Issue #2311 - Part 2 - Link ffmpeg real DFT functions

dom/media/platforms/ffmpeg/FFmpegLibWrapper.cpp

@@ -147,6 +147,9 @@ FFmpegLibWrapper::Link()
   AV_FUNC(avcodec_free_frame, AV_FUNC_54)
   AV_FUNC(avcodec_send_packet, AV_FUNC_58)
   AV_FUNC(avcodec_receive_frame, AV_FUNC_58)
+  AV_FUNC_OPTION(av_rdft_init, AV_FUNC_AVCODEC_ALL)
+  AV_FUNC_OPTION(av_rdft_calc, AV_FUNC_AVCODEC_ALL)
+  AV_FUNC_OPTION(av_rdft_end, AV_FUNC_AVCODEC_ALL)
   AV_FUNC(av_log_set_level, AV_FUNC_AVUTIL_ALL)
   AV_FUNC(av_malloc, AV_FUNC_AVUTIL_ALL)
   AV_FUNC(av_freep, AV_FUNC_AVUTIL_ALL)

dom/media/platforms/ffmpeg/FFmpegLibWrapper.h

@@ -5,6 +5,7 @@
 #ifndef __FFmpegLibWrapper_h__
 #define __FFmpegLibWrapper_h__
 
+#include "FFmpegRDFTTypes.h" // for AvRdftInitFn, etc.
 #include "mozilla/Attributes.h"
 #include "mozilla/Types.h"
 
@@ -75,6 +76,11 @@ struct FFmpegLibWrapper
   int (*avcodec_send_packet)(AVCodecContext* avctx, const AVPacket* avpkt);
   int (*avcodec_receive_frame)(AVCodecContext* avctx, AVFrame* frame);
 
+  // libavcodec optional
+  AvRdftInitFn av_rdft_init;
+  AvRdftCalcFn av_rdft_calc;
+  AvRdftEndFn av_rdft_end;
+
   // libavutil
   void (*av_log_set_level)(int level);
   void*	(*av_malloc)(size_t size);

dom/media/platforms/ffmpeg/FFmpegRDFTTypes.h

@@ -0,0 +1,27 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef FFmpegRDFTTypes_h
+#define FFmpegRDFTTypes_h
+
+struct RDFTContext;
+
+typedef float FFTSample;
+
+enum RDFTransformType {
+    DFT_R2C,
+    IDFT_C2R,
+    IDFT_R2C,
+    DFT_C2R,
+};
+
+extern "C" {
+
+  typedef RDFTContext* (*AvRdftInitFn)(int nbits, enum RDFTransformType trans);
+  typedef void (*AvRdftCalcFn)(RDFTContext *s, FFTSample *data);
+  typedef void (*AvRdftEndFn)(RDFTContext *s);
+
+}
+
+#endif // FFmpegRDFTTypes_h