[FFmpeg-devel] [PATCH] RTP local udp port issue fix (ticket 916)

[Luca Abeni]

On Wed, 2012-01-18 at 01:10 +0400, Dmitry Volyntsev wrote:
> Could you, please, clarify, should I separate the patch to 1)
> patch1:fix of the issue without modification of RTSP_RTP_PORT_MAX and
> if(RTSP_RTP_PORT_MIN != 0) thing + patch2: RTSP_RTP_PORT_MAX
> modification and if(RTSP_RTP_PORT_MIN != 0) thing OR 2) patch1: fix of
> the issue with modification of RTSP_RTP_PORT_MAX  +
> patch2:if(RTSP_RTP_PORT_MIN != 0) thing ?
Note that I do not think this detail (the patch split) is very important
(your modifications look ok to me), and you should follow the opinion of
official ffmpeg developers... Anyway, I think that the patch should be
split similarly to this:
Patch 1 @@ -1103,7 +1103,7 @@ int ff_rtsp_make_setup_request(AVFormatContext *s, const char *host, int port,
                               int lower_transport, const char *real_challenge)
 {
     RTSPState *rt = s->priv_data;
-    int rtx = 0, j, i, err, interleave = 0;
+    int rtx = 0, j, i, err, interleave = 0, port_off;
     RTSPStream *rtsp_st;
     RTSPMessageHeader reply1, *reply = &reply1;
     char cmd[2048];
@@ -1120,8 +1120,11 @@ int ff_rtsp_make_setup_request(AVFormatContext *s, const char *host, int port,
     /* for each stream, make the setup request */
     /* XXX: we assume the same server is used for the control of each
      * RTSP stream */
+    port_off = av_get_random_seed() % (RTSP_RTP_PORT_MAX - RTSP_RTP_PORT_MIN);
+    /* even random offset */
+    port_off -= port_off & 0x01;
 
-    for (j = RTSP_RTP_PORT_MIN, i = 0; i < rt->nb_rtsp_streams; ++i) {
+    for (j = RTSP_RTP_PORT_MIN + port_off, i = 0; i < rt->nb_rtsp_streams; ++i) {
         char transport[2048];
 
         /*
(plus maybe the rtsp.h modifications)

Patch 2 @@ -1158,16 +1161,15 @@ int
ff_rtsp_make_setup_request(AVFormatContext *s, const char *host, int
port,
             }
 
             /* first try in specified port range */
-            if (RTSP_RTP_PORT_MIN != 0) {
-                while (j <= RTSP_RTP_PORT_MAX) {
-                    ff_url_join(buf, sizeof(buf), "rtp", NULL, host,
-1,
+            while (j <= RTSP_RTP_PORT_MAX) {
+                ff_url_join(buf, sizeof(buf), "rtp", NULL, host, -1,
                                 "?localport=%d", j);
-                    /* we will use two ports per rtp stream (rtp and
rtcp) */
-                    j += 2;
-                    if (ffurl_open(&rtsp_st->rtp_handle, buf,
AVIO_FLAG_READ_WRITE,
-                                   &s->interrupt_callback, NULL) == 0)
+                /* we will use two ports per rtp stream (rtp and rtcp)
*/
+                j += 2;
+                if (!ffurl_open(&rtsp_st->rtp_handle, buf,
+                                AVIO_FLAG_READ_WRITE,
+                                &s->interrupt_callback, NULL))
                         goto rtp_opened;
-                }
             }



				Luca