[mythtv-users] Tutorial on Encoding (mostly re: file sizes)

[Ross Campbell]

On 9/20/05, Tony McDowell <svet-am at cableone.net> wrote:
> the main purpose of our machine is for recording / encoding
> video for playback *only* on our TV, what are some good encoding settings?
>
> I am pretty sure that I will encode at 640x480 but don't know about any
> other settings or how they will affect file size.  For a normal 1-hour show
> (most of our favorites are this long), what kind of file sizes am I looking
> at?  This will affect the size of the hard disk I buy for the storage.

First off, you can never have enough hard disk space, and sooner or
later a hard drive is going to fail and you're going to wish that you
had RAID.

Okay, so...

If you stick with 720x480 and the stock settings in mythtv and a
PVR-X50 card, you're probably going to burn about 2.1GB PER HOUR for
recordings.

I tuned the recording settings down so that my shows take just under
1gb per 30 minute show. This makes it easy to fit more content onto
DVDs for me.

I set my settings for mythtranscode to be somewhat aggressive, I bump
resolution down, I bump audio rate down, and have decreased the
min/max bitrate settings. This lets me transcode shows I don't want to
burn to DVD, or want to watch later and store them while only taking
about 900MB PER HOUR. Most of the time, I can't tell any difference.

I'm away from my system, so I can't give any more specific info, but
that should help you get started with planning. You should start with
default values and adjust them *SLIGHTLY* (probably down), test and
repeat until you find the best settings for you.

I would plan on buying a 400gb drive if you're going to store all of
your recordings on that drive.

-Ross