Take the 2-minute tour ×
Video Production Stack Exchange is a question and answer site for engineers, producers, editors, and enthusiasts spanning the fields of video, and media creation. It's 100% free, no registration required.

I have Toshiba 29PB200ZE (just purchased). Now the problem is it displays pixels with very blur effect. Reason is that the Cable operators in India (using Standard Channel Broadcasting) broadcasting 720p resolution output. As I have 1080p HDTV it does not displays output properly. Means that tiering the pixels.

Is there any converter available that converts 720p output from Channel (set top box) to 1080p so that I can view output properly.

If I go for HD Channels then issue will not be arised. But as HD channels have very high price range so could not afford them.

Edit: I am using 3 pin (red, yellow and white) cable which connects Set Top Box (digital signals) and my HDTV Toshiba 29PB200ZE. Is performance can be improved by installing other higher density cable like Coaxial?

share|improve this question
    
Welcome to AVP! Interesting question. However, I'm not sure that it is on-topic here at AVP. We'll see what the community thinks. Please have a look at the faq concerning what types of questions are on-topic. Having said that, I'll take a stab at answering :) –  JoshP Apr 12 '13 at 12:27
    
@JoshP - personally, while the question is more of a home A/V than professional A/V question. The formats in question are still used by professionals and the idea of upscaling is relevant as well, so I think it merits keeping. It also might not be horrible to expand in to consumer A/V since I'm not sure if there is a better forum for that on SE, but that's probably more a question to discuss in Meta. –  AJ Henderson Apr 12 '13 at 17:20
add comment

2 Answers 2

up vote 5 down vote accepted

What you are talking about is upscaling and any current HDTV will do upscaling automatically. Upscaling doesn't work miracles though, it will only make it so that the lower quality signal can be watched on a higher quality display. It just multiplies the pixels so that a 720 by 480 (.9 pixel compressed) signal for example doesn't end up only taking up 1/4 of your screen. It doesn't make the video any higher quality (it in fact will be slightly lower quality than if you were to watch it at the native resolution).

Your problem however is not lack of upscaling. Your problem is using the wrong signal. You are currently connecting your cable box to your TV through what is known as a composite cable. It's an old type of analog connection that includes all the video information on the single yellow pin and sends left and right audio on the white and red pins respectively. It is only capable of reproducing a standard definition signal so you are not actually using HD signals.

To benefit from 720 or 1080 signals, you will have to either use analog Component video (the red/green/blue connectors) or use an HDMI cable. It's worth noting that as long as your TV and cable box both have component inputs/outputs, you can actually re-purpose the existing Composite cable to carry a component signal, but there will be no audio (you need a separate white/red pair for the audio, which is the same format as with the composite signal).

Once you fix the cable and hookup issue, you should see better image quality. Personally, I'd recommend using HDMI if it is available on both your cable box and TV as that is the easiest to setup and will give a nice digital signal.

share|improve this answer
    
@Horatio - thanks for the fix, even though I know them in my head, I often type them backwards. Too many C words. –  AJ Henderson Apr 12 '13 at 14:25
    
Thumbs up. Very nice explanation. Sure I will go for HDMI cable. The true fact (after researching and confirm by your explanation) if channels are not HD then I cannot view HD output from HDTV. I have to check after connecting HDMI cable to STB with HDTV. –  NullPointer Apr 13 '13 at 4:10
    
AJ Henderson, I checked my STB and found that it does not has HDMI port :( So could not checked with HDMI cable. As I told earlier that most of the local channels are with STD and not HD it's really disturbing while watching TV. I wish if it is possible to get any intermediate converter which can convert STD to HD according to HDTV. I also tried to watch in 4:3 aspect ration but not got that much clear picture as the old CRT ones had displayed. –  NullPointer Apr 16 '13 at 10:40
    
@PHP - unfortunately, that is just the way it is. An SD signal being up-converted on an HD set is going to look really bad. As long as it is actually taking up the full screen (or a 4:3 ratio of the screen), then what you are seeing is already being up-converted since it is taking an image with 720 by 640 pixels of information and displaying it on a screen with 1920 by 1080 pixels. A lot of the difference you see is probably the analog to digital conversion too. An old SD set works by scanning an electron beam across phosphors. It's effectively an analog process that lacks the precision.. –  AJ Henderson Apr 16 '13 at 13:04
    
of a digital display. It gives it a softer feel which is going to tend to look better for low resolution even if the image is technically clearer on the digital display. You might be able to get a better up-scaler that would try to approximate this feel, but it's not going to make any major improvement. Did you switch to using component (r,g,b,w,r) cables or are you still using the yellow,white,red? –  AJ Henderson Apr 16 '13 at 13:06
show 5 more comments

The cabling is likely your problem. The composite cables you're using (red, yellow, white) will only move analog signal from the set top box to the TV. Likewise with RG59 or RG6 (coaxial).

While both varieties of cables there are technically capable of passing digital signals (they don't care... they're just dumb cables), set top boxes typically only output 480i signals on those particular outputs.

They only way you're going to get 720p signal to your TV is by using one of the set top box's outputs capable of transmitting 720p: HDMI, DVI, VGA, or the component RCA outputs (red, green, blue). Not all set top boxes have all of these.

Incidentally, if you don't have any HD content, the improvement will be marginal. Standard 480i signals often just don't look that good when displayed on a large flat screen.

share|improve this answer
    
VGA is an analog component signal. DVI can do both the analog signal in the format VGA uses (R/G/B/H/V) or the digital format that HDMI carries, but does so on different pins. HDMI is pure digital. –  AJ Henderson Apr 12 '13 at 13:48
    
VGA is an analog connection, but what is transmitted itself may be at 720p(1280 × 720) or 1080p(1920 x 1080) resolution. Resampling a low-resolution "standard def" image (which is probably what the STB is sending over the composite cable) is a much bigger visual problem than analog/digital signal. If a 720p channel is being downsampled for output over composite and then stretched (resampled) by the tv set to native resolution, you have even more degradation. –  horatio Apr 12 '13 at 14:14
    
Thanks for the clarification... will edit –  JoshP Apr 12 '13 at 14:17
    
@horatio - you're totally right. Picture is being displayed with distortion. Actually channels are not that much capable which can be displayed in 1080p HDTV. This shows that I have to go for HD channels. But all channels (which are) being broadcasted are not HD channels. Only few are there and all local channels are being transmitted with STD. So there is no sense to watch them in HDTV. I realize after purchasing the HDTV (just purchased 3 days before). Currently I found temp solution to view STD channels in Movie Mode. Which dulls the brightness but shows clear picture. Any Suggestion? –  NullPointer Apr 13 '13 at 4:18
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.