What is standard TV Resolution?

[dragin33]

I've been looking all around to find out what the standard resolution for TV is so that i can record at that resolution. I've found some sites that say 320x240, 480x440, 720x480 and more. So can someone just tell me what the standard resolution for regular cable TV broadcasts is?

[V_D_O]

AFAIK, and I'm not an expert, NTSC is 640x525, 29.97fps, and PAL is 720x625, 25fps.

But there are extra blanking lines included in these figures - the actual NTSC picture is 525 vertical lines of which only 486 are viewable, and PAL is 625 vertical lines, of which only 576 are visible, which is why 640x480 monitor pictures look small on a TV. The extra lines are used for, for example, teletext info.

I'm not sure that made any sense - I'm not entirely certain its all correct, but its all I know.

[riekl]

The question here is what format you are looking for By definition 480i is the best you are going to get out of svideo or rca jacks. so anything over (xxx)x480 is just filler.

Once you start getting into HDTV then you have a great deal more content to play with 540, 720p, 1080i, etc. (maybe we can drool hard enough and get 1080p ! someday soon !)

[Soundman]

Hello. One other thing to remember is that, because an NTSC or PAL video signal is analog, there is no actual horizontal resolution the way there is in a digital picture. There are definitely a fixed number of vertical lines. The numbers given by V_D_O sound about right, but I think the amount of blank lines at the top and bottom varies slightly.

Horizontally, it is just an analog signal. You can sample it at any rate that you want when you convert it to digital. However, there is no point in sampling at a higher resolution than can be achieved within the the analog bandwidth of an NTSC signal. I believe that an ideal NTSC signal maxes out at about 720 useful samples per scanline. In practice, you often don't get that clear of a signal.

My advice would be to sample at the same resolution used by DVD's, which is standardized at 720x480. This may be slight overkill in the horizontal dimension, but definitely not in the vertical dimension. If you record MPEG-2's at this resolution, then they should already be in the right format to burn to DVD's later if you choose.

None of what I have said applies to HDTV signals.

'Hope this helps
Soundman

[dragin33]

I just want to make sure that i'm recording at full unadaulterated resolution.

[V_D_O]

In that case, I'd go with 720x480, 29.97fps.

[ScottW]

I was looking for confirmation of the same question. I have analog cable (no box) plugged into an AIW8500DV. According to http://www.lordsmurf.com (see Understanding Your Source) analog cable broadcasts at "approximately 325-350 lines of horzontal resolution (about 336x480 in digital terms)."

With that said, I created a custom quality called TV. It's used for recording TV shows (not movies) and can be burned to DVD fairly easily.

Frames per second: 29.970
Dimensions (pixels): Custom... 352 x 480
Video Bitrate: 3670016 bits per second
Bidirectional (Interpolative) Frames Per Group: 2
Predictive Frames Per Group: 2
Video Noise-Reduction Filter Enable? (Off)
Motion Precision: 98%

Any comments on this config?

Thanks
-sdw

[exorcism]

afaik, ntsc is 'technically' 720x540, but only about 640x480 are displayed on a tv, and dvd's are encoded at 720x480 cause the extra 60 lines are for data (closed captioning, macrovision, whatever else they stick in there)

and since tv is analog, you will not get an 'optimal resolution' that 'matches' directly up with the tv resolution. the resolutions are pretty much theoretical anyway.