qzdoom/game-music-emu/gme/Music_Emu.cpp

411 lines
10 KiB
C++
Raw Normal View History

// Game_Music_Emu 0.5.2. http://www.slack.net/~ant/
#include "Music_Emu.h"
#include "Multi_Buffer.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"
int const stereo = 2; // number of channels for stereo
int const silence_max = 6; // seconds
int const silence_threshold = 0x10;
long const fade_block_size = 512;
int const fade_shift = 8; // fade ends with gain at 1.0 / (1 << fade_shift)
2011-03-11 00:44:38 +00:00
Music_Emu::equalizer_t const Music_Emu::tv_eq = { -8.0, 180, 0, 0, 0, 0, 0, 0, 0, 0 };
void Music_Emu::clear_track_vars()
{
current_track_ = -1;
out_time = 0;
emu_time = 0;
emu_track_ended_ = true;
track_ended_ = true;
fade_start = INT_MAX / 2 + 1;
fade_step = 1;
silence_time = 0;
silence_count = 0;
buf_remain = 0;
warning(); // clear warning
}
void Music_Emu::unload()
{
voice_count_ = 0;
clear_track_vars();
Gme_File::unload();
}
Music_Emu::Music_Emu()
{
effects_buffer = 0;
sample_rate_ = 0;
mute_mask_ = 0;
tempo_ = 1.0;
gain_ = 1.0;
// defaults
max_initial_silence = 2;
silence_lookahead = 3;
ignore_silence_ = false;
equalizer_.treble = -1.0;
equalizer_.bass = 60;
static const char* const names [] = {
"Voice 1", "Voice 2", "Voice 3", "Voice 4",
"Voice 5", "Voice 6", "Voice 7", "Voice 8"
};
set_voice_names( names );
Music_Emu::unload(); // non-virtual
}
Music_Emu::~Music_Emu() { delete effects_buffer; }
blargg_err_t Music_Emu::set_sample_rate( long rate )
{
require( !sample_rate() ); // sample rate can't be changed once set
RETURN_ERR( set_sample_rate_( rate ) );
RETURN_ERR( buf.resize( buf_size ) );
sample_rate_ = rate;
return 0;
}
void Music_Emu::pre_load()
{
require( sample_rate() ); // set_sample_rate() must be called before loading a file
Gme_File::pre_load();
}
void Music_Emu::set_equalizer( equalizer_t const& eq )
{
equalizer_ = eq;
set_equalizer_( eq );
}
void Music_Emu::mute_voice( int index, bool mute )
{
require( (unsigned) index < (unsigned) voice_count() );
int bit = 1 << index;
int mask = mute_mask_ | bit;
if ( !mute )
mask ^= bit;
mute_voices( mask );
}
void Music_Emu::mute_voices( int mask )
{
require( sample_rate() ); // sample rate must be set first
mute_mask_ = mask;
mute_voices_( mask );
}
void Music_Emu::set_tempo( double t )
{
require( sample_rate() ); // sample rate must be set first
double const min = 0.02;
double const max = 4.00;
if ( t < min ) t = min;
if ( t > max ) t = max;
tempo_ = t;
set_tempo_( t );
}
void Music_Emu::post_load_()
{
set_tempo( tempo_ );
remute_voices();
}
blargg_err_t Music_Emu::start_track( int track )
{
clear_track_vars();
int remapped = track;
RETURN_ERR( remap_track_( &remapped ) );
current_track_ = track;
RETURN_ERR( start_track_( remapped ) );
emu_track_ended_ = false;
track_ended_ = false;
if ( !ignore_silence_ )
{
// play until non-silence or end of track
for ( long end = max_initial_silence * stereo * sample_rate(); emu_time < end; )
{
fill_buf();
if ( buf_remain | (int) emu_track_ended_ )
break;
}
emu_time = buf_remain;
out_time = 0;
silence_time = 0;
silence_count = 0;
}
return track_ended() ? warning() : 0;
}
void Music_Emu::end_track_if_error( blargg_err_t err )
{
if ( err )
{
emu_track_ended_ = true;
set_warning( err );
}
}
// Tell/Seek
blargg_long Music_Emu::msec_to_samples( blargg_long msec ) const
{
blargg_long sec = msec / 1000;
msec -= sec * 1000;
return (sec * sample_rate() + msec * sample_rate() / 1000) * stereo;
}
long Music_Emu::tell() const
{
blargg_long rate = sample_rate() * stereo;
blargg_long sec = out_time / rate;
return sec * 1000 + (out_time - sec * rate) * 1000 / rate;
}
blargg_err_t Music_Emu::seek( long msec )
{
blargg_long time = msec_to_samples( msec );
if ( time < out_time )
RETURN_ERR( start_track( current_track_ ) );
return skip( time - out_time );
}
blargg_err_t Music_Emu::skip( long count )
{
require( current_track() >= 0 ); // start_track() must have been called already
out_time += count;
// remove from silence and buf first
{
long n = min( count, silence_count );
silence_count -= n;
count -= n;
n = min( count, buf_remain );
buf_remain -= n;
count -= n;
}
if ( count && !emu_track_ended_ )
{
emu_time += count;
end_track_if_error( skip_( count ) );
}
if ( !(silence_count | buf_remain) ) // caught up to emulator, so update track ended
track_ended_ |= emu_track_ended_;
return 0;
}
blargg_err_t Music_Emu::skip_( long count )
{
// for long skip, mute sound
const long threshold = 30000;
if ( count > threshold )
{
int saved_mute = mute_mask_;
mute_voices( ~0 );
while ( count > threshold / 2 && !emu_track_ended_ )
{
RETURN_ERR( play_( buf_size, buf.begin() ) );
count -= buf_size;
}
mute_voices( saved_mute );
}
while ( count && !emu_track_ended_ )
{
long n = buf_size;
if ( n > count )
n = count;
count -= n;
RETURN_ERR( play_( n, buf.begin() ) );
}
return 0;
}
// Fading
void Music_Emu::set_fade( long start_msec, long length_msec )
{
fade_step = sample_rate() * length_msec / (fade_block_size * fade_shift * 1000 / stereo);
fade_start = msec_to_samples( start_msec );
}
// unit / pow( 2.0, (double) x / step )
static int int_log( blargg_long x, int step, int unit )
{
int shift = x / step;
int fraction = (x - shift * step) * unit / step;
return ((unit - fraction) + (fraction >> 1)) >> shift;
}
void Music_Emu::handle_fade( long out_count, sample_t* out )
{
for ( int i = 0; i < out_count; i += fade_block_size )
{
int const shift = 14;
int const unit = 1 << shift;
int gain = int_log( (out_time + i - fade_start) / fade_block_size,
fade_step, unit );
if ( gain < (unit >> fade_shift) )
track_ended_ = emu_track_ended_ = true;
sample_t* io = &out [i];
for ( int count = min( fade_block_size, out_count - i ); count; --count )
{
*io = sample_t ((*io * gain) >> shift);
++io;
}
}
}
// Silence detection
void Music_Emu::emu_play( long count, sample_t* out )
{
check( current_track_ >= 0 );
emu_time += count;
if ( current_track_ >= 0 && !emu_track_ended_ )
end_track_if_error( play_( count, out ) );
else
memset( out, 0, count * sizeof *out );
}
// number of consecutive silent samples at end
static long count_silence( Music_Emu::sample_t* begin, long size )
{
Music_Emu::sample_t first = *begin;
*begin = silence_threshold; // sentinel
Music_Emu::sample_t* p = begin + size;
while ( (unsigned) (*--p + silence_threshold / 2) <= (unsigned) silence_threshold ) { }
*begin = first;
return size - long(p - begin);
}
// fill internal buffer and check it for silence
void Music_Emu::fill_buf()
{
assert( !buf_remain );
if ( !emu_track_ended_ )
{
emu_play( buf_size, buf.begin() );
long silence = count_silence( buf.begin(), buf_size );
if ( silence < buf_size )
{
silence_time = emu_time - silence;
buf_remain = buf_size;
return;
}
}
silence_count += buf_size;
}
blargg_err_t Music_Emu::play( long out_count, sample_t* out )
{
if ( track_ended_ )
{
memset( out, 0, out_count * sizeof *out );
}
else
{
require( current_track() >= 0 );
require( out_count % stereo == 0 );
assert( emu_time >= out_time );
// prints nifty graph of how far ahead we are when searching for silence
//dprintf( "%*s \n", int ((emu_time - out_time) * 7 / sample_rate()), "*" );
long pos = 0;
if ( silence_count )
{
// during a run of silence, run emulator at >=2x speed so it gets ahead
long ahead_time = silence_lookahead * (out_time + out_count - silence_time) + silence_time;
while ( emu_time < ahead_time && !(buf_remain || emu_track_ended_) )
fill_buf();
// fill with silence
pos = min( silence_count, out_count );
memset( out, 0, pos * sizeof *out );
silence_count -= pos;
if ( emu_time - silence_time > silence_max * stereo * sample_rate() )
{
track_ended_ = emu_track_ended_ = true;
silence_count = 0;
buf_remain = 0;
}
}
if ( buf_remain )
{
// empty silence buf
long n = min( buf_remain, out_count - pos );
memcpy( &out [pos], buf.begin() + (buf_size - buf_remain), n * sizeof *out );
buf_remain -= n;
pos += n;
}
// generate remaining samples normally
long remain = out_count - pos;
if ( remain )
{
emu_play( remain, out + pos );
track_ended_ |= emu_track_ended_;
if ( !ignore_silence_ || out_time > fade_start )
{
// check end for a new run of silence
long silence = count_silence( out + pos, remain );
if ( silence < remain )
silence_time = emu_time - silence;
if ( emu_time - silence_time >= buf_size )
fill_buf(); // cause silence detection on next play()
}
}
if ( out_time > fade_start )
handle_fade( out_count, out );
}
out_time += out_count;
return 0;
}
// Gme_Info_
blargg_err_t Gme_Info_::set_sample_rate_( long ) { return 0; }
void Gme_Info_::pre_load() { Gme_File::pre_load(); } // skip Music_Emu
void Gme_Info_::post_load_() { Gme_File::post_load_(); } // skip Music_Emu
void Gme_Info_::set_equalizer_( equalizer_t const& ){ check( false ); }
void Gme_Info_::mute_voices_( int ) { check( false ); }
void Gme_Info_::set_tempo_( double ) { }
blargg_err_t Gme_Info_::start_track_( int ) { return "Use full emulator for playback"; }
blargg_err_t Gme_Info_::play_( long, sample_t* ) { return "Use full emulator for playback"; }