Resolution for X(S)VCD

[PIPEÑO]

Hi
I have some very good quality DivX videos in 640x480. I've converted them to XVCD format in an average bitrate (i mean, comparing all the videos i've converted) of 1850 kbps CBR and in normal NTSC resolution and they've all worked fine on my DVD player.
Anyway I've been thinkin' about start converting in XSVCD.
So, my question is... can I convert these videos with their original resolution to X(S)VCD (640x480)?
And, will I get better quality image with XSVCD (with a bitrate that might be 1900 CBR) instead of XVCD?

Regards,
PIPEÑO

[Conquest10]

you can try variable bitrate instead of constant bitrate to get more out of your file. resolutions you could go with are: 352x480, 480x480, and 720x480. all of those will give you good results.

[PIPEÑO]

yeah, but, if i need to encode a certain time (mins-secs) and fit that time into a cd, i guess i can't use VBR, 'cause i won't know how much bitrate i need to put, right? (hope you understood that )

and what if i use 640x480? how will it look??

and will i get better results with MPEG-1 or MPEG-2 (using same bitrate -about 1900 CBR-)?

[Conquest10]

use this.
https://www.videohelp.com/calc.htm
some people say mpeg2 is better. i feel they are the same up to a certain bitrate.

[PIPEÑO]

yeah, i know there's a calculator (i already used it for the XVCDs i've done ). but what i said is that, how can you calculate the VBR for a video? i guess you can't, right? you can't know the final size of a VBR video, right?
that's what i meant

hope i get another opinion for the format i should use and about the 640x480 resolution

[ZippyP.]

Using 2-pass VBR gives a very accurate filesize. The size is determined by the average bitrate (and clip length), which is normally set to fill up the disk space. You also must select the high and low limits for the bitrate.

CQ VBR on the other hand gives unpredictable filesizes.

8)

[Conquest10]

yeah, i know there's a calculator (i already used it for the XVCDs i've done ). but what i said is that, how can you calculate the VBR for a video? i guess you can't, right? you can't know the final size of a VBR video, right?
that's what i meant

hope i get another opinion for the format i should use and about the 640x480 resolution

it works. if you don't believe me, then go right ahead and just waste space if you want.

[PIPEÑO]

ok, sorry, i'll try it
and what about 640x480? can i use it? which results should i get (in MPEG-1 and MPEG-2)?
and anyone else thinks that MPEG-2 is better than MPEG-1 (please read above if you don't know what i want)?

[adam]

xvcd and xsvcd are not standards, you can use whatever resolution you want. Just try it and see if your dvd player can play it or not, and whether you are happy with the quality. 640x480 actually has a 4:3 aspect ratio, which is what a VCD or SVCD would be scaled to anyway, so even though the resolution doesn't comply with either standard, its not entirely impractical.

Personally, at those bitrate I think 640x480 is way too big. You would get much better results with 352x480, and then if you used mpeg2 you would be complying with the CVD format and would be guaranteed playback on any svcd compatible dvd player.

Mpeg2 has some improvements over mpeg1 in way of quality benefits, but for the most part these benefits are not realized unless you are using interlacing or very high bitrates. Up to maybe 5mbits, mpeg1 and mpeg2 theoretically should look pretty identical at comparable settings. However, obviously programmers are going to optimize their encoders for specific purposes, so you may find that TMPGenc, for example produces higher quality 500kbit video at mpeg1 than mpeg2, yet higher quality 2000kbits video with mpeg2 than mpeg1.

[ZippyP.]

Mpeg2 and mpeg1 will give the same results for the same resolution and bitrate. If you are going outside of the VCD-SVCD standards for resolution then you will probably just have to try it and see. (What Adam said.)

[PIPEÑO]

OK! Thanks a lot y'all!