Best Quality With XVCD

[kejl89]

I have been trying different formats to find which one has the best quality. My DVD player can only play VCD and XVCD so I chose XVCD because it allows you to change the resolution and bitrate. But the thing is, after trying multiple settings, I still can’t seem to get it right. When I used 720x480 as the resolution, the output file had what looked like blocks over parts of the picture in certain scenes. And I still can’t figure out which bitrate works the best. So my question is, what settings should I use to fit a 95 min movie on two 74 min CDs, and obtain the highest quality (time is not an issue.)?

[kejl89]

Sorry, I forgot to mention that I am using TMPGEnc.

[jefe74]

I use 352 X 240 resolution for xvcds. I have a xvcd bitrate calculator that I downloaded for TMPGEnc. I don't remember where I downloaded it, but if you email me, I can send it to you.

You can also look here:

http://www.vcdhelp.com/calc.htm

This is a tool on this site that might help as well.

[kinneera]

An excellent compromise on resolution is 352x480. Just be sure to set the DAR (display aspect ratio, or output aspect ratio in TMPGEnc) to 4:3.

For bitrate, do 2-pass VBR and use a bitrate calculator to figure out the maximum average bitrate for each CD based on the cut point you want. I generally use the IFO file from Smartripper to cut it somewhere near halfway through the movie where there was a chapter change on the DVD.

[kejl89]

Ok, I tried using the 352X480 resolution and the 2-pass VBR bitrate, and it is still blurry in spots where the characters are walking around. Now after seeing the calculator page, I relized that although I used the SVCD for the max (like it said) I just guessed on the min and chose like 1500 (instead of 0). Is that why it was blurry? Or should I use the Manual VBR or Automatic VBR instead? And also, does anyone have any idea why when using 720X480 resolution I got blocks in some places on certain scences?

[kinneera]

Yes, you definitely want to leave the minimum at a very low value or zero (I use 300), or the encoder doesn't have the leeway to perform its VBR algorithms optimally.

As for blocks, this is just a characteristic of MPEG (it is, after all, a block-based image compression scheme, like JPEG). The short description is that blocks are encoded with a certain number of bits, and then various frames are compared to one another to see if a matching block can be found at a different location. Then it is encoded as a motion vector, which requires fewer bits, which allows more to be dedicated to image information. 720x480 requires 4x as many blocks as VCD standard 352x480, and 2x as many as 352x480. 720x480 is rarely suitable for video under 2500Kbps, the generally accepted max for XVCD/SVCD, and is really only optimal at 7Mbps or above (hence, DVD). Generally, the target compression ratio for MPEG is no more than 30:1, with 15:1 being optimal, and about 8:1 being transparent. FitCD (an excellent bitrate calculator) will demonstrate that the effect of using 720x480 is that the compression increases to an average of 50:1 or greater even at the highest allowable XVCD/SVCD bitrate.

[kinneera]

Almost forgot to mention...352x480 will definitely look blurrier on a computer screen, but should look quite good on a TV screen.

[kejl89]

I didn't notice before, but won't encoding at 352x480 distort the movie since the normal resolution is 352X240?

[JCPicache]

i also use XVCDs, and my main goal was to have it look great on a TV (almost DVD-like) and look good on a PC.

i normally stick with 480x480, bitrate 1600-2000kbps, audio 160kbps. i've been able to fit about 70 mins on an 80min CDR.

the cool thing is, i can watch it using my home dvd player, and it looks great. then i can take it with me and watch it on my laptop and it'll still look wonderful.

try the templates available already. some of em are pretty good. or if you want, i can show you mine (altho i'm not really doing anything new here).

[kinneera]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR size=1 color=black></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-01-16 19:26:34, kejl89 wrote:
I didn't notice before, but won't encoding at 352x480 distort the movie since the normal resolution is 352X240?
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR size=1 color=black></TD></TR></TABLE>

Not as long as the display aspect ratio is set correctly. This is why 480x480 doesn't look distorted on SVCDs. (And 720x480 or 704x480, neither of which is exactly 4:3).

352x480 is often preferred for XSVCD, since it is D2 or half-D1 res, which is theoretically portable to DVD in the future.