ffmpeg support

audio-decoder.rkt

@@ -2,6 +2,9 @@
 
   (require "flac-decoder.rkt"
            "mp3-decoder.rkt"
+           "ffmpeg-decoder.rkt"
+           "audio-sniffer.rkt"
+           "private/utils.rkt"
            racket/contract
            racket/string
            racket/path
@@ -52,12 +55,38 @@
                                 mp3-stop
                                 'ao))
 
+  ;; FFmpeg decodere
+  (hash-set! audio-readers
+             'ffmpeg
+             (make-audio-reader '("ogg" "oga" "opus"
+                                  "m4a" "mp4" "m4b"
+                                  "aac"
+                                  "wav"
+                                  "aiff" "aif" "aifc"
+                                  "wma"
+                                  "webm" "mkv" "mka")
+                                ffmpeg-valid?
+                                ffmpeg-open
+                                ffmpeg-read
+                                ffmpeg-seek
+                                ffmpeg-stop
+                                'ao))
+
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;; Known extensions
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
   (define known-extensions
-    '("flac" "mp3"))
+    '("flac"   ; FLAC decoder
+      "mp3"    ; mp3 decoder
+      "ogg" "oga" "opus"
+      "m4a" "mp4" "m4b"
+      "aac"
+      "wav"
+      "aiff" "aif" "aifc"
+      "wma"
+      "webm" "mkv" "mka" ; FFMPEG decoder
+      ))
 
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;; Register audio reader
@@ -92,7 +121,11 @@
     (set! ext (format "~a" ext))
     (when (string-prefix? ext ".")
       (set! ext (substring ext 1)))
-    (not (null? (filter (λ (e) (string-ci=? ext e)) known-extensions)))
+    (if (not (null? (filter (λ (e) (string-ci=? ext e)) known-extensions)))
+        #t
+        (begin
+          (warn-sound "extension '~a' not in known-extensions '~a'" ext known-extensions)
+          #f))
     )
 
   (define/contract (audio-file-valid? file)
@@ -189,17 +222,33 @@
   (define (right-reader? reader ext)
     (not (null? (filter (λ (e) (string-ci=? ext e)) (audio-reader-exts reader)))))
 
+  (define reader-for-kind
+    (make-hash '((mp3 . ffmpeg)            ; ffmpeg does a better job on gapless playback...
+                 (flac . flac)
+                 (ogg . ffmpeg)
+                 (vorbis . ffmpeg)
+                 (opus . ffmpeg)
+                 (wav . ffmpeg)
+                 (aiff . ffmpeg)
+                 (mp4 . ffmpeg)
+                 (aac . ffmpeg)
+                 (alac . ffmpeg)
+                 (ac3 . ffmpeg)
+                 (ape . ffmpeg)
+                 (wavpack . ffmpeg)
+                 (wma . ffmpeg)
+                 (matroska . ffmpeg))))
+
+
   (define (find-reader audio-file)
-    (let* ((f (build-path audio-file))
-           (ext (substring (format "~a" (path-get-extension audio-file)) 1)))
-      (letrec ((f (λ (keys)
-                    (if (null? keys)
-                        #f
-                        (let ((reader (hash-ref audio-readers (car keys))))
-                          (if (right-reader? reader ext)
-                              (list (car keys) reader)
-                              (f (cdr keys))))))))
-        (f (hash-keys audio-readers))
+    ; First try to sniff the format
+    (let ((format (audio-sniff-format/extension audio-file)))
+      (let ((reader-kind (hash-ref reader-for-kind format #f)))
+        (if (eq? reader-kind #f)
+            #f
+            (let ((reader (hash-ref audio-readers reader-kind)))
+              (list reader-kind reader))
+            )
         )
       )
     )