1 files changed, 225 insertions, 0 deletions

diff --git a/lib/rbcodec/codecs/libgme/blip_buffer.c b/lib/rbcodec/codecs/libgme/blip_buffer.c
new file mode 100644
index 0000000000..ba0a6558d2
--- /dev/null
+++ b/lib/rbcodec/codecs/libgme/blip_buffer.c
@@ -0,0 +1,225 @@
+// Blip_Buffer 0.4.1. http://www.slack.net/~ant/
+
+#include "blip_buffer.h"
+
+#include <limits.h>
+#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 */
+
+#include "blargg_source.h"
+
+void Blip_init( struct Blip_Buffer* this )
+{
+        this->factor_        = UINT_MAX/2 + 1;;
+        this->buffer_center_ = NULL;
+        this->buffer_size_   = 0;
+        this->sample_rate_   = 0;
+        this->bass_shift_    = 0;
+        this->clock_rate_    = 0;
+        this->bass_freq_     = 16;
+        this->length_        = 0;
+
+        // assumptions code makes about implementation-defined features
+        #ifndef NDEBUG
+                // right shift of negative value preserves sign
+                buf_t_ i = -0x7FFFFFFE;
+                assert( (i >> 1) == -0x3FFFFFFF );
+
+                // casting to short truncates to 16 bits and sign-extends
+                i = 0x18000;
+                assert( (short) i == -0x8000 );
+        #endif
+
+        Blip_clear( this );
+}
+
+void Blip_clear( struct Blip_Buffer* this )
+{
+        bool const entire_buffer = true;
+
+        this->offset_       = 0;
+        this->reader_accum_ = 0;
+        this->modified      = false;
+
+        if ( this->buffer_ )
+        {
+                int count = (entire_buffer ? this->buffer_size_ : Blip_samples_avail( this ));
+                memset( this->buffer_, 0, (count + blip_buffer_extra_) * sizeof (delta_t) );
+        }
+}
+
+blargg_err_t Blip_set_sample_rate( struct Blip_Buffer* this, int new_rate, int msec )
+{
+        // Limit to maximum size that resampled time can represent
+        int max_size = (((blip_resampled_time_t) -1) >> BLIP_BUFFER_ACCURACY) -
+                blip_buffer_extra_ - 64; // TODO: -64 isn't needed
+        int new_size = (new_rate * (msec + 1) + 999) / 1000;
+        if ( new_size > max_size )
+                new_size = max_size;
+
+        // Resize buffer
+        if ( this->buffer_size_ != new_size ) {
+                this->buffer_center_ = this->buffer_ + BLIP_MAX_QUALITY/2;
+                this->buffer_size_ = new_size;
+    }
+
+        // update things based on the sample rate
+        this->sample_rate_ = new_rate;
+        this->length_      = new_size * 1000 / new_rate - 1;
+        if ( this->clock_rate_ )
+                Blip_set_clock_rate( this, this->clock_rate_ );
+        Blip_bass_freq( this, this->bass_freq_ );
+
+        Blip_clear( this );
+
+        return 0; // success
+}
+
+blip_resampled_time_t Blip_clock_rate_factor( struct Blip_Buffer* this, int rate )
+{
+        int factor = (int) ( this->sample_rate_ * (1LL << BLIP_BUFFER_ACCURACY) / rate);
+        assert( factor > 0 || !this->sample_rate_ ); // fails if clock/output ratio is too large
+        return (blip_resampled_time_t) factor;
+}
+
+void Blip_bass_freq( struct Blip_Buffer* this, int freq )
+{
+        this->bass_freq_ = freq;
+        int shift = 31;
+        if ( freq > 0 && this->sample_rate_ )
+        {
+                shift = 13;
+                int f = (freq << 16) / this->sample_rate_;
+                while ( (f >>= 1) && --shift ) { }
+        }
+    this->bass_shift_ = shift;
+}
+
+void Blip_end_frame( struct Blip_Buffer* this, blip_time_t t )
+{
+        this->offset_ += t * this->factor_;
+        assert( Blip_samples_avail( this ) <= (int) this->buffer_size_ ); // time outside buffer length
+}
+
+int Blip_count_samples( struct Blip_Buffer* this, blip_time_t t )
+{
+        blip_resampled_time_t last_sample  = Blip_resampled_time( this, t ) >> BLIP_BUFFER_ACCURACY;
+        blip_resampled_time_t first_sample = this->offset_                  >> BLIP_BUFFER_ACCURACY;
+        return (int) (last_sample - first_sample);
+}
+
+blip_time_t Blip_count_clocks( struct Blip_Buffer* this, int count )
+{
+        if ( count > this->buffer_size_ )
+                count = this->buffer_size_;
+        blip_resampled_time_t time = (blip_resampled_time_t) count << BLIP_BUFFER_ACCURACY;
+        return (blip_time_t) ((time - this->offset_ + this->factor_ - 1) / this->factor_);
+}
+
+void Blip_remove_samples( struct Blip_Buffer* this, int count )
+{
+        if ( count )
+        {
+                Blip_remove_silence( this, count );
+
+                // copy remaining samples to beginning and clear old samples
+                int remain = Blip_samples_avail( this ) + blip_buffer_extra_;
+                memmove( this->buffer_, this->buffer_ + count, remain * sizeof *this->buffer_ );
+                memset( this->buffer_ + remain, 0, count * sizeof *this->buffer_ );
+        }
+}
+
+int Blip_read_samples( struct Blip_Buffer* this, blip_sample_t out_ [], int max_samples, bool stereo )
+{
+        int count = Blip_samples_avail( this );
+        if ( count > max_samples )
+                count = max_samples;
+
+        if ( count )
+        {
+                int const bass = this->bass_shift_;
+                delta_t const* reader = this->buffer_ + count;
+                int reader_sum = this->reader_accum_;
+
+                blip_sample_t* BLARGG_RESTRICT out = out_ + count;
+                if ( stereo )
+                        out += count;
+                int offset = -count;
+
+                if ( !stereo )
+                {
+                        do
+                        {
+                                int s = reader_sum >> delta_bits;
+
+                                reader_sum -= reader_sum >> bass;
+                                reader_sum += reader [offset];
+
+                                BLIP_CLAMP( s, s );
+                                out [offset] = (blip_sample_t) s;
+                        }
+                        while ( ++offset );
+                }
+                else
+                {
+                        do
+                        {
+                                int s = reader_sum >> delta_bits;
+
+                                reader_sum -= reader_sum >> bass;
+                                reader_sum += reader [offset];
+
+                                BLIP_CLAMP( s, s );
+                                out [offset * 2] = (blip_sample_t) s;
+                        }
+                        while ( ++offset );
+                }
+
+                this->reader_accum_ = reader_sum;
+
+                Blip_remove_samples( this, count );
+        }
+        return count;
+}
+
+void Blip_mix_samples( struct Blip_Buffer* this,  blip_sample_t const in [], int count )
+{
+        delta_t* out = this->buffer_center_ + (this->offset_ >> BLIP_BUFFER_ACCURACY);
+
+        int const sample_shift = blip_sample_bits - 16;
+        int prev = 0;
+        while ( --count >= 0 )
+        {
+                int s = *in++ << sample_shift;
+                *out += s - prev;
+                prev = s;
+                ++out;
+        }
+        *out -= prev;
+}
+
+// Blip_Synth
+
+void volume_unit( struct Blip_Synth* this, int new_unit )
+{
+        this->delta_factor = (int) (new_unit * (1LL << blip_sample_bits) / FP_ONE_VOLUME);
+}
+
+void Synth_init( struct Blip_Synth* this )
+{
+        this->buf = 0;
+        this->last_amp = 0;
+        this->delta_factor = 0;
+}