip >>= 1;
+			in += step;
+			
+			if ( !remain )
+			{
+				imp = impulses [0];
+				skip = skip_bits;
+				remain = res;
+			}
+			
+			out [0] = (sample_t) l;
+			out [1] = (sample_t) r;
+			out += 2;
+		}
+		while ( in <= end_pos );
+	}
+	
+	imp_phase = res - remain;
+	
+	int left = write_pos - in;
+	write_pos = &buf [left];
+	memmove( buf.begin(), in, left * sizeof *in );
+	
+	return out - out_begin;
+}
+
+#endif