1 files changed, 225 insertions, 165 deletions

diff --git a/apps/codecs/libgme/multi_buffer.c b/apps/codecs/libgme/multi_buffer.c
index 26cb8cdec6..554778c3de 100644
--- a/apps/codecs/libgme/multi_buffer.c
+++ b/apps/codecs/libgme/multi_buffer.c
@@ -1,4 +1,4 @@
-// Blip_Buffer 0.4.1. http://www.slack.net/~ant/
+// Multi_Buffer 0.4.1. http://www.slack.net/~ant/
 
 #include "multi_buffer.h"
 
@@ -15,212 +15,272 @@ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
 
 #include "blargg_source.h"
 
-#ifdef BLARGG_ENABLE_OPTIMIZER
-        #include BLARGG_ENABLE_OPTIMIZER
-#endif
-
-// Stereo_Buffer
- 
-void Buffer_init( struct Stereo_Buffer* this )
-{
-        Blip_init( &this->bufs [0] );
-        Blip_init( &this->bufs [1] );
-        Blip_init( &this->bufs [2] );
-                        
-        this->chan.center = &this->bufs [0];
-        this->chan.left = &this->bufs [1];
-        this->chan.right = &this->bufs [2];
-        
-        this->length_ = 0;
-        this->sample_rate_ = 0;
-        this->channels_changed_count_ = 1;
-        this->samples_per_frame_ = 2;
+// Tracked_Blip_Buffer
+
+int const blip_buffer_extra = 32; // TODO: explain why this value
+
+void Tracked_init( struct Tracked_Blip_Buffer* this )
+{
+        Blip_init( &this->blip );
+        this->last_non_silence = 0;
 }
 
-blargg_err_t Buffer_set_sample_rate( struct Stereo_Buffer* this, long rate, int msec )
+void Tracked_clear( struct Tracked_Blip_Buffer* this )
 {
-        int i;
-        for ( i = 0; i < buf_count; i++ )
-                RETURN_ERR( Blip_set_sample_rate( &this->bufs[i], rate, msec ) );
-                
-        this->sample_rate_ = Blip_sample_rate( &this->bufs [0] );
-        this->length_ = Blip_length( &this->bufs [0] );
-        return 0;
+        this->last_non_silence = 0;
+        Blip_clear( &this->blip );
 }
 
-void Buffer_clock_rate( struct Stereo_Buffer* this, long rate )
+void Tracked_end_frame( struct Tracked_Blip_Buffer* this, blip_time_t t )
 {
-        int i;
-        for ( i = 0; i < buf_count; i++ )
-                Blip_set_clock_rate( &this->bufs [i], rate );
+        Blip_end_frame( &this->blip, t );
+        if ( this->blip.modified )
+        {
+                this->blip.modified = false;
+                this->last_non_silence = Blip_samples_avail( &this->blip ) + blip_buffer_extra;
+        }
 }
 
-void Buffer_bass_freq( struct Stereo_Buffer* this, int bass )
+unsigned Tracked_non_silent( struct Tracked_Blip_Buffer* this )
 {
-        unsigned i;
-        for ( i = 0; i < buf_count; i++ )
-                Blip_bass_freq( &this->bufs [i], bass );
+        return this->last_non_silence | unsettled( &this->blip );
 }
 
-struct channel_t Buffer_channel( struct Stereo_Buffer* this )
+static inline void remove_( struct Tracked_Blip_Buffer* this, int n )
 {
-        return this->chan;
+        if ( (this->last_non_silence -= n) < 0 )
+                this->last_non_silence = 0;
 }
 
-void Buffer_clear( struct Stereo_Buffer* this )
+void Tracked_remove_silence( struct Tracked_Blip_Buffer* this, int n )
 {
-        this->stereo_added = 0;
-        this->was_stereo   = false;
-        int i;
-        for ( i = 0; i < buf_count; i++ )
-                Blip_clear( &this->bufs [i], 1 );
+        remove_( this, n );
+        Blip_remove_silence( &this->blip, n );
 }
 
-void Buffer_end_frame( struct Stereo_Buffer* this, blip_time_t clock_count )
+void Tracked_remove_samples( struct Tracked_Blip_Buffer* this, int n )
+{
+        remove_( this, n );
+        Blip_remove_samples( &this->blip, n );
+}
+
+void Tracked_remove_all_samples( struct Tracked_Blip_Buffer* this )
+{
+        int avail = Blip_samples_avail( &this->blip );
+        if ( !Tracked_non_silent( this ) )
+                Tracked_remove_silence( this, avail );
+        else
+                Tracked_remove_samples( this, avail );
+}
+
+int Tracked_read_samples( struct Tracked_Blip_Buffer* this, blip_sample_t out [], int count )
+{
+        count = Blip_read_samples( &this->blip, out, count, false );
+        remove_( this, count );
+        return count;
+}
+
+// Stereo_Mixer
+
+// mixers use a single index value to improve performance on register-challenged processors
+// offset goes from negative to zero
+
+void Mixer_init( struct Stereo_Mixer* this )
 {
-        this->stereo_added = 0;
-        unsigned i;
-        for ( i = 0; i < buf_count; i++ )
+        this->samples_read = 0;
+}
+
+static void mix_mono( struct Stereo_Mixer* this, blip_sample_t out_ [], int count )
+{
+        int const bass = this->bufs [2]->blip.bass_shift_;
+        delta_t const* center = this->bufs [2]->blip.buffer_ + this->samples_read;
+        int center_sum = this->bufs [2]->blip.reader_accum_;
+
+        typedef blip_sample_t stereo_blip_sample_t [stereo];
+        stereo_blip_sample_t* BLARGG_RESTRICT out = (stereo_blip_sample_t*) out_ + count;
+        int offset = -count;
+        do
         {
-                this->stereo_added |= Blip_clear_modified( &this->bufs [i] ) << i;
-                Blip_end_frame( &this->bufs [i], clock_count );
+                int s = center_sum >> delta_bits;
+
+                center_sum -= center_sum >> bass;
+                center_sum += center [offset];
+
+                BLIP_CLAMP( s, s );
+
+                out [offset] [0] = (blip_sample_t) s;
+                out [offset] [1] = (blip_sample_t) s;
         }
+        while ( ++offset );
+
+        this->bufs [2]->blip.reader_accum_ = center_sum;
 }
 
-long Buffer_read_samples( struct Stereo_Buffer* this, blip_sample_t* out, long count )
+static void mix_stereo( struct Stereo_Mixer* this, blip_sample_t out_ [], int count )
 {
-        require( !(count & 1) ); // count must be even
-        count = (unsigned) count / 2;
-        
-        long avail = Blip_samples_avail( &this->bufs [0] );
-        if ( count > avail )
-                count = avail;
-        if ( count )
+        blip_sample_t* BLARGG_RESTRICT out = out_ + count * stereo;
+        // do left + center and right + center separately to reduce register load
+        struct Tracked_Blip_Buffer* const* buf = &this->bufs [2];
+        while ( true ) // loop runs twice
         {
-                int bufs_used = this->stereo_added | this->was_stereo;
-                //dprintf( "%X\n", bufs_used );
-                if ( bufs_used <= 1 )
-                {
-                        Buffer_mix_mono( this, out, count );
-                        Blip_remove_samples( &this->bufs [0], count );
-                        Blip_remove_silence( &this->bufs [1], count );
-                        Blip_remove_silence( &this->bufs [2], count );
-                }
-                else if ( bufs_used & 1 )
-                {
-                        Buffer_mix_stereo( this, out, count );
-                        Blip_remove_samples( &this->bufs [0], count );
-                        Blip_remove_samples( &this->bufs [1], count );
-                        Blip_remove_samples( &this->bufs [2], count );
-                }
-                else
-                {
-                        Buffer_mix_stereo_no_center( this, out, count );
-                        Blip_remove_silence( &this->bufs [0], count );
-                        Blip_remove_samples( &this->bufs [1], count );
-                        Blip_remove_samples( &this->bufs [2], count );
-                }
-                
-                // to do: this might miss opportunities for optimization
-                if ( !Blip_samples_avail( &this->bufs [0] ) )
+                --buf;
+                --out;
+
+                int const bass = this->bufs [2]->blip.bass_shift_;
+                delta_t const* side = (*buf)->blip.buffer_ + this->samples_read;
+                delta_t const* center = this->bufs [2]->blip.buffer_ + this->samples_read;
+
+                int side_sum = (*buf)->blip.reader_accum_;
+                int center_sum = this->bufs [2]->blip.reader_accum_;
+
+                int offset = -count;
+                do
                 {
-                        this->was_stereo   = this->stereo_added;
-                        this->stereo_added = 0;
+                        int s = (center_sum + side_sum) >> delta_bits;
+
+                        side_sum   -= side_sum   >> bass;
+                        center_sum -= center_sum >> bass;
+
+                        side_sum   += side   [offset];
+                        center_sum += center [offset];
+
+                        BLIP_CLAMP( s, s );
+
+                        ++offset; // before write since out is decremented to slightly before end
+                        out [offset * stereo] = (blip_sample_t) s;
                 }
+                while ( offset );
+
+                (*buf)->blip.reader_accum_ = side_sum;
+
+                if ( buf != this->bufs )
+                        continue;
+
+                // only end center once
+                this->bufs [2]->blip.reader_accum_ = center_sum;
+                break;
         }
-        
-        return count * 2;
 }
 
-unsigned Buffer_channels_changed_count( struct Stereo_Buffer* this )
+void Mixer_read_pairs( struct Stereo_Mixer* this, blip_sample_t out [], int count )
 {
-        return this->channels_changed_count_;
+        // TODO: if caller never marks buffers as modified, uses mono
+        // except that buffer isn't cleared, so caller can encounter
+        // subtle problems and not realize the cause.
+        this->samples_read += count;
+        if ( Tracked_non_silent( this->bufs [0] ) | Tracked_non_silent( this->bufs [1] ) )
+        mix_stereo( this, out, count );
+        else
+        mix_mono( this, out, count );
 }
 
-void Buffer_channels_changed( struct Stereo_Buffer* this )
+// Multi_Buffer
+
+void Buffer_init( struct Multi_Buffer* this )
 {
-        this->channels_changed_count_++;
+        int const spf = 2;
+
+        Tracked_init( &this->bufs [0] );
+        Tracked_init( &this->bufs [1] );
+        Tracked_init( &this->bufs [2] );
+
+        Mixer_init( &this->mixer );
+
+        this->length_                 = 0;
+        this->sample_rate_            = 0;
+        this->channels_changed_count_ = 1;
+        this->channel_types_          = NULL;
+        this->channel_count_          = 0;
+        this->samples_per_frame_      = spf;
+        this->immediate_removal_      = true;
+
+        this->mixer.bufs [2] = &this->bufs [2];
+        this->mixer.bufs [0] = &this->bufs [0];
+        this->mixer.bufs [1] = &this->bufs [1];
+
+        this->chan.center = &this->bufs [2].blip;
+        this->chan.left   = &this->bufs [0].blip;
+        this->chan.right  = &this->bufs [1].blip;
 }
 
-void Buffer_mix_stereo( struct Stereo_Buffer* this, blip_sample_t* out_, blargg_long count )
+blargg_err_t Buffer_set_sample_rate( struct Multi_Buffer* this, int rate, int msec )
 {
-        blip_sample_t* BLIP_RESTRICT out = out_;
-        int const bass = BLIP_READER_BASS( this->bufs [1] );
-        BLIP_READER_BEGIN( left, this->bufs [1] );
-        BLIP_READER_BEGIN( right, this->bufs [2] );
-        BLIP_READER_BEGIN( center, this->bufs [0] );
-        
-        for ( ; count; --count )
-        {
-                int c = BLIP_READER_READ( center );
-                blargg_long l = c + BLIP_READER_READ( left );
-                blargg_long r = c + BLIP_READER_READ( right );
-                if ( (int16_t) l != l )
-                        l = 0x7FFF - (l >> 24);
-                
-                BLIP_READER_NEXT( center, bass );
-                if ( (int16_t) r != r )
-                        r = 0x7FFF - (r >> 24);
-                
-                BLIP_READER_NEXT( left, bass );
-                BLIP_READER_NEXT( right, bass );
-                
-                out [0] = l;
-                out [1] = r;
-                out += 2;
-        }
-        
-        BLIP_READER_END( center, this->bufs [0] );
-        BLIP_READER_END( right, this->bufs [2] );
-        BLIP_READER_END( left, this->bufs [1] );
+        int i;
+        for ( i = bufs_size; --i >= 0; )
+                RETURN_ERR( Blip_set_sample_rate( &this->bufs [i].blip, rate, msec ) );
+
+        this->sample_rate_ = Blip_sample_rate( &this->bufs [0].blip );
+        this->length_      = Blip_length( &this->bufs [0].blip );
+        return 0;
 }
 
-void Buffer_mix_stereo_no_center( struct Stereo_Buffer* this, blip_sample_t* out_, blargg_long count )
+void Buffer_clock_rate( struct Multi_Buffer* this, int rate )
 {
-        blip_sample_t* BLIP_RESTRICT out = out_;
-        int const bass = BLIP_READER_BASS( this->bufs [1] );
-        BLIP_READER_BEGIN( left, this->bufs [1] );
-        BLIP_READER_BEGIN( right, this->bufs [2] );
-        
-        for ( ; count; --count )
-        {
-                blargg_long l = BLIP_READER_READ( left );
-                if ( (int16_t) l != l )
-                        l = 0x7FFF - (l >> 24);
-                
-                blargg_long r = BLIP_READER_READ( right );
-                if ( (int16_t) r != r )
-                        r = 0x7FFF - (r >> 24);
-                
-                BLIP_READER_NEXT( left, bass );
-                BLIP_READER_NEXT( right, bass );
-                
-                out [0] = l;
-                out [1] = r;
-                out += 2;
-        }
-        
-        BLIP_READER_END( right, this->bufs [2] );
-        BLIP_READER_END( left, this->bufs [1] );
+        int i;
+        for ( i = bufs_size; --i >= 0; )
+                Blip_set_clock_rate( &this->bufs [i].blip, rate );
+}
+
+void Buffer_bass_freq( struct Multi_Buffer* this, int bass )
+{
+        int i;
+        for ( i = bufs_size; --i >= 0; )
+                Blip_bass_freq( &this->bufs [i].blip, bass );
+}
+
+blargg_err_t Buffer_set_channel_count( struct Multi_Buffer* this, int n, int const* types )
+{
+        this->channel_count_ = n;
+        this->channel_types_ = types;
+        return 0;
 }
 
-void Buffer_mix_mono( struct Stereo_Buffer* this, blip_sample_t* out_, blargg_long count )
+struct channel_t Buffer_channel( struct Multi_Buffer* this, int i )
 {
-        blip_sample_t* BLIP_RESTRICT out = out_;
-        int const bass = BLIP_READER_BASS( this->bufs [0] );
-        BLIP_READER_BEGIN( center, this->bufs [0] );
-        
-        for ( ; count; --count )
+        (void) i;
+        return this->chan;
+}
+
+void Buffer_clear( struct Multi_Buffer* this )
+{
+        int i;
+        this->mixer.samples_read = 0;
+        for ( i = bufs_size; --i >= 0; )
+                Tracked_clear( &this->bufs [i] );
+}
+
+void Buffer_end_frame( struct Multi_Buffer* this, blip_time_t clock_count )
+{
+    int i;
+    for ( i = bufs_size; --i >= 0; )
+                Tracked_end_frame( &this->bufs [i], clock_count );
+}
+
+int Buffer_read_samples( struct Multi_Buffer* this, blip_sample_t out [], int out_size )
+{
+        require( (out_size & 1) == 0 ); // must read an even number of samples
+        out_size = min( out_size, Buffer_samples_avail( this ) );
+
+        int pair_count = (int) (out_size >> 1);
+        if ( pair_count )
         {
-                blargg_long s = BLIP_READER_READ( center );
-                if ( (int16_t) s != s )
-                        s = 0x7FFF - (s >> 24);
-                
-                BLIP_READER_NEXT( center, bass );
-                out [0] = s;
-                out [1] = s;
-                out += 2;
+                Mixer_read_pairs( &this->mixer, out, pair_count );
+
+                if ( Buffer_samples_avail( this ) <= 0 || this->immediate_removal_ )
+                {
+                        int i;
+                        for ( i = bufs_size; --i >= 0; )
+                        {
+                                buf_t* b = &this->bufs [i];
+                                // TODO: might miss non-silence settling since it checks END of last read
+                                if ( !Tracked_non_silent( b ) )
+                                        Tracked_remove_silence( b, this->mixer.samples_read );
+                                else
+                                        Tracked_remove_samples( b, this->mixer.samples_read );
+                        }
+                        this->mixer.samples_read = 0;
+                }
         }
-        
-        BLIP_READER_END( center, this->bufs [0] );
+
+        return out_size;
 }