[Live-devel] Access violation during ReorderPacketBuffer::freepacket

[Jeff Shanab]

I have been trying to solve this issue in my code since before I updated to the 2013.03.07 code.
Inspection always shows the packet having a valid address but the guts of the packet are tagged with the heap code for destruction.
It is ALWAYS immediately follows the error message :

   MultiFramedRTPSource error: Hit limit when reading incoming packet over TCP. Increase MAX_PACKET_SIZE;

Could it be that by calling break right after we print that message, that readSuccess or bPacket has not been updated?
The break causes the line:

   if (!readSuccess) fReorderingBuffer->freePacket(bPacket);



to crash because bPacket points to a partially destructed object. (in the freePacket() call on the line "delete packet")



While coming up with a good test that makes this crash has proven elusive. The crash itself is very, very consistent.

It always crashes on the same line after printing the exact same error.



This error seemed to just show up about 6 months ago but way to many things changed to make any correlation, updateing live555 on 3/07 did not change it. I think I just have a certain camera brand that tends to trigger it more often than others now.



I am trying to go thru the code and figure it out, but I was hoping you could take a look at that section and see if anything pops out at you.


This is a low quality H264 stream without audio from a security camera multichannel encoder. It purposely has a few channels without video which forces re-connections.
The bandwidth is very low so the Max_Packet_SIZE error makes me speculate an occasional long stream of garbage data causing  trouble finding end of a valid packet Thus the reason it takes days to show up.

This crash occurs often enough to be a real game killer.
Sometimes it will happen 3 times in an hour but most the time it shows up after about 2-3 days of operation.



   Jeff Shanab, Manager-Software Engineering
   D 630.633.4515 | C 630.453.7764 | F 630.633.4815 | jshanab at smartwire.com<mailto:jshanab at smartwire.com>
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