Video Streaming Server

David Hopwood <>
Sun Aug 13 03:46:49 CEST 2006


lang er wrote:
> Thank you for your suggestion.
> 
> Do you mean a C program reads video stream from device and transfer
> data to Erlang server using local socket, then Erlang server streams
> video data to client?

Yes, that's what I was suggesting.

> In surveillance system, QoS( network delay especially) is very important,
> I think your solution may introduce some additional network delay .
> Normally, 200-500 ms is acceptable, I will write a prototype to test
> it.

I would be surprised if the delay was as much as 200 ms. Presumably, the
vendor SDK must be able to decode each frame fast enough to keep up with
the frame rate, and a local socket connection will not add that much
extra latency.

> I wonder if this is the standard way Erlang program use external SDK.
> I have read some posts in this list, and got a impression that Erlang
> is used in telecommunication device systems and hardware controller
> programs. Don't they need interact with SDK(dynamic linked library)?

It is possible to use a linked-in driver, but that means running code
for which you don't have source in the same process as the Erlang emulator.
There can be incompatibilities with signals, memory management, threading,
etc., and because bugs in the vendor code can crash the whole emulator,
you may lose some of the reliability advantages of using Erlang.

-- 
David Hopwood <>





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