* flac support

* taglib support It is possible to play some music already.
2025-08-13 14:13:35 +02:00
parent 820c68a1aa
commit ad7f1345ad
16 changed files with 1522 additions and 35 deletions
--- a/libflac/flac-decoder.rkt
+++ b/libflac/flac-decoder.rkt
@@ -0,0 +1,131 @@
+(module flac-decoder racket/base
+
+  (require ffi/unsafe
+           "libflac-ffi.rkt"
+           "flac-definitions.rkt"
+           "../utils/utils.rkt")
+
+  (provide flac-open
+           flac-read
+           flac-read-meta
+           flac-stream-state
+           (all-from-out "flac-definitions.rkt")
+           test-file test-file2 test-file3
+           kinds
+           last-buffer last-buf-len
+           )
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Functions to do the good stuff  
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+  (define (flac-open flac-file cb-stream-info cb-audio)
+    (if (file-exists? flac-file)
+        (let ((handler (flac-ffi-decoder-handler)))
+          (handler 'new)
+          (handler 'init flac-file)
+          (let ((h (make-flac-handle handler)))
+            (set-flac-handle-cb-stream-info! h cb-stream-info)
+            (set-flac-handle-cb-audio! h cb-audio)
+            h))
+        #f))
+
+  (define (flac-stream-state handle)
+    ((flac-handle-ffi-decoder-handler handle) 'state))
+
+
+  (define kinds (make-hash))
+  (define last-buffer #f)
+  (define last-buf-len #f)
+  (define (process-frame handle frame buffer)
+    (let* ((h (flac-ffi-frame-header frame))
+           (cb-audio (flac-handle-cb-audio handle))
+           (ffi (flac-handle-ffi-decoder-handler handle))
+           (type (hash-ref h 'number-type))
+           (channels (hash-ref h 'channels))
+           (block-size (hash-ref h 'blocksize)))
+      (let ((buffers (ffi 'get-buffers buffer channels block-size)))
+        (set! last-buffer buffers)
+        (set! last-buf-len (hash-ref h 'blocksize))
+        (hash-set! kinds type #t)
+        (when (procedure? cb-audio)
+          (cb-audio h buffers))
+        ))
+    ;(displayln "Processing frame"))
+    #t
+    )
+  
+  (define (process-meta handle meta)
+    (let ((type (FLAC__StreamMetadata-type meta)))
+      (display (format "  Got metadata type: ~a\n" type))
+      (cond
+        ([eq? type 'streaminfo]
+         (let ((mh (flac-ffi-meta meta)))
+           (let ((si (make-flac-stream-info
+                      (hash-ref mh 'min-blocksize) (hash-ref mh 'max-blocksize)
+                      (hash-ref mh 'min-framesize) (hash-ref mh 'max-framesize)
+                      (hash-ref mh 'sample-rate)
+                      (hash-ref mh 'channels)
+                      (hash-ref mh 'bits-per-sample)
+                      (hash-ref mh 'total-samples))))
+             (set-flac-handle-stream-info! handle si)
+             (let ((cb (flac-handle-cb-stream-info handle)))
+               (when (procedure? cb)
+                 (cb si))))))
+        )
+      ))
+
+  (define (flac-read handle)
+    (let* ((ffi-handler (flac-handle-ffi-decoder-handler handle))
+           (state (ffi-handler 'state)))
+      (letrec ((reader (lambda (frame-nr)
+                         (let* ((st (ffi-handler 'state)))
+                           (ffi-handler 'process-single)
+                           (unless (eq? state st)
+                             (set! state st)
+                             (displayln
+                              (format "Now in state ~a (frame-nr = ~a) (int-state = ~a)"
+                                      st frame-nr (ffi-handler 'int-state)))
+                             )
+                           (when (ffi-handler 'has-errno?)
+                             (displayln
+                              (format "Error in stream: ~a" (ffi-handler 'errno)))
+                             )
+                           (when (ffi-handler 'has-meta-data?)
+                             (ffi-handler 'process-meta-data
+                                          (lambda (meta) (process-meta handle meta)))
+                             )
+                           (when (ffi-handler 'has-write-data?)
+                             (ffi-handler 'process-write-data
+                                          (lambda (frame buffer)
+                                            (process-frame handle frame buffer)))
+                             )
+                           (if (eq? st 'end-of-stream)
+                             'end-of-stream
+                             (reader (+ frame-nr 1)))))
+                       ))
+        (reader 0))))
+
+  (define (flac-read-meta handle)
+    (let* ((ffi-handler (flac-handle-ffi-decoder-handler handle))
+           (state (ffi-handler 'state)))
+      (while (not (or (eq? state 'read-metadata)
+                      (eq? state 'end-of-stream)
+                      (eq? state 'aborted)
+                      (eq? state 'memory-allocation-error)
+                      (eq? state 'uninitialized)))
+             (ffi-handler 'process-single)
+             (set! state (ffi-handler 'state))
+             state)
+      (if (eq? state 'read-metadata)
+          (begin
+            (ffi-handler 'process-meta-data
+                         (lambda (meta) (process-meta handle meta)))
+            (flac-handle-stream-info handle))
+          #f)))
+                         
+  (define test-file "C:/devel/racket/racket-sound/libflac/capr24.flac")
+  (define test-file2 "C:/Muziek/Klassiek-Kamermuziek/Beethoven/Rachel Podger/01 Violin Sonata No. 1 in D Major, Op. 12 No. 1- I. Allegro con brio.flac")
+  (define test-file3 "c:/Muziek/Pop/Radiohead/The Best of Radiohead (2008)/02. Paranoid Android.flac")
+
+  ); end of module