diff options
Diffstat (limited to 'plugins/gme/game-music-emu-svn/gme/Dual_Resampler.cpp')
| -rw-r--r-- | plugins/gme/game-music-emu-svn/gme/Dual_Resampler.cpp | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-svn/gme/Dual_Resampler.cpp b/plugins/gme/game-music-emu-svn/gme/Dual_Resampler.cpp new file mode 100644 index 00000000..090b0acf --- /dev/null +++ b/plugins/gme/game-music-emu-svn/gme/Dual_Resampler.cpp @@ -0,0 +1,131 @@ +// Game_Music_Emu 0.5.5. http://www.slack.net/~ant/ + +#include "Dual_Resampler.h" + +#include <stdlib.h> +#include <string.h> + +/* Copyright (C) 2003-2006 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" + +unsigned const resampler_extra = 256; + +Dual_Resampler::Dual_Resampler() { } + +Dual_Resampler::~Dual_Resampler() { } + +blargg_err_t Dual_Resampler::reset( int pairs ) +{ + // expand allocations a bit + RETURN_ERR( sample_buf.resize( (pairs + (pairs >> 2)) * 2 ) ); + resize( pairs ); + resampler_size = oversamples_per_frame + (oversamples_per_frame >> 2); + return resampler.buffer_size( resampler_size ); +} + +void Dual_Resampler::resize( int pairs ) +{ + int new_sample_buf_size = pairs * 2; + if ( sample_buf_size != new_sample_buf_size ) + { + if ( (unsigned) new_sample_buf_size > sample_buf.size() ) + { + check( false ); + return; + } + sample_buf_size = new_sample_buf_size; + oversamples_per_frame = int (pairs * resampler.ratio()) * 2 + 2; + clear(); + } +} + +void Dual_Resampler::play_frame_( Blip_Buffer& blip_buf, dsample_t* out ) +{ + long pair_count = sample_buf_size >> 1; + blip_time_t blip_time = blip_buf.count_clocks( pair_count ); + int sample_count = oversamples_per_frame - resampler.written(); + + int new_count = play_frame( blip_time, sample_count, resampler.buffer() ); + assert( new_count < resampler_size ); + + blip_buf.end_frame( blip_time ); + assert( blip_buf.samples_avail() == pair_count ); + + resampler.write( new_count ); + + long count = resampler.read( sample_buf.begin(), sample_buf_size ); + assert( count == (long) sample_buf_size ); + + mix_samples( blip_buf, out ); + blip_buf.remove_samples( pair_count ); +} + +void Dual_Resampler::dual_play( long count, dsample_t* out, Blip_Buffer& blip_buf ) +{ + // empty extra buffer + long remain = sample_buf_size - buf_pos; + if ( remain ) + { + if ( remain > count ) + remain = count; + count -= remain; + memcpy( out, &sample_buf [buf_pos], remain * sizeof *out ); + out += remain; + buf_pos += remain; + } + + // entire frames + while ( count >= (long) sample_buf_size ) + { + play_frame_( blip_buf, out ); + out += sample_buf_size; + count -= sample_buf_size; + } + + // extra + if ( count ) + { + play_frame_( blip_buf, sample_buf.begin() ); + buf_pos = count; + memcpy( out, sample_buf.begin(), count * sizeof *out ); + out += count; + } +} + +void Dual_Resampler::mix_samples( Blip_Buffer& blip_buf, dsample_t* out ) +{ + Blip_Reader sn; + int bass = sn.begin( blip_buf ); + const dsample_t* in = sample_buf.begin(); + + for ( int n = sample_buf_size >> 1; n--; ) + { + int s = sn.read(); + blargg_long l = (blargg_long) in [0] * 2 + s; + if ( (BOOST::int16_t) l != l ) + l = 0x7FFF - (l >> 24); + + sn.next( bass ); + blargg_long r = (blargg_long) in [1] * 2 + s; + if ( (BOOST::int16_t) r != r ) + r = 0x7FFF - (r >> 24); + + in += 2; + out [0] = l; + out [1] = r; + out += 2; + } + + sn.end( blip_buf ); +} + |