CVD:What is it,how to test it & what to expect!

[vhelp]

ameliak,

First, ...Thank you for taking the time to D/L my clip!

>> I just downloaded and burnt your sample mpg as a SVCD. Works fine on
>> PC, but when I play yours on my Standalone, it plays back but the
>> screen is blank??
>> ...
>> So what would you conclude from this?
...that it's not capable of playing 352x480 MPEG-2 clips, or, it could
be a combo of the 48k audio and/or 352x480 resolution at play here,
that is causing your playing issues.
** Maybe you could try and re-MUX the audio and video ???
It's just a thought/theory. Try it and see. I'm not much of a MUXing
tech., but maybe you've done some MUXing around. Or, perhaps someone
could help you here, as I'm not an experinced MUXer!!
Otherwise, I don't know whta else to say, or suggest or say, but that
you DVD player doesn't like these kinds of ENCODES, be it CVD or xCVDs
or whatever you want to call it! Thank you for trying.

-vhelp

[AmeliaK]

Thanks for your help.

I think I am leaning towards my Standalone not being capable of playing back anything other than VCD and SVCD (& DVD obviously ). I know the results I am getting are pretty much the same as when I try and Play xVCD or xSVCD.

The worse part about it is, when I frame advance every 3rd frame is fine (no green horizontal lines) and the image looks soooo gooood, just a shame it doesn't all play back fine

In any case thanks for your help, looks like I need a new DVD player.

Best Regards
Amelia

[SatStorm]

-Deleted-

[Latexxx]

Exactly there are 3 different types of image that scart connectors can give: rgb, s-video and composite. Examples: My Philips DVD722 (about 300€) gives RGB, S-VIDEO and composite out simultaneously. If I connect it to scart-1 connector of tv, I can choose between RGB and composite, in scart-2 I can choose between S-VIDEO and composite. My Nokia DVB 9808 S gives RGB and composite out. So I can choose between RGB and composite.

[SatStorm]

-Deleted-

[energy80s]

Satstorm, just about every cheap Scart lead now has all 21 pins wired. As you said, the quality of the actual wire is usually shite and you notice a drop in contrast/brightness levels over any great distance, that's why you are better off paying 20 quid and getting a decent double screened lead with gold plated connectors. It doesn't have to be oxygen free cable, just proper screening of the wire. This is usually noticeable by the thickness of the Scart cable compared to stanard "freebees".

[Fred Finkle]

Hello..

Created an CVD clip.. Played it on my Pioneer DV444.. The picture quality looked good enough, but I was left with a smaller boxed viewing window in the middle of the screen ? Normal SVCD's take up the full screen width with black bars top/bottom or none at all depending on the source.

I have 16:9 TV.. Film was Rush hour 2 in 2:35:1 aspect.

Can some one help please ? to get this to a fuller size screen ?

Encoded it as 4:3, 4:3 with boarders, 16:9.. they all appear to box the picture up into the middle of the screen.

[SatStorm]

-Deleted-

[susie]

May I ask where do I fill in GOP = 15 (NTSC) in the following screen shot ?

Thanks

[kinneera]

You just have to bump up the number of P pictures from 3 to 4. Then the total number of frames per GOP will be 15.

[mediamonk]

hi
i am a dvd to ogm man who has bought a dvd player and wants to give cvd a go.i have learned much about the video specs and authoring but i haven,t seen many posts about the audio.
The specs say CVD supports 5.1 audio.what i would like to know is can i use the original ac3 file in the mpeg stream.and if so how to go about it.

thanks in advance.

mediamonk

[SatStorm]

You can in theory, if you are lucky and your DVD standalone supports the feature and if you are using Linux.
Philips supports this feature, but only for SVCD, not CVD. Only a few chinese players are capable for the same thing with CVD. I believe older Amoinosonic players can do that...

In praxis, with SVCD/CVD you are limited with souround sound.
With a dolby prologic 2 audio amplifier, ain't bad you know...

[susie]

Thanks Kinneera

You just have to bump up the number of P pictures from 3 to 4. Then the total number of frames per GOP will be 15.

[jrennie]

Well just as an update. After grabbing the video at DVD res, then reencoding via ReMPG, I was able to make a CVD that worked with my Hollywood+ DVD decoder.

Wont be able to try it on the standalone till later. The picture quality came up very nicely though.

Jason

[ratt794]

I have to correct some issues recently posted because they are flat out wrong. People should not be misled.

First of all some facts:

Resolution is ALLWAYS (Horiz)x(Vertical) and since a TV has a 4:3 aspect ratio you need MORE horizontal than vertical pixels.
To Claim that 352x480 is S-VHS quality is simply FALSE. S-VHS requires at least 480 x 480 resolution due to the 400 Line Resolution.

S-Video Connections have unlimited Y component Bandwidth - thus capture ABOVE 352xXXX is possible and a benefit - I do it all the time with my ATI AIW 128 Pro using the TV Tuner or S-Video Input. There is a noticable Sharpness difference between 352x480 and 480x480 on S-Video or Tuner Capture and even greater difference when 720x480 is compared to 352x480. If your TV can show the Color "Dot Crawl" on sharp color transitions than it has at least 3.58 MHz of Y Bandwidth and would show the improvement over 352xXXX pixels. Even a 19" set can do this although it likely would not have S-Video inputs.

Some Facts about Video Resolutions:

The 70% Nyquist Rule is done to allow smooth looking edges rather than staircase looking ones (if you went full Nyquist Bandwidth).

1) 352 Horizontal Pixels = 2.3 MHz Video Bandwidth (70% of Nyquist or 1/2 Sample Rate) - this is slightly higher than VHS of 2.2 MHz.

2) 480 Horizontal Pixels = 3.2 MHz Video Bandwidth (70% of Nyquist or 1/2 Sample Rate) - This about Equals S-VHS / Hi-8mm

3) 640 Horizontal Pixels = 4.2 MHz Video Bandwidth (70% of Nyquist or 1/2 Sample Rate) - This Equals NTSC Broadcast Resolution

4) 720 Horizontal Pixels = 4.8 Mhz Video Bandwidth (70% of Nyquist or 1/2 Sample Rate) - This is Full D1 and DVD resolution

NTSC Video ALLWAYS has 480 Visible scanlines out of 525 - PAL is 576 visible out of 625 - this is the Vertical Resolution and is fixed unless you down-sample to 240 or 288 lines (1/2) resolution like with VCD.

Going from 352x240 to 352x480 DOES NOT give you a signinficantly sharper picture and will only do so in the vertical direction. Most DVD Players will interpolate 240 lines up to 480 for display anyway. The extra lines allow for INTERLACED video and will smooth out motion if done correctly. This is the only real advantage to the 480 line versus 240 line video.

[DOGLOOP]

Nelson 37 made a valuable point:

S-video can clearly produce "viewable" resolution of over 425 x 560 (laserdisc) & again "viewable" resoltion of over 425 x @720 (dvd).
Now, both of these specs would be interlaced analog OUTPUT.
S-video users can claim horiz resolution up to @ 450 lines, but I have not seen that reliably produced.

Agreed tho, cvd is a very clever way to go & many of my laserdisc rips require no encoding from capture to be compliant & video quality is top for the space & ease of use.

[JudgeTracy]

[quote="SatStorm"]

About VHS, the resolution officially is 352 X 288/240 and not 352 X 576/480. SVHS officially is 352 X 576/480. Those 2 resolutions are facts, and I am not gonna waste time to support facts! If someone disagree, I have no problem. I let him state what he wants, the way he wants. The facts ain't need proofs![quote]


I CAN'T LET INCORRECT INFO GO UNCHALLENGED

VCD is "officially" 352x240/288, not VHS. And SVHS is not "officially" 352x576/480. If this were so, the only difference between VHS and SVHS would be that SVHS is interlaced and VHS isn't. This is not the case.

Don't get analog standards, such as VHS, SVHS, etc mxed up with digital standards such as VCD/SVCD/DVD.

Don't take my word for it. Research it yourself - there are lots of resources on the 'net!

Here's a link I found from a Yahoo! search of <+"lines of resolution" +faq +svhs> that gives the details for PAL standards (NTSC is slightly different in that it has 525 left-right lines @ 60 hz), plus an explanation of how lines of resolution are calculated:

http://www.cs.tut.fi/~leopold/Ld/VideoFormats.html

BOTTOM LINE. The max horizontal lines of resolution that can be captured with 352 pixels is 264, which is a little better than VHS, but only 2/3 of SVHS resolution. (Most consumer VHS equipment, however, will get no better than 150-180 lines - VHS really sucks!) 640 pixels can capture 480 horizontal lines of resolution, which is a little more than SVHS, a dab less than Beta SP, and as noted in an earlier post, is standard broadcast resolution. 720 pixels can capture 540 horizontal lines, DVD quality (though most DVs and DVDs really max at about 500), and a little more than Beta SP.

JudgeTracy
2164 Productions[/b]

[ratt794]

Judge Tracy:

You basically said what I did with one exception-

TV scanlines are across from left to right and there are 525 of them for NTSC. This makes the Vertical resolution effective at 480 visible lines as the rest are during the vertical blanking interval. Think of it as 480 slices from top to bottom.

THEY DO NOT SCAN UP / DOWN BUT ACROSS THE SCREEN.
look closely at a bigscreen TV (Non-HD) and you will see the horizontal scanlines.

[JudgeTracy]

Sorry for the confusion. To clarify, the "left-right" lines go:

AAAAAAAAAAAAAAAAAAAA
BBBBBBBBBBBBBBBBBBBB
AAAAAAAAAAAAAAAAAAAA
BBBBBBBBBBBBBBBBBBBB
AAAAAAAAAAAAAAAAAAAA
BBBBBBBBBBBBBBBBBBBB
AAAAAAAAAAAAAAAAAAAA
BBBBBBBBBBBBBBBBBBBB

Where the A lines are drawn first, then we go back and draw the B lines. Then we go back and draw a different set of A lines, then a different set of B lines, and so on and so on. This is "interlacing."

This example shows eight "left-right" lines or "vertical" lines of resolution. NTSC would have 525 of these, PAL 625.

NON-interlaced formats, such as VCD would only draw the A lines.

Unless I say "left to right" lines, my students don't know what I'm talking about. Hehehe

Horizontal lines of resolution are counted across the screen. For example, this would be 40 horizontal lines of resolution:
||||||||||||||||||||||||||||||||||||||||
NOTE: white space between the lines! You have to have white space to see the black space, otherwise it would just be a black bar! My students call these "up and down" lines.

JudgeTracy
2164 Productions

PS. I liked your response, Ratt, and thanks for illuminating the situation. I responded to the earlier post before I saw yours. I guess I'm little redundant, huh? Wouldn't be the first time I've been accused of that!

[Poplar]

Hi, guys. Finally figured out what's wrong with my CVD encodings and did some tests.
For film sources, I encoded CVD and SVCD at same bitrate (2500kbps). I would say there is no noticeable difference between CVD and SVCD. If I had to choose, I would stick with SVCD, because I think it's a little bit sharper. Perhaps those 128 extra lines do matter after all, at least for film sources.
For analog VHS source, I captured and encoded 352x480. CVD is noticeably better than SVCD at same bitrate. This is a good discovery. Indeed, capturing VHS source above 352X480 is a waste of bandwidth.
Just my observation. Go and test for yourself.

[JudgeTracy]

Hi, guys. Finally figured out what's wrong with my CVD encodings and did some tests.
For film sources, I encoded CVD and SVCD at same bitrate (2500kbps). I would say there is no noticeable difference between CVD and SVCD. If I had to choose, I would stick with SVCD, because I think it's a little bit sharper. Perhaps those 128 extra lines do matter after all, at least for film sources.
For analog VHS source, I captured and encoded 352x480. CVD is noticeably better than SVCD at same bitrate. This is a good discovery. Indeed, capturing VHS source above 352X480 is a waste of bandwidth.
Just my observation. Go and test for yourself.

352x480 is better for VHS sources because any resolution over that is wasted. 352 pixels compressed at 2520 will usually look better than 480 pixels compressed at 2520, because it is compressed less, and thus, has less distortion.

If you're coming from DVD or a SVHS source, there may be some advantages to SVCD over CVD, because SVCD can get about 100 more lines of resolution. But, this comes at the cost of image clarity compared to a CVD at the same rate.

JudgeTracy
2164 Productions

[Fred©]

Hi guys,

I downloaded the vhelp sample of CVD, burned it with NERO and my DVD player did not accepted it !!!

It would be supposed to accept CVD, because it is a Suzuky (Nintaus) N-9901, that claims to play DVCD (double VCD, that I understand to be the same CVD, isnt it?)...

The sound almost does not play and the video seems to be doubled the max resolution the DVD supports... like only half screen was playing, but divided into many horizontal slices of video, black screen, video again, black screen, video , etc... WHAT IS THIS?

Fred©

[SatStorm]

@ JudgeTracy and ratt794
It seems that both of you mastered the knowledge better than me, in much less time. (6 posts or so for you JudjeTracy to became mpeg master?)

Anyway, let's clearify more this, even with my pure english

Why VHS is 352 X 288 and SVHS is 352 X 576.

On VHS we have 144 vertical active lines + 144 vertical non active lines per field.
2 fields combine a frame. Those Fields are in OFFSET posititon between them to FILL 576 vertical lines, which is needed in PAL.
So, 2 lines of 2 fields of a total frame goes like this

VHS

field 1 field 2

AAAA
NNNN
------AAAAA
------NNNNN

Many lines per 2 fieds in a frame looks like this
AAAA
NNNN
------AAAAA
------NNNNN
AAAA
NNNN
------AAAAA
------NNNNN
AAAA
NNNN
------AAAAA
------NNNNN
AAAA
NNNN
------AAAAA
------NNNNN
AAAA
NNNN
------AAAAA
------NNNNN


A= Actice, N= Non Active

A frame must end up having 576 vertical lines in total. But ONLY the active lines have picture info, so if you want the correct resolution you count ONLY the active ones.
That's is a method we use in the digital world.

Why now we capture @ 576 Vertical lines? It is easy to understand:
Capture cards count those no-active lines as black active ones, because that is the way grabbing goes... Non-active lines means "nothing of info is there". Unfortunatelly, with PCs, the term "nothing" is a value. So, the "nothing" must be determined somehow. The easiest way is to be determined as a BLACK line.
So, VHS is a combination of 144+144 =288 Horizontal active lines plus 144+144 non active (black for PCs) lines per frame. All together are made 576 lines, but only the 288 are usefull!

An encoder is capable to detect the non active lines when encodes and DELETE them. How it detect them? That is the secret of the good encoders: The best an encoder detect and delete those black lines, the best resutls we have.
So, you end up with the true resolution of 288 Vertical lines from the true active lines of VHS. Guess what, this is the resolution of VCD too...

With SVHS, there are no no-active lines. All are active, but still fields are in offset mode. That's why you end up with 352 X 576
And that's why SVHS is double the VHS resolution



About sites and infos I can find in the net, I know....
I think I'll upload a site which stated that SatStorm is the president of USA. Then, some people in some forums gonna post that page as a fact to someone else. Then, one day, I might be president of USA...
Good idea, let pass it to Pinky and the Brain...

[ratt794]

Man What stuff are you smoking - must be good! I have allready stated the facts and I am no going to do it again. You are misinformed TOTALLY.
I have been in the Audio - Video Business for over 20 years and also know the NTSC and MPEG standards like the back of my hand so what I have posted is the truth and nothing but the truth so help me God!

[SatStorm]

Well, my friend RATT, I hope now you and your 20 years of experience help the forum more than me.

Have fun
SatStorm

[kitty]

Suzie - load the unlock template (may be in a subdirectory) after loading the SVCD template.

SatStorm - please keep up the good work and do NOT let the sh*theads discourage you. We need your knowledge here!

[kingtuk]

What about the interlace option in TMPGEnc? Will it still play on a home dvd player if you don't interlace?
Someone please give me the ultimate settings for archiving a NTSC CVD so I can move it to a DVD-R (when I get one) and have it play in 80% of the players out there...

[threev]

OK guys, back to fundamental questions. Is SVCD as an accepted format on DVD players going to go away? go away soon? And if it does stick around, why can't you just pile on the SVCD's on a DVD-R? Won't that play ok?

Or is there something special about recordable DVD's and their ability to store and play SVCD? If that is the case then I will feel more compelled to use the CVD standard for future migration to DVD recordables.

[Bud]

I use DVDiT to put all my SVCD format on DVD-R. Works perfect for me. I can get at least two movies on one DVD-R, sometimes three movies with menues. They play back on my Pioneer DV 343, Panasonic LV 55, Samsung M301 with no problems. Check the www.KVCD.Net site for additional information and templates to do this.

Aloha
Bud

[energy80s]

Are you re-encoding your SVCD's? Or are you playing them as SVCD's on a DVD-R disc?