[asterisk-bugs] [Asterisk 0013013]: [patch] unwrap_timestamp() is bogus for video frames

[noreply at bugs.digium.com]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=13013 
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Reported By:                jpgrayson
Assigned To:                Corydon76
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Project:                    Asterisk
Issue ID:                   13013
Category:                   Channels/chan_iax2
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     assigned
Asterisk Version:           SVN 
SVN Branch (only for SVN checkouts, not tarball releases):  1.4  
SVN Revision (number only!):  
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             07-07-2008 14:19 CDT
Last Modified:              07-08-2008 11:37 CDT
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Summary:                    [patch] unwrap_timestamp() is bogus for video frames
Description: 
In chan_iax2, unwrap_timestamp() takes the 16-bit timestamp found in the
iax2 packet header and the 32-bit timestamp in the chan_iax2_pvt structure
and reconstructs a full 32-bit timestamp for the incoming packet.

The problem is that this function is totally bogus for video frames. The
fundamental problem is that video mini frames only have 15-bits of
timestamp in the packet header, not 16-bits like voice frames.

The consequence of this is that asterisk will periodically fail to detect
timestamp rollover for video frames. This results in big swaths of video
packets to be thrown in the bit bucket.

unwrap_timestamp() needs to account for video frames which only have
15-bits of timestamp information.
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---------------------------------------------------------------------- 
 svnbot - 07-08-08 11:37  
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Repository: asterisk
Revision: 129047

U   branches/1.4/channels/chan_iax2.c

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r129047 | tilghman | 2008-07-08 11:37:47 -0500 (Tue, 08 Jul 2008) | 7
lines

Timestamp decoding for video mini-frames is bogus, because the timestamp
only
includes 15 bits, unlike voice frames, which contain a 16-bit timestamp.
(closes issue http://bugs.digium.com/view.php?id=13013)
 Reported by: jpgrayson
 Patches: 
       chan_iax2_unwrap_ts.patch uploaded by jpgrayson (license 492)

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http://svn.digium.com/view/asterisk?view=rev&revision=129047 

Issue History 
Date Modified   Username       Field                    Change               
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07-08-08 11:37  svnbot         Checkin                                      
07-08-08 11:37  svnbot         Note Added: 0089896                          
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