diff options
Diffstat (limited to 'gme/Music_Emu.cpp')
-rw-r--r-- | gme/Music_Emu.cpp | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/gme/Music_Emu.cpp b/gme/Music_Emu.cpp new file mode 100644 index 00000000..31c7233c --- /dev/null +++ b/gme/Music_Emu.cpp @@ -0,0 +1,410 @@ +// 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) + +Music_Emu::equalizer_t const Music_Emu::tv_eq = { -8.0, 180 }; + +void Music_Emu::clear_track_vars() +{ + current_track_ = -1; + out_time = 0; + emu_time = 0; + emu_track_ended_ = true; + track_ended_ = true; + fade_start = LONG_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 - (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"; } |