From 303f927d707a8625c6ce29eceebd09bab055d992 Mon Sep 17 00:00:00 2001 From: Eike Hein Date: Wed, 12 Jun 2019 04:45:09 +0900 Subject: [PATCH] rtspconnection: Start CSeq at 1 RFC 7826 recommends (but does not require) starting at 0, but at least one known server implementation fails to copy request sequence numbers <1 into responses due to an incorrect null check. The server known to exhibit this behavior is the Parrot Streaming Server, serving video from their UAV devices. A fix has been submitted upstream as well: https://github.com/Parrot-Developers/librtsp/pull/2 The Parrot developers are known to have tested with LibVLC. In WireShark debugging, LibVLC appears to start with a CSeq of 2, which is likely why this bug went unnoticed. This reverts 487595a7d6e2d, which set this to 0 citing the RFC. The switch to 0 was thus a recent one; it's therefore possible server implementors relied on the previous GStreamer client behavior in their tests as well. Fixes #624. --- gst-libs/gst/rtsp/gstrtspconnection.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/gst-libs/gst/rtsp/gstrtspconnection.c b/gst-libs/gst/rtsp/gstrtspconnection.c index 60aaad1d53..fd4262fb36 100644 --- a/gst-libs/gst/rtsp/gstrtspconnection.c +++ b/gst-libs/gst/rtsp/gstrtspconnection.c @@ -362,7 +362,8 @@ gst_rtsp_connection_create (const GstRTSPUrl * url, GstRTSPConnection ** conn) newconn->url = gst_rtsp_url_copy (url); newconn->timer = g_timer_new (); newconn->timeout = 60; - newconn->cseq = 0; /* RFC 7826: "it is RECOMMENDED to start at 0." */ + newconn->cseq = 1; /* RFC 7826: "it is RECOMMENDED to start at 0.", + but some servers don't copy values <1 due to bugs. */ newconn->remember_session_id = TRUE;