[mythtv] Improving closed captions/subtitles

Gregorio Gervasio, Jr. gregorio.gervasio at gmail.com
Sat Feb 1 00:27:05 UTC 2014

>>>>> faginbagin  writes:

> I'd like to improve the appearance and legibility of 608/708 captions
> in fixes/0.27. Some of the problems I see are:

> - Default font size is smaller than should be necessary to fit 15
> lines in a 90% safe area. I estimate the default FontMono pixel size
> could be increased from 32 to 38 for a 1280x720 display and I think I
> have a relatively simple algorithm to compute a good font pixel size
> for a variety of algorithms.

> - I suspect support for subtitle zoom was added because of the first
> problem. Maybe it can be eliminated at some point?

        I don't know about 708 caption zoom, but I submitted the initial
patch for 608 caption and DVD/BD subtitle zoom because I wanted them to
be *smaller* -- I don't want them covering up too much of the display,
especially on a big screen where smaller subtitles/captions are
perfectly readable.  I typically use zoom values of 60%-70%.  Removing
the zoom would be a regression for me, since what I want can't be
addressed just by using a smaller font size.

> - Captions are shifted too far to the left. As a result, it is hard to
> tell who is speaking when two people are on screen. I believe they
> should be positioned to center 32 characters per line when the video
> is 4:3 aspect and 42 characters per line when the video is 16:9, based
> on what I've gleaned about the 708 standard.

        I think some of the left-shifting of 708 captions may be due to
bad formatting (possibly due to lazy conversion of 608 captions).  The
ones I've seen are also shifted when viewed on non-MythTV systems.  I
have seen 708 captions (usually ABC shows) that are centered correctly.

Gregorio Gervasio, Jr.
gregorio.gervasio at gmail.com

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