Optimal 2-pass VBR settings

[CU]

Hi there

I'm relatively new to the whole encoding scene, as well as to these forums, so please forgive me if these questions have already been posted and answered in the past.

Having recently purchased a DVD player, I've gotten into the habit of converting DivX movies to SVCDs so that I can watch them on my 74cm TV instead of a small computer monitor. To date, I've been doing this by splitting up the movies into 2 or 3 parts depending on the length and creating MPEG-2 files encoded at 2520kbits to burn onto 80min CD's.

This results in a great quality image in the DVD playback and doesn't take too long to encode, but I've noticed that high-motion scenes do tend to get quite blocky/noisy and the quality suffers as a result. Having browsed these forums a bit, I've gathered that the way to deal with this is to use 2-pass VBR, which although approximately twice as slow will deal better with the high-motion scenes.

What I wanted to ask is, what kind of settings do I use in the 2-pass VBR parameters to achieve the same kind of visual quality as I see in CBR, even in motion-rich scenes? (I'm using TMPGEnc)

Encoding time isn't a problem, as I usually leave it running in batch mode overnight. Also, if someone could tell me what the difference between using 2-pass VBR with various parameters and CBR with the Highest quality motion search mode enabled is?

Thanks in advance,
CU

[bugster]

If encoding a 2520 CBR gives macro blocks on high motion scenes, VBR with 2520 max (SVCD spec) is not the answer. You will still get the same macro blocks as the max data rate cannot be exceeded. (Actually TmpGenc does exceed it sometimes, but only slightly and for a few frames). To get rid of macro blocks you could try several things.

1) Check the soften block noise checkbox
2) Increase the bitrate (hence producing a VSVCD which may not play on your player)
3) try CVD, slightly lower horizontal resolution, hence requires slightly less data per frame than SVCD. Search forums for details.

With any of these, VBR or CBR will do, VBR will simply allow you to get more data per disc than a CBR encode at the same rate as the max in a VBR encode.

Hope this helps

[CU]

Thanks for the reply and the tips, I'll give them a try and dig up some info on CVD's.

[CU]

As a matter of interest, COULD someone tell me what the difference between CBR with Highest Quality motion search and 2-pass VBR with a high average value is, besides the difference in file-size?

[wulf109]

I use 2-pass VBR at 2250 average,4500 maximum.0 minimum. I get no macroblocking. If you want to use 2520 as your average then set the maximum to 5000.

[snowmoon]

Using those values will result in SVCD that is unplayable in the majority of SVCD capable players.

[wulf109]

Works fine in all four of my DVD players. If your concerned just makea test recording.