ffmpeg: use extern "C" for forward declarations

Change-Id: I3bb7f53ececb108f9db7b0f9eb47b85b3482644a

src/media/audio/audio_frame_resizer.h

@@ -26,7 +26,9 @@
 
 #include <mutex>
 
+extern "C" {
 struct AVAudioFifo;
+}
 
 namespace jami {
 

src/media/audio/audiobuffer.h

@@ -32,6 +32,7 @@
 
 extern "C" {
 #include <libavutil/samplefmt.h>
+struct AVFrame;
 }
 
 #include "ring_types.h"
@@ -39,8 +40,6 @@ extern "C" {
 
 #include <ciso646> // fix windows compiler bug
 
-struct AVFrame;
-
 namespace jami {
 
 /**

src/media/audio/resampler.h

@@ -26,8 +26,10 @@
 #include "media_buffer.h"
 #include "noncopyable.h"
 
+extern "C" {
 struct AVFrame;
 struct SwrContext;
+}
 
 namespace jami {
 

src/media/libav_utils.h

@@ -25,9 +25,11 @@
 #include <map>
 #include <string>
 
+extern "C" {
 struct AVDictionary;
 struct AVFrame;
 struct AVPixFmtDescriptor;
+}
 
 namespace jami { namespace libav_utils {
 

src/media/media_buffer.h

@@ -26,7 +26,9 @@
 #include <memory>
 #include <functional>
 
+extern "C" {
 struct AVFrame;
+}
 
 namespace DRing {
 struct FrameBuffer; //  from dring/videomanager_interface.h

src/media/media_decoder.h

@@ -40,12 +40,14 @@
 #include <memory>
 #include <chrono>
 
+extern "C" {
 struct AVCodecContext;
 struct AVStream;
 struct AVDictionary;
 struct AVFormatContext;
 struct AVCodec;
 enum AVMediaType;
+}
 
 namespace DRing {
 class AudioFrame;

src/media/media_encoder.h

@@ -39,10 +39,12 @@
 #include <string>
 #include <vector>
 
+extern "C" {
 struct AVCodecContext;
 struct AVFormatContext;
 struct AVDictionary;
 struct AVCodec;
+}
 
 namespace jami {
 

src/media/media_filter.h

@@ -28,9 +28,11 @@
 #include <string>
 #include <vector>
 
+extern "C" {
 struct AVFilterContext;
 struct AVFilterGraph;
 struct AVFilterInOut;
+}
 
 namespace jami {
 

src/media/video/video_base.h

@@ -39,7 +39,6 @@
 
 extern "C" {
 #include <libavutil/pixfmt.h>
-}
 
 struct AVPacket;
 struct AVDictionary;
@@ -47,6 +46,7 @@ struct AVDictionary;
 #ifndef AVFORMAT_AVIO_H
 struct AVIOContext;
 #endif
+}
 
 namespace DRing {
 class MediaFrame;