Choosing VCD or SVCD

[Freek]

I was wondering if anyone knows when to use VCD or SVCD?
I know SVCD has higher resolution and takes up more space but I want to know if there's a way to see if the movie source is good enough for SVCD.
For example when the movie is encoded as mpeg-1 i'm assuming VCD is the best way to go but what if the movie has a resolution of 640x480 and is encoded with Divx?
Is there a guideline that states if the movie is below a certain resolution or encoded in a particular way SVCD over VCD is just a waste of space.

[jagabo]

It's a judgement call. If the video is much over VCD resolution, and you care about the resolution, use SVCD.

It's also a matter of running time. If you need an hour of video on one CD, use VCD. An hour on one SVCD will usually look pretty bad.

In NTSC countries you also want to consider frame rate. A 23.976 fps source will be converted to 29.97 fps VCD by repeating every 4th frame. SVCD can use 3:2 pulldown instead and will play more smoothly.

[jman98]

Jagabo's answer is excellent. If you know what you are doing and have access to something like CCE, you can get away with lower bit rates for SVCD and increased playing time because the encoder is so good. I was once given a sample clip of a rather extreme example where a guy used CCE to shrik Kill Bill Vol. 1 down to one CD-R in SVCD format. I would say that the quality was between VCD and SVCD, which was impressive considering how much video he got on one disc.

I'd say it just depends on you. Do you want as much quality as possible? Then you must use SVCD. Do you want as few discs as possible? Then you must use VCD.

[jagabo]

There's another thing: a wide screen video might arrive as a 640x272 AVI file. If you encode that to SVCD non-anamorphically it you will have an MPEG file with a 480x272 picture inside a 480x480 frame. Nearly half the frame will be black borders that compress very well. That will help your ~2600 kbps SVCD video bitrate go that much further.

[Freek]

Thanks a lot for the response.
So what you're saying is, that if the resolution is higher then that of VCD it has use to go for SVCD and if it's equal or below the resolution of VCD, it's useless to use SVCD.
I'l keep reading up about this subject, it's more difficult then I expected tbh.

[xxiangg]

I have made some DVD, VCD, and SVCD in the past. Frankly,
if it is possible, DVD is the way to go. Not just because
of picture quality. But DVD has a much better compatibility.
In addition, DVD disk is cheap enough compared with CD's.

If you want to choose between SVCD and VCD, SVCD has much
better picture quality than VCD. I transfer some VHS home
video tapes to SVCD. Even VCD suppose to be in the same
class with VHS in terms of resolution. I found transfer
VHS -> DV -> SVCD produced much better quality than
VHS -> DV -> VCD. The difference is obvevious. I only made
a few VCD's for some video clips with original resolution
arround 120x80 or so. If your original video clips quality
is good, even its resolution is 320x240, you will see the
difference between VCD and SVCD.

[jagabo]

So what you're saying is, that if the resolution is higher then that of VCD it has use to go for SVCD and if it's equal or below the resolution of VCD, it's useless to use SVCD.

That's about right. The judgement call revolves around where exactly you make the switch. If you have a source that's 360x240 it may look about the same on both VCD and SVCD.

It also depends on your player. Some players simply display the 240 lines from VCD twice (remember, SD NTSC TV is always 480 scan lines) -- both fields show exactly the same scan lines. Some will interpolate the second field to smooth out the "jaggies". If you do the up-conversion to SVCD in software you'll probably use a bilinear or bicubic filter which will be roughly equivalent to the latter.

Be aware that the ability to play VCD and SVCD are NOT part of the DVD spec. Not all players will play them. I would say most play VCD, but most do not play SVCD.

[xxiangg]

So what you're saying is, that if the resolution is higher then that of VCD it has use to go for SVCD and if it's equal or below the resolution of VCD, it's useless to use SVCD.

That's about right. The judgement call revolves around where exactly you make the switch. If you have a source that's 360x240 it may look about the same on both VCD and SVCD.

It also depends on your player. Some players simply display the 240 lines from VCD twice (remember, SD NTSC TV is always 480 scan lines) -- both fields show exactly the same scan lines. Some will interpolate the second field to smooth out the "jaggies". If you do the up-conversion to SVCD in software you'll probably use a bilinear or bicubic filter which will be roughly equivalent to the latter.

Be aware that the ability to play VCD and SVCD are NOT part of the DVD spec. Not all players will play them. I would say most play VCD, but most do not play SVCD.

Although both VCD and SVCD can handle 320x240, but SVCD bit rate
is much higher than VCD. My impression for low quality VCD is due to
its low bit rate, VCD cannot produce pictures as smooth as SVCD. I tried
both TMPGenc and Pinnacle 8. The quality of the MPGE1 is poor and you
cannot increase the bit rate to improve its quality, because VCD has its
standard bit rate.