ffmpeg support

libao.rkt

@@ -10,6 +10,7 @@
          )
 
 (provide ao-open-live
+         ao-device-bits
          ao-open-file
          ao-play
          ao-close
@@ -35,6 +36,8 @@
 (define-struct ao-handle (handle-num
                           [bits #:auto #:mutable]
                           [bytes-per-sample #:auto #:mutable]
+                          [dev-bits #:auto #:mutable]
+                          [dev-bytes-per-sample #:auto #:mutable]
                           [byte-format #:auto #:mutable]
                           [channels #:auto #:mutable]
                           [rate #:auto #:mutable]
@@ -113,15 +116,17 @@
                   (err-sound "ao-open-live - cannote create player")
                   (set-ao-handle-closed! handle #t)
                   handle)
-                (begin
-                  (info-sound "ao-open-live - created player")
+                (let ((out-bits (ffi:ao_real_output_bits_async player)))
+                  (info-sound "ao-open-live - created player at ~a bits" out-bits)
+                  (set-ao-handle-dev-bits! handle out-bits)
+                  (set-ao-handle-dev-bytes-per-sample! handle (/ out-bits 8))
                   (set-ao-handle-closed! handle #f)
                   handle
                   )
                 )
             )
       )
-      )
+    )
                     
 
 (rc:define/contract (ao-close handle)
@@ -143,6 +148,10 @@
 (define (any? x)
   #t)
 
+(rc:define/contract (ao-device-bits handle)
+  (rc:-> ao-handle? integer?)
+  (ao-handle-dev-bits handle))
+
 (rc:define/contract (ao-play handle music-id at-time-in-s music-duration-s buffer buf-len buf-type)
   (rc:-> ao-handle? integer? number? number? any? integer? ao-supported-music-format? void?)                    
   (let* ((bytes-per-sample (ao-handle-bytes-per-sample handle))