[mythtv-users] Is Wider better?

Jonathan Rogers jonner at teegra.net
Mon Jun 4 19:25:19 UTC 2007


On Thu, 2007-05-10 at 08:38 -0400, Michael T. Dean wrote:
> Some countries use WSS.  See (from earlier in the thread) 
> http://www.gossamer-threads.com/lists/mythtv/users/267286#267286 .  Some 
> STB's do the same cropping that Myth does for you.

That is very interesting, though probably of decreasing importance with
the rise of digital TV.

> > What's annoying to me is that though ATSC was designed with widescreen
> > in mind, all the local channels I've seen only broadcast proper 16:9
> > streams when it's HD (720p or 1080i). All the SD streams are 480i and
> > 4:3, even though many of those shows are letterboxed, since they started
> > out as 16:9. It seems to me that 720x480 or 704x480 should look as good
> > as DVD-Video, but the ATSC broadcasts never do because of the
> > letterboxing and low bitrates. This is especially common on PBS.
> 
> But, if the source material is letterboxed 480i, any transformations 
> they do on the video can be done by you.  And, you're not going to get 
> very different quality either way (sure they could spend more time 
> pre-processing than you can during real-time playback, but you can 
> always transcode offline).  In other words, when they originally got the 
> show from the network, they probably got a 480i letterboxed version.  
> Even though they can now do real widescreen, they're probably not 
> getting a new copy to broadcast.

While most programs on broadcast TV clearly did start from NTSC (480i)
sources, there are many programs that did originate at a higher quality.
I've seen most of this on PBS, where they frequently broadcast the same
programs on their HD streams and SD streams at different times. Based on
what I've read, 16:9 480i and 480p are both part of the ATSC
specifications, either of which could look a lot better than letterboxed
4:3 480i at the same bitrate, especially for the programs that clearly
originated from HD sources.

It also seems suboptimal that the watcher has to manually tell the
playback system (MythTV in this case) to zoom in to get full use of the
display when the underlying technology supports automatic configuration.
It's not a big annoyance, but it feels like I'm being penalized for
using a 16:9 display to watch 16:9 video.
-- 
Jonathan Rogers <jonner at teegra.net>
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