SVCD v.s. VCD

[moviebuff2]

Hi everyone

Would someone please tell me how a SVCD compares to a VCD, in terms of size? For example, from the same DVD, if I can create an MPEG (VCD) file that is 600MB, what will be the size of an MPEG2 (SVCD) be?

Thanks

[jimmalenko]

It's all about bitrate.

VCD is normally 1150kbps MPEG-1 video, 224kbps MP2 audio. SVCD can be up to about 2500kbps MPEG-2 video, and up to 384kbps MP2 audio. The filesize (in MB) is simply:

running time (seconds) x combined video & audio bitrate (kbps)
8192

So a 60 minute VCD clip would be:

60 x 60 x 1374
8192

= 604MB.

[DRP]

It's simpler than that even. Audio bitrates are nominally the same for both VCD & SVCD so that part can be ignored. The video bitrate is all that matters. It's just the difference between 2500 & 1150. A 600MB VCD would become a ~1304MB SVCD.

Multiply by 2500/1150

[moviebuff2]

Thank you both.



running time (seconds) x SVCD-combined video & audio bitrate (kbps)
8192/ running time (seconds) x VCD-combined video & audio bitrate (kbps)
8192
=

SVCD-combine video & audio birate
VCD-combined video & audio birate

=

(2500 + 384)/(1150 + 224)

=

2884/1374

= 2.098981

Conclusion: the size of an MP2 (SVCD) is approximately 2 times the size of an MPG (VCD). 8)

[DRP]

Well yeah but you will find in all likelihood that your DVD player will have dramas playing an SVCD with a video bitrate of 2500 + audio bitrate of 384. It probably won't be able to spin the disc fast enough to read the data at a rate of 2884kbps. With my particular player (Sony DVP-NS415) the absolute limit is 2500+224. If I even try to stretch it to 2520+224 (TMPGEnc's default rate for video) I get little skips in the audio every so often as the player's buffer runs out because the read bitrate is too high. You have to take into consideration the maximum permissible overall bitrate as well as the individual maximums for the audio & video elementary streams.

[Abond]

One should simply take in mind the fact that SVCD is VARIABLE bitrate video mpeg2. That is if my average bitrate is 1150 kbps for video (min.300, max 2500) it woulde be EQUAL in size for the same duration VCD (which is CONSTANT bitrate video 1150 kbps).

[jimmalenko]

One should simply take in mind the fact that SVCD is VARIABLE bitrate video mpeg2. That is if my average bitrate is 1150 kbps for video (min.300, max 2500) it woulde be EQUAL in size for the same duration VCD (which is CONSTANT bitrate video 1150 kbps).

It's all about bitrate.

[Abond]

Yeah, but the people don't understand the relation between constant bitrate and average bitrate. The fact that TMPG default is 2500 constant bitrate for SVCD they get as related to the standart, but it is not - this is only the maximum bitrate for SVCD video. I think also the audio bitrate is not tied to 224 for SVCD - it can be less or more. All the streams IIRC should not exceed 2720 kbps for SVCD.
At the end - yeah, it's all about bitrate.

[DRP]

One should simply take in mind the fact that SVCD is VARIABLE bitrate video mpeg2. That is if my average bitrate is 1150 kbps for video (min.300, max 2500) it woulde be EQUAL in size for the same duration VCD (which is CONSTANT bitrate video 1150 kbps).

Man that would be one ugly looking SVCD!! :P

[jimmalenko]

Yeah, but the people don't understand the relation between constant bitrate and average bitrate. The fact that TMPG default is 2500 constant bitrate for SVCD they get as related to the standart, but it is not - this is only the maximum bitrate for SVCD. If I think also the audio bitrate is not tied to 224 for SVCD - it can be less or more. All the streams IIRC should not exceed 2720 kbps for SVCD.
At the end - yeah, it's all about bitrate.

Yeah, that's why I said up to and then the upper limits in my post. I thought up to might imply that it can be less ie. variable.

I see what you're saying though

[Abond]

Man that would be one ugly looking SVCD!! :P

Why you think so?

Yeah, that's why I said up to and then the upper limits in my post. I thought up to might imply that it can be less ie. variable.

For me and for you it is clear. For moviebuff2 I doubt.

[DRP]

Yeah, but the people don't understand the relation between constant bitrate and average bitrate. The fact that TMPG default is 2500

No it isn't. TMPGEnc actually uses 2520 as it's default. No idea why but it's 2520.

All the streams IIRC should not exceed 2720 kbps for SVCD.

That sounds about right. I consistently make SVCD with total bitrate of 2724 and they play fine. More than that though and there are issues.

[Abond]

No it isn't. TMPGEnc actually uses 2520 as it's default. No idea why but it's 2520.

All the streams IIRC should not exceed 2720 kbps for SVCD.

That sounds about right. I consistently make SVCD with total bitrate of 2724 and they play fine. More than that though and there are issues.

Well, I really don't remember the defualts exactly. What bothered me constantly is that it defaulted at CBR.
I tested my DVD player with bitrates as high as 4500 max (video only!) and it plays perfectly, but it is ofcourse model dependant.

[DRP]

Man that would be one ugly looking SVCD!! :P

Why you think so?

Oh I dunno... SVCD @ ~1150 VBR bitrate. Try it and find out. They'll be macroblocks up the yin yang. Wouldn't even look good as a CVD.

[Abond]

Oh I dunno... SVCD @ ~1150 VBR bitrate. Try it and find out. They'll be macroblocks up the yin yang. Wouldn't even look good as a CVD.

Well, I have SVCDs with an average of 950-1050. For the time being I couldn't see macroblocks neither on TV nor on PC. I have still also one of my first SVCD made with TMPG defaults. There was macroblocking as you described.

[vitualis]

When making SVCDs, the bitrate will probably around 1.2 to 2x the bitrate of a VCD. However, remember that you are working with fixed media.

For a pretty standard movie, a VCD will require 2 CDs. For SVCDs, it will be 2 to 3 CDs.

Regards.

[whitejremiah]

ive made 1 disc SVCD's with CCE before and they turned out REALLY nice, given i was using some just rediculous amount of passes...but the point being is that it can very quite a bit...yes with svcd most people will make em 2 or 3 discs...but its not nessacery to still fit the specifications....between the two, i'd personally rather use svcd...it seems to keep more of the video details intact.

[DRP]

Like previously said, it's all about the bitrate. The bitrate will determine whether you use VCD, CVD or SVCD and the storage media you intend to use determines the bitrate.

VCD < 1600kbps
1600 < CVD < 2000
2000 < SVCD < 2500

It is generally accepted that an SVCD @ 1600kbps is about the same picture quality as VCD @ 1150 therefore 1600kbps is the lower limit for SVCD. Personally I've found that CVD looks better than SVCD below 2000 because the horizontal resolution has very little influence on how the human eye perceives the sharpness of an image on a screen, but the lower resolution reduces macroblocking which comes in to becoming noticeable once you go below 2000.

To be honest I can't notice any improvement in quality when going above 1150 with VCD, but CVD suffers a bit when you go below 1600. But sometimes I make VCD with bitrates higher than 1150 just to fill the disc space.

[whitejremiah]

yea...its kinda in what looks acceptable to you...some people are fine with vcd quality.....in which case its probably the best bet...it encodes faster and you can generally do alright with 2 discs for one movie......svcd requires more discs and a higher bitrate (due to the resolution) unless your doing some crazy stuff like what i did toying with CCE.....i would highly advise against that though, because the way i did it, it chewed up my computer's processor power for like 2 solid days...not really worth it, more of an experiment than anything.........as for CVD.....well, to be quite blatent, i havent tried it...from what i hear, its compatability with dvd players has quite something to be desired.........if your dvd player supports it though, i'd say give kvcd a stab....its basically a rather highly optimized vcd template for tmpgenc...produces pretty good quality and you can fit a fair amount to a disc with it.....but you definately wanna find out if your player supports it before encoding a ton of movies to it......