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Diffstat (limited to 'plugins/gme/game-music-emu-0.5.5/gme/Fir_Resampler.cpp')
| -rw-r--r-- | plugins/gme/game-music-emu-0.5.5/gme/Fir_Resampler.cpp | 199 |
1 files changed, 0 insertions, 199 deletions
diff --git a/plugins/gme/game-music-emu-0.5.5/gme/Fir_Resampler.cpp b/plugins/gme/game-music-emu-0.5.5/gme/Fir_Resampler.cpp deleted file mode 100644 index f2c905a9..00000000 --- a/plugins/gme/game-music-emu-0.5.5/gme/Fir_Resampler.cpp +++ /dev/null @@ -1,199 +0,0 @@ -// Game_Music_Emu 0.5.5. http://www.slack.net/~ant/ - -#include "Fir_Resampler.h" - -#include <string.h> -#include <stdlib.h> -#include <stdio.h> -#include <math.h> - -/* Copyright (C) 2004-2006 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" - -#undef PI -#define PI 3.1415926535897932384626433832795029 - -static void gen_sinc( double rolloff, int width, double offset, double spacing, double scale, - int count, short* out ) -{ - double const maxh = 256; - double const step = PI / maxh * spacing; - double const to_w = maxh * 2 / width; - double const pow_a_n = pow( rolloff, maxh ); - scale /= maxh * 2; - - double angle = (count / 2 - 1 + offset) * -step; - while ( count-- ) - { - *out++ = 0; - double w = angle * to_w; - if ( fabs( w ) < PI ) - { - double rolloff_cos_a = rolloff * cos( angle ); - double num = 1 - rolloff_cos_a - - pow_a_n * cos( maxh * angle ) + - pow_a_n * rolloff * cos( (maxh - 1) * angle ); - double den = 1 - rolloff_cos_a - rolloff_cos_a + rolloff * rolloff; - double sinc = scale * num / den - scale; - - out [-1] = (short) (cos( w ) * sinc + sinc); - } - angle += step; - } -} - -Fir_Resampler_::Fir_Resampler_( int width, sample_t* impulses_ ) : - width_( width ), - write_offset( width * stereo - stereo ), - impulses( impulses_ ) -{ - write_pos = 0; - res = 1; - imp_phase = 0; - skip_bits = 0; - step = stereo; - ratio_ = 1.0; -} - -Fir_Resampler_::~Fir_Resampler_() { } - -void Fir_Resampler_::clear() -{ - imp_phase = 0; - if ( buf.size() ) - { - write_pos = &buf [write_offset]; - memset( buf.begin(), 0, write_offset * sizeof buf [0] ); - } -} - -blargg_err_t Fir_Resampler_::buffer_size( int new_size ) -{ - RETURN_ERR( buf.resize( new_size + write_offset ) ); - clear(); - return 0; -} - -double Fir_Resampler_::time_ratio( double new_factor, double rolloff, double gain ) -{ - ratio_ = new_factor; - - double fstep = 0.0; - { - double least_error = 2; - double pos = 0; - res = -1; - for ( int r = 1; r <= max_res; r++ ) - { - pos += ratio_; - double nearest = floor( pos + 0.5 ); - double error = fabs( pos - nearest ); - if ( error < least_error ) - { - res = r; - fstep = nearest / res; - least_error = error; - } - } - } - - skip_bits = 0; - - step = stereo * (int) floor( fstep ); - - ratio_ = fstep; - fstep = fmod( fstep, 1.0 ); - - double filter = (ratio_ < 1.0) ? 1.0 : 1.0 / ratio_; - double pos = 0.0; - input_per_cycle = 0; - for ( int i = 0; i < res; i++ ) - { - gen_sinc( rolloff, int (width_ * filter + 1) & ~1, pos, filter, - double (0x7FFF * gain * filter), - (int) width_, impulses + i * width_ ); - - pos += fstep; - input_per_cycle += step; - if ( pos >= 0.9999999 ) - { - pos -= 1.0; - skip_bits |= 1 << i; - input_per_cycle++; - } - } - - clear(); - - return ratio_; -} - -int Fir_Resampler_::input_needed( blargg_long output_count ) const -{ - blargg_long input_count = 0; - - unsigned long skip = skip_bits >> imp_phase; - int remain = res - imp_phase; - while ( (output_count -= 2) > 0 ) - { - input_count += step + (skip & 1) * stereo; - skip >>= 1; - if ( !--remain ) - { - skip = skip_bits; - remain = res; - } - output_count -= 2; - } - - long input_extra = input_count - (write_pos - &buf [(width_ - 1) * stereo]); - if ( input_extra < 0 ) - input_extra = 0; - return input_extra; -} - -int Fir_Resampler_::avail_( blargg_long input_count ) const -{ - int cycle_count = input_count / input_per_cycle; - int output_count = cycle_count * res * stereo; - input_count -= cycle_count * input_per_cycle; - - blargg_ulong skip = skip_bits >> imp_phase; - int remain = res - imp_phase; - while ( input_count >= 0 ) - { - input_count -= step + (skip & 1) * stereo; - skip >>= 1; - if ( !--remain ) - { - skip = skip_bits; - remain = res; - } - output_count += 2; - } - return output_count; -} - -int Fir_Resampler_::skip_input( long count ) -{ - int remain = write_pos - buf.begin(); - int max_count = remain - width_ * stereo; - if ( count > max_count ) - count = max_count; - - remain -= count; - write_pos = &buf [remain]; - memmove( buf.begin(), &buf [count], remain * sizeof buf [0] ); - - return count; -} |