svcd resolution

[shinakuma8]

OK, I am fairly new with the svcd stuff. I'm a little bit confused about the resolution.

My question is if I want to re-encode vcds into svcds, what should I do with the resolution? PAL vcds are 352x288, and PAL svcds have 352x576, the vertical resolution is twice of the original vcd. So I don't know what to do exactly, can someone explain?

[wmansir]

Why do you want to re-encode a VCD to an SVCD? You could resize the picture, but no matter what you do it will probably look worse than the original.

and actually SVCD is 480x576. 352x576 is the resolution of CVD, a less popular format. (Less popular meaning fewer DVD players support it)

[shinakuma8]

Yeah, when you first hear converting vcd into svcd, it does sound dumb. But I have my good reasons.

Basically, I have these foreign tv series. Each eposide is roughly 50 minutes and comes on 1 vcd. What I want to do is saving some cds by re-encoding 2 vcds onto 1 vbr svcd. (since they don't quite fit unchanged) That way, I can save half the cds I need to use to burn them. In the past, I've encoded them into divx with good success. But of course, I can't play them back on a standalone player.

That's why I want to do vbr svcd. Also, my player is capable of playing cvd standard. Anyway, my confusion is basically about this weird vertical resolution. (weird in terms of vcd resolution) Oh yeah, my source is vcd pal, so it's 352x288. I figured the best resolution to use would be 352xXXX. But do I just stretch it out vertically like that? cuz it doesn't seem right.

help? :)

[SatStorm]

Less NTSC Region 1 players you mean...
With Pal Region 2 Standalones, CVD is the same as SVCD in terms of compatibility.
Also, any 352 X 576/480 file burned on DVD -/+ R disc gonna play. Try do this with 480 X 576/480 (svcd framesize...)

@shinakuma8: There is no reason to do this, you don't gain something. Keep your vcds as is

[shinakuma8]

The reason I want to do this is so I use less cds. I can cut down 40 cds to 20. Requires less physical space (aka my cd holders) to store them.

Now, can some one answer my question? should I used the 352x576 resolution? because it doesn't seem right.

[Boulder]

The easiest way is to make a test CD using a CD-RW disc. That way you'll see how it's going to look on your TV and you'll see if it works.

I'd say that you should choose a resolution closest to the source as the VCDs are probably already heavily compressed. I don't think that major upsizing would do any good to the image quality in this case. Also consider using a filter like Convolution3d or SmoothHiQ to get rid of some of those blocks. I don't know if Marc FD's MPEG2Dec3 (see the Avisynth forum) supports MPEG-1, it also has some post-processing capabilities.

[shinakuma8]

Any guild on how to use SmoothHiQ with TMPG? It would be nice if I can use the filter to remove blocks and noise. The built in noise remover for TMPG is way too slow.

[Boulder]

I'd do the encoding by frameserving the file to TMPGEnc with Avisynth and use Convolution3d as the anti-noise filter. Read the FAQ at the Avisynth forum, it contains useful info about Avisynth. Use the search as well, you'll probably learn a thing or two. It's better to learn things by playing around with them.

[RadicalEd]

K well 2 things.
1. Yeah, 352 x 576 should seem really strange because its double the height of VCD but not the width. Basically, the dvd player just resizes it to 704 x 576 on playback, the half resolution is to up the bits per pixel and therefore the encoded quality.

and 2. 100 minutes on one CVD will look like crap because it will be a bitrate of about 900 kbps. You prolly shouldnt attempt this unless the quality is absolutely irrelivant.

[shinakuma8]

well, the thing is since the source is vcd, it's not great to begin with. And you are right, the average bit rate is 1000. But since it's VBR, not that bad actually, consider the original source was only 1150 for the vcd.

I just figured out how to frameserver with convolution3d, so hopefully, that will remove some noise in the vcd source. Now the question is, if I encode to 352x288, would the svcd play? Or should I encode it to 352x576. Of course 352x288 is much better because it's less pixels and it's the same as my source.

[WarpEnterprises]

Another "x" type besides 352x576 is encoding mpeg1 VBR 352x288, which would fit exactly for your problem.
I make such xVCD quite often and have not found a DVD-player NOT capable of playing VBR, at least if you stick to a min bitrate of ~500 which is required for quality too. Depending on the source(DVD, and/or letterboxed) you will be able to get 100-110 mins, even if you use a sharpening resizer.

[RadicalEd]

right, but vcd and svcd are very different. First off mpeg-1 was built to perform well in the 1-2 mbps range at lower resolutions. Mpeg 2 was built to perform at 2 and up and with higher resolutions. And 1000 kbps for twice the pixels would be like encoding it at the same resolution at 500 kbps.
Hmm..
damn, I dunno what to tell you to do... hmm... maybe just find out if VBR mpeg-1 will work on your player and re-encode with some filtering. Yeah, that'd probably be the best thing.

[shinakuma8]

here's an update for everyone who might be interested in how it turned out for me.

I ended up encoding the svcd at 352x288 resolution. 500-1500kbps max and min range with average around 980kbps because I dropped sound to 192kbps. I can perfectly fit 2 episodes on each cd without wasting any space at all. And after I added menu support, the svcds played back flawlessly on my Apex dvd player.

I turned off convolution3d because it didn't really improve the image at all for some reason. When played on PowerDVD, you can notice the degration in image quality. But when played back on TV, you really can't notice too much difference between my svcd and the original vcd.

anyway, I guess mission accomplished. Although I guess it probably won't play on many standalone players. I got lucky, that mine will play almost anything. :)

thanks for all your help and input.

[RadicalEd]

cool that it worked :D