Fix build with recent ffmpeg releases.
https://bugs.gentoo.org/show_bug.cgi?id=419453

Index: mediastreamer-2.7.3/src/videoenc.c
===================================================================
--- mediastreamer-2.7.3.orig/src/videoenc.c
+++ mediastreamer-2.7.3/src/videoenc.c
@@ -53,7 +53,6 @@ void ms_ffmpeg_log_callback(void* ptr, i
 
 void ms_ffmpeg_check_init(){
 	if(!avcodec_initialized){
-		avcodec_init();
 		avcodec_register_all();
 		avcodec_initialized=TRUE;
 #ifdef ENABLE_LOG_FFMPEG
@@ -107,6 +106,7 @@ typedef struct EncState{
 	uint32_t framenum;
 	VideoStarter starter;
 	bool_t req_vfu;
+	AVDictionary * ff_opts;
 }EncState;
 
 static int enc_set_fps(MSFilter *f, void *arg){
@@ -214,6 +214,7 @@ static void enc_init(MSFilter *f, enum C
 	s->req_vfu=FALSE;
 	s->framenum=0;
 	s->av_context.codec=NULL;
+	s->ff_opts = NULL;
 }
 
 static void enc_h263_init(MSFilter *f){
@@ -300,9 +301,9 @@ static void prepare_h263(EncState *s){
 	if (s->profile==0){
 		s->codec=CODEC_ID_H263;
 	}else{
-		c->flags|=CODEC_FLAG_H263P_UMV;
+		av_dict_set(&(s->ff_opts), "umv", "1", 0);
 		c->flags|=CODEC_FLAG_AC_PRED;
-		c->flags|=CODEC_FLAG_H263P_SLICE_STRUCT;
+		av_dict_set(&(s->ff_opts), "structured_slices", "1", 0);
 		/*
 		c->flags|=CODEC_FLAG_OBMC;
 		c->flags|=CODEC_FLAG_AC_PRED;
@@ -342,9 +343,9 @@ static void enc_preprocess(MSFilter *f){
 		ms_error("could not find encoder for codec id %i",s->codec);
 		return;
 	}
-	error=avcodec_open(&s->av_context, s->av_codec);
+	error=avcodec_open2(&s->av_context, s->av_codec, &(s->ff_opts));
 	if (error!=0) {
-		ms_error("avcodec_open() failed: %i",error);
+		ms_error("avcodec_open2() failed: %i",error);
 		return;
 	}
 	video_starter_init(&s->starter);
@@ -372,7 +373,7 @@ static void add_rfc2190_header(mblk_t **
 	// assume video size is CIF or QCIF
 	if (context->width == 352 && context->height == 288) header->b_wptr[1] = 0x60;
 	else header->b_wptr[1] = 0x40;
-	if (context->coded_frame->pict_type != FF_I_TYPE) header->b_wptr[1] |= 0x10;
+	if (context->coded_frame->pict_type != AV_PICTURE_TYPE_I) header->b_wptr[1] |= 0x10;
 	header->b_wptr += 4;
 	header->b_cont = *packet;
 	*packet = header;
@@ -779,7 +780,7 @@ static void process_frame(MSFilter *f, m
 		s->req_vfu=TRUE;
 	}
 	if (s->req_vfu){
-		pict.pict_type=FF_I_TYPE;
+		pict.pict_type=AV_PICTURE_TYPE_I;
 		s->req_vfu=FALSE;
 	}
 	comp_buf->b_rptr=comp_buf->b_wptr=comp_buf->b_datap->db_base;
@@ -799,7 +800,7 @@ static void process_frame(MSFilter *f, m
 		if (s->framenum==1){
 			video_starter_first_frame (&s->starter,f->ticker->time);
 		}
-		if (c->coded_frame->pict_type==FF_I_TYPE){
+		if (c->coded_frame->pict_type==AV_PICTURE_TYPE_I){
 			ms_message("Emitting I-frame");
 		}
 		comp_buf->b_wptr+=error;
Index: mediastreamer-2.7.3/src/h264dec.c
===================================================================
--- mediastreamer-2.7.3.orig/src/h264dec.c
+++ mediastreamer-2.7.3/src/h264dec.c
@@ -46,7 +46,6 @@ typedef struct _DecData{
 static void ffmpeg_init(){
 	static bool_t done=FALSE;
 	if (!done){
-		avcodec_init();
 		avcodec_register_all();
 		done=TRUE;
 	}