TV Resolution

[c_hernandez32]

I have had a problem about the resolution of TV. I heard that it is only better than that of VCD and less than SVCD (I think)? But I recorded a XSVCD at 740x480 at 2.5MB and the quality S*CKS!!! I expected it to be that of a commercial VHS, but nope.

I use high quality cables. I used the splitter and cable that went to my cable modem onto my ATI AIW 8500DV card. The video is all blocky and weird. I am watching on my Philips 750VR via S-Cable. Any suggestions? Plus my XSVCD audio is all wierd and broken. Could that be a problem with the CD-RW write speed? It played fine on my PC though.

[non-linear]

First of all, the NTSC broadcast standard is 720x480, so you're wasting some resolution there. Secondly, the problem is that you're using a bitrate that is way too low for the resolution you want.

Since you're using CD media, you have to decide whether to sacrifice quality for quantity (I don't think too much video will fit on a CD). If you want the quality, consider getting a DVD burner and make DVDs instead of CDs. Burners have really come down in price. if not, then you may want to decrease the resolution or increase the bitrate (but that will cut down on the amount of video you can fit on a CD).

[trevlac]

To answer your 1st question: NTSC TV is considered to have slightly less "resolution" than a standard SVCD. In pixels NTSC TV would be at best 450x480. SVHS would be about 533x480 on the low end and VHS would be 320x480 at best. (These are all rough pixel numbers)

Your other information seems to be all over the place. Not sure why you are doing 720x480 vs 480x480. 720 requires a higher bitrate. When you say it plays fine on your PC, if you mean the audio and video, then your settop has a problem with the disc or the format.

[trevlac]

First of all, the NTSC broadcast standard is 720x480, so you're wasting some resolution there.

What do you mean by this? Wasting by not capturing? NTSC analog is not even close to 720x480 as far as resolution goes.

[xtreemkareem]

NTSC Analog is less than 720X480. And 2.5 Mb/s? That causes macroblocking for 480X480 SVCD resolution sometimes... way too low for your resolution. My suggestion is that if you have a good card that captures decent MPEG 1 or 2 in real time and you don't plan on editing, either capture in 1/2 D1 resolution (352X480 NTSC) or 1/4 D1 VCD Resolution (352X240 NTSC). If doing lossless capture, capture either 704X480 or 352X480 and downsize one notch to get best quality (i.e. 704X480 --> 352X480; 352X480 --> 352X240). As far as bitrates go, 1200~ kbps for 352X240, 2500 kbps for 352X480 and 5000+ kbps for 704/720X480, which quite frankly is overkiill for a NTSC broadcast. THe best balance of quality and file size for DVD playback with a decent playback compatability is your 352X480 CVD. As far as your choppy audio in playback, make shure that your audio bitrate isn't oo low/or too high and that the sampling rate isn't anything other that 44.1 or 48 khz. Also, don't burn much higher than 24X just to be safe.

[lordsmurf]

Couple of my guides should set you straight.

[non-linear]

First of all, the NTSC broadcast standard is 720x480, so you're wasting some resolution there.

What do you mean by this? Wasting by not capturing? NTSC analog is not even close to 720x480 as far as resolution goes.

I mean that since the NTSC broadcast standard is 720x480 and he's capturing 740x480, there's 20 lines more than the NTSC standard uses, so there's data being wasted there.

NTSC analog is 720x480. I'm not talking about how many lines of resolution any service provider actually uses, I'm talking about the actual resolution of the NTSC standard.

[trevlac]

@non-linear

Oh, I didn't notice the 740. I bet it was a typo.

The following is only met to give you and others a guide. There is no reason you should really care. However, your statements about standards are misleading at best.

There is no frame size in pixels for the NTSC standard. It is analog. There are 484 + 2 half lines which are 63.555 microseconds long. Of the 63.555 microseconds, about 52.666 of this signal length contains an active picture. IF one was to digitize this at a sample rate of 13.5 MHz one would get 711 samples. 52.6666 * 13.5 = 711. Samples can then be turned into pixels.

The standard document for analog TV is ITU-R BT.470.6
The standard document that specifies analog to digital conversion is ITU-R BT.601-5

Based upon these standards NTSC can be roughly said to have a frame size of 711x486 when using ITU-601 sample rate. PAL would be 702x576.

This of course is not the same as resolution. A big blurry picture does not necessarily have more 'resolution' than a small sharp one. Resolution for analog is generally given as "Lines of Horizontal Luma" resolution. AKA TVL. NTSC broadcast is generally said to have 330 TVL. TVL can be roughly translated to 'Pixel resolution' for a given aspect ratio by multiplying by the AR. 330*4/3 = 440x480 for NTSC broadcast. This number would be the max at the standard luma bandwidth for NTSC of 4.2MHz. (Also in the 470 std)

BTW: The standards can be downloaded for free here

[c_hernandez32]

Thanks alot of alot responses. In all its seems that people agree on medium resolution for recording. Is this true? What would be better SVCD or CVD? I don't care much for future conversion to DVD, at least not right now. I wanted to know if making a cDVD is feasible? I used the close standards for making a XSVCD for recording, but I think that 2.5 MB is a little too small.

[fvd72]

CVD is better than SVCD for few reasons:

1. RESOLUTION

CVD has a 352x480 (168,960 pixels) vs. SVCD 480x480 (230400 pixels). If you use the same bitrate for both standards, CVD would look much better than SVCD because it "uses" more of that bitrate for each pixel.

2. COMPATIBILITY

CVD is compatible with DVD standards, SVCD is not. If you have a CVD you should be able to play it in most standalone DVD players. Later on, if you want to transfer everything on a DVD you don't have to reencode it. SVCD works only on very few standalone DVD players, and if you want to transfer on a DVD you have to reencode it.

[rtkeen]

"First of all, the NTSC broadcast standard is 720x480, so you're wasting some resolution there."

Let an old television engineer set you straight here ...

The NTSC/FCC BROADCAST standard is 4.2 MHz bandwidth, and 483 active video lines. 720x480 is a CCIR/BTU standard (ITU.656) that allows digitized bandwidths up to 6.75 MHz(Nyquist).

Just a little clarification there ...

[trevlac]

As far as 'standards' go (DVD, VCD, SVCD, CVD, cDVD) it all depends on your machine. cDVD is not likely to work (this would be a DVD file structure on a CDR).

For Resolution, people will tell you lots of things. They may even babble about kell and nyquist. Fact of the matter is there are 2 dimensions. Vertical is the same for all formats 480 for NTSC. No need to compare. Horizontal can be measured in TV Lines or Pixels. For a 4:3 TV (which most are) TV Lines = Pixels / 1.333.

How is TVL determined ? By luma signal bandwidth. NTSC broadcast is 4.2, VHS is 3.2, DVD is 6.75 MHz.

Lets do some math:

Pixel Resolution = 2 * BW * ActiveScan
TVL = Pixel / AR

- For our purposes ActiveScan = 52.666 on an NTSC TV. ITU-601 gives 53.333 (for digital like dvd) but the difference does not show on your TV.
- AR = 4/3 or 1.33

DVD
Pixels = 2 * 6.75 * 52.666 == 711x480 (720 if you use 53.333)
TVL = 711/1.33 == 534 (or 540 if you use 53.333)

NTSC B-Cast
Pixels = 2 * 4.2 * 52.666 == 442x480
TVL = 442 / 1.33 == 332

NTSC VHS
Pixels = 2 * 3 * 52.666 == 316x480
TVL = 316 / 1.33 == 237

As you can see, SVCD(480x480) will cover full bandwidth NTSC B-Cast. CVD(352x480) will not. Will you notice? Maybe not. Maybe your show does not have too much detail. Maybe your cables/switches limit your bandwidth. Maybe 352x480 is good enough. You have to test to know these answers.

[trevlac]

CVD is better than SVCD for few reasons:

1. RESOLUTION

CVD has a 352x480 (168,960 pixels) vs. SVCD 480x480 (230400 pixels). If you use the same bitrate for both standards, CVD would look much better than SVCD because it "uses" more of that bitrate for each pixel.

Frame size is not resolution. It is easier to compress a smaller image, but you do loose resolution if your source was larger than your new frame size. Loss of resolution due to compression is a valid point, but I think you can put 1 hr shows on an SVCD at the max svcd bitrate. If you are too cheap to buy more CDR you get what you deserve. If you want to fit more, buy dvd.

2. COMPATIBILITY

CVD is compatible with DVD standards, SVCD is not. If you have a CVD you should be able to play it in most standalone DVD players. Later on, if you want to transfer everything on a DVD you don't have to reencode it. SVCD works only on very few standalone DVD players, and if you want to transfer on a DVD you have to reencode it.

These comments all depend upon your player. A player that plays SVCD generally will play a 480x480 DVD. Check out some guides. People are not re-encoding. BTW, I never saw a player that says it plays CVD. In fact, my Samsung says it plays SVCD, but it does not fully support all options.


Having said all of that, CVD does have size advantages. SVCD has source resolution advantages. Pick based upon your goal.

[trevlac]

"First of all, the NTSC broadcast standard is 720x480, so you're wasting some resolution there."

Let an old television engineer set you straight here ...

The NTSC/FCC BROADCAST standard is 4.2 MHz bandwidth, and 483 active video lines. 720x480 is a CCIR/BTU standard (ITU.656) that allows digitized bandwidths up to 6.75 MHz(Nyquist).

Just a little clarification there ...

Thank God someone can provide some good info. I know people are trying to help, but the amount of dis-information spread on the topic of resolution and frame size seems to be out of control. They tell 2 friends, and so on, and so on.....

Not to bust on you, but I believe 601 is the "STUDIO ENCODING PARAMETERS OF DIGITAL TELEVISION FOR STANDARD 4:3
AND WIDE-SCREEN 16:9 ASPECT RATIOS", where as 656 defines the interface between digital systems. :P

[fvd72]

CVD is better than SVCD for few reasons:

1. RESOLUTION

CVD has a 352x480 (168,960 pixels) vs. SVCD 480x480 (230400 pixels). If you use the same bitrate for both standards, CVD would look much better than SVCD because it "uses" more of that bitrate for each pixel.

Frame size is not resolution. It is easier to compress a smaller image, but you do loose resolution if your source was larger than your new frame size. Loss of resolution due to compression is a valid point, but I think you can put 1 hr shows on an SVCD at the max svcd bitrate. If you are too cheap to buy more CDR you get what you deserve. If you want to fit more, buy dvd.

I still believe that I was right.

1. We are talking about low bitrates (it is important because at high bitrates is another story).

2. Frame size, resolution and aspect ratio are different things. No mater the frame size, the DVD player would strech the picture to fill the active window or the TV screen. The aspect ratio means the ratio between height and width of the picture: 4:3 for TV screen, 16:9 for widesreen, etc.

3. Do the math:
CVD has 168960 pixels per frame
SVCD has 230400 pixels per frame
It means that CVD has 61440 less pixels than SVCD, and that means
26.6666% less pixels.

Case 1. Low bitrate. Same quality. SVCD's bitrate has to be with 26.666% biger than the VCD's bitrate.
Case 2. Low bitrate. Same bitrate (2.5). CVD can use the extra bitrate to give a better quality picture.

Loss of resolution due to compression is a valid point

I don't understand what you call "resolution," but I guess that you wanted to say "Loss of quality due to compression is a valid point." You control the frame rate directly when you encode the picture, but you can't controll the quality in the same way. Still you have control.

If you still don't believe me, try this:

Rip a short video sequence from a DVD. It has to be with decent to high motion. Have diferent version of the same video:
1. D1, bitrate 6 (the ripp)
2. D1, bitrate 2.5
3. D2, bitrate 2.5
4. D2, bitrate 6

Now compare the videos. You will see that 1. is the best, 3. is better than 2., 4. is better than 2. and 3. This scenario is valid because we are talking about low bitrates.

Also, you can gain some extra "space" for video stream by compressing the audio (AC3).

[c_hernandez32]

OK, OK, OK!!! I have heard different people say varying comments about TV resolution and SVCD and CVD for the last few days. I thank everybody that wrote, but just to make things easier:

What is better, assuming highest bitrate and VBR for each format, recording TV programs in SVCD or CVD?

What is better, assuming highest bitrate and 2 pass VBR for each format, converting DVDs to SVCDs or CVD's (ignoring features such as subtitles and multiple audio soundtracks)?

[xtreemkareem]

Quite simple - CVD, IMHO. SVCD/CVD are usually limited by a max video bitrate of 2520 kbps... some DVD players that support XSVCD will support higher video bitrates... but assuming the 2520 kbps limit here, CVD allowes more data per pixel per frame which = better quality. Quality ultimately lies in resolution and bitrate. However, Bitrate is susually more important. A VCD @ 1600 kbps will look better than the same SVCD @ 2000 kbps because even though the VCD (352X240) will be less than half resolution of an SVCD, from a relative standpoint it has much more data per pixel which makes the picture look better. Low bitrate will result in lots of macroblocking and other artifacts which make your video look literally like shit. 352X480 is a valid DVD resolution for a reason - when given adequate video bitrate, it looks pretty damn good. 480X480 SVCD will only have a slightly noticable shrapness difference on a HDTV compared to CVD.... but on any TV that little extra edge in data per pixel (2520 / (352*480) = 14.9 bits per pixel for CVD vs. 2520 / (480*480) = 10.9 bits per pixel for SVCD... that's a 27% difference in relative data!!). There you go, you have the math to prove it. So go CVD and you won't have any regrets... maybe one day you'll feel lazy and not want to rencode that video and just slap it onto a DVD... you saveds yourself a few hours of your life by plannin ahead. Vive le CVD!

[c_hernandez32]

There you go!!! Thank you!! Finally the simpliest answer! One last thing I heard that TV resolution has a high resolution. Is there any way to software test the quality of the cable signal that is coming into my video card? Or a physical test to ensure the best quality?

[trevlac]

What is better, assuming highest bitrate and VBR for each format, recording TV programs in SVCD or CVD?

What is better, assuming highest bitrate and 2 pass VBR for each format, converting DVDs to SVCDs or CVD's ?

It depends on your source. You should try some small samples and tell us what you think. My answer to fvd72 will tell you why I think this.

--------
@fvd72

I agree with you point. Let me restate it to make sure I get it. Compressing a smaller frame video at a low bitrate will produce higher quality output than a larger frame video at the same low bitrate.

Now let me restate my point. Before compression, a smaller frame is of lower resolution than a larger frame. Let's do a mind test. Take a 720 high detail image. Shrink it to 66.6% of it's orginal size (480). Streatch it back to 720. Now take the same image and shrink it to 49% of it's original size (352). Streatch it back to 720. Compare the results. Which retains more of the original detail?

So these 2 factors can offset each other.

It is my contention that 2.5Mbps is plenty for a 480x480 frame. The 'xtra head room' available to a 352x480 frame is wasted. So, given no gain due to compression, CVD looses due to a smaller frame.

There caveats: 1) mpeg compression efficiency is dependant upon the amount of movement in the source. The more action, the more CVD wins. 2) Resolution lost due to shrinking a frame is dependant upon how much detail was there in the first place. SVCD may not gain anything on Fred Flintstone, but it would win on fine detail animation.

On a final note: It is my understanding that Digital TV services like Dish Network and Direct TV send mpeg that is 544 or 480 at a bitrate of about 2.5Mbps (depending on the source).

[wulf109]

I've been using DVD Shrink to compress 2GB 45 minute TV episodes to 800MB's. Then convert the 800MB file to XSVCD with TMPEG/MpegTools and Headache. This results in 720x480 and Bitrate viewer gives an average bitrate of 2500,peak bitrate about 6000.
Best looking XSVCD I've ever seen. Some DVD players will choke on the high bitrate,many will not. My Sampo,Daewoo,and Norcent players handle them without problems.

[trevlac]

There you go!!! Thank you!! Finally the simpliest answer! One last thing I heard that TV resolution has a high resolution. Is there any way to software test the quality of the cable signal that is coming into my video card? Or a physical test to ensure the best quality?

The simple answer is worth the price How are you going to know unless you try?

BTW: NTSC TV resolution can be 440x480. Hard to test what they send you, unless you get them to send a test pattern. Get the AVIA disc to test everything after the plug in the wall.

[trevlac]

Let's be honest here.

Has anyone ever compared CVD to SVCD? :P You know, a real live test on your real live TV.

[vitualis]

I suggest that you read some older threads, especially those by SatStorm and adam regarding CVD vs SVCD.

Yes, you have more bits per pixel with CVD than SVCD, but SVCD also has a higher resolution and is hence, a little bit sharper. You also tend to get more aliasing artifacts with CVD.

You cannot say outright that one looks better than the other. It depends on many factors including the actual material, the bitrate you are using as well as your display (i.e., TV).

I never played around with CVD or SVCD very much but from experience, I tend to agree with adam's opinion... For a high bitrate disc (i.e., where the average bitrate is > 2000 kbit/s) SVCD tends to look better.

Where the average bitrate is below 2000 kbit/s, CVD tends to look better.

Ultimately, it will depend on your eyes which one looks better than the other.

Regards.

[proxyx99]

I have had a problem about the resolution of TV. I heard that it is only better than that of VCD and less than SVCD (I think)? But I recorded a XSVCD at 740x480 at 2.5MB and the quality S*CKS!!! I expected it to be that of a commercial VHS, but nope.

It seem that you are confusing couple things:
TV resolution, your interpretation of standard frame sizes for video reproduction and dic/file formats used to carry video.

I'm stunned to learn that NTSC brodcast is 720x480. It is not. It is NTSC standard DVD frame size (for lack of better definition). NTSC brodcast is 525 lines of resolution/60 fields. End of story. Your TV is not receiving 720x480 from your cable or satelite or air waves. NO such thing.
Standard TV resolution is defined by a max number of lines it can reproduce (under any! circumstances - read sources) and it is from 500 to 750 (lately) depending on the TV maker.
Video disc standards are DVD, SVCD (+ clones), VCD. Period.

Its interesting to read arguments saying that cutting your resolution in half is better. Not for me! and maybe on a 13 inch TV. Higher pixel count is better and smaller pixel size is better. Talking about that... it seems to me that the discussion was about getting good SVCD reproduction on a TV and what affects it. Obviously c_hernandez32 has managed to manufacture a piece that was incompatible with his player and there may be several reasons for that. But that has nothing to do with his assumption that VHS is better then SVCD, since he never produced a playable SVCD disc in a first place. So maybe you will show him how to do that instead of deliberating about brodcast standards that you guys need to brush up yourself as we have major issues with basic definitions here. That is not clearing up issues for c_hernandez32.

PS. A little piece that will help you understand how poorly developed US standards are in a first place. Excerpt from press (Korea Times) about newest crap US came up with to share with the world. Like: 240! (yes this is what you got from cable here: 240 lines max on your cable, hard to believe?, huh). Let's talk PAL maybe ?!

South Korea was one of the first countries to choose the U.S. Advanced Television Systems Committee (ATSC) standard for its digital terrestrial broadcasting, adopting it for high definition (HD) TV transmission in 1997.

After a series of field tests between 1999 and 2000, which turned out to be unsatisfactory, local terrestrial broadcasters began expressing their preference for the European Digital Video Broadcasting-Terrestrial (DVB-T) standard despite a staunch pro-ATSC lobby within the government, possibly stemming from South Korea's close political ties with the United States.

Backers of the European DVB-T, including terrestrial broadcasters, broadcast technology experts and non-governmental organizations, claim the format is superior to the U.S. ATSC standard as it supports mobile and portable devices.....

[lordsmurf]

Nobody seems to be reading here..

No. NTSC is NOT 704x480 or 720x480 in terms of broadcasts. That is only a NTSC digital spec supported by DVD.

[trevlac]

Edit: ... removed dumb statements.

[trevlac]

Yes, you have more bits per pixel with CVD than SVCD, but SVCD also has a higher resolution and is hence, a little bit sharper.
....
Ultimately, it will depend on your eyes which one looks better than the other.

Thank god someone understands what I was saying. I may not be clear. I appologize for that.


It also depends upon your equipment and your source. So you must test for your case. If there was one always right answer, I'd be scared.


@proxyx99

You are throwing out half truths. I'm not sure why. One can compare DVD, SVCD, HHR to an analog source. After all, analog is what comes out of most DVD players. Don't give up with just the vertical. Also, c_hernandez32 doesn't seem to be asking about the capabilities of his TV. He wants to know the resolution of his CATV source. It's hard to say what he gets, but If your getting 240 TVL, you are doing about VHS (or 3MHz). I can tell you my CATV is better than VHS any day.


@xtreemkareem

You seem to miss the point that if CVD has many more bits per pixel this is because it has many less pixels.


@c_hernandez32

Have you been about to sort out the fact from the fiction? Does a little test match what you think ?

[c_hernandez32]

I thank everyone for their differing versions, but I think I will have to "field test" the cvd, svcd, and xsvcd. Its all been very insightful.

[trevlac]

@c_hernandez32

Can you post the results of your test? It's really nice when someone does that. I've read too many threads where I never get to know the end of the story. That really helps if you are trying to compare other people's experience with your own.

Thanks

[Cornucopia]

Yes, you have more bits per pixel with CVD than SVCD, but SVCD also has a higher resolution and is hence, a little bit sharper. You also tend to get more aliasing artifacts with CVD.

(Slightly OT) One reason for that aliasing is probably because people will often take the full resolution source (720 wide) and resize directly to 352. This is not a simple integer conversion and aliasing can arise because of the truncating of rounded/averaged resulting samples. This is also NOT the correct way to do this particular resize (at least according to most TV engineers).:

Correct 720-->352...

Crop 720 -->704 (8 on each side)
Resize by 50% to 352

This is appropriate for CVD and VCD.

SVCD is still 2/3. No way around that, and I wouldn't crop to 704 first with that material.

Looking at it this way, the resize for CVD and VCD is simpler (mathematically) than SVCD and may subsequently contain less "resize artifacts". After changing your procedures, you may want to rethink which one has truer fidelity to the original.

***Back on topic***
NTSC DVD resolution is 480 vertical. ITU601 NTSC digital resolution is 486 vertical. Small difference but can be important during resizing or field order/deinterlace operations.

I think everyone has really been arguing the same argument, just different facets of it.

Look at it this way, if...

• QUALITY = RESOLUTION * FIDELITY
  and
  FIDELITY = 1/(ARTIFACTS * X)
  then
  QUALITY = RESOLUTION / (ARTIFACTS * X)

For a given bitrate then, SVCD has more resolution, but more artifacts. CVD has less resolution, but less artifacts. The type and quantity of artifacts, and the "X" (which is our subjective perceptions and biases) determine which has better overall quality.

As a rule of thumb, for Very low bitrates, the artifacts of SVCD will not be worth the additional resolution and will favor CVD. Moderately low may have both roughly equal in appropriateness. Somewhat higher bitrates will favor SVCD over CVD.

Remember, professional compressionists spend alot of time trying out the various options and checking/comparing them to find the optimal output for a particular program. They start with the best possible/available master, with the least amount of existing compression/artifacts and move down from there, depending on their space/time/money requirements.
They often take the more eggregious (sp?) sections and determine the settings from them, and/or encode different segments of a program with different settings, tweaking as they go.

If you have the time, this way of working is a good example to follow.

Scott