Extended timestamp field may be present in type 3 chunk headers

As described in Adobe’s RTMP specification dated 21 Dec 2012; also:

* RTMPY ticket #107, “Compressed headers also can have an extended
  timestamp”,
  http://web.archive.org/web/20120624031323/http://dev.rtmpy.org/ticket/107
* https://rarut.wordpress.com/2012/03/21/announcing-nginx-rtmp-module/

This resolves intermittent hangs, segfaults and crashes I was seeing when
starting ABC News 24 streams, e.g.:

rtmpdump -r rtmp://cp81899.live.edgefcs.net/live/news24-med@28772 --live

Some of the packets seemed to contain junk timestamp fields, which often
required the extended field.

diff --git a/librtmp/rtmp.c b/librtmp/rtmp.c
index 2693b65013a210816a317e326af1a700adb632b0..6e788bbed97622a132fdad1f8651dd6026b5e11b 100644 (file)
--- a/librtmp/rtmp.c
+++ b/librtmp/rtmp.c
@@ -3573,6 +3573,7 @@ RTMP_ReadPacket(RTMP *r, RTMPPacket *packet)
   char *header = (char *)hbuf;
   int nSize, hSize, nToRead, nChunk;
   int didAlloc = FALSE;
+  int extendedTimestamp;
 
   RTMP_Log(RTMP_LOGDEBUG2, "%s: fd=%d", __FUNCTION__, r->m_sb.sb_socket);
 
@@ -3675,17 +3676,19 @@ RTMP_ReadPacket(RTMP *r, RTMPPacket *packet)
                packet->m_nInfoField2 = DecodeInt32LE(header + 7);
            }
        }
-      if (packet->m_nTimeStamp == 0xffffff)
+    }
+
+  extendedTimestamp = packet->m_nTimeStamp == 0xffffff;
+  if (extendedTimestamp)
+    {
+      if (ReadN(r, header + nSize, 4) != 4)
        {
-         if (ReadN(r, header + nSize, 4) != 4)
-           {
-             RTMP_Log(RTMP_LOGERROR, "%s, failed to read extended timestamp",
-                 __FUNCTION__);
-             return FALSE;
-           }
-         packet->m_nTimeStamp = AMF_DecodeInt32(header + nSize);
-         hSize += 4;
+         RTMP_Log(RTMP_LOGERROR, "%s, failed to read extended timestamp",
+             __FUNCTION__);
+         return FALSE;
        }
+      packet->m_nTimeStamp = AMF_DecodeInt32(header + nSize);
+      hSize += 4;
     }
 
   RTMP_LogHexString(RTMP_LOGDEBUG2, (uint8_t *)hbuf, hSize);
@@ -3730,6 +3733,10 @@ RTMP_ReadPacket(RTMP *r, RTMPPacket *packet)
   if (!r->m_vecChannelsIn[packet->m_nChannel])
     r->m_vecChannelsIn[packet->m_nChannel] = malloc(sizeof(RTMPPacket));
   memcpy(r->m_vecChannelsIn[packet->m_nChannel], packet, sizeof(RTMPPacket));
+  if (extendedTimestamp)
+    {
+      r->m_vecChannelsIn[packet->m_nChannel]->m_nTimeStamp = 0xffffff;
+    }
 
   if (RTMPPacket_IsReady(packet))
     {