1 files changed, 74 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6pre/gme/Downsampler.cpp b/plugins/gme/game-music-emu-0.6pre/gme/Downsampler.cpp
new file mode 100644
index 00000000..aeb50fc5
--- /dev/null
+++ b/plugins/gme/game-music-emu-0.6pre/gme/Downsampler.cpp
@@ -0,0 +1,74 @@
+// Game_Music_Emu 0.6-pre. http://www.slack.net/~ant/
+
+#include "Downsampler.h"
+
+/* Copyright (C) 2004-2008 Shay Green. This module is free software; you
+can redistribute it and/or modify it under the terms of the GNU Lesser
+General Public License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version. This
+module is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+details. You should have received a copy of the GNU Lesser General Public
+License along with this module; if not, write to the Free Software Foundation,
+Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
+
+#include "blargg_source.h"
+
+int const shift = 14;
+int const unit = 1 << shift;
+
+void Downsampler::clear_()
+{
+	pos = 0;
+	Resampler::clear_();
+}
+
+Downsampler::Downsampler()
+{
+	clear();
+}
+
+blargg_err_t Downsampler::set_rate_( double new_factor )
+{
+	step = (int) (new_factor * unit + 0.5);
+	return Resampler::set_rate_( 1.0 / unit * step );
+}
+
+Resampler::sample_t const* Downsampler::resample_( sample_t** out_,
+		sample_t const* out_end, sample_t const in [], int in_size )
+{
+	in_size -= write_offset;
+	if ( in_size > 0 )
+	{
+		sample_t* BLARGG_RESTRICT out = *out_;
+		sample_t const* const in_end = in + in_size;
+		
+		int const step = this->step;
+		int       pos  = this->pos;
+		
+		// TODO: IIR filter, then linear resample
+		// TODO: detect skipped sample, allowing merging of IIR and resample?
+		
+		do
+		{
+			#define INTERP( i, out )\
+				out = (in [0 + i] * (unit - pos) + ((in [2 + i] + in [4 + i] + in [6 + i]) << shift) +\
+				in [8 + i] * pos) >> (shift + 2);
+			
+			int out_0;
+			INTERP( 0,                  out_0 )
+			INTERP( 1, out [0] = out_0; out [1] )
+			out += stereo;
+			
+			pos += step;
+			in += ((unsigned) pos >> shift) * stereo;
+			pos &= unit - 1;
+		}
+		while ( in < in_end && out < out_end );
+		
+		this->pos = pos;
+		*out_ = out;
+	}
+	return in;
+}