sdp: Allow passing an AVFormatContext to the SDP generation

Options from the AVFormatContext can be read for modifying
the generated SDP.
Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/internal.h

@@ -124,10 +124,12 @@ int ff_url_join(char *str, int size, const char *proto,
  * @param dest_type the destination address type, may be NULL
  * @param port the destination port of the media stream, 0 if unknown
  * @param ttl the time to live of the stream, 0 if not multicast
+ * @param fmt the AVFormatContext, which might contain options modifying
+ *            the generated SDP
  */
 void ff_sdp_write_media(char *buff, int size, AVCodecContext *c,
                         const char *dest_addr, const char *dest_type,
-                        int port, int ttl);
+                        int port, int ttl, AVFormatContext *fmt);
 
 /**
  * Write a packet to another muxer than the one the user originally

libavformat/movenc.c

@@ -1359,7 +1359,7 @@ static int mov_write_udta_sdp(AVIOContext *pb, AVCodecContext *ctx, int index)
     char buf[1000] = "";
     int len;
 
-    ff_sdp_write_media(buf, sizeof(buf), ctx, NULL, NULL, 0, 0);
+    ff_sdp_write_media(buf, sizeof(buf), ctx, NULL, NULL, 0, 0, NULL);
     av_strlcatf(buf, sizeof(buf), "a=control:streamid=%d\r\n", index);
     len = strlen(buf);
 

libavformat/sdp.c

@@ -300,7 +300,7 @@ xiph_fail:
     return NULL;
 }
 
-static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c, int payload_type)
+static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c, int payload_type, AVFormatContext *fmt)
 {
     char *config = NULL;
 
@@ -449,7 +449,7 @@ static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c,
     return buff;
 }
 
-void ff_sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, const char *dest_type, int port, int ttl)
+void ff_sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, const char *dest_type, int port, int ttl, AVFormatContext *fmt)
 {
     const char *type;
     int payload_type;
@@ -472,7 +472,7 @@ void ff_sdp_write_media(char *buff, int size, AVCodecContext *c, const char *des
         av_strlcatf(buff, size, "b=AS:%d\r\n", c->bit_rate / 1000);
     }
 
-    sdp_write_media_attributes(buff, size, c, payload_type);
+    sdp_write_media_attributes(buff, size, c, payload_type, fmt);
 }
 
 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
@@ -521,7 +521,8 @@ int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
         for (j = 0; j < ac[i]->nb_streams; j++) {
             ff_sdp_write_media(buf, size,
                                   ac[i]->streams[j]->codec, dst[0] ? dst : NULL,
-                                  dst_type, (port > 0) ? port + j * 2 : 0, ttl);
+                                  dst_type, (port > 0) ? port + j * 2 : 0, ttl,
+                                  ac[i]);
             if (port <= 0) {
                 av_strlcatf(buf, size,
                                    "a=control:streamid=%d\r\n", i + j);
@@ -537,7 +538,7 @@ int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
     return AVERROR(ENOSYS);
 }
 
-void ff_sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, const char *dest_type, int port, int ttl)
+void ff_sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, const char *dest_type, int port, int ttl, AVFormatContext *fmt)
 {
 }
 #endif