Commit 14c7e628 authored by trioan's avatar trioan
Browse files

use blargg blip buffer

parent c9fe65d1
......@@ -16,4 +16,6 @@ SOURCES_CXX := $(CORE_DIR)/lynx/lynxdec.cpp \
$(CORE_DIR)/lynx/susie.cpp \
$(CORE_DIR)/lynx/system.cpp \
$(CORE_DIR)/lynx/eeprom.cpp \
$(CORE_DIR)/libretro/libretro.cpp
$(CORE_DIR)/libretro/libretro.cpp \
$(CORE_DIR)/blip/Blip_Buffer.cpp \
$(CORE_DIR)/blip/Stereo_Buffer.cpp
// Blip_Buffer 0.4.1. http://www.slack.net/~ant/
#include <blip/Blip_Buffer.h>
#include <assert.h>
#include <climits>
#include <string.h>
#include <stdlib.h>
#include <math.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 */
#ifdef BLARGG_ENABLE_OPTIMIZER
#include BLARGG_ENABLE_OPTIMIZER
#endif
Blip_Buffer::Blip_Buffer()
{
factor_ = (blip_u64)ULLONG_MAX;
offset_ = 0;
buffer_ = 0;
buffer_size_ = 0;
sample_rate_ = 0;
reader_accum_ = 0;
bass_shift_ = 0;
clock_rate_ = 0;
bass_freq_ = 16;
length_ = 0;
}
Blip_Buffer::~Blip_Buffer()
{
if (buffer_)
free( buffer_ );
}
void Blip_Buffer::clear( int entire_buffer )
{
offset_ = 0;
reader_accum_ = 0;
modified_ = 0;
if ( buffer_ )
{
long count = (entire_buffer ? buffer_size_ : samples_avail());
memset( buffer_, 0, (count + blip_buffer_extra_) * sizeof (buf_t_) );
}
}
Blip_Buffer::blargg_err_t Blip_Buffer::set_sample_rate( long new_rate, int msec )
{
// start with maximum length that resampled time can represent
blip_s64 new_size = (ULLONG_MAX >> BLIP_BUFFER_ACCURACY) - blip_buffer_extra_ - 64;
// simple safety check, since code elsewhere may not be safe for sizes approaching (2 ^ 31).
if(new_size > ((1LL << 30) - 1))
new_size = (1LL << 30) - 1;
if ( msec != blip_max_length )
{
blip_s64 s = ((blip_s64)new_rate * (msec + 1) + 999) / 1000;
if ( s < new_size )
new_size = s;
else
assert( 0 ); // fails if requested buffer length exceeds limit
}
if ( buffer_size_ != new_size )
{
void* p = realloc( buffer_, (new_size + blip_buffer_extra_) * sizeof *buffer_ );
if ( !p )
return "Out of memory";
buffer_ = (buf_t_*) p;
}
buffer_size_ = new_size;
// update things based on the sample rate
sample_rate_ = new_rate;
length_ = new_size * 1000 / new_rate - 1;
if ( msec )
assert( length_ == msec ); // ensure length is same as that passed in
if ( clock_rate_ )
clock_rate( clock_rate_ );
bass_freq( bass_freq_ );
clear();
return 0; // success
}
blip_resampled_time_t Blip_Buffer::clock_rate_factor( long rate ) const
{
double ratio = (double) sample_rate_ / rate;
blip_s64 factor = (blip_s64) floor( ratio * (1LL << BLIP_BUFFER_ACCURACY) + 0.5 );
assert( factor > 0 || !sample_rate_ ); // fails if clock/output ratio is too large
return (blip_resampled_time_t) factor;
}
void Blip_Buffer::bass_freq( int freq )
{
bass_freq_ = freq;
int shift = 31;
if ( freq > 0 )
{
shift = 13;
long f = (freq << 16) / sample_rate_;
while ( (f >>= 1) && --shift ) { }
}
bass_shift_ = shift;
}
void Blip_Buffer::end_frame( blip_time_t t )
{
offset_ += t * factor_;
assert( samples_avail() <= (long) buffer_size_ ); // time outside buffer length
}
void Blip_Buffer::remove_silence( long count )
{
assert( count <= samples_avail() ); // tried to remove more samples than available
offset_ -= (blip_resampled_time_t) count << BLIP_BUFFER_ACCURACY;
}
long Blip_Buffer::count_samples( blip_time_t t ) const
{
unsigned long last_sample = resampled_time( t ) >> BLIP_BUFFER_ACCURACY;
unsigned long first_sample = offset_ >> BLIP_BUFFER_ACCURACY;
return (long) (last_sample - first_sample);
}
blip_time_t Blip_Buffer::count_clocks( long count ) const
{
if ( !factor_ )
{
assert( 0 ); // sample rate and clock rates must be set first
return 0;
}
if ( count > buffer_size_ )
count = buffer_size_;
blip_resampled_time_t time = (blip_resampled_time_t) count << BLIP_BUFFER_ACCURACY;
return (blip_time_t) ((time - offset_ + factor_ - 1) / factor_);
}
void Blip_Buffer::remove_samples( long count )
{
if ( count )
{
remove_silence( count );
// copy remaining samples to beginning and clear old samples
long remain = samples_avail() + blip_buffer_extra_;
memmove( buffer_, buffer_ + count, remain * sizeof *buffer_ );
memset( buffer_ + remain, 0, count * sizeof *buffer_ );
}
}
// Blip_Synth_
Blip_Synth_Fast_::Blip_Synth_Fast_()
{
buf = 0;
last_amp = 0;
delta_factor = 0;
}
void Blip_Synth_Fast_::volume_unit( double new_unit )
{
delta_factor = int (new_unit * (1L << blip_sample_bits) + 0.5);
}
long Blip_Buffer::read_samples( blip_sample_t* BLIP_RESTRICT out, long max_samples, int stereo )
{
long count = samples_avail();
if ( count > max_samples )
count = max_samples;
if ( count )
{
int const bass = BLIP_READER_BASS( *this );
BLIP_READER_BEGIN( reader, *this );
#ifndef WANT_STEREO_SOUND
if ( !stereo )
{
for ( blip_long n = count; n; --n )
{
blip_long s = BLIP_READER_READ( reader );
if ( (blip_sample_t) s != s )
s = 0x7FFF - (s >> 24);
*out++ = (blip_sample_t) s;
BLIP_READER_NEXT( reader, bass );
}
}
else
#endif
{
for ( blip_long n = count; n; --n )
{
blip_long s = BLIP_READER_READ( reader );
if ( (blip_sample_t) s != s )
s = 0x7FFF - (s >> 24);
*out = (blip_sample_t) s;
out += 2;
BLIP_READER_NEXT( reader, bass );
}
}
BLIP_READER_END( reader, *this );
remove_samples( count );
}
return count;
}
void Blip_Buffer::mix_samples( blip_sample_t const* in, long count )
{
buf_t_* out = buffer_ + (offset_ >> BLIP_BUFFER_ACCURACY) + blip_widest_impulse_ / 2;
int const sample_shift = blip_sample_bits - 16;
int prev = 0;
while ( count-- )
{
blip_long s = (blip_long) *in++ << sample_shift;
*out += s - prev;
prev = s;
++out;
}
*out -= prev;
}
// Band-limited sound synthesis buffer
// Various changes and hacks for use in Mednafen.
#ifdef __GNUC__
#define blip_inline inline __attribute__((always_inline))
#else
#define blip_inline inline
#endif
#include <limits.h>
#include <stdint.h>
// Blip_Buffer 0.4.1
#ifndef BLIP_BUFFER_H
#define BLIP_BUFFER_H
// Internal
typedef int32_t blip_long;
typedef uint32_t blip_ulong;
typedef int64_t blip_s64;
typedef uint64_t blip_u64;
// Time unit at source clock rate
typedef blip_long blip_time_t;
// Output samples are 16-bit signed, with a range of -32768 to 32767
typedef short blip_sample_t;
enum { blip_sample_max = 32767 };
class Blip_Buffer {
public:
typedef const char* blargg_err_t;
// Set output sample rate and buffer length in milliseconds (1/1000 sec, defaults
// to 1/4 second), then clear buffer. Returns NULL on success, otherwise if there
// isn't enough memory, returns error without affecting current buffer setup.
blargg_err_t set_sample_rate( long samples_per_sec, int msec_length = 1000 / 4 );
// Set number of source time units per second
void clock_rate( long );
// End current time frame of specified duration and make its samples available
// (along with any still-unread samples) for reading with read_samples(). Begins
// a new time frame at the end of the current frame.
void end_frame( blip_time_t time );
// Read at most 'max_samples' out of buffer into 'dest', removing them from from
// the buffer. Returns number of samples actually read and removed. If stereo is
// true, increments 'dest' one extra time after writing each sample, to allow
// easy interleving of two channels into a stereo output buffer.
long read_samples( blip_sample_t* dest, long max_samples, int stereo = 0 );
// Additional optional features
// Current output sample rate
long sample_rate() const;
// Length of buffer, in milliseconds
int length() const;
// Number of source time units per second
long clock_rate() const;
// Set frequency high-pass filter frequency, where higher values reduce bass more
void bass_freq( int frequency );
// Number of samples delay from synthesis to samples read out
int output_latency() const;
// Remove all available samples and clear buffer to silence. If 'entire_buffer' is
// false, just clears out any samples waiting rather than the entire buffer.
void clear( int entire_buffer = 1 );
// Number of samples available for reading with read_samples()
long samples_avail() const;
// Remove 'count' samples from those waiting to be read
void remove_samples( long count );
// Experimental features
// Count number of clocks needed until 'count' samples will be available.
// If buffer can't even hold 'count' samples, returns number of clocks until
// buffer becomes full.
blip_time_t count_clocks( long count ) const;
// Number of raw samples that can be mixed within frame of specified duration.
long count_samples( blip_time_t duration ) const;
// Mix 'count' samples from 'buf' into buffer.
void mix_samples( blip_sample_t const* buf, long count );
// not documented yet
void set_modified() { modified_ = 1; }
int clear_modified() { int b = modified_; modified_ = 0; return b; }
typedef blip_u64 blip_resampled_time_t;
void remove_silence( long count );
blip_resampled_time_t resampled_duration( int t ) const { return t * factor_; }
blip_resampled_time_t resampled_time( blip_time_t t ) const { return t * factor_ + offset_; }
blip_resampled_time_t clock_rate_factor( long clock_rate ) const;
public:
Blip_Buffer();
~Blip_Buffer();
// Deprecated
typedef blip_resampled_time_t resampled_time_t;
blargg_err_t sample_rate( long r ) { return set_sample_rate( r ); }
blargg_err_t sample_rate( long r, int msec ) { return set_sample_rate( r, msec ); }
private:
// noncopyable
Blip_Buffer( const Blip_Buffer& );
Blip_Buffer& operator = ( const Blip_Buffer& );
public:
typedef blip_time_t buf_t_;
blip_u64 factor_;
blip_resampled_time_t offset_;
buf_t_* buffer_;
blip_long buffer_size_;
blip_long reader_accum_;
int bass_shift_;
private:
long sample_rate_;
long clock_rate_;
int bass_freq_;
int length_;
int modified_;
friend class Blip_Reader;
};
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#define BLIP_BUFFER_ACCURACY 32
#define BLIP_PHASE_BITS 8
// Number of bits in resample ratio fraction. Higher values give a more accurate ratio
// but reduce maximum buffer size.
//#ifndef BLIP_BUFFER_ACCURACY
// #define BLIP_BUFFER_ACCURACY 16
//#endif
// Number bits in phase offset. Fewer than 6 bits (64 phase offsets) results in
// noticeable broadband noise when synthesizing high frequency square waves.
// Affects size of Blip_Synth objects since they store the waveform directly.
//#ifndef BLIP_PHASE_BITS
// #if BLIP_BUFFER_FAST
// #define BLIP_PHASE_BITS 8
// #else
// #define BLIP_PHASE_BITS 6
// #endif
//#endif
// Internal
typedef blip_u64 blip_resampled_time_t;
int const blip_widest_impulse_ = 16;
int const blip_buffer_extra_ = blip_widest_impulse_ + 2;
int const blip_res = 1 << BLIP_PHASE_BITS;
class blip_eq_t;
class Blip_Synth_Fast_ {
public:
Blip_Buffer* buf;
int last_amp;
int delta_factor;
void volume_unit( double );
Blip_Synth_Fast_();
void treble_eq( blip_eq_t const& ) { }
};
class Blip_Synth_ {
public:
Blip_Buffer* buf;
int last_amp;
int delta_factor;
void volume_unit( double );
Blip_Synth_( short* impulses, int width );
void treble_eq( blip_eq_t const& );
private:
double volume_unit_;
short* const impulses;
int const width;
blip_long kernel_unit;
int impulses_size() const { return blip_res / 2 * width + 1; }
void adjust_impulse();
};
// Quality level. Start with blip_good_quality.
const int blip_med_quality = 8;
const int blip_good_quality = 12;
const int blip_high_quality = 16;
// Range specifies the greatest expected change in amplitude. Calculate it
// by finding the difference between the maximum and minimum expected
// amplitudes (max - min).
template<int quality,int range>
class Blip_Synth {
public:
// Set overall volume of waveform
void volume( double v ) { impl.volume_unit( v * (1.0 / (range < 0 ? -range : range)) ); }
// Configure low-pass filter (see blip_buffer.txt)
void treble_eq( blip_eq_t const& eq ) { impl.treble_eq( eq ); }
// Get/set Blip_Buffer used for output
Blip_Buffer* output() const { return impl.buf; }
void output( Blip_Buffer* b ) { impl.buf = b; impl.last_amp = 0; }
// Update amplitude of waveform at given time. Using this requires a separate
// Blip_Synth for each waveform.
void update( blip_time_t time, int amplitude );
// Low-level interface
// Add an amplitude transition of specified delta, optionally into specified buffer
// rather than the one set with output(). Delta can be positive or negative.
// The actual change in amplitude is delta * (volume / range)
void offset( blip_time_t, int delta, Blip_Buffer* ) const;
void offset( blip_time_t t, int delta ) const { offset( t, delta, impl.buf ); }
// Works directly in terms of fractional output samples. Contact author for more info.
void offset_resampled( blip_resampled_time_t, int delta, Blip_Buffer* ) const;
// Same as offset(), except code is inlined for higher performance
void offset_inline( blip_time_t t, int delta, Blip_Buffer* buf ) const {
offset_resampled( t * buf->factor_ + buf->offset_, delta, buf );
}
void offset_inline( blip_time_t t, int delta ) const {
offset_resampled( t * impl.buf->factor_ + impl.buf->offset_, delta, impl.buf );
}
private:
Blip_Synth_Fast_ impl;
};
// Low-pass equalization parameters
class blip_eq_t {
public:
// Logarithmic rolloff to treble dB at half sampling rate. Negative values reduce
// treble, small positive values (0 to 5.0) increase treble.
blip_eq_t( double treble_db = 0 );
// See blip_buffer.txt
blip_eq_t( double treble, long rolloff_freq, long sample_rate, long cutoff_freq = 0 );
private:
double treble;
long rolloff_freq;
long sample_rate;
long cutoff_freq;
void generate( float* out, int count ) const;
friend class Blip_Synth_;
};
int const blip_sample_bits = 30;
#define BLIP_RESTRICT
// Optimized reading from Blip_Buffer, for use in custom sample output
// Begin reading from buffer. Name should be unique to the current block.
#define BLIP_READER_BEGIN( name, blip_buffer ) \
const Blip_Buffer::buf_t_* BLIP_RESTRICT name##_reader_buf = (blip_buffer).buffer_;\
blip_long name##_reader_accum = (blip_buffer).reader_accum_
// Get value to pass to BLIP_READER_NEXT()
#define BLIP_READER_BASS( blip_buffer ) ((blip_buffer).bass_shift_)
// Constant value to use instead of BLIP_READER_BASS(), for slightly more optimal
// code at the cost of having no bass control
int const blip_reader_default_bass = 9;
// Current sample
#define BLIP_READER_READ( name ) (name##_reader_accum >> (blip_sample_bits - 16))
// Current raw sample in full internal resolution
#define BLIP_READER_READ_RAW( name ) (name##_reader_accum)
// Advance to next sample
#define BLIP_READER_NEXT( name, bass ) \
(void) (name##_reader_accum += *name##_reader_buf++ - (name##_reader_accum >> (bass)))
// End reading samples from buffer. The number of samples read must now be removed
// using Blip_Buffer::remove_samples().
#define BLIP_READER_END( name, blip_buffer ) \
(void) ((blip_buffer).reader_accum_ = name##_reader_accum)
// Compatibility with older version
const long blip_unscaled = 65535;
const int blip_low_quality = blip_med_quality;
const int blip_best_quality = blip_high_quality;
// Deprecated; use BLIP_READER macros as follows:
// Blip_Reader r; r.begin( buf ); -> BLIP_READER_BEGIN( r, buf );
// int bass = r.begin( buf ) -> BLIP_READER_BEGIN( r, buf ); int bass = BLIP_READER_BASS( buf );
// r.read() -> BLIP_READER_READ( r )
// r.read_raw() -> BLIP_READER_READ_RAW( r )
// r.next( bass ) -> BLIP_READER_NEXT( r, bass )
// r.next() -> BLIP_READER_NEXT( r, blip_reader_default_bass )
// r.end( buf ) -> BLIP_READER_END( r, buf )
class Blip_Reader {
public:
int begin( Blip_Buffer& );
blip_long read() const { return accum >> (blip_sample_bits - 16); }
blip_long read_raw() const { return accum; }
void next( int bass_shift = 9 ) { accum += *buf++ - (accum >> bass_shift); }
void end( Blip_Buffer& b ) { b.reader_accum_ = accum; }
private:
const Blip_Buffer::buf_t_* buf;
blip_long accum;
};
// End of public interface
#include <assert.h>
template<int quality,int range>
blip_inline void Blip_Synth<quality,range>::offset_resampled( blip_resampled_time_t time,
int delta, Blip_Buffer* blip_buf ) const
{
// Fails if time is beyond end of Blip_Buffer, due to a bug in caller code or the
// need for a longer buffer as set by set_sample_rate().
assert( (blip_long) (time >> BLIP_BUFFER_ACCURACY) < blip_buf->buffer_size_ );
delta *= impl.delta_factor;
blip_long* BLIP_RESTRICT buf = blip_buf->buffer_ + (time >> BLIP_BUFFER_ACCURACY);
int phase = (int) (time >> (BLIP_BUFFER_ACCURACY - BLIP_PHASE_BITS) & (blip_res - 1));
blip_long left = buf [0] + delta;
// Kind of crappy, but doing shift after multiply results in overflow.
// Alternate way of delaying multiply by delta_factor results in worse
// sub-sample resolution.
blip_long right = (delta >> BLIP_PHASE_BITS) * phase;
left -= right;
right += buf [1];
buf [0] = left;
buf [1] = right;
}
#undef BLIP_FWD
#undef BLIP_REV
template<int quality,int range>
blip_inline void Blip_Synth<quality,range>::offset( blip_time_t t, int delta, Blip_Buffer* buf ) const
{
offset_resampled( t * buf->factor_ + buf->offset_, delta, buf );
}
template<int quality,int range>
blip_inline void Blip_Synth<quality,range>::update( blip_time_t t, int amp )
{
int delta = amp - impl.last_amp;
impl.last_amp = amp;
offset_resampled( t * impl.buf->factor_ + impl.buf->offset_, delta, impl.buf );
}
blip_inline blip_eq_t::blip_eq_t( double t ) :
treble( t ), rolloff_freq( 0 ), sample_rate( 44100 ), cutoff_freq( 0 ) { }
blip_inline blip_eq_t::blip_eq_t( double t, long rf, long sr, long cf ) :
treble( t ), rolloff_freq( rf ), sample_rate( sr ), cutoff_freq( cf ) { }
blip_inline int Blip_Buffer::length() const { return length_; }
blip_inline long Blip_Buffer::samples_avail() const { return (long) (offset_ >> BLIP_BUFFER_ACCURACY); }
blip_inline long Blip_Buffer::sample_rate() const { return sample_rate_; }
blip_inline int Blip_Buffer::output_latency() const { return blip_widest_impulse_ / 2; }
blip_inline long Blip_Buffer::clock_rate() const { return clock_rate_; }
blip_inline void Blip_Buffer::clock_rate( long cps ) { factor_ = clock_rate_factor( clock_rate_ = cps ); }
blip_inline int Blip_Reader::begin( Blip_Buffer& blip_buf )
{
buf = blip_buf.buffer_;
accum = blip_buf.reader_accum_;
return blip_buf.bass_shift_;