Set top box tip for 768p fixed pixel displays

Sole_Survivor · 10-29-2005, 02:11 PM

I did some poking around since the summer about where to keep my box set to @ 720 or 1080 for my 768p set, and I would like to thank all those who commented, Rsawdey & Strawberry, special thanks.

My verdict is in.........

If your watching CBS, the signal is 1080i, keep the set top at 1080i, I noticed better resolution in comparing picture quality at 720 & 1080i with a 1080i signal.
The set cross converts the 1080i signal to 768p 60fps.
If you set your box to 720p when watching a 1080i signal here is what happens,

1. You de interlaced 1080i to 720p
2. Now your TV has to up convert 720p to scale to 768.

Keeping the 1080i signal at 1080i going into set means the signal has got cross converted once instead of twice.

Same thing when watching ABC 720p, now if you keep the set top at 1080i the the signal starts at 720p then gets interlaced at 1080i then gets de interlaced at 768p.
So when watching ABC or fox or any 720p signal, keep the box at 720p.

I can't really say to always keep the signal in it's original form, because 480i looks a lot better at the 720p setting than 480 i or p. And 720p up converting DVD players work best with fixed pixel displays.
These sets are designed to cross convert 1080i to 768p & 720p to 768p, the result is an amazing picture no scan lines, but by changing the signal twice instead of the one cross conversion can result in a loss of some color saturation as well as detail.

Also if one noticed, I said cross converted.
There has been a false cliche of calling 1080i down converting to the 720-768 format.
To convert 720p or 1080i to 480p or i is down converting. Converting 720p to 1080i or vice versa is correctly called cross conversion.

**rbinck** · 10-29-2005, 04:21 PM

More likely your set deinterlaces 1080i/30fps to 1080p/30fps into an internal video memory then scales the 1080p/30fps to 768p/30fps and the result is refreshed twice for the 60Hz display. If you have a single chip video processor the deinterlacing and scaling is probably combined into a single step.

Sole_Survivor · 10-29-2005, 05:48 PM

Not sure about that, but either way the signal shouldn't be going through an additional change before the set scales it to it's native resolution.

Sole_Survivor · 10-30-2005, 06:00 AM

rbinck,
Can former Voom customers still get those exclusive channels with their old equipment but now have to pay Dish network? I know this isn't the thread for that, just wondering though. I looked into Dish but their HD DVR doesn't record 2 shows at once IN HD, 1 has to be in standard. Staying with Direct.

**rbinck** · 10-30-2005, 05:58 PM

No it requires Dish Network equipment.

10-29-2005, 02:11 PM	#1
Sole_Survivor Sole Survivor Join Date: Jan 2005 Location: Providence, RI Age: 41 Posts: 119	Set top box tip for 768p fixed pixel displays I did some poking around since the summer about where to keep my box set to @ 720 or 1080 for my 768p set, and I would like to thank all those who commented, Rsawdey & Strawberry, special thanks. My verdict is in......... If your watching CBS, the signal is 1080i, keep the set top at 1080i, I noticed better resolution in comparing picture quality at 720 & 1080i with a 1080i signal. The set cross converts the 1080i signal to 768p 60fps. If you set your box to 720p when watching a 1080i signal here is what happens, 1. You de interlaced 1080i to 720p 2. Now your TV has to up convert 720p to scale to 768. Keeping the 1080i signal at 1080i going into set means the signal has got cross converted once instead of twice. Same thing when watching ABC 720p, now if you keep the set top at 1080i the the signal starts at 720p then gets interlaced at 1080i then gets de interlaced at 768p. So when watching ABC or fox or any 720p signal, keep the box at 720p. I can't really say to always keep the signal in it's original form, because 480i looks a lot better at the 720p setting than 480 i or p. And 720p up converting DVD players work best with fixed pixel displays. These sets are designed to cross convert 1080i to 768p & 720p to 768p, the result is an amazing picture no scan lines, but by changing the signal twice instead of the one cross conversion can result in a loss of some color saturation as well as detail. Also if one noticed, I said cross converted. There has been a false cliche of calling 1080i down converting to the 720-768 format. To convert 720p or 1080i to 480p or i is down converting. Converting 720p to 1080i or vice versa is correctly called cross conversion.

10-29-2005, 04:21 PM	#2
rbinck Administrator Join Date: Apr 2004 Location: Katy, Texas Posts: 12,336	More likely your set deinterlaces 1080i/30fps to 1080p/30fps into an internal video memory then scales the 1080p/30fps to 768p/30fps and the result is refreshed twice for the 60Hz display. If you have a single chip video processor the deinterlacing and scaling is probably combined into a single step. __________________ www.highdefinitionblog.com www.BlogOfHawaii.com Last edited by rbinck; 10-29-2005 at 04:23 PM.

10-30-2005, 05:58 PM	#5
rbinck Administrator Join Date: Apr 2004 Location: Katy, Texas Posts: 12,336	No it requires Dish Network equipment. __________________ www.highdefinitionblog.com www.BlogOfHawaii.com

10-29-2005, 05:48 PM	#3
Sole_Survivor Sole Survivor Join Date: Jan 2005 Location: Providence, RI Age: 41 Posts: 119	Not sure about that, but either way the signal shouldn't be going through an additional change before the set scales it to it's native resolution.

10-30-2005, 06:00 AM	#4
Sole_Survivor Sole Survivor Join Date: Jan 2005 Location: Providence, RI Age: 41 Posts: 119	rbinck, Can former Voom customers still get those exclusive channels with their old equipment but now have to pay Dish network? I know this isn't the thread for that, just wondering though. I looked into Dish but their HD DVR doesn't record 2 shows at once IN HD, 1 has to be in standard. Staying with Direct.