[mythtv-users] Cropping NTSC to 16:9

[Nick Rout]

On Sat, Feb 14, 2009 at 8:01 AM, 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:
>
> MANUAL ZOOM
> 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?
>
> CROPPING
> 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?
>

is there a setting on the cable box to fix that?