rockbox/apps/codecs/libgme/hes_emu.c
2011-08-13 16:41:14 +00:00

877 lines
22 KiB
C

// Game_Music_Emu 0.5.2. http://www.slack.net/~ant/
#include "hes_emu.h"
#include "blargg_endian.h"
#include "blargg_source.h"
/* Copyright (C) 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 */
int const timer_mask = 0x04;
int const vdp_mask = 0x02;
int const i_flag_mask = 0x04;
int const unmapped = 0xFF;
long const period_60hz = 262 * 455L; // scanlines * clocks per scanline
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)
const char gme_wrong_file_type [] = "Wrong file type for this emulator";
static void clear_track_vars( struct Hes_Emu* this )
{
this->current_track_ = -1;
this->out_time = 0;
this->emu_time = 0;
this->emu_track_ended_ = true;
this->track_ended = true;
this->fade_start = (blargg_long)(LONG_MAX / 2 + 1);
this->fade_step = 1;
this->silence_time = 0;
this->silence_count = 0;
this->buf_remain = 0;
}
void Hes_init( struct Hes_Emu* this )
{
this->sample_rate_ = 0;
this->mute_mask_ = 0;
this->tempo_ = (int)(FP_ONE_TEMPO);
// defaults
this->max_initial_silence = 2;
this->ignore_silence = false;
// Unload
this->voice_count_ = 0;
clear_track_vars( this );
this->timer.raw_load = 0;
this->silence_lookahead = 6;
Sound_set_gain( this, (int)(FP_ONE_GAIN*1.11) );
Rom_init( &this->rom, 0x2000 );
Apu_init( &this->apu );
Adpcm_init( &this->adpcm );
Cpu_init( &this->cpu );
/* Set default track count */
this->track_count = 255;
}
static blargg_err_t check_hes_header( void const* header )
{
if ( memcmp( header, "HESM", 4 ) )
return gme_wrong_file_type;
return 0;
}
// Setup
blargg_err_t Hes_load( struct Hes_Emu* this, void* data, long size )
{
// Unload
this->voice_count_ = 0;
clear_track_vars( this );
assert( offsetof (struct header_t,unused [4]) == header_size );
RETURN_ERR( Rom_load( &this->rom, data, size, header_size, &this->header, unmapped ) );
RETURN_ERR( check_hes_header( this->header.tag ) );
/* if ( header_.vers != 0 )
warning( "Unknown file version" );
if ( memcmp( header_.data_tag, "DATA", 4 ) )
warning( "Data header missing" );
if ( memcmp( header_.unused, "\0\0\0\0", 4 ) )
warning( "Unknown header data" ); */
// File spec supports multiple blocks, but I haven't found any, and
// many files have bad sizes in the only block, so it's simpler to
// just try to load the damn data as best as possible.
long addr = get_le32( this->header.addr );
/* long rom_size = get_le32( this->header.size ); */
long const rom_max = 0x100000;
if ( addr & ~(rom_max - 1) )
{
/* warning( "Invalid address" ); */
addr &= rom_max - 1;
}
/* if ( (unsigned long) (addr + size) > (unsigned long) rom_max )
warning( "Invalid size" );
if ( rom_size != rom.file_size() )
{
if ( size <= rom.file_size() - 4 && !memcmp( rom.begin() + size, "DATA", 4 ) )
warning( "Multiple DATA not supported" );
else if ( size < rom.file_size() )
warning( "Extra file data" );
else
warning( "Missing file data" );
} */
Rom_set_addr( &this->rom, addr );
this->voice_count_ = osc_count + adpcm_osc_count;
Apu_volume( &this->apu, this->gain_ );
Adpcm_volume( &this->adpcm, this->gain_ );
// Setup buffer
this->clock_rate_ = 7159091;
Buffer_clock_rate( &this->stereo_buf, 7159091 );
this->buf_changed_count = Buffer_channels_changed_count( &this->stereo_buf );
Sound_set_tempo( this, this->tempo_ );
Sound_mute_voices( this, this->mute_mask_ );
// Reset track count
this->track_count = 255;
this->m3u.size = 0;
return 0;
}
// Emulation
void recalc_timer_load( struct Hes_Emu* this );
void recalc_timer_load( struct Hes_Emu* this )
{
this->timer.load = this->timer.raw_load * this->timer_base + 1;
}
// Hardware
void irq_changed( struct Hes_Emu* this );
void run_until( struct Hes_Emu* this, hes_time_t present );
void Cpu_write_vdp( struct Hes_Emu* this, int addr, int data )
{
switch ( addr )
{
case 0:
this->vdp.latch = data & 0x1F;
break;
case 2:
if ( this->vdp.latch == 5 )
{
/* if ( data & 0x04 )
warning( "Scanline interrupt unsupported" ); */
run_until( this, Cpu_time( &this->cpu ) );
this->vdp.control = data;
irq_changed( this );
}
else
{
dprintf( "VDP not supported: $%02X <- $%02X\n", this->vdp.latch, data );
}
break;
case 3:
dprintf( "VDP MSB not supported: $%02X <- $%02X\n", this->vdp.latch, data );
break;
}
}
int Cpu_done( struct Hes_Emu* this )
{
check( time() >= end_time() ||
(!(r.status & i_flag_mask) && time() >= irq_time()) );
if ( !(this->cpu.r.status & i_flag_mask) )
{
hes_time_t present = Cpu_time( &this->cpu );
if ( this->irq.timer <= present && !(this->irq.disables & timer_mask) )
{
this->timer.fired = true;
this->irq.timer = (hes_time_t)future_hes_time;
irq_changed( this ); // overkill, but not worth writing custom code
#if defined (GME_FRAME_HOOK_DEFINED)
{
unsigned const threshold = period_60hz / 30;
unsigned long elapsed = present - last_frame_hook;
if ( elapsed - period_60hz + threshold / 2 < threshold )
{
last_frame_hook = present;
GME_FRAME_HOOK( this );
}
}
#endif
return 0x0A;
}
if ( this->irq.vdp <= present && !(this->irq.disables & vdp_mask) )
{
// work around for bugs with music not acknowledging VDP
//run_until( present );
//irq.vdp = future_hes_time;
//irq_changed();
#if defined(GME_FRAME_HOOK_DEFINED)
last_frame_hook = present;
GME_FRAME_HOOK( this );
#endif
return 0x08;
}
}
return 0;
}
void Emu_cpu_write( struct Hes_Emu* this, hes_addr_t addr, int data )
{
hes_time_t time = Cpu_time( &this->cpu );
if ( (unsigned) (addr - start_addr) <= end_addr - start_addr )
{
GME_APU_HOOK( this, addr - apu.start_addr, data );
// avoid going way past end when a long block xfer is writing to I/O space
hes_time_t t = min( time, this->cpu.end_time + 8 );
Apu_write_data( &this->apu, t, addr, data );
return;
}
if ( (unsigned) (addr - io_addr) < io_size )
{
hes_time_t t = min( time, this->cpu.end_time + 6 );
Adpcm_write_data( &this->adpcm, t, addr, data );
return;
}
switch ( addr )
{
case 0x0000:
case 0x0002:
case 0x0003:
Cpu_write_vdp( this, addr, data );
return;
case 0x0C00: {
run_until( this, time );
this->timer.raw_load = (data & 0x7F) + 1;
recalc_timer_load( this );
this->timer.count = this->timer.load;
break;
}
case 0x0C01:
data &= 1;
if ( this->timer.enabled == data )
return;
run_until( this, time );
this->timer.enabled = data;
if ( data )
this->timer.count = this->timer.load;
break;
case 0x1402:
run_until( this, time );
this->irq.disables = data;
// flag questionable values
if ( (data & 0xF8) && (data & 0xF8) != 0xF8 ) {
dprintf( "Int mask: $%02X\n", data );
}
break;
case 0x1403:
run_until( this, time );
if ( this->timer.enabled )
this->timer.count = this->timer.load;
this->timer.fired = false;
break;
#ifndef NDEBUG
case 0x1000: // I/O port
case 0x0402: // palette
case 0x0403:
case 0x0404:
case 0x0405:
return;
default:
dprintf( "unmapped write $%04X <- $%02X\n", addr, data );
return;
#endif
}
irq_changed( this );
}
int Emu_cpu_read( struct Hes_Emu* this, hes_addr_t addr )
{
hes_time_t time = Cpu_time( &this->cpu );
addr &= page_size - 1;
switch ( addr )
{
case 0x0000:
if ( this->irq.vdp > time )
return 0;
this->irq.vdp = (hes_time_t)future_hes_time;
run_until( this, time );
irq_changed( this );
return 0x20;
case 0x0002:
case 0x0003:
dprintf( "VDP read not supported: %d\n", addr );
return 0;
case 0x0C01:
//return timer.enabled; // TODO: remove?
case 0x0C00:
run_until( this, time );
dprintf( "Timer count read\n" );
return (unsigned) (this->timer.count - 1) / this->timer_base;
case 0x1402:
return this->irq.disables;
case 0x1403:
{
int status = 0;
if ( this->irq.timer <= time ) status |= timer_mask;
if ( this->irq.vdp <= time ) status |= vdp_mask;
return status;
}
case 0x180A:
case 0x180B:
case 0x180C:
case 0x180D:
return Adpcm_read_data( &this->adpcm, time, addr );
#ifndef NDEBUG
case 0x1000: // I/O port
// case 0x180C: // CD-ROM
// case 0x180D:
break;
default:
dprintf( "unmapped read $%04X\n", addr );
#endif
}
return unmapped;
}
// see hes_cpu_io.h for core read/write functions
// Emulation
void run_until( struct Hes_Emu* this, hes_time_t present )
{
while ( this->vdp.next_vbl < present )
this->vdp.next_vbl += this->play_period;
hes_time_t elapsed = present - this->timer.last_time;
if ( elapsed > 0 )
{
if ( this->timer.enabled )
{
this->timer.count -= elapsed;
if ( this->timer.count <= 0 )
this->timer.count += this->timer.load;
}
this->timer.last_time = present;
}
}
void irq_changed( struct Hes_Emu* this )
{
hes_time_t present = Cpu_time( &this->cpu );
if ( this->irq.timer > present )
{
this->irq.timer = (hes_time_t)future_hes_time;
if ( this->timer.enabled && !this->timer.fired )
this->irq.timer = present + this->timer.count;
}
if ( this->irq.vdp > present )
{
this->irq.vdp = (hes_time_t)future_hes_time;
if ( this->vdp.control & 0x08 )
this->irq.vdp = this->vdp.next_vbl;
}
hes_time_t time = (hes_time_t)future_hes_time;
if ( !(this->irq.disables & timer_mask) ) time = this->irq.timer;
if ( !(this->irq.disables & vdp_mask) ) time = min( time, this->irq.vdp );
// Set cpu irq time
this->cpu.state->time += Cpu_update_end_time( &this->cpu, this->cpu.r.status,
this->cpu.end_time, (this->cpu.irq_time = time) );
}
static void adjust_time( blargg_long* time, hes_time_t delta );
static void adjust_time( blargg_long* time, hes_time_t delta )
{
if ( *time < (blargg_long)future_hes_time )
{
*time -= delta;
if ( *time < 0 )
*time = 0;
}
}
blargg_err_t run_clocks( struct Hes_Emu* this, blip_time_t* duration_ );
blargg_err_t run_clocks( struct Hes_Emu* this, blip_time_t* duration_ )
{
blip_time_t duration = *duration_; // cache
Cpu_run( this, duration );
/* warning( "Emulation error (illegal instruction)" ); */
check( time() >= duration );
//check( time() - duration < 20 ); // Txx instruction could cause going way over
run_until( this, duration );
// end time frame
this->timer.last_time -= duration;
this->vdp.next_vbl -= duration;
#if defined (GME_FRAME_HOOK_DEFINED)
last_frame_hook -= *duration;
#endif
// End cpu frame
this->cpu.state_.base -= duration;
if ( this->cpu.irq_time < (hes_time_t)future_hes_time ) this->cpu.irq_time -= duration;
if ( this->cpu.end_time < (hes_time_t)future_hes_time ) this->cpu.end_time -= duration;
adjust_time( &this->irq.timer, duration );
adjust_time( &this->irq.vdp, duration );
Apu_end_frame( &this->apu, duration );
Adpcm_end_frame( &this->adpcm, duration );
return 0;
}
blargg_err_t play_( struct Hes_Emu* this, long count, sample_t* out );
blargg_err_t play_( struct Hes_Emu* this, long count, sample_t* out )
{
long remain = count;
while ( remain )
{
remain -= Buffer_read_samples( &this->stereo_buf, &out [count - remain], remain );
if ( remain )
{
if ( this->buf_changed_count != Buffer_channels_changed_count( &this->stereo_buf ) )
{
this->buf_changed_count = Buffer_channels_changed_count( &this->stereo_buf );
// Remute voices
Sound_mute_voices( this, this->mute_mask_ );
}
int msec = Buffer_length( &this->stereo_buf );
blip_time_t clocks_emulated = (blargg_long) msec * this->clock_rate_ / 1000;
RETURN_ERR( run_clocks( this, &clocks_emulated ) );
assert( clocks_emulated );
Buffer_end_frame( &this->stereo_buf, clocks_emulated );
}
}
return 0;
}
// Music emu
blargg_err_t Hes_set_sample_rate( struct Hes_Emu* this, long rate )
{
require( !this->sample_rate_ ); // sample rate can't be changed once set
Buffer_init( &this->stereo_buf );
RETURN_ERR( Buffer_set_sample_rate( &this->stereo_buf, rate, 1000 / 20 ) );
// Set bass frequency
Buffer_bass_freq( &this->stereo_buf, 60 );
this->sample_rate_ = rate;
return 0;
}
void Sound_mute_voice( struct Hes_Emu* this, int index, bool mute )
{
require( (unsigned) index < (unsigned) this->voice_count_ );
int bit = 1 << index;
int mask = this->mute_mask_ | bit;
if ( !mute )
mask ^= bit;
Sound_mute_voices( this, mask );
}
void Sound_mute_voices( struct Hes_Emu* this, int mask )
{
require( this->sample_rate_ ); // sample rate must be set first
this->mute_mask_ = mask;
// Set adpcm voice
struct channel_t ch = Buffer_channel( &this->stereo_buf );
if ( mask & (1 << this->voice_count_ ) )
Adpcm_set_output( &this->adpcm, 0, 0, 0, 0 );
else
Adpcm_set_output( &this->adpcm, 0, ch.center, ch.left, ch.right );
// Set apu voices
int i = this->voice_count_ - 1;
for ( ; i--; )
{
if ( mask & (1 << i) )
{
Apu_osc_output( &this->apu, i, 0, 0, 0 );
}
else
{
assert( (ch.center && ch.left && ch.right) ||
(!ch.center && !ch.left && !ch.right) ); // all or nothing
Apu_osc_output( &this->apu, i, ch.center, ch.left, ch.right );
}
}
}
void Sound_set_tempo( struct Hes_Emu* this, int t )
{
require( this->sample_rate_ ); // sample rate must be set first
int const min = (int)(FP_ONE_TEMPO*0.02);
int const max = (int)(FP_ONE_TEMPO*4.00);
if ( t < min ) t = min;
if ( t > max ) t = max;
this->play_period = (hes_time_t) ((period_60hz*FP_ONE_TEMPO) / t);
this->timer_base = (int) ((1024*FP_ONE_TEMPO) / t);
recalc_timer_load( this );
this->tempo_ = t;
}
void fill_buf( struct Hes_Emu* this );
blargg_err_t Hes_start_track( struct Hes_Emu* this, int track )
{
clear_track_vars( this );
// Remap track if playlist available
if ( this->m3u.size > 0 ) {
struct entry_t* e = &this->m3u.entries[track];
track = e->track;
}
this->current_track_ = track;
Buffer_clear( &this->stereo_buf );
memset( this->cpu.ram, 0, sizeof this->cpu.ram ); // some HES music relies on zero fill
memset( this->sgx, 0, sizeof this->sgx );
Apu_reset( &this->apu );
Adpcm_reset( &this->adpcm );
Cpu_reset( &this->cpu );
unsigned i;
for ( i = 0; i < sizeof this->header.banks; i++ )
Cpu_set_mmr( this, i, this->header.banks [i] );
Cpu_set_mmr( this, page_count, 0xFF ); // unmapped beyond end of address space
this->irq.disables = timer_mask | vdp_mask;
this->irq.timer = (hes_time_t)future_hes_time;
this->irq.vdp = (hes_time_t)future_hes_time;
this->timer.enabled = false;
this->timer.raw_load= 0x80;
this->timer.count = this->timer.load;
this->timer.fired = false;
this->timer.last_time = 0;
this->vdp.latch = 0;
this->vdp.control = 0;
this->vdp.next_vbl = 0;
this->cpu.ram [0x1FF] = (idle_addr - 1) >> 8;
this->cpu.ram [0x1FE] = (idle_addr - 1) & 0xFF;
this->cpu.r.sp = 0xFD;
this->cpu.r.pc = get_le16( this->header.init_addr );
this->cpu.r.a = track;
recalc_timer_load( this );
this->last_frame_hook = 0;
this->emu_track_ended_ = false;
this->track_ended = false;
if ( !this->ignore_silence )
{
// play until non-silence or end of track
long end;
for ( end =this-> max_initial_silence * stereo * this->sample_rate_; this->emu_time < end; )
{
fill_buf( this );
if ( this->buf_remain | (int) this->emu_track_ended_ )
break;
}
this->emu_time = this->buf_remain;
this->out_time = 0;
this->silence_time = 0;
this->silence_count = 0;
}
/* return track_ended() ? warning() : 0; */
return 0;
}
// Tell/Seek
static blargg_long msec_to_samples( blargg_long msec, long sample_rate )
{
blargg_long sec = msec / 1000;
msec -= sec * 1000;
return (sec * sample_rate + msec * sample_rate / 1000) * stereo;
}
long Track_tell( struct Hes_Emu* this )
{
blargg_long rate = this->sample_rate_ * stereo;
blargg_long sec = this->out_time / rate;
return sec * 1000 + (this->out_time - sec * rate) * 1000 / rate;
}
blargg_err_t Track_seek( struct Hes_Emu* this, long msec )
{
blargg_long time = msec_to_samples( msec, this->sample_rate_ );
if ( time < this->out_time )
RETURN_ERR( Hes_start_track( this, this->current_track_ ) );
return Track_skip( this, time - this->out_time );
}
blargg_err_t skip_( struct Hes_Emu* this, long count );
blargg_err_t skip_( struct Hes_Emu* this, long count )
{
// for long skip, mute sound
const long threshold = 30000;
if ( count > threshold )
{
int saved_mute = this->mute_mask_;
Sound_mute_voices( this, ~0 );
while ( count > threshold / 2 && !this->emu_track_ended_ )
{
RETURN_ERR( play_( this, buf_size, this->buf ) );
count -= buf_size;
}
Sound_mute_voices( this, saved_mute );
}
while ( count && !this->emu_track_ended_ )
{
long n = buf_size;
if ( n > count )
n = count;
count -= n;
RETURN_ERR( play_( this, n, this->buf ) );
}
return 0;
}
blargg_err_t Track_skip( struct Hes_Emu* this, long count )
{
require( this->current_track_ >= 0 ); // start_track() must have been called already
this->out_time += count;
// remove from silence and buf first
{
long n = min( count, this->silence_count );
this->silence_count -= n;
count -= n;
n = min( count, this->buf_remain );
this->buf_remain -= n;
count -= n;
}
if ( count && !this->emu_track_ended_ )
{
this->emu_time += count;
// End track if error
if ( skip_( this, count ) )
this->emu_track_ended_ = true;
}
if ( !(this->silence_count | this->buf_remain) ) // caught up to emulator, so update track ended
this->track_ended |= this->emu_track_ended_;
return 0;
}
// Fading
void Track_set_fade( struct Hes_Emu* this, long start_msec, long length_msec )
{
this->fade_step = this->sample_rate_ * length_msec / (fade_block_size * fade_shift * 1000 / stereo);
this->fade_start = msec_to_samples( start_msec, this->sample_rate_ );
}
// unit / pow( 2.0, (double) x / step )
static int int_log( blargg_long x, int step, int unit );
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 handle_fade( struct Hes_Emu* this, long out_count, sample_t* out );
void handle_fade( struct Hes_Emu* this, long out_count, sample_t* out )
{
int i;
for ( i = 0; i < out_count; i += fade_block_size )
{
int const shift = 14;
int const unit = 1 << shift;
int gain = int_log( (this->out_time + i - this->fade_start) / fade_block_size,
this->fade_step, unit );
if ( gain < (unit >> fade_shift) )
this->track_ended = this->emu_track_ended_ = true;
sample_t* io = &out [i];
int count;
for ( count = min( fade_block_size, out_count - i ); count; --count )
{
*io = (sample_t) ((*io * gain) >> shift);
++io;
}
}
}
// Silence detection
void emu_play( struct Hes_Emu* this, long count, sample_t* out );
void emu_play( struct Hes_Emu* this, long count, sample_t* out )
{
check( current_track_ >= 0 );
this->emu_time += count;
if ( this->current_track_ >= 0 && !this->emu_track_ended_ ) {
// End track if error
if ( play_( this, count, out ) )
this->emu_track_ended_ = true;
}
else
memset( out, 0, count * sizeof *out );
}
// number of consecutive silent samples at end
static long count_silence( sample_t* begin, long size );
static long count_silence( sample_t* begin, long size )
{
sample_t first = *begin;
*begin = silence_threshold; // sentinel
sample_t* p = begin + size;
while ( (unsigned) (*--p + silence_threshold / 2) <= (unsigned) silence_threshold ) { }
*begin = first;
return size - (p - begin);
}
// fill internal buffer and check it for silence
void fill_buf( struct Hes_Emu* this )
{
assert( !this->buf_remain );
if ( !this->emu_track_ended_ )
{
emu_play( this, buf_size, this->buf );
long silence = count_silence( this->buf, buf_size );
if ( silence < buf_size )
{
this->silence_time = this->emu_time - silence;
this->buf_remain = buf_size;
return;
}
}
this->silence_count += buf_size;
}
blargg_err_t Hes_play( struct Hes_Emu* this, long out_count, sample_t* out )
{
if ( this->track_ended )
{
memset( out, 0, out_count * sizeof *out );
}
else
{
require( this->current_track_ >= 0 );
require( out_count % stereo == 0 );
assert( this->emu_time >= this->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 ( this->silence_count )
{
// during a run of silence, run emulator at >=2x speed so it gets ahead
long ahead_time = this->silence_lookahead * (this->out_time + out_count - this->silence_time) + this->silence_time;
while ( this->emu_time < ahead_time && !(this->buf_remain | this->emu_track_ended_) )
fill_buf( this );
// fill with silence
pos = min( this->silence_count, out_count );
memset( out, 0, pos * sizeof *out );
this->silence_count -= pos;
if ( this->emu_time - this->silence_time > silence_max * stereo * this->sample_rate_ )
{
this->track_ended = this->emu_track_ended_ = true;
this->silence_count = 0;
this->buf_remain = 0;
}
}
if ( this->buf_remain )
{
// empty silence buf
long n = min( this->buf_remain, out_count - pos );
memcpy( &out [pos], this->buf + (buf_size - this->buf_remain), n * sizeof *out );
this->buf_remain -= n;
pos += n;
}
// generate remaining samples normally
long remain = out_count - pos;
if ( remain )
{
emu_play( this, remain, out + pos );
this->track_ended |= this->emu_track_ended_;
if ( !this->ignore_silence || this->out_time > this->fade_start )
{
// check end for a new run of silence
long silence = count_silence( out + pos, remain );
if ( silence < remain )
this->silence_time = this->emu_time - silence;
if ( this->emu_time - this->silence_time >= buf_size )
fill_buf( this ); // cause silence detection on next play()
}
}
if ( this->out_time > this->fade_start )
handle_fade( this, out_count, out );
}
this->out_time += out_count;
return 0;
}