[mythtv] Patch to autodetect 4:3 Zoom aspect ratio

Mårten Bohlin mabo at mochc.net
Wed Feb 27 13:49:29 UTC 2008

On Wed, Feb 27, 2008 at 2:15 PM, aaron <memoryguy at gmail.com> wrote:
> On 2/26/08, aaron <memoryguy at gmail.com> wrote:
>  >
>  > Although it's not perfect. It *seems* (haven't played enough, and it's
>  > time for bed...) that the case where the channel logo partially covers
>  > the black bar it fails to detect that it's letterboxed.
>  >
>  Okay, I tried a couple more videos and you were right, Marten (please
>  forgive my spelling, I don't know how to enter the correct "a")
>  The detection does not get fooled by the channel logo, nor the rating
>  logo (that is, the giant "PG", "G", etc) up the top left corner.
>  Excellent!
>  But it's still not detecting properly for some recordings. In my case,
>  an episode of Stargate Atlantis stays in "Off" mode, but then switches
>  during the commercial break when the commercials are letterboxed. And
>  on an episode of The Office it keeps jumping back and forth during the
>  episode.
>  The bars on The Office look (to me) about as dark as other shows that
>  don't have a problem. Stargate's boxes are a little lighter, but I
>  didn't think they were *that* much lighter ... they're still darker
>  than the "black0" pillarbox colour.
>  When I get a chance I'll try digging into the code a bit more. Alas,
>  my free time is often very limited. I *may* get a chance this
>  weekend....
>  But, on a positive note, when it does work correctly it's a great feature :)

Hi! Thanks to everybody that tests this patch and are giving me feed back.

I have adjusted it now so it should not be to picky about the 4:3
aspect of the source video. And I have also added a cool debug mode
that shows where detection is done. It also paints a black box in the
top left corner that is the brightest version of black that is
considered as black. (I can not see it on my screen since it looks
totally black)

Here is a snapshot of it and explanation of how to reed it:

To enable it turn it on in the Adjust Fill menu. I hope that this will
help us to get all the parameters perfect for everybody.

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