standard audio pipeline

libmpg123-ffi.rkt

@@ -9,6 +9,7 @@
            )
 
 
+  ;(define lib (ffi-lib "/home/hans/tmp/lib/libmpg123.so")) ;(get-lib '("libmpg123") '("0" #f)))
   (define lib (get-lib '("libmpg123") '("0" #f)))
   (define-ffi-definer define-libmpg123 lib
     #:default-make-fail make-not-available)
@@ -95,6 +96,53 @@
          )
   )
 
+  (define _mpg123_param
+    (_enum '(force-mono = #x7
+             mono-left = #x1
+             mono-right = #x2
+             mono-mix = #x4
+             force-stereo = #x8
+             force-8bit = #x10
+             quiet = #x20
+             gapless = #x40
+             no-resync = #x80
+             seekbuffer = #x100
+             fuzzy = #x200
+             force-float = #x400
+             plain-id3text = #x800
+             ignore-streamlength = #x1000
+             skip-id3v2 = #x2000
+             ignore-infoframe = #x4000
+             auto-resample = #x8000
+             )
+           _int
+           )
+    )
+
+
+  #|
+  /** Flag bits for MPG123_FLAGS, use the usual binary or to combine. */
+  enum mpg123_param_flags
+         
+  	 MPG123_FORCE_MONO   = 0x7  /**<     0111 Force some mono mode: This is a test bitmask for seeing if any mono forcing is active. */
+	,MPG123_MONO_LEFT    = 0x1  /**<     0001 Force playback of left channel only.  */
+	,MPG123_MONO_RIGHT   = 0x2  /**<     0010 Force playback of right channel only. */
+	,MPG123_MONO_MIX     = 0x4  /**<     0100 Force playback of mixed mono.         */
+	,MPG123_FORCE_STEREO = 0x8  /**<     1000 Force stereo output.                  */
+	,MPG123_FORCE_8BIT   = 0x10 /**< 00010000 Force 8bit formats.                   */
+	,MPG123_QUIET        = 0x20 /**< 00100000 Suppress any printouts (overrules verbose).                    */
+	,MPG123_GAPLESS      = 0x40 /**< 01000000 Enable gapless decoding (default on if libmpg123 has support). */
+	,MPG123_NO_RESYNC    = 0x80 /**< 10000000 Disable resync stream after error.                             */
+	,MPG123_SEEKBUFFER   = 0x100 /**< 000100000000 Enable small buffer on non-seekable streams to allow some peek-ahead (for better MPEG sync). */
+	,MPG123_FUZZY        = 0x200 /**< 001000000000 Enable fuzzy seeks (guessing byte offsets or using approximate seek points from Xing TOC) */
+	,MPG123_FORCE_FLOAT  = 0x400 /**< 010000000000 Force floating point output (32 or 64 bits depends on mpg123 internal precision). */
+	,MPG123_PLAIN_ID3TEXT = 0x800 /**< 100000000000 Do not translate ID3 text data to UTF-8. ID3 strings will contain the raw text data, with the first byte containing the ID3 encoding code. */
+	,MPG123_IGNORE_STREAMLENGTH = 0x1000 /**< 1000000000000 Ignore any stream length information contained in the stream, which can be contained in a 'TLEN' frame of an ID3v2 tag or a Xing tag */
+	,MPG123_SKIP_ID3V2 = 0x2000 /**< 10 0000 0000 0000 Do not parse ID3v2 tags, just skip them. */
+	,MPG123_IGNORE_INFOFRAME = 0x4000 /**< 100 0000 0000 0000 Do not parse the LAME/Xing info frame, treat it as normal MPEG data. */
+	,MPG123_AUTO_RESAMPLE = 0x8000 /**< 1000 0000 0000 0000 Allow automatic internal resampling of any kind (default on if supported). Especially when going lowlevel with replacing output buffer, you might want to unset this flag. Setting MPG123_DOWNSAMPLE or MPG123_FORCE_RATE will override this. */
+  |#
+
   (define _mpg123_handle _pointer)
 
 
@@ -177,6 +225,28 @@
                  lib
                  (_fun _int -> _string*/utf-8)))
 
+
+  ;MPG123_EXPORT int mpg123_getparam 	( 	mpg123_handle *  	mh,;
+  ;		enum mpg123_parms  	type,
+  ;		long *  	value,
+  ;		double *  	fvalue 
+  ;	)
+  (define-libmpg123 mpg123_getparam2
+    (_fun _mpg123_handle _mpg123_param
+          (value : (_ptr io _long ))
+          (fvalue : (_ptr io _double ))
+          -> (r : _MPG123_Result)
+          -> (values r value fvalue)))
+
+  ;MPG123_EXPORT int mpg123_param2 	( 	mpg123_handle *  	mh,
+  ;		int  	type,
+  ;		long  	value,
+  ;		double  	fvalue 
+  ;	)
+  (define-libmpg123 mpg123_param2
+    (_fun _mpg123_handle _mpg123_param
+          _long _double
+          -> _int))
   
   
 #|  
@@ -298,6 +368,24 @@ int main(int argc, char *argv[])
       #t
       )
 
+    (define (params)
+      (for-each
+       (λ (p)
+         (let-values ([(r v fv) (mpg123_getparam2 mh p 0 0.0)])
+           (info-sound "~a: ~a - ~a - ~a" p r v fv)))
+       '(force-mono mono-left mono-right mono-mix
+         force-stereo force-8bit
+         quiet 
+         gapless 
+         no-resync seekbuffer fuzzy 
+         force-float
+         plain-id3text ignore-streamlength skip-id3v2 ignore-infoframe
+         auto-resample 
+         )))
+
+    (define (set-param p val)
+      (mpg123_param2 mh p val (exact->inexact val)))
+
     (define (init file)
       (let ((r (mpg123_open mh file)))
         (unless (eq? r 'MPG123_OK)
@@ -369,6 +457,8 @@ int main(int argc, char *argv[])
         [(eq? cmd 'seek) (seek (car args))]
         [(eq? cmd 'tell) (tell)]
         [(eq? cmd 'file) mp3-file]
+        [(eq? cmd 'params) (params)]
+        [(eq? cmd 'set-param) (set-param (car args) (cadr args))]
         [else (error (format "Unknown command: ~a" cmd))]
         )
       )

play-test.rkt

@@ -9,11 +9,14 @@
          )
 
 (define test-file3 #f)
+(define test-file4 #f)
 (define test-file3-id 3)
+(define test-file4-id 4)
 (let ((os (system-type 'os)))
   (when (eq? os 'unix)
     ;(set! test-file3 "/muziek/Klassiek-Viool/Alina Ibragimova/Paganini_24 Caprices (2021)/24. 24 Caprices, Op 1 - No. 24 in A minor- Tema con variazioni. Quasi presto.flac")
     (set! test-file3 "/tmp/test.mp3")
+    (set! test-file4 "/tmp/test1.mp3")
     )
   (when (eq? os 'windows)
     (set! test-file3 "C:\\Muziek\\Klassiek-Strijkkwartet\\Quatuor Zaïde\\Franz\\01 Erlkönig, D. 328 (Arr. For String Quartet by Eric Mouret).flac")
@@ -26,6 +29,8 @@
 
 (define current-seconds 0)
 (define ao-h #f)
+(define current-file-id -1)
+(define current-audio-h #f)
 
 (sl-log-to-display)
 
@@ -43,7 +48,7 @@
     (when (eq? ao-h #f)
       (set! ao-h (ao-open-live bits-per-sample rate channels 'native-endian)))
     ;(displayln 'ao-play)
-    (ao-play ao-h test-file3-id second duration buffer buf-len ao-type)
+    (ao-play ao-h current-file-id second duration buffer buf-len ao-type)
     (set! duration (inexact->exact (round duration)))
     ;(displayln 'done)
     (let ((second-printer (λ (buf-seconds)
@@ -87,6 +92,9 @@
                                        (ao-set-volume! ao-h 150))
                                      (when (= (round current-seconds) 40)
                                        (ao-set-volume! ao-h 100))
+                                     (when (= (round current-seconds) 10)
+                                       (when (= current-file-id 3)
+                                         (audio-seek current-audio-h 97.0)))
                                      (waiter)))))
                              ))
             (waiter))))
@@ -102,13 +110,17 @@
 (define (play)
   (set! ao-h #f)
   (let ((audio-h (audio-open test-file3 audio-meta audio-play)))
+    (set! current-file-id test-file3-id)
+    (set! current-audio-h audio-h)
     (audio-read audio-h)
-    (ao-close ao-h)
+    )
-    (set! ao-h #f)))
+  (let ((audio-h (audio-open test-file4 audio-meta audio-play)))
-    ;(sleep 1.0)
+    (set! current-file-id test-file4-id)
-    ;(play)))
+    (set! current-audio-h audio-h)
-
+    (audio-read audio-h)
-;(flac-read flac-h)
+    )
+  (ao-close ao-h)
+  (set! ao-h #f))
 
 (play)