rtsp: rename certain options after a deprecation period

The "timeout" option name inherently clashes with the meaning of the
HTTP libavformat protocol option with the same name. Rename it after a
deprecation period to make it compatible with the HTTP one.

doc/APIchanges

@@ -15,6 +15,13 @@ libavutil:     2017-10-21
 
 API changes, most recent first:
 
+2018-02-xx - xxxxxxx - lavf 58.8.100 - avformat.h
+  Deprecate the current names of the RTSP "timeout", "stimeout", "user-agent"
+  options. Introduce "listen_timeout" as replacement for the current "timeout"
+  option, and "user_agent" as replacement for "user-agent". Once the deprecation
+  is over, the old "timeout" option will be removed, and "stimeout" will be
+  renamed to "stimeout" (the "timeout" option will essentially change semantics).
+
 2018-01-xx - xxxxxxx - lavf 58.7.100 - avformat.h
   Deprecate AVFormatContext filename field which had limited length, use the
   new dynamically allocated url field instead.

libavformat/rtsp.c

@@ -93,10 +93,18 @@ const AVOption ff_rtsp_options[] = {
     RTSP_MEDIATYPE_OPTS("allowed_media_types", "set media types to accept from the server"),
     { "min_port", "set minimum local UDP port", OFFSET(rtp_port_min), AV_OPT_TYPE_INT, {.i64 = RTSP_RTP_PORT_MIN}, 0, 65535, DEC|ENC },
     { "max_port", "set maximum local UDP port", OFFSET(rtp_port_max), AV_OPT_TYPE_INT, {.i64 = RTSP_RTP_PORT_MAX}, 0, 65535, DEC|ENC },
-    { "timeout", "set maximum timeout (in seconds) to wait for incoming connections (-1 is infinite, imply flag listen)", OFFSET(initial_timeout), AV_OPT_TYPE_INT, {.i64 = -1}, INT_MIN, INT_MAX, DEC },
+    { "listen_timeout", "set maximum timeout (in seconds) to wait for incoming connections (-1 is infinite, imply flag listen)", OFFSET(initial_timeout), AV_OPT_TYPE_INT, {.i64 = -1}, INT_MIN, INT_MAX, DEC },
+#if FF_API_OLD_RTSP_OPTIONS
+    { "timeout", "set maximum timeout (in seconds) to wait for incoming connections (-1 is infinite, imply flag listen) (deprecated, use listen_timeout)", OFFSET(initial_timeout), AV_OPT_TYPE_INT, {.i64 = -1}, INT_MIN, INT_MAX, DEC },
     { "stimeout", "set timeout (in microseconds) of socket TCP I/O operations", OFFSET(stimeout), AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, DEC },
+#else
+    { "timeout", "set timeout (in microseconds) of socket TCP I/O operations", OFFSET(stimeout), AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, DEC },
+#endif
     COMMON_OPTS(),
-    { "user-agent", "override User-Agent header", OFFSET(user_agent), AV_OPT_TYPE_STRING, {.str = LIBAVFORMAT_IDENT}, 0, 0, DEC },
+    { "user_agent", "override User-Agent header", OFFSET(user_agent), AV_OPT_TYPE_STRING, {.str = LIBAVFORMAT_IDENT}, 0, 0, DEC },
+#if FF_API_OLD_RTSP_OPTIONS
+    { "user-agent", "override User-Agent header (deprecated, use user_agent)", OFFSET(user_agent), AV_OPT_TYPE_STRING, {.str = LIBAVFORMAT_IDENT}, 0, 0, DEC },
+#endif
     { NULL },
 };
 

libavformat/version.h

@@ -88,6 +88,9 @@
 #ifndef FF_API_FORMAT_FILENAME
 #define FF_API_FORMAT_FILENAME          (LIBAVFORMAT_VERSION_MAJOR < 59)
 #endif
+#ifndef FF_API_OLD_RTSP_OPTIONS
+#define FF_API_OLD_RTSP_OPTIONS         (LIBAVFORMAT_VERSION_MAJOR < 59)
+#endif
 
 
 #ifndef FF_API_R_FRAME_RATE