Fixes a bug in read_frame

lib/av/av.cpp

@@ -53,7 +53,8 @@ namespace av {
 
 
 	packet read_frame(format_context& ctx, packet_buffer& p){
-		if(!av_read_frame(ctx.get(), &p)){
+		auto ret = av_read_frame(ctx.get(), &p);
+		if(ret < 0){
 			return {nullptr, &av_free_packet};
 		} else {
 			return {&p, &av_free_packet};

lib/av/av.hpp

@@ -4,15 +4,10 @@
 
 extern "C" {
 #include <libavutil/pixfmt.h>
-#include <libavcodec/avcodec.h> // only needed for AVCodecID
+#include <libavcodec/avcodec.h> // only needed for AVCodecID and AVPacket
 
-typedef struct AVDictionary AVDictionary;
 typedef struct AVFormatContext AVFormatContext;
 typedef struct AVInputFormat AVInputFormat;
-typedef struct AVCodecContext AVCodecContext;
-typedef struct AVCodec AVCodec;
-typedef struct AVPacket AVPacket;
-typedef struct AVFrame AVFrame;
 }
 
 #include <memory>

lib/fingerprints/wvlt_rgb.hpp

@@ -12,15 +12,6 @@
 #include <utility>
 #include <vector>
 
-namespace boost {
-	namespace serialization {
-		template<class Archive, class T, size_t N>
-		void serialize(Archive & ar, std::array<T,N> & a, const unsigned int /*version*/) {
-			ar & make_array(a.data(), a.size());
-		}
-	} // namespace serialization
-} // namespace boost
-
 
 namespace fingerprints {
 struct wvlt_rgb {

lib/image_io.cpp

@@ -72,7 +72,6 @@ av::frame open_image(std::string const & filename){
 	// some decoders need extra passes
 	while(!finished) {
 		avcodec_decode_video2(codec_context.get(), frame.get(), &finished, &empty_packet);
-		av_free_packet(&empty_packet);
 	}
 
 	return frame;