[FFmpeg-devel] [PATCH v1 2/2] avformat/rtpproto, sdp: write rtcp port to sdp file

[Jun Li]

Fix #8474
Write rtcp port attribute to sdp file when necessary.

Signed-off-by: Jun Li <junli1026 at gmail.com>
---
 libavformat/rtpproto.c | 11 +++++++++++
 libavformat/rtpproto.h |  2 ++
 libavformat/sdp.c      | 12 ++++++++++--
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/libavformat/rtpproto.c b/libavformat/rtpproto.c
index 1f0a82ac7e..81a39cc3de 100644
--- a/libavformat/rtpproto.c
+++ b/libavformat/rtpproto.c
@@ -524,6 +524,17 @@ int ff_rtp_get_local_rtp_port(URLContext *h)
     return ff_udp_get_local_port(s->rtp_hd);
 }
 
+/**
+ * Return the remote rtcp port used by the RTP connection
+ * @param h media file context
+ * @return the remote port number
+ */
+int ff_rtp_get_remote_rtcp_port(URLContext *h)
+{
+    RTPContext *s = h->priv_data;
+    return s->rtcp_port;
+}
+
 /**
  * Return the local rtcp port used by the RTP connection
  * @param h media file context
diff --git a/libavformat/rtpproto.h b/libavformat/rtpproto.h
index 131aac5f3c..d42327ea5c 100644
--- a/libavformat/rtpproto.h
+++ b/libavformat/rtpproto.h
@@ -27,4 +27,6 @@ int ff_rtp_set_remote_url(URLContext *h, const char *uri);
 
 int ff_rtp_get_local_rtp_port(URLContext *h);
 
+int ff_rtp_get_remote_rtcp_port(URLContext *h);
+
 #endif /* AVFORMAT_RTPPROTO_H */
diff --git a/libavformat/sdp.c b/libavformat/sdp.c
index 34e9839b67..c3c2909090 100644
--- a/libavformat/sdp.c
+++ b/libavformat/sdp.c
@@ -26,11 +26,13 @@
 #include "libavutil/opt.h"
 #include "libavcodec/xiph.h"
 #include "libavcodec/mpeg4audio.h"
+#include "avio_internal.h"
 #include "avformat.h"
 #include "internal.h"
 #include "avc.h"
 #include "hevc.h"
 #include "rtp.h"
+#include "rtpproto.h"
 #if CONFIG_NETWORK
 #include "network.h"
 #endif
@@ -480,10 +482,16 @@ static char *latm_context2config(AVFormatContext *s, AVCodecParameters *par)
     return config;
 }
 
-static char *sdp_write_media_attributes(char *buff, int size, AVStream *st, int payload_type, AVFormatContext *fmt)
+static char *sdp_write_media_attributes(char *buff, int size, AVStream *st, int payload_type, AVFormatContext *fmt, int port)
 {
     char *config = NULL;
     AVCodecParameters *p = st->codecpar;
+    URLContext* url_ctx = ffio_geturlcontext(fmt->pb);
+    if (url_ctx) {
+        int rtcp_port = ff_rtp_get_remote_rtcp_port(url_ctx);
+        if (rtcp_port > 0 && rtcp_port != port+1)
+            av_strlcatf(buff, size, "a=rtcp:%d\r\n", rtcp_port);
+    }
 
     switch (p->codec_id) {
         case AV_CODEC_ID_DIRAC:
@@ -766,7 +774,7 @@ void ff_sdp_write_media(char *buff, int size, AVStream *st, int idx,
         av_strlcatf(buff, size, "b=AS:%"PRId64"\r\n", p->bit_rate / 1000);
     }
 
-    sdp_write_media_attributes(buff, size, st, payload_type, fmt);
+    sdp_write_media_attributes(buff, size, st, payload_type, fmt, port);
 }
 
 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
-- 
2.17.1