[mythtv-users] Yeechang: Ticket #1660

Tony Lill ajlill at ajlc.waterloo.on.ca
Wed Apr 4 22:00:32 UTC 2007

Chris Pinkham <cpinkham at bc2va.org> writes:

> Branching off the SavePositionMap() stuff into another thread is only
> putting a band-aid on the situation, anything else along the line could
> cause that reader to hang up too long and cause dropped data.

I'm wondering what that "anything else" could be. When I was looking
at the mpegrecorder, the only interaction with the system I could see
was reading from the device and doing the database stuff. Everything
else was data processing which should be more-or-less constant per
frame. With the database out of the way, there should be no need for
buffering on the read side. If the data-processing can't keep up with
the data stream, eventually any buffer can be overrun.

IMHO, the fundamental problem is that the path from the device to the
file has real-time contraints, and the database does not. Getting the
database out of that path is the correct solution, and throwing
buffering at is is the band-aid. But I could be biased !-) 

I've wondered if all the read-side buffering in the other recorders
could be dropped if you used my patch, or something like it.
Tony Lill,                         Tony.Lill at AJLC.Waterloo.ON.CA
President, A. J. Lill Consultants        fax/data (519) 650 3571
539 Grand Valley Dr., Cambridge, Ont. N3H 2S2     (519) 241 2461
--------------- http://www.ajlc.waterloo.on.ca/ ----------------

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	- Linus Torvalds, August 1991

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