rtsp: Add listen mode

This makes the RTSP demuxer act as a server, listening for an
incoming connection.

Signed-off-by: Martin Storsjö <martin@martin.st>

Changelog

@@ -31,6 +31,7 @@ version <next>:
 - join audio filter
 - audio channel mapping filter
 - Microsoft ATC Screen decoder
+- RTSP listen mode
 
 
 version 0.8:

doc/protocols.texi

@@ -347,6 +347,8 @@ Flags for @code{rtsp_flags}:
 @table @option
 @item filter_src
 Accept packets only from negotiated peer address and port.
+@item listen
+Act as a server, listening for an incoming connection.
 @end table
 
 When receiving data over UDP, the demuxer tries to reorder received packets
@@ -379,6 +381,12 @@ To send a stream in realtime to a RTSP server, for others to watch:
 avconv -re -i @var{input} -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
 @end example
 
+To receive a stream in realtime:
+
+@example
+avconv -rtsp_flags listen -i rtsp://ownaddress/live.sdp @var{output}
+@end example
+
 @section sap
 
 Session Announcement Protocol (RFC 2974). This is not technically a

libavformat/rtsp.c

@@ -63,7 +63,8 @@
 
 #define RTSP_FLAG_OPTS(name, longname) \
     { name, longname, OFFSET(rtsp_flags), AV_OPT_TYPE_FLAGS, {0}, INT_MIN, INT_MAX, DEC, "rtsp_flags" }, \
-    { "filter_src", "Only receive packets from the negotiated peer IP", 0, AV_OPT_TYPE_CONST, {RTSP_FLAG_FILTER_SRC}, 0, 0, DEC, "rtsp_flags" }
+    { "filter_src", "Only receive packets from the negotiated peer IP", 0, AV_OPT_TYPE_CONST, {RTSP_FLAG_FILTER_SRC}, 0, 0, DEC, "rtsp_flags" }, \
+    { "listen", "Wait for incoming connections", 0, AV_OPT_TYPE_CONST, {RTSP_FLAG_LISTEN}, 0, 0, DEC, "rtsp_flags" }
 
 #define RTSP_MEDIATYPE_OPTS(name, longname) \
     { name, longname, OFFSET(media_type_mask), AV_OPT_TYPE_FLAGS, { (1 << (AVMEDIA_TYPE_DATA+1)) - 1 }, INT_MIN, INT_MAX, DEC, "allowed_media_types" }, \
@@ -83,6 +84,7 @@ const AVOption ff_rtsp_options[] = {
     RTSP_MEDIATYPE_OPTS("allowed_media_types", "Media types to accept from the server"),
     { "min_port", "Minimum local UDP port", OFFSET(rtp_port_min), AV_OPT_TYPE_INT, {RTSP_RTP_PORT_MIN}, 0, 65535, DEC|ENC },
     { "max_port", "Maximum local UDP port", OFFSET(rtp_port_max), AV_OPT_TYPE_INT, {RTSP_RTP_PORT_MAX}, 0, 65535, DEC|ENC },
+    { "timeout", "Maximum timeout (in seconds) to wait for incoming connections. -1 is infinite. Implies flag listen", OFFSET(initial_timeout), AV_OPT_TYPE_INT, {-1}, INT_MIN, INT_MAX, DEC },
     { NULL },
 };
 
@@ -1714,14 +1716,24 @@ static int udp_read_packet(AVFormatContext *s, RTSPStream **prtsp_st,
             }
 #if CONFIG_RTSP_DEMUXER
             if (tcp_fd != -1 && p[0].revents & POLLIN) {
-                RTSPMessageHeader reply;
-
-                ret = ff_rtsp_read_reply(s, &reply, NULL, 0, NULL);
-                if (ret < 0)
-                    return ret;
-                /* XXX: parse message */
-                if (rt->state != RTSP_STATE_STREAMING)
-                    return 0;
+                if (rt->rtsp_flags & RTSP_FLAG_LISTEN) {
+                    if (rt->state == RTSP_STATE_STREAMING) {
+                        if (!ff_rtsp_parse_streaming_commands(s))
+                            return AVERROR_EOF;
+                        else
+                            av_log(s, AV_LOG_WARNING,
+                                   "Unable to answer to TEARDOWN\n");
+                    } else
+                        return 0;
+                } else {
+                    RTSPMessageHeader reply;
+                    ret = ff_rtsp_read_reply(s, &reply, NULL, 0, NULL);
+                    if (ret < 0)
+                        return ret;
+                    /* XXX: parse message */
+                    if (rt->state != RTSP_STATE_STREAMING)
+                        return 0;
+                }
             }
 #endif
         } else if (n == 0 && ++timeout_cnt >= MAX_TIMEOUTS) {

libavformat/rtsp.h

@@ -372,11 +372,17 @@ typedef struct RTSPState {
      * Minimum and maximum local UDP ports.
      */
     int rtp_port_min, rtp_port_max;
+
+    /**
+     * Timeout to wait for incoming connections.
+     */
+    int initial_timeout;
 } RTSPState;
 
 #define RTSP_FLAG_FILTER_SRC  0x1    /**< Filter incoming UDP packets -
                                           receive packets only from the right
                                           source address and port. */
+#define RTSP_FLAG_LISTEN 0x2         /**< Wait for incoming connections. */
 
 /**
  * Describe a single stream, as identified by a single m= line block in the
@@ -528,6 +534,12 @@ int ff_rtsp_setup_input_streams(AVFormatContext *s, RTSPMessageHeader *reply);
  */
 int ff_rtsp_setup_output_streams(AVFormatContext *s, const char *addr);
 
+/**
+ * Parse RTSP commands (OPTIONS, PAUSE and TEARDOWN) during streaming in
+ * listen mode.
+ */
+int ff_rtsp_parse_streaming_commands(AVFormatContext *s);
+
 /**
  * Parse an SDP description of streams by populating an RTSPState struct
  * within the AVFormatContext; also allocate the RTP streams and the

libavformat/rtspcodes.h

@@ -37,4 +37,18 @@ RTSP_STATUS_SERVICE         =503, /**< Service Unavailable */
 RTSP_STATUS_VERSION         =505, /**< RTSP Version not supported */
 };
 
+enum RTSPMethod {
+    DESCRIBE,
+    ANNOUNCE,
+    OPTIONS,
+    SETUP,
+    PLAY,
+    PAUSE,
+    TEARDOWN,
+    GET_PARAMETER,
+    SET_PARAMETER,
+    REDIRECT,
+    RECORD,
+    UNKNOWN = -1,
+};
 #endif /* AVFORMAT_RTSPCODES_H */