Audio Encoder laag.

ffmpeg-definitions.rkt

@@ -29,7 +29,20 @@
          fmpg-buffer-start-sample
          fmpg-buffer-end-sample
          fmpg-sample-position
-         ffmpeg-version)
+         ffmpeg-version
+
+         ;; Shared FFmpeg/swresample bindings for encoder-side PCM conversion.
+         ;; Keeping these exports here prevents a second, divergent FFmpeg FFI
+         ;; version layer in private/pcm-converter.rkt.
+         AV_SAMPLE_FMT_S32
+         swr_alloc_set_opts2
+         swr_init
+         swr_free
+         swr_get_out_samples
+         swr_get_delay
+         swr_convert
+         ffmpeg-make-default-channel-layout
+         ffmpeg-channel-layout-uninit!)
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; C - Types & Functions
@@ -248,6 +261,21 @@
    )
   )
 
+(def-avutil av_channel_layout_default
+  (_fun _AVChannelLayout-pointer _int -> _void))
+
+(def-avutil av_channel_layout_uninit
+  (_fun _AVChannelLayout-pointer -> _void))
+
+(define (ffmpeg-make-default-channel-layout channels)
+  (let ((p (malloc (ctype-sizeof _AVChannelLayout) 'atomic-interior)))
+    (av_channel_layout_default p channels)
+    p))
+
+(define (ffmpeg-channel-layout-uninit! p)
+  (when p (av_channel_layout_uninit p))
+  #t)
+
 ; _AVCodecParameters:
 ;   codec_type  : AVMediaType
 ;   codec_id    : int / AVCodecID