1 files changed, 90 insertions, 0 deletions

diff --git a/lib/rbcodec/codecs/libgme/track_filter.h b/lib/rbcodec/codecs/libgme/track_filter.h
new file mode 100644
index 0000000000..3689be9620
--- /dev/null
+++ b/lib/rbcodec/codecs/libgme/track_filter.h
@@ -0,0 +1,90 @@
+// Removes silence from beginning of track, fades end of track. Also looks ahead
+// for excessive silence, and if found, ends track.
+
+// Game_Music_Emu 0.6-pre
+#ifndef TRACK_FILTER_H
+#define TRACK_FILTER_H
+
+#include "blargg_common.h"
+
+typedef short sample_t;
+typedef int sample_count_t;
+
+enum { indefinite_count = INT_MAX/2 + 1 };
+enum { buf_size = 2048 };
+
+struct setup_t {
+    sample_count_t max_initial; // maximum silence to strip from beginning of track
+    sample_count_t max_silence; // maximum silence in middle of track without it ending
+    int lookahead;   // internal speed when looking ahead for silence (2=200% etc.)
+};
+
+struct Track_Filter {
+    void* emu_;
+    struct setup_t setup_;
+    const char* emu_error;
+    bool silence_ignored_;
+    
+    // Timing
+    int out_time;  // number of samples played since start of track
+    int emu_time;  // number of samples emulator has generated since start of track
+    int emu_track_ended_; // emulator has reached end of track
+    volatile int track_ended_;
+    
+    // Fading
+    int fade_start;
+    int fade_step;
+    
+    // Silence detection
+    int silence_time;   // absolute number of samples where most recent silence began
+    int silence_count;  // number of samples of silence to play before using buf
+    int buf_remain;     // number of samples left in silence buffer
+    sample_t buf [buf_size];
+};
+
+// Initializes filter. Must be done once before using object.
+blargg_err_t track_init( struct Track_Filter* this, void* );
+void track_create( struct Track_Filter* this );
+
+// Gets/sets setup
+static inline struct setup_t const* track_get_setup( struct Track_Filter* this ) { return &this->setup_; }
+static inline void track_setup( struct Track_Filter* this, struct setup_t const* s ) { this->setup_ = *s; }
+
+// Disables automatic end-of-track detection and skipping of silence at beginning
+static inline void track_ignore_silence( struct Track_Filter* this, bool disable ) { this->silence_ignored_ = disable; }
+
+// Clears state and skips initial silence in track
+blargg_err_t track_start( struct Track_Filter* this );
+    
+// Sets time that fade starts, and how long until track ends.
+void track_set_fade( struct Track_Filter* this, sample_count_t start, sample_count_t length );
+
+// Generates n samples into buf
+blargg_err_t track_play( struct Track_Filter* this, int n, sample_t buf [] );
+
+// Skips n samples
+blargg_err_t track_skip( struct Track_Filter* this, int n );
+
+// Number of samples played/skipped since start_track()
+static inline int track_sample_count( struct Track_Filter* this ) { return this->out_time; }
+
+// True if track ended. Causes are end of source samples, end of fade,
+// or excessive silence.
+static inline bool track_ended( struct Track_Filter* this ) { return this->track_ended_; }
+
+// Clears state
+void track_stop( struct Track_Filter* this );
+    
+// For use by callbacks
+
+// Sets internal "track ended" flag and stops generation of further source samples
+static inline void track_set_end( struct Track_Filter* this ) { this->emu_track_ended_ = true; }
+
+// For use by skip_() callback
+blargg_err_t skippy_( struct Track_Filter* this, int count );
+void fill_buf( struct Track_Filter* this );
+
+// Skip and play callbacks
+blargg_err_t skip_( void* emu, int count );
+blargg_err_t play_( void* emu, int count, sample_t out [] );
+#endif