[mythtv-users] Cropping NTSC to 16:9

Jeff junk_inbox at verizon.net
Sat Feb 14 01:21:50 UTC 2009

On Fri, Feb 13, 2009 at 2:01 PM, Christopher Meredith
<chmeredith at gmail.com>wrote:

> I use an SA3250HD cable box. I get my analog channels via s-video and
> my HD channels via firewire. My premium HD channels are 5c encrypted
> so I can't grab them over firewire. They all have standard definition
> equivalents on my channel lineup, but as I have a 16:9 TV, I'd like to
> keep the 16:9 aspect ratio even if I can't keep the HD resolution.
> When tuned to the HD channels, the cable box "letterboxes" the feed
> before outputting to s-video. I would like to see if I can create a
> video source or at least set custom "per channel" options that will
> crop out the top/bottom black bars and display the video in 16:9
> resolution. There are a couple things I've tried:
> Obviously, if I am watching such a channel and I set the manual zoom
> to "full," it displays exactly as I have in mind. The problem is this
> is not an automatic solution and I can't figure out a way to set the
> default zoom method on a per-channel basis. Is this possible?
> The other method I tried is using a video filter to crop the black
> bars out. The problem appears to be that the "crop" filter in MythTV
> doesn't work the same way as the crop filter in, say, mplayer. It
> appears that when using an NTSC capture card, the recorded video will
> always be 720x480 and the crop settings are meant to be used with
> equal values all around. If I set the record filter to "crop=4:0:4:0",
> it does crop out the unwanted bars, but the recorded video is still
> 720x480 and the "dead space" is filled with distorted patterns. The
> same is true if I use the same string in the playback filter field.
> Can anyone recommend a method to "un-letterbox" an NTSC feed and
> automatically display a 16:9 resolution?
> Thanks!
> Christopher


  Check if there's a way in the box to set it to 'anamorphic' output.   That
will output the 16:9 video stretched in a 4:3 frame.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mythtv.org/pipermail/mythtv-users/attachments/20090213/047aadd5/attachment.htm>

More information about the mythtv-users mailing list