Improving image quality with DoCCE4U?

[brashquido]

Hi All,

I've got some problem projects I'm looking for some advice on. Problems in that I am wanting to make 1:1 conversions of them, but in doing so I'm only left with a bitrate of between 2100kbps and 2600kbps to encode the movie with in CCE. The resulting video quality is still quite good, but there are noticable image artifacts in sections. And as I watch my movies on a 100" screen, these artfacts are quite noticable. Especially dark moving objects over light coloured backgrounds. They seem to have a dirty halo around the dark images as they move.

Obviously I can just drop the non-english audio tracks which in most cases will give me an extra 500kbps per dropped AC3 track to encode my video with. However, I'm not keen on giving up on the 1:1 idea if I can aviode it, and I was wondering if there is a way to tweak DoCCE4U so that it's optimized for low bitrate encoding? Or am I simply asking too much of CCE?

[waldok]

I'm afraid there is no miracle. The best you can do to get satisfactory results at 2600kbps is to encode up to 5 pass VBR with CCE (above 5 pass I doubt you will see any difference). I don't see any other "tweaking" possible. Allocating less bitrate to simple scenes and more bitrate to complicated ones is the goal of VBR.
Maybe you can try and play with the IMage quality settings in CCE, might improve things for certain scenes, but you shouldn't expect any miracle at 2600 kbps.

Keep in mind that this is typical SVCD bitrate range, and you will use it at DVD resolution, so more data will have to "fit" into this bitrate, which means less quality.

I also usually want to keep at least one extra audio track and subs with my movie. The solution I found was to be a bit more "tough" on extras (unless they are really worth it). I wouldn't go below an average 4500kbps for the movie itself. You can use some "1 clik tool" to figure out how much you can compress your extras so the main movie will still have a decent bitrate.

Good luck

Waldok

[69Mws]

There's also a problem if you want to really squeeze your extras down by using very low Bitrate in CCE in order to save more space for the movie.

Did you ever try using an avg bitrate of 500 or maybe 800? I can do what I want, CCE will hang up during encoding at such low avg bitrate.

I figured that ~1000 is quite a "healthy" limit (sure not for quality), but below may be critical for the encoding process.

Greetz
69Mws

[waldok]

CCE does not like too low bitrates. In this case, TmpgEnc or Procoder might be of some use. Or you encode the extras with a "one click" program.

Waldok:cool:

[Ben]

Hi,

On a remarkably similar note... If I'm intending to re-encode a DVD of Red Dwarf, to fit all 6 episodes onto 1 DVD-R the bitrate will be at about the same level as the above, approximately 2600kbps, which at full-screen 4:3 PAL resolution will end up looking pretty poo. So, my question is, as this bitrate is about the right kind of rate for an SVCD, can I resize the video in the Avisynth script to PAL SVCD res, encode as normal using DoCCE4U and then reauthor by following Doom9's SVCD to DVD-R guide?

I can't foresee any particular problems with this, if necessary I can change the resolution stored in the IFO's in IFOEdit, I think... Is this a sensible idea or am I heading into a world of pain and misery by even thinking about this?

Thanks.

[69Mws]

Originally posted by waldok
CCE does not like too low bitrates. In this case, TmpgEnc or Procoder might be of some use. Or you encode the extras with a "one click" program.

Waldok:cool:

yup, that's what I'm doing sometimes plus I can squeeze the menus also down if needed

[69Mws]

Ben:

You can do whatever you want with your AVS Scripts, but be aware that your streams will no longer be inside DVD specifications and will not be imported in Scenarsit without further tweaking (changing Header Informations with ReStream and such things), when they have SVCD resolution at the end.

Greetz
69Mws

[Ben]

Yeah, the resulting mpeg2 streams will have to be patched to fool Scenarist into thinking they're OK, and then authored VOBs will be patched afterwards... Also, it will make the DVD less compatible, but I already know my standalone can play SVCD DVD's so that's not too much of a problem.

I might just experiment a bit and see what happens, it's more fun that way. :devil:

[quinn]

You could also do 352x480 instead of 480x480 - You lose some horizontal resolution, but the video will look better at lower bitrates, and 352x480 is a legal dvd resolution.

[69Mws]

....or 352x576 when dealing with PAL, not to forget :)

Cheers
69Mws

[adam]

I have never before heard of anyone having problems with low bitrate and CCE. I can encode anything I want at 500kbits and it encodes fine. I can only speak for CCE 2.5 though.

I always resize my extra's down to 352x480 and use a bitrate of around 700kbits-1mbit in CCE. Quality is perfectly fine for extra's, in my opinion, and it leaves me plenty of bitrate for my main movie.

[69Mws]

adam:

I don't seem to be the only one to have trouble with low bitrates (<1000 kbps), others also reported that. When using "normal" bitrates, I never had such issues like freezing during processing :confused:

Anyway, how did you do the resizing? Did you implement it in the AVS Script or by checking "Half horizontal resolution" in CCE?

Greetz
69Mws

[adam]

Well if CCE has a bug in this area it hasn't affected me yet.

I do resizing through avisynth. I just edited the AVS generator in DIF4U so that it adds the resize line whenever it IVTC's anything. This pretty much takes care of the extra's for every commercial NTSC DVD, though I always check the vobs first to make sure.

[69Mws]

I wanted to try this resizing stuff with my last DVD (german R2 of Jumanji Collector's Edition).

This one has 7 Titlesets. First one is the main movie, rest is interlaced extra-stuff (PAL).

So I put the resizing parameter for "half-DVD" resolution (352x576 PAL; got the parameters for AVS from FitCD by loading one of the *.d2v's) into the relating AVS scripts (Titlesets 2-6) and tried a very low bitrate of 500 kbps.

The good thing is that CCE didn't freeze at this low bitrate. When I used that low bitrate without resizing, it freezed during encoding.

The bad thing is that however my final result is oversized (4.42 GB).

I deleted the encoded files and started RA again for new calculation, but used higher bitrate for extras (1200 kbps).

I'm curious now, if the result will be oversized again. If so, I'll try again encoding the extra-stuff without resizing and see what happens then.

Anyone else experienzed oversizing-issues when resizing some of the PGCs to "half-DVD" resolution?

Greetz
69Mws

[Fmazzanti]

I didn't try the resizing myself, but once I tried a project where I substituted extras by dummies by unchecking them in RA. The result was an undersized project by 0.5Gb or so... I would say that you can trust RA calculation only under 'nrmal' conditions (check everything at the right resolution), otherwise it won't work...

BTW I also feel that bitrates below 3000 are really poor for DVD projects. However, this also depends on the material you're encoding.
I would say PAL needs more bitrate than NTSC because of the higher resolution. Also 4:3 projects are more affected than 16:9 because they cover more area on the screen. In this way, PAL 4:3 would be the more dbitrate demanding material, whereas NTSC 16:9 would be the less exigent one. Depending on what you do, you may find the resolution acceptable or not.

In my case (I'm a PAL guy) the combo DIF4U+DoCCE4U+RA usually produces bitrates of 2500-3500 on DVD's of 6.5+ Gb (and there are many of these out there!). This has always bothered me. But then, why try to keep everything in a single DVD? One option I'm thinking about is to put almost everything on the DVD, and encode one or two (large) extras in a SVCD, let's say. With RA, the missing extras in the DVD will be replaced by dummies, such that the navigation structure is still intact, while leaving more room to the main movie.

[Grover]

would say PAL needs more bitrate than NTSC because of the higher resolution. on DVD's of 6.5+ Gb (and there are many of these out there!).

Just read your post and smiled.

I'm just ripping a project now - The Deer Hunter (PAL R4) which has the main movie just on its own at 7.56GB (no subs, one audio track, 2ch, 224K). I think I'll need to go 5-6+ passes on this one. :D

Cheers...