Read peaks directly from source at high zoom levels.

Clip.H

@@ -25,16 +25,16 @@ typedef unsigned long nframes_t;
 
 class Clip
 {
-    char *_filename;
+    const char *_filename;
     Peaks _peaks;
 
     nframes_t _length;                                              /* length of clip in samples */
 
 public:
 
-    Clip ( const char *filename )
+    Clip ( const char *filename ) : _peaks( this )
         {
-            _filename = NULL;
+            _filename = filename;
 
             // FIXME: open file
 

Peaks.C

@@ -31,6 +31,7 @@
 
 #include <sndfile.h>
 
+#include "Clip.H"
 
 void
 Peaks::downsample ( int s, int e, float *mhi, float *mlo ) const
@@ -63,6 +64,54 @@ Peaks::read ( int X, float *hi, float *lo ) const
     downsample( start, end, hi, lo );
 }
 
+void
+Peaks::read_peaks ( int s, int e, float *mhi, float *mlo ) const
+{
+    /* this could be faster, but who cares. Don't zoom in so far! */
+
+    SNDFILE *in;
+    SF_INFO si;
+
+    memset( &si, 0, sizeof( si ) );
+
+    in = sf_open( _clip->name(), SFM_READ, &si );
+
+/*     if ( si.channels != 1 ) */
+/*         abort(); */
+/*     if ( si.samplerate != timeline.sample_rate ) */
+/*         abort(); */
+
+    sf_seek( in, s, SEEK_SET );
+
+    int chunksize = e - s;
+
+    float *fbuf = new float[ chunksize ];
+
+    size_t len;
+
+    /* read in a buffer */
+    len = sf_read_float( in, fbuf, chunksize );
+
+    Peak p;
+    p.max = -1.0;
+    p.min = 1.0;
+
+    for ( int i = 0; i < len; ++i )
+    {
+        if ( fbuf[i] > p.max )
+            p.max = fbuf[i];
+        if ( fbuf[i] < p.min )
+            p.min = fbuf[i];
+    }
+
+    sf_close( in );
+
+    delete fbuf;
+
+    *mhi = p.max;
+    *mlo = p.min;
+}
+
 
 /* virtual array. Index is a Pixel value, and it returns the
  * (resampled) peaks for that pixel based on the current timeline
@@ -75,16 +124,18 @@ Peaks::operator[] ( int X ) const
 
     if ( timeline.fpp < _peaks->chunksize )
     {
-        printf( "we need to a smaller chunksize! examine the source!\n" );
-    }
+        int start = timeline.x_to_ts( X );
+        int end   = timeline.x_to_ts( X + 1 );
 
-    int start = timeline.x_to_ts( X ) / _peaks->chunksize;
-    int end   = timeline.x_to_ts( X + 1 ) / _peaks->chunksize;
-
-/*     int start = X * timeline.fpp; */
-/*     int end = (X + 1) * timeline.fpp; */
+        read_peaks( start, end, &p.max, &p.min );
+    }
+    else
+    {
+        int start = timeline.x_to_ts( X ) / _peaks->chunksize;
+        int end   = timeline.x_to_ts( X + 1 ) / _peaks->chunksize;
 
-    downsample( start, end, &p.max, &p.min );
+        downsample( start, end, &p.max, &p.min );
+    }
 
     return p;
 }
@@ -179,6 +230,8 @@ Peaks::make_peaks ( const char *filename, int chunksize )
 
     if ( si.channels != 1 )
         abort();
+    if ( si.samplerate != timeline.sample_rate )
+        abort();
 
     FILE *fp = fopen( peakname( filename ), "w" );
 
@@ -216,7 +269,7 @@ Peaks::make_peaks ( const char *filename, int chunksize )
     while ( len == chunksize );
 
     fclose( fp );
-
     sf_close( in );
 
+    delete fbuf;
 }

Peaks.H

@@ -26,6 +26,7 @@ struct Peak {
     float max;
 };
 
+class Clip;
 
 class Peaks
 {
@@ -35,19 +36,26 @@ class Peaks
         Peak data[];
     };
 
+
+    Clip *_clip;
+
     peaks *_peaks;
 
     size_t _len;
 
+    void read_peaks ( int s, int e, float *mhi, float *mlo ) const;
+
 public:
 
-    Peaks ( void )
+    Peaks ( Clip *c )
         {
             _peaks = new peaks;
 
             _peaks->chunksize = 0;
 //            _peaks->data = NULL;
             _len = 0;
+
+            _clip = c;
         }
 
     void downsample ( int s, int e, float *mhi, float *mlo ) const;

Region.C

@@ -237,9 +237,10 @@ Region::draw ( void )
 
 //    fl_pop_clip();
 
-    fl_color( FL_RED );
-    fl_line( x() -  _start, y(), x() - _start, y() + h() );
-    fl_line( x() + w() - _end, y(), x() + w() - _end, y() + h() );
+
+/*     fl_color( FL_RED ); */
+/*     fl_line( x() - timeline.ts_to_x(  _start ), y(), x() - timeline.ts_to_x( _start ), y() + h() ); */
+/*     fl_line( x() + w() - _end, y(), x() + w() - _end, y() + h() ); */
 
     draw_label();
 

Timeline.H

@@ -28,6 +28,7 @@ struct Timeline {
 
     float fpp;                                                  /* frames per pixel */
 
+    nframes_t sample_rate;
 
     int
     ts_to_x( nframes_t ts )

main.C

@@ -67,6 +67,9 @@ main ( int argc, char **argv )
     timeline.scroll = new Fl_Scroll( 0, 24, 800, 600 - 24 );
     timeline.fpp = 256;
 
+
+    timeline.sample_rate = 44100;
+
     Fl_Pack *tracks = new Fl_Pack( 0, 0, 5000, 5000 );
     tracks->type( Fl_Pack::VERTICAL );