lavf/http: Document method option.

Signed-off-by: Stephan Holljes <klaxa1337@googlemail.com>

doc/protocols.texi

@@ -278,6 +278,16 @@ Set initial byte offset.
 @item end_offset
 Try to limit the request to bytes preceding this offset.
 
+@item method
+When used as a client option it sets the HTTP method for the request.
+
+When used as a server option it sets the HTTP method that is going to be
+expected from the client(s).
+If the expected and the received HTTP method do not match the client will
+be given a Bad Request response.
+When unset the HTTP method is not checked for now. This will be replaced by
+autodetection in the future.
+
 @item listen
 If set to 1 enables experimental HTTP server. This can be used to send data when
 used as an output option, or read data from a client with HTTP POST when used as

libavformat/http.c

@@ -126,7 +126,7 @@ static const AVOption options[] = {
     { "location", "The actual location of the data received", OFFSET(location), AV_OPT_TYPE_STRING, { 0 }, 0, 0, D | E },
     { "offset", "initial byte offset", OFFSET(off), AV_OPT_TYPE_INT64, { .i64 = 0 }, 0, INT64_MAX, D },
     { "end_offset", "try to limit the request to bytes preceding this offset", OFFSET(end_off), AV_OPT_TYPE_INT64, { .i64 = 0 }, 0, INT64_MAX, D },
-    { "method", "Override the HTTP method", OFFSET(method), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
+    { "method", "Override the HTTP method or set the expected HTTP method from a client", OFFSET(method), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D | E },
     { "reconnect", "auto reconnect after disconnect before EOF", OFFSET(reconnect), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, D },
     { "listen", "listen on HTTP", OFFSET(listen), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, D | E },
     { NULL }