[rtmpdump] [PATCH] Extended timestamp field may be present in type 3 chunk headers

[Martin Panter]

>From c5a88e2ba458588b4b88a4e5b1411c9ee9c03afb Mon Sep 17 00:00:00 2001
From: Martin Panter <vadmium à gmail·com>
Date: Wed, 18 Sep 2013 11:58:01 +1000
Subject: [PATCH] Extended timestamp field may be present in type 3 chunk
 headers
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Content-Transfer-Encoding: 8bit

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.
---
Original in case G Mail messes this up:
https://github.com/vadmium/rtmpdump/commit/c5a88e2.patch

 librtmp/rtmp.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/librtmp/rtmp.c b/librtmp/rtmp.c
index 014ff8b..91ad27f 100644
--- 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))
     {
-- 
1.8.3.4