[mythtv] recorders max rate (space requirements)

Daniel Kristjansson danielk at cat.nyu.edu
Mon Jun 20 11:57:08 UTC 2005

On Mon, 2005-06-20 at 10:11 +0800, David Shirley wrote:
> Hi All,
> Just wondering how mythbackend works out the space requirements for
> recordings... or rather the max rate for the card?
> As you can see below I have a max rate of 138mg/min, however when I record
> tv shows normally - the most I ever use is approx 60 mg/min
> Cheers
> Dave
> 2005-06-19 22:57:22.122 AutoExpire: Found 1 recorders w/max rate of 138
> MiB/min
> 2005-06-19 22:57:22.126 AutoExpire: space: 2.0 GB w/freq: 10 min
> 2005-06-19 22:57:24.165 Recording starts soon, AUTO-Startup assumed
> 2005-06-19 22:57:24.172 Estimated program length: 150 minutes, size: 26017
> MB, free space: 15464 MB
> 2005-06-19 22:57:24.174 SUPPRESSED recording 'Se7en' on channel 1007 on
> cardid 1, sourceid 1. Only 15464 Megs of disk space available.

See TVRec::GetMaxBitrate() in libs/libmythtv/tv_rec.cpp

Not super sophisticated, for MPEG recorders it just assumes that your
bitrate requirements don't exceed the DVD maximum sustained bitrate.

If you would like to write something more sophisticated, that say looks
at your MPEG settings in the DB, that would be welcome. The reason I
put that function is TVRec is so that it would be easy to put code
in the mpeg and frame grabber recorders to figure out a more accurate
maximum bitrate.

-- Daniel

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