seeking support

flac-decoder.rkt

@@ -10,6 +10,7 @@
            flac-read-meta
            flac-stream-state
            flac-stop
+           flac-seek
            (all-from-out "flac-definitions.rkt")
            kinds
            last-buffer last-buf-len
@@ -132,6 +133,19 @@
             (flac-handle-stream-info handle))
           #f)))
 
+  (define (flac-seek handle percentage)
+    (dbg-sound "seek to percentage ~a" percentage)
+    (let ((ffi-handler (flac-handle-ffi-decoder-handler handle)))
+      (let ((total-samples (flac-total-samples handle)))
+        (unless (eq? total-samples #f)
+          (let ((sample (inexact->exact (round (* (exact->inexact (/ percentage 100.0)) total-samples)))))
+            (ffi-handler 'seek-to-sample sample))
+          )
+        )
+      )
+    )
+    
+
   (define (flac-stop handle)
     (let ((ct (current-milliseconds)))
       (dbg-sound "requesting stop at: ~a" ct)