multipass settings

[c.pugwash]

I have managed to follow the guides to create a single pass m2v file with cce, and the picture looks good on a 32 inch widescreen but say later I got a plasma screen would it still look good ? would I get better results with a 3 or 4 multipass?
Does anybody know any good settings for doing a multipass.

thanx

[FORC3]

The more passes, the better the quality you get.
Try 5(+) Passes and you´ll get good quality when using a high enough bitrate.

[wmansir]

If your staying withing SVCD specs you have a max bitrate limit (usually around 2500kbps for the video), and as your average bitrate approches that limit VBR becomes less effective.

As a general rule I use CBR at 2200kbps and above. For 1700-2200kbps I use 3 pass VBR. If I have to go below 1700, I usually bump it up to 4+ passes.

Regarding the Plasma screen, due to the limits of the SVCD format it will not look as good as DVD on a high definition screen. The low bitrate is one factor, but you also have the decreased resolution of the format. These deficiencies aren't too noticable on a standard TV, but increased resolution and clarity of HDTV will make them apparent, especially when compared to a good DVD. Of course, your computer monitor is also a high definition display, so any flaws you see in the video there will also be visible on a HDTV.

[auenf]

Originally posted by FORC3
The more passes, the better the quality you get.
Try 5(+) Passes and you´ll get good quality when using a high enough bitrate.

this is true, but above 5 passes, there isnt much differences at all.

Enf...

[bgates222]

how many hours would a movie take to encode with a 5x pass?

[Justinus]

And as the more passes, the more bitrate is likely to swing based on the max, min and avg bitrates (I set avg 2200 and max 2524, the bitrate was high up to 7000+ at some scene for a couple frames. I used 4 passes). If you want to stay in the spec, IMHO better use CBR.

BTW it takes roughly about 10+ hours for 5 passes based on which softwares and setting you use, and PC you have.

[bgates222]

IF YOU DO A ONE PASS AND CREATE THE VIDEO FILE CAN YOU THEN LOAD THE .ECL AT A LATER TIME AND DO ANOTHER PASS ON IT OR WILL IT OVERWRITE THE FIRST ONE?

[Justinus]

@bgate222

Yes, you can. However, what your so-called "video file" is vaf file in this context, not m2v or whatever video stream files. The vaf file is to contain video information of that movie before the encoding. If you want to do only CBR, you have a choice whether to create vaf file or not. But if you want to do VBR, it'll automatically create vaf file.

According to the CCE manual v2.64 it says (p.22):

"A video information file has a history of information for a plurality of times of encoding, and information is accumulated each time encoding is executed. This information improves the image quality for encoding by the Multipass VBR system."


This means that after you do one pass, you then can reuse vaf file again and do multi-pass as you like, but it'll overwrite m2v file (I assume that you're doing MPEG-2 movie). So, if you want to compare the quality or accidentally have different movies with the same name, just move it to other directories or change the output name on the setting windows.

However, the drawback, as I experimented by myself, is the bitrate distribution. When it comes across several passes, the bitrate distribution is better and better. This means that it's hard to keep the whole movie in the SVCD spec (there's another way to prevent this though I'm not sure 100% yet. You have to control the max local bitrate by setting in the Advance mode after creating vaf file. If you try to click that button before creating vaf file, it'd say it couldn't find vaf file). However, if you just want to make DVD, no need to worry about this minor issue.

Another thing, if you're using 2.64 (not sure about 2.66), there'll be a new option come out (VCD and SVCD). You don't have to worry about max or min bitrate anymore. Just do frameserving and resize the movie according to either VCD or SVCD spec.