-

libflac/libflac-ffi.rkt

@@ -403,6 +403,7 @@
 
 (define _FLAC__StreamDecoder-pointer (_cpointer 'flac-streamdecoder))
 (define _FLAC__Data-pointer (_cpointer/null 'flac-client-data))
+;(define _FLAC__StreamMetadata-pointer (_cpointer/null 'flac-stream-metadata))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; FLAC Callback function definitions
@@ -482,6 +483,16 @@
   (_fun _FLAC__StreamDecoder-pointer FLAC__uint64
           -> _bool))
 
+;FLAC_API FLAC__StreamMetadata *FLAC__metadata_object_clone(const FLAC__StreamMetadata *object);
+(define-libflac FLAC__metadata_object_clone
+  (_fun _FLAC__StreamMetadata-pointer
+        -> _FLAC__StreamMetadata-pointer))
+  
+;FLAC_API void FLAC__metadata_object_delete(FLAC__StreamMetadata *object);
+(define-libflac FLAC__metadata_object_delete
+  (_fun _FLAC__StreamMetadata-pointer
+        -> _void))
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Our interface for decoding to racket
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -499,7 +510,9 @@
     0)
 
   (define (meta-callback fl meta client-data)
-    (set! meta-data (append meta-data (list meta))))
+    (let ((meta-clone (FLAC__metadata_object_clone meta)))
+      (unless (eq? meta-clone #f)
+        (set! meta-data (append meta-data (list meta-clone))))))
 
   (define (error-callback fl errno client-data)
     (set! error-no errno)
@@ -530,7 +543,10 @@
     (decoder-state (int-state)))
 
   (define (process-meta-data cb)
-    (for-each cb meta-data)
+    (for-each (λ (meta-entry)
+                (cb meta-entry)
+                (FLAC__metadata_object_delete meta-entry))
+              meta-data)
     (set! meta-data '()))
 
   (define (process-write-data cb)

play-test.rkt

@@ -15,7 +15,7 @@
     )
   )
 
-(ao-set-async-mode! 'scheme)
+(ao-set-async-mode! 'ffi)
 ;(define fmt (ao-mk-format 24 48000 2 'big-endian))
 ;(define ao-h (ao-open-live #f fmt))