[mythtv] Improving closed captions/subtitles

faginbagin mythtv at hbuus.com
Sun Feb 9 23:17:58 UTC 2014

On 2/8/2014 5:29 PM, Gregorio Gervasio, Jr. wrote:
>>>>>> faginbagin  writes:
> [...]
>> Hi Gregorio,
>> I have something for 608 captions that I'm currently testing. I'd like
>> to test for your use case and I have some questions about the range of
>> zoom values you mention:
>> - Do you find you change the zoom value based on the video you're
>> viewing, or is it something you set on a per-frontend basis, i.e. set
>> it once and then forget it?
>> - If it's something you change on a per-video basis, under what
>> circumstances do you use 60% and when do you use 70%?
>> - If you set it once per frontend, which ones get 60% and which ones get 70% and why?
>> - How large is your biggest screen, and what's the zoom factor and
>> what's the resolution, e.g. 1280x720 or 1920x1080?
>> - Any other factors that might help me avoid a regression in your view?
> I just set the zoom numbers once per frontend.  I think the settings for
> most of my frontends are:
> 60% for subtitles
> 67% for CC608
> 70% for CC708
> This is because DVD/BD subtitles seem to look largest.  I have a few
> frontends (eg. on my desktop PC) where the video window is smaller and
> (also 4:3 aspect ratio), so I bump up the zoom to ~80%.

Thanks for the info. I was concerned about the 60% zoom because, with my changes, the default font size at 1920x1080 goes from 48 to 63. I think it's great, but you would not. If you had been using 60% for 608 captions, you'd be using a font size of 48*.6 = 28 (truncated from 28.8) Given the minimum threshold for zoom factor of 50%, the closest you could get with my changes would be 63*.5 = 31 (truncated from 31.5), which is about 10% bigger. But, since you are using 67%, that means you are using a font size of 48*.67 = 32, so you will be able to get that size with my changes using a zoom factor of 32/63 = 50.7% or 51%. 708 captions are still the same size as before and I don't think my changes have any effect on DVD/BD subtitles, but I can double check DVD subtitles and, using screen shots, make sure the subtitles are no larger than 608 captions with a 32 pixel size. I don't have a BD drive or BD content, so I hope that will be sufficient.


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