rtsp: Parse RTP-Info headers

Originally committed as revision 26236 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/rtsp.c

@@ -684,6 +684,61 @@ static void rtsp_parse_transport(RTSPMessageHeader *reply, const char *p)
     }
 }
 
+static void handle_rtp_info(RTSPState *rt, const char *url,
+                            uint32_t seq, uint32_t rtptime)
+{
+    int i;
+    if (!rtptime || !url[0])
+        return;
+    if (rt->transport != RTSP_TRANSPORT_RTP)
+        return;
+    for (i = 0; i < rt->nb_rtsp_streams; i++) {
+        RTSPStream *rtsp_st = rt->rtsp_streams[i];
+        RTPDemuxContext *rtpctx = rtsp_st->transport_priv;
+        if (!rtpctx)
+            continue;
+        if (!strcmp(rtsp_st->control_url, url)) {
+            rtpctx->base_timestamp = rtptime;
+            break;
+        }
+    }
+}
+
+static void rtsp_parse_rtp_info(RTSPState *rt, const char *p)
+{
+    int read = 0;
+    char key[20], value[1024], url[1024] = "";
+    uint32_t seq = 0, rtptime = 0;
+
+    for (;;) {
+        p += strspn(p, SPACE_CHARS);
+        if (!*p)
+            break;
+        get_word_sep(key, sizeof(key), "=", &p);
+        if (*p != '=')
+            break;
+        p++;
+        get_word_sep(value, sizeof(value), ";, ", &p);
+        read++;
+        if (!strcmp(key, "url"))
+            av_strlcpy(url, value, sizeof(url));
+        else if (!strcmp(key, "seq"))
+            seq = strtol(value, NULL, 10);
+        else if (!strcmp(key, "rtptime"))
+            rtptime = strtol(value, NULL, 10);
+        if (*p == ',') {
+            handle_rtp_info(rt, url, seq, rtptime);
+            url[0] = '\0';
+            seq = rtptime = 0;
+            read = 0;
+        }
+        if (*p)
+            p++;
+    }
+    if (read > 0)
+        handle_rtp_info(rt, url, seq, rtptime);
+}
+
 void ff_rtsp_parse_line(RTSPMessageHeader *reply, const char *buf,
                         RTSPState *rt, const char *method)
 {
@@ -728,6 +783,10 @@ void ff_rtsp_parse_line(RTSPMessageHeader *reply, const char *buf,
         p += strspn(p, SPACE_CHARS);
         if (method && !strcmp(method, "DESCRIBE"))
             av_strlcpy(rt->control_uri, p , sizeof(rt->control_uri));
+    } else if (av_stristart(p, "RTP-Info:", &p) && rt) {
+        p += strspn(p, SPACE_CHARS);
+        if (method && !strcmp(method, "PLAY"))
+            rtsp_parse_rtp_info(rt, p);
     }
 }