Depressing: Videopak cheats on high res stills

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I just did some experiments with high resolution stills. One thing that seems to me is videopak does not really burn them. Here is what I did: I made some high res bmp files: 704x576, put in videopak, make sure the res selection is 576, burn them on my rewritable disc. When I examine these files in SEGMENT dir, using media player, virtualdub, etc, they all turn out to be 352x288. I looked at some comercial vcds, sure, they have SEGMENT dat files with 704x576. Isn't videopak cheating?

-- Nerian (nerian@altavista.com), February 18, 2000

Answers

Yes I have tried the same thing (except I did it with NTSC 352x240) I used the Xing Player to watch them and the size was standard. Then I tried the disc in my DVD Player, the High Res still looked so much better, and just to make sure, I put one sandard pic right before a track with a High-Res, I could which was the High-Res. To conclude, the problem is not with Video Pack, it is with the software player.

-- Jay (jlinkhome@yahoo.com), February 19, 2000.

I am not so sure. I agree the players are not particularly good at telling the true picture sizes. But converting the *.dat to *.mpg using mpegtool, I can get 704x576 mpg from the commercial vcd, while only 352x288 from videopak produced one. There must be some professional software out there that actually got this right, but not videopak or EzCreator. Don't know about WinOnCD ...

-- Nerian (nerian@altavista.com), February 19, 2000.

Hi Guys

Firtly, windows media player does not play vcd stills or a vcd mpeg stream correctly at all.

WINDOWS MEDIA PLAYER IS NOT CAPABLE OF PLAYING A STILLS VCD AT ALL and MAKES A TOTAL MESS OF A MPEG STREAM.

A DVD and VCD are designed to play, whether you like it or not, on a 4:3 aspect ratio computer screen or analogue TV. The specs give that information. Windows Media Player does not do that.

Have a good look at the frame it produces, in NTSC at full screen it will only fill the width and not the height. In PAL it will only fill the height and not the width. Whilst you use media player you will always get the wrong answers and unless you are producing the stills correctly in the first place you will have compressed horizontals in NTSC and expanded horizontals in PAL when played on your DVD player AND if played correctly on your PC.

The other thing about stills is that if you start big enough in size then when you compress to smaller sizes the information is compressed with the change, so it will basically always be possible to got back to the original size or any size in between without "loss". If you have a picture that is scanned at 1800 x 1200 and you compress OR RESIZE it to 352 x 240 then you can also take it back to the original size without "loss". If you crop the picture to 352 x 240 you cannot do that. The "loss" in quotes refers to as viewed at normal sizes on the PC or TV.

So it does not matter one way or the other what your final resize is, it can be 352 x 240 or 704 x 480 and on the TV screen or Computer you will not tell the difference. You will see one hell of a difference if you only start from 352 x 240 because then the picture is expanded without the information being available to produce the goods.

All you have to do is make two slides one at 704 x 480 and one at 352 x 240 in NTSC from the same large source and play them, you will not see the difference.

If you wish, I will send anyone who wants the truth a small demo in NTSC via email (2.3M) that proves what I have said here, burn it to a CD-RW and see for yourselves on your DVD player or if you have Video Pack I will send anyone a project in stills that clearly shows what I am saying here.

If you use a player such as Cyberlinks VCD PowerPLayer, even the cheap one, it will play vcd's correctly.

With the so called "high definition" still at 704 x 480 VP4 option the cyberlink player never shows a 352 x 240 high still even when you use the resize button, it is always the size generated from a 704 wide picture as the base and when you play it full screen it compresses the information back to 640 wide, as it should do, and thats exactly what the windows program and others DONOT do.

I wonder how many of you are aware that if you want to exchange VP4 menu VCD's with people using multi system TV's that all menus on the VCD must be in the native format. In other words an NTSC vcd must have PAL size menus for someone to use in a PAL country. Fortunately, playing on the computer does not invoke the same problems.

The hornets nest is now open, come on all you F18's lets have a "dog fight", but back your "shots" up with examples!

-- Ross McL (rmclennan@esc.net.au), February 20, 2000.


If anyone wants, I can send the commercial .dat I am talking about. I think it is worth looking into. It is not big since this has merely two intra frames.

-- Nerian (nerian@altavista.com), February 20, 2000.

hay i have a panasonic laserdisk that support cdv and would like it very much if you could make a iso image of that cd so i could try and make cdv's to play in the drive thanks wantobe hacker developer thank i use kazaa to share files i'll be looking for cdv_format in my search anybody help cool if i can work it i'll post my results thanks to much free time!

-- kminfo mccracken (kminfo@uswestmail.net), February 20, 2002.


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