Submit a patch to the VGM codec by Mauricio Gama which saves some more RAM through changes of the buffer configuration and an update of the resampler code. Additionally enable VGM for low memory targets and update the manual.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30327 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 19 insertions, 40 deletions

diff --git a/apps/codecs/libgme/vgm_emu.c b/apps/codecs/libgme/vgm_emu.c
index d599056bca..391bd02d73 100644
--- a/apps/codecs/libgme/vgm_emu.c
+++ b/apps/codecs/libgme/vgm_emu.c
@@ -89,8 +89,7 @@ void Vgm_init( struct Vgm_Emu* this )
         Synth_init( &this->pcm );
         
         Buffer_init( &this->buf );
-        Buffer_init( &this->stereo_buf );
-        this->blip_buf = &this->stereo_buf.bufs [0];
+        Blip_init( &this->blip_buf );
 
         // Init fm chips        
         Ym2413_init( &this->ym2413 );
@@ -279,7 +278,7 @@ blargg_err_t Vgm_load_mem( struct Vgm_Emu* this, byte const* new_data, long new_
         if ( !this->psg_rate )
                 this->psg_rate = 3579545;
         
-        Buffer_clock_rate( &this->stereo_buf, this->psg_rate );
+        Blip_set_clock_rate( &this->blip_buf, this->psg_rate );
         
         // Disable FM
         this->fm_rate = 0;
@@ -342,14 +341,14 @@ blargg_err_t setup_fm( struct Vgm_Emu* this )
 {
         int fm_rate = 0;
         if ( !this->disable_oversampling )
-                this->fm_rate = (this->sample_rate * 3) / 2; // oversample factor = 1.5
+                fm_rate = (this->sample_rate * 3) / 2; // oversample factor = 1.5
         RETURN_ERR( init_fm( this, &fm_rate ) );
         
         if ( uses_fm( this ) )
         {
                 this->voice_count = 8;
                 RETURN_ERR( Resampler_setup( &this->resampler, fm_rate, fm_gain, this->sample_rate, this->gain ) );
-                RETURN_ERR( Resampler_reset( &this->resampler, Buffer_length( &this->stereo_buf ) * this->sample_rate / 1000 ) );
+                RETURN_ERR( Resampler_reset( &this->resampler, Blip_length( &this->blip_buf ) * this->sample_rate / 1000 ) );
                 Sms_apu_volume( &this->psg, ((this->gain/5)-(this->gain*5)/1000) * fm_gain );
         }
         else
@@ -399,7 +398,7 @@ static blargg_err_t play_( struct Vgm_Emu* this, long count, sample_t* out )
                 return 0;
         }
                 
-        Resampler_play( &this->resampler, count, out, &this->stereo_buf );
+        Resampler_play( &this->resampler, count, out, &this->blip_buf );
         return 0;
 }
 
@@ -428,19 +427,16 @@ static inline blip_time_t to_psg_time( struct Vgm_Emu* this, vgm_time_t t )
 
 static void write_pcm( struct Vgm_Emu* this, vgm_time_t vgm_time, int amp )
 {
-        if ( this->blip_buf )
-        {
-                check( amp >= 0 );
-                blip_time_t blip_time = to_psg_time( this, vgm_time );
-                int old = this->dac_amp;
-                int delta = amp - old;
-                this->dac_amp = amp;
-                Blip_set_modified( this->blip_buf );
-                if ( old >= 0 ) // first write is ignored, to avoid click
-                        Synth_offset_inline( &this->pcm, blip_time, delta, this->blip_buf );
-                else
-                        this->dac_amp |= this->dac_disabled;
-        }
+        check( amp >= 0 );
+        blip_time_t blip_time = to_psg_time( this, vgm_time );
+        int old = this->dac_amp;
+        int delta = amp - old;
+        this->dac_amp = amp;
+        Blip_set_modified( &this->blip_buf );
+        if ( old >= 0 ) // first write is ignored, to avoid click
+                Synth_offset_inline( &this->pcm, blip_time, delta, &this->blip_buf );
+        else
+                this->dac_amp |= this->dac_disabled;
 }
 
 blip_time_t run( struct Vgm_Emu* this, vgm_time_t end_time )
@@ -514,22 +510,7 @@ blip_time_t run( struct Vgm_Emu* this, vgm_time_t end_time )
                 
                 case cmd_ym2612_port1:
                         if ( Ym2612_run_until( &this->ym2612, to_fm_time( this, vgm_time ) ) )
-                        {
-                                if ( pos [0] == ym2612_dac_pan_port )
-                                {
-                                        struct Blip_Buffer* blip_buf = NULL;
-                                        switch ( pos [1] >> 6 )
-                                        {
-                                        case 0: blip_buf = NULL; break;
-                                        case 1: blip_buf = &this->stereo_buf.bufs [2]; break;
-                                        case 2: blip_buf = &this->stereo_buf.bufs [1]; break;
-                                        case 3: blip_buf = &this->stereo_buf.bufs [0]; break;
-                                        }
-                                        this->blip_buf = blip_buf;
-                                }
-                        
                                 Ym2612_write1( &this->ym2612, pos [0], pos [1] );
-                        }
                         pos += 2;
                         break;
                         
@@ -664,7 +645,7 @@ void update_fm_rates( struct Vgm_Emu* this, int* ym2413_rate, int* ym2612_rate )
 blargg_err_t Vgm_set_sample_rate( struct Vgm_Emu* this, long rate )
 {
         require( !this->sample_rate ); // sample rate can't be changed once set
-        RETURN_ERR( Buffer_set_sample_rate( &this->stereo_buf, rate, 1000 / 30 ) );
+        RETURN_ERR( Blip_set_sample_rate( &this->blip_buf, rate, 1000 / 30 ) );
         RETURN_ERR( Buffer_set_sample_rate( &this->buf, rate, 1000 / 20 ) );
         
         // Set bass frequency
@@ -712,7 +693,7 @@ void Sound_mute_voices( struct Vgm_Emu* this, int mask )
         if ( uses_fm( this ) )
         {
                 for ( i = sms_osc_count; --i >= 0; )
-                        Sms_apu_set_output( &this->psg, i, ( mask & 0x80 ) ? 0 : &this->stereo_buf.bufs [0], NULL, NULL );
+                        Sms_apu_set_output( &this->psg, i, ( mask & 0x80 ) ? 0 : &this->blip_buf, NULL, NULL );
                 if ( Ym2612_enabled( &this->ym2612 ) )
                 {
                         Synth_volume( &this->pcm, (mask & 0x40) ? 0 : (int)((long long)(0.1115*FP_ONE_VOLUME) / 256 * fm_gain * this->gain / FP_ONE_VOLUME) );
@@ -743,7 +724,7 @@ void Sound_set_tempo( struct Vgm_Emu* this, int t )
         if ( this->file_begin )
         {
                 this->vgm_rate = (long) ((44100LL * t) / FP_ONE_TEMPO);
-                this->blip_time_factor = (int) (((1LL << blip_time_bits) * Blip_clock_rate( &this->stereo_buf.bufs [0] )) / this->vgm_rate);
+                this->blip_time_factor = (int) (((1LL << blip_time_bits) * Blip_clock_rate( &this->blip_buf )) / this->vgm_rate);
                 //debug_printf( "blip_time_factor: %ld\n", blip_time_factor );
                 //debug_printf( "vgm_rate: %ld\n", vgm_rate );
                 // TODO: remove? calculates vgm_rate more accurately (above differs at most by one Hz only)
@@ -761,8 +742,6 @@ blargg_err_t Vgm_start_track( struct Vgm_Emu* this )
         
         Sms_apu_reset( &this->psg, get_le16( header( this )->noise_feedback ), header( this )->noise_width );
         
-        this->blip_buf = &this->stereo_buf.bufs [0];
-        
         this->dac_disabled = -1;
         this->pos          = this->file_begin + header_size;
         this->pcm_data     = this->pos;
@@ -785,7 +764,7 @@ blargg_err_t Vgm_start_track( struct Vgm_Emu* this )
                 if ( Ym2612_enabled( &this->ym2612 ) )
                         Ym2612_reset( &this->ym2612 );
                 
-                Buffer_clear( &this->stereo_buf );
+                Blip_clear( &this->blip_buf, 1 );
                 Resampler_clear( &this->resampler );
         }