[Live-devel] Multiple NALUs concatenated together in one afterGettingFrame

[Deanna Earley]

Good morning all.

We're trying to track down an issue we're seeing very occasionally.
This manifested itself as a crash in our code when storing the SPS frames where the size overrun the 1KiB buffer we'd allocated for it (now fixed).
I was originally thinking it was memory corruption elsewhere causing undefined behaviour and random data to be passed around.
I eventually managed to capture the data it was trying to write and it looks like valid data, but...

It's missing the H.264 prefixes between NALUs and joined them together in one afterGettingFrame call (see https://dl.dropboxusercontent.com/u/2931731/Bugs/largesps.dat).
A crash dump I have (from a another occasion) shows the frameSize passed to my sink as 0x90583 bytes.

As I understand it, the H.264 over RTP profile specifies no prefix.
Is this likely to be a a framing issue (multiples NALUs sent in one packet from the camera without prefixes) or something in liveMedia joining the frames together?

Unfortunately, it occurs very infrequently with only 3 crashes and one dumped data file in 3 weeks making it very difficult to monitor the network stream.

Does anyone have any other thoughts on how to debug this?

This was first seen on our old code with liveMedia from 2009 ish, but still occurs on 2015.04.01 and I expect 2015.04.22.

Thanks

-- 
Deanna Earley | Lead developer | icatchercctv

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