Low quality divx: Should i encode with higher bitrate?

[digital_frog]

I have a 512x224 Divx @ 799 kb/s that I want to convert to SVCD. I'm using the standard Tmpgenc template for SVCD but the results are pretty crappy (lots of block noise).

What I want to ask is should a) I increase the bitrate to say, 3000-3500 or should I activate the "soften block noise" option in Tmpgenc?

Btw if the answer is to increase the bitrate, do I increase the average bitrate or max bitrate or both?

Thanks for any insights.

DF

[Gazorgan]

What bitrate are you using now? Anything above 2000 average should give good results (especially since you will have to letterbox the hell out of the source to keep it in proprtion). Remember your source is most like non-interlaced and VGA 1:1 in your TMPGEnc settings.

Garbage in = Garbage out Some AVI's aren't worth converting.

[macleod]

SVCD spec 480x480 (NTSC). Your source is 512x224. You might want to just go for VCD OR encode SVCD, however, retain the aspect ratio of your source (there is a guide which explains how to do this using TMPGENC).

[digital_frog]

Thanks for the replies.

Gazorgan: I'm using the default 1600 avg with the settings you mention (VGA 1:1 progressive). I thought of increasing as well but didn't know if that would make the SVCD out of spec or create problems with SVCD2DVD which I'm planning to use to put several SVCDs on DVD. So you think 2000 might do the trick? Or should I increase even more?

Macleod: Yes, I'm encoding at 480x480 with full screen / preserve aspect ratio.

DF

[bugster]

Thanks for the replies.

I'm planning to use to put several SVCDs on DVD. ?

Macleod: Yes, I'm encoding at 480x480 with full screen / preserve aspect ratio.

DF

So if your target medium is DVD why encode to SVCD specs. Use 1/2 D1 (352 * 480) with the rest of the settings the same as for SVCD. This is DVD compliant which SVCD is not. Therfore it is 100% compatible with all DVD players (which SVCD on DVD is not) and doesn't require any patching or messing about to be accepted by most authoring programs.

[digital_frog]

I see your point. The thing is if encode as half DVD I'm maxing out the bitrate and will end up with a very big file, without much improvement to show for it in terms of quality. By keeping it SVCD I'm thinking I can fit two, maybe three of them on a DVD by using SVCD2DVD.

Also, since the resolution is almost SVCD size (at least the horizontal anyway) it seems a shame to cut it down to VCD / half DVD resolution.

[bugster]

1/2 D1 is 352 * 480. SVCD is 480 * 480. The Vertical resolution is the same. The horizontal res is a little less. Using SVCD bitrates a 1/2 D1 encode will look as good or maybe even slightly better (in some circumstances) than the same movie encoded for SVCD. And the filesize will be the same. So you can fit as many of these on a DVD as you can SVCD's. Main difference is that it is fully standards compliant.

Its your choice.

[Gazorgan]

1/2 D1, with say a CQ of 3000 should be fine. That's double your current bitrate, and less pixels as well. Do a small test encode to see (1 minutes worth). 4000 is about max for 1/2 D1 (waste of bitrate after that).

I personally use for 1/2D1 a max of 4000 and an average around 3000, with MP2 audio around 160-192 . I also do some 352x240 progressive encodes with a bitrate around 2000 that are artifact free. Again, do some test encodes and see how they look on your settop player.

[digital_frog]

Bugster: Ok, I stand corrected. So if I understand correctly, you're saying if encode as 1/2 DVD at, lets say 3000 kb/s, I'll get a better result than SVCD at 480x480 @ 1600?

Btw, what about PAL divx's? Do I do the same? Or is the loss of horizontal res too much?

Gazorgan: Ok, got it. You just answered my question. Just one thing: You mention 1/2D1 @ 3000 avg/4000 max, but progressive encodes at 352x240 @ 2000. Do you mean you do that for an interlaced source when converting to progressive or vice versa?

Thanks for the help guys. Appreciate it.

DF