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

Matt S. skd5aner at gmail.com
Wed Feb 27 17:33:08 UTC 2008

On Wed, Feb 27, 2008 at 8:49 AM, Mårten Bohlin <mabo at mochc.net> wrote:
> 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:
> http://www.mochc.net/myth-dev/LetterBoxDebugg.jpg
> 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.
> /Mårten
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Cool, and very useful, feature!  I would recommend opening a ticket in
trac and submitting this as an enhancement.  Even though it's not
quite ready for inclusion, you can at least keep track of your patches
and process in a ticket so that when it is ready it can be considered
for inclusion.

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