# ASK DBSTalk: Is the composite input on the 921 supposed to be good for anything??



## Gary Swanson (Feb 1, 2004)

I thought I would try the input connection with my RePlay unit (the only PVR I can count on) and the results were terrible. Pretty much unwatchable. I was hoping the PQ would be upconverted. Was I expecting to much?


----------



## jsanders (Jan 21, 2004)

Gary Swanson said:


> I thought I would try the input connection with my RePlay unit (the only PVR I can count on) and the results were terrible. Pretty much unwatchable. I was hoping the PQ would be upconverted. Was I expecting to much?


It does get upconverted if you set the "SD/HD" remote to turn on the blue HD indicator on the front panel of the 921. The input is not very good at all. So, basically, upconverted garbage in gives garbage out.

I've used it to set the brightness and contrast from Video Essentials, as this upconverts to calibrate the 1080i input. I didn't find the HDNet test patterns to be useful for brightness/contrast.


----------



## Mark Lamutt (Mar 24, 2002)

I don't use it. During my initial system testing I tried it out, a saw that it's not something that I would find useful to use.


----------



## 928gt (Dec 17, 2003)

About the only thing I can think of using it for is maybe one of those X10 Wireless Security Cameras. 

Might be cool to check who is at the front of the house ... and if they are worth interupting my HD viewing pleasure.

On the other hand since we have HD DVRs we can always just use "Pause" 

Dave


----------



## jsanders (Jan 21, 2004)

928gt said:


> About the only thing I can think of using it for is maybe one of those X10 Wireless Security Cameras.
> 
> Might be cool to check who is at the front of the house ... and if they are worth interupting my HD viewing pleasure.
> 
> ...


Ha ha ha ha ha! Oh, that is funny! It is a great idea too! It just tells me that with all different people with all different ideas and uses and abuses of products, from the developers standpoint, you will never be able to fathom what the customer is going to do with what you sell them! :lol:

You want to see who is at the front door? Just turn to channel 000! The cool thing is that a security camera is a bad resolution in the first place, so, connecting it to the composite input doesn't mean any loss!

You forgot to tell us where to get one of those cameras!


----------



## 928gt (Dec 17, 2003)

> Ha ha ha ha ha! Oh, that is funny! It is a great idea too! It just tells me that with all different people with all different ideas and uses and abuses of products, from the developers standpoint, you will never be able to fathom what the customer is going to do with what you sell them!


How TRUE !!



> You want to see who is at the front door? Just turn to channel 000! The cool thing is that a security camera is a bad resolution in the first place, so, connecting it to the composite input doesn't mean any loss!


Exactly !!



> You forgot to tell us where to get one of those cameras!


Easy, do a search for "X10 wireless Camera" and you will get a zillion hits. You can get one of these systems for around $50-75 complete and you would actually be amazed at the quality. As a matter of fact the picture quality from most of these are better than that "0" input.

With a little macro programming and the right remote setup you actually get these systems to pop up in a PIP window (if your TV supports PIP) anytime movement is "seen" by the camera.

Fun stuff...


----------



## Slordak (Dec 17, 2003)

So the quality on this input is bad? Is it worse than not running the input through the 921 (i.e. compare connecting directly to the TV versus 921 to TV)? And this is presumably a hardware problem then that we can expect no relief from?

I don't understand the use cases for this input if the quality is generally accepted as being poor overall. I suppose if the source of the image is poor enough, it shouldn't matter?


----------



## jsanders (Jan 21, 2004)

Slordak said:


> So the quality on this input is bad? Is it worse than not running the input through the 921 (i.e. compare connecting directly to the TV versus 921 to TV)? And this is presumably a hardware problem then that we can expect no relief from?
> 
> I don't understand the use cases for this input if the quality is generally accepted as being poor overall. I suppose if the source of the image is poor enough, it shouldn't matter?


Yea, the quality of the input is pretty bad. It is worse than not running it through the 921 at all. Pretty bad huh... :nono:


----------



## jsanders (Jan 21, 2004)

928gt said:


> Easy, do a search for "X10 wireless Camera" and you will get a zillion hits. You can get one of these systems for around $50-75 complete and you would actually be amazed at the quality. As a matter of fact the picture quality from most of these are better than that "0" input.
> 
> With a little macro programming and the right remote setup you actually get these systems to pop up in a PIP window (if your TV supports PIP) anytime movement is "seen" by the camera.
> 
> Fun stuff...


Thanks! :grin:


----------



## Slordak (Dec 17, 2003)

Maybe this should be retitled as a bug or hardware shortcoming, i.e. "composite passthrough on 921 significantly degrades signal quality". Probably needs to go with the other bugs about how any time the 921 tries to convert or "enhance" the signal in some way (e.g. convert 480i to 1080i), the signal winds up losing quality due to the generally cheap hardware inside the box.


----------



## jsanders (Jan 21, 2004)

No doubt there are issues. It is a fine line here between hardware and software. They might not make it better. Even still, I don't think it is a priority. A composite input isn't such a great thing in the first place. I wouldn't want to distract the developers to work on this problem. Fix the OTA issues, timer issues, and channel guide issues, along with stability problems first!

It isn't reasonable to expect the 921 to have videophile scalers when up-converting signals. All they need to do to fix your scaling issues is to make the "SD/HD" button cycle through 480p, 1080i, and "No Scaling" to let your external scaler do the work. Not a big issue, and I think we would all enjoy that functionality.


----------



## BarryO (Dec 16, 2003)

jsanders said:


> All they need to do to fix your scaling issues is to make the "SD/HD" button cycle through 480p, 1080i, and "No Scaling" to let your external scaler do the work. Not a big issue, and I think we would all enjoy that functionality.


No, that's not all. With a composite input, the 921 must separate the chroma and luminance signals, whether or not it scales them to other scan rates, in order to converter them to either component or RGB outputs. This is _not_ an easy thing to do well, as the spectra of the two signals overlap. The best TV's and scalers do this with 3D motion-adaptive comb filters; the not-quite-the-best ones use some type of 2D comb filter.

I can't imagine the 921 designers bothered doing something this fancy and expensive. The simplest way to separate the signals is simple hi-pass/low-pass filters, as used in cheap TV's. Doing this gets you approximately VHS quality pictures, no matter how good your scaling is.


----------



## Slordak (Dec 17, 2003)

jsanders said:


> No doubt there are issues. It is a fine line here between hardware and software. They might not make it better. Even still, I don't think it is a priority. A composite input isn't such a great thing in the first place. I wouldn't want to distract the developers to work on this problem. Fix the OTA issues, timer issues, and channel guide issues, along with stability problems first!


I totally agree, with regards to this being not a priority. The number of individuals who will actually use this is pretty low, for the most part, so I don't think this is a priority (even if there was anything they could do, which there probably isn't). You're absolutely right that there are a number of other bugs and issues which need fixes first.


----------



## BobMurdoch (Apr 24, 2002)

It might be usueful if you have a game machine and you are out of inputs on your TV or A/V receiver (or you don't want to pull the receiver out of the unit to rewire it every time if you hide the game machine when not in use.)

My XBox is hooked in with component inputs and a TOSlink cable, so this wouldn't work with me, but several of you may have multiple systems for which this would make sense (ie. a PS2 AND a GameCube).


----------



## SimpleSimon (Jan 15, 2004)

928gt said:


> About the only thing I can think of using it for is maybe one of those X10 Wireless Security Cameras.
> 
> Might be cool to check who is at the front of the house ... and if they are worth interupting my HD viewing pleasure.
> 
> ...


Oh Yeah! Thanks for the idea! Just plugged in my NightWatch - works great!

However, the 921 does NOT allow PIP when using OTA or AUX inputs. I created a feature request for it. Don't know if it's hardware feasible.

Also, I've found it difficult to get out of AUX mode and back to watching a PVR show. Gotta change channels and then go back to the PVR menu and reselect the event.


----------

