Add a libfdk-aac decoder

This can be useful for decoding AAC object types that are not supported
by the native AAC decoder, e.g. AAC-LD and AAC-ELD.

configure

@@ -181,7 +181,7 @@ External library support:
   --enable-libdc1394       enable IIDC-1394 grabbing using libdc1394
                            and libraw1394 [no]
   --enable-libfaac         enable AAC encoding via libfaac [no]
-  --enable-libfdk-aac      enable AAC encoding via libfdk-aac [no]
+  --enable-libfdk-aac      enable AAC de/encoding via libfdk-aac [no]
   --enable-libfreetype     enable libfreetype [no]
   --enable-libgsm          enable GSM de/encoding via libgsm [no]
   --enable-libilbc         enable iLBC de/encoding via libilbc [no]
@@ -1756,6 +1756,7 @@ vc1_parser_select="mpegvideo"
 # external libraries
 libfaac_encoder_deps="libfaac"
 libfaac_encoder_select="audio_frame_queue"
+libfdk_aac_decoder_deps="libfdk_aac"
 libfdk_aac_encoder_deps="libfdk_aac"
 libfdk_aac_encoder_select="audio_frame_queue"
 libgsm_decoder_deps="libgsm"

libavcodec/Makefile

@@ -571,6 +571,7 @@ OBJS-$(CONFIG_WTV_DEMUXER)             += mpeg4audio.o mpegaudiodata.o
 
 # external codec libraries
 OBJS-$(CONFIG_LIBFAAC_ENCODER)            += libfaac.o
+OBJS-$(CONFIG_LIBFDK_AAC_DECODER)         += libfdk-aacdec.o
 OBJS-$(CONFIG_LIBFDK_AAC_ENCODER)         += libfdk-aacenc.o
 OBJS-$(CONFIG_LIBGSM_DECODER)             += libgsm.o
 OBJS-$(CONFIG_LIBGSM_ENCODER)             += libgsm.o

libavcodec/allcodecs.c

@@ -410,7 +410,7 @@ void avcodec_register_all(void)
 
     /* external libraries */
     REGISTER_ENCODER(LIBFAAC,           libfaac);
-    REGISTER_ENCODER(LIBFDK_AAC,        libfdk_aac);
+    REGISTER_ENCDEC (LIBFDK_AAC,        libfdk_aac);
     REGISTER_ENCDEC (LIBGSM,            libgsm);
     REGISTER_ENCDEC (LIBGSM_MS,         libgsm_ms);
     REGISTER_ENCDEC (LIBILBC,           libilbc);

libavcodec/version.h

@@ -27,7 +27,7 @@
  */
 
 #define LIBAVCODEC_VERSION_MAJOR 55
-#define LIBAVCODEC_VERSION_MINOR 16
+#define LIBAVCODEC_VERSION_MINOR 17
 #define LIBAVCODEC_VERSION_MICRO  0
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \