MY BRAIN HURTS - just what the hell has happened to my vcd?

[EddyH]

OK, I had thought I was fairly experienced with all this VCD stuff, regularly getting good quality xVCD output of around two hours+ on a single 80m disc (or three hours even - I'm intensely proud of my LOTR1 disc), tracking down a really good sound encoder (better than anything listed here but really slow ), making de-titled nero menu screens without needing the faker font, still-pic music tracks, getting into DVD styled discs with VCDEasy, etc...

but...

something recently happened that's got me stumped. I'm getting really odd effects on certain discs I've made recently. Most particularly a single-disc copy of Laputa, Castle in the Sky that I've been working on a while. It's worked perfectly - until just up til now, just as I've finally got my perfect bit rate and extra bits/menus on the disc!
The film will play perfectly if left alone, but if I pause it, fastforward/rewind, or search to a particular time.. some really, really weird jpeg distortion sets in. Like the colour and saturation have been so compressed that they're down to a single shade per macroblock, but the lightness is fine (however if I make my TV black & white, the changed colours still show up as blocky shades).

It plays perfectly on the PC, just goes really weird on my standalone DVD player. I remember having this problem before in the past (while making SVCDs I think, then it lingered into xVCD - can't remember how I cleared it or if it just went away). Tried many combinations of CDR/CDRW used (cheap 74 thru expensive 80), burn speed (4 thru 16), burn drive (old Ricoh and new LG), burn program (nero, vcdeasy...), actual disc setup (bare, menus, cdi on/off etc), re-encoding, playback settings..... arrrrghhh!!!

The only thing I can think of is that, as I've been using the same encoder all along - TMPEG - somethings gone Phut deep inside as we've come into 2003... tried a couple different versions of that too, currently having a go at a third (the most very recent, Plus trial version) with slightly altered setup. Anyone have any clues? Any other VCD I have, including "recently" made ones (up to mid december) and all the other not-quite-perfect Laputa tests are fine, so it doesn't seem to be the player at fault. This is really doing my head in; going to spend the hour or so needed to make some final test clips with the new version, then I'm just going to throw it to the floor and see what the replies have come in!

Currently I'm thinking, maybe there's some kind of new DivX copy protection that only lets you encode X number of times before it throws subtle ****-ups at the encoder that only show with cheap hardware. The only time it happened before was when I had other animes that were proving difficult to get a balanced rate for as well!
It's as likely as anything else.


Extreme Details:

PC - Duron 850, 192 ram, gigabyte something m/b, win98se. LG 4320 DVD/CDRW combo as main burning drive (4/8-10/32), somewhat worse for wear Ricoh 7060 as backup (1-4/6)

Progs & settings - TMPEGs 2.58 and 2.52(?) for the video (PAL 352x224 inside 352x288, at 25fps, from NTSC divx 640x352 at 24fps - "do not frame rate conversion") and multiplexing,
Cool Edit 96 with MP2 plugin for converting audio to PAL44 from NTSC48 and encoding (128 for single disc and 224k/s for experimental HR two-disc).
Nero 5.5.xxxx for VCD authoring and setup (with menu and pictures as 704x528 (menu)/576 (pic) BMPs from paint package), and VCDEasy as backup (used to make very basic disc so far, meaning to make nice professional one later when this is fixed!)

Video setup as 2pVBR, 790k average (or 1550 & 1660 for the two discs), 16k minimum with 128k audio or 0 with 224 (to keep dvd player happy, minimum 137k combined rate with tests), 2472 or 2376k maximum (again, dvd player has xVCD max of ~2650).
PAL 625 4:3 shape, auto VBV, highest quality motion search.
GOP 1xI, 4xP 4xB (25f/GOP base), can't remember if i set a max length, scene detection on.
Picture sharpened about 70 horizontal and 30 vertical with a field base (?? ), DNFRC, and source range set to start and end of DivX to overcome an odd bug that sometimes puts a load of black twice the length of the film on the end of the file. Sized as 352x224 custom centred from noninterlaced 16:9, for letterboxed widescreen output on 4:3 TV (set doesn't overscan enough for 336/etc to not produce sideboxing!).
Matrices set for animation defaults, raw YUV NOT output (movie has some *extreme* light/darks that I'd like to guarantee my DVD will properly output), Floating point DC turned on, no search by part pixel (no slow scrolls but plenty still pics), soften block noise by about 30-40 for both boxes.
Sound taken from normally very reliable, high quality external source (cooledit's GNU mp2 encoder), at 128k and 224k, as joint stereo. Error correction on 224 version. It still sounds ok at the low rate because the original mp3 was 128JS and limited at around 14.4k anyway

Multiplexed as MPEG-1 VideoCD, non standard, putting the audio onto the list first (as seems to be the way with official/pressed videocds). Burnt as fully standard compliant disc under Nero (VCDEasy didn't seem to give a rat's a$$ about standards apart from throwing up a lot of minor errors - "usually a sign of tmpgenc"!!).
Also included on disc - still screen intro-menu, about seven hi-rez PAL stills, and two distinctly unstandard tracks, combining high quality title and credits music (160-224k) with very low rate low-rez decorative stills.

Playback thru WiMP v6.2 (?), and SM Electronic 2500 DVD player. Suppose I should give my DVD software a go too (PowerDVD XP), but it doesnt like VCDs of any kind least of all xVCD...

Apart from that comprehensive list I'm not sure what else to say!

[vitualis]

something recently happened that's got me stumped. I'm getting really odd effects on certain discs I've made recently. Most particularly a single-disc copy of Laputa, Castle in the Sky that I've been working on a while. It's worked perfectly - until just up til now, just as I've finally got my perfect bit rate and extra bits/menus on the disc!
The film will play perfectly if left alone, but if I pause it, fastforward/rewind, or search to a particular time.. some really, really weird jpeg distortion sets in. Like the colour and saturation have been so compressed that they're down to a single shade per macroblock, but the lightness is fine (however if I make my TV black & white, the changed colours still show up as blocky shades).

The only thing that I can suggest is that whatever XVCD encoding settings you used this time just happened to create an MPEG that causes an idiosyncratic problem...

Currently I'm thinking, maybe there's some kind of new DivX copy protection that only lets you encode X number of times before it throws subtle ****-ups at the encoder that only show with cheap hardware. The only time it happened before was when I had other animes that were proving difficult to get a balanced rate for as well!
It's as likely as anything else.

No need to delve into conspirarcy theories. This is definitely not it.

Suppose I should give my DVD software a go too (PowerDVD XP), but it doesnt like VCDs of any kind least of all xVCD...

Strange. My copy of PowerDVD XP plays VCDs (and XVCDs) just fine...

All your settings you posted seemed "okay" (as per XVCD-ness).

Have you tried muxing the MPEG with another muxer (e.g., bbMPEG)? This is a stab in the dark but see if that helps.

Good luck.

Regards.

[EddyH]

Further to the 'few tests' i was going to do:
The critical point seemed to come in all of the different combinations of settings, when i changed the coding matrix from Default or MPEG Standard to CG/Animation. Very odd, but certainly explains why it's only happened with cartoon discs!

I'm thinking that it's a bug that's welled up in recent TMPGEncs, as I tested out a load of old anime discs i made with similar setups, and they were all fine... it appears to have gone wrong around the point i tried making batman/spriggan/laputa, anything before maybe september or august is fine feh!

Now i'm re-encoding laputa with everything the same but Matrix changed back to Default. With luck it'll all work fine without very much impact on the picture quality.... It's not that typical anyway; far too many colours, painted backgrounds, soft-edged lines on the characters, etc, probably better suited to the standard setup.

I may yet have a go with another muxer though, good idea As for it all causing idiosyncratic problems, nuh-uh; it's gone wrong with three different animes/cartoons, setup in a zillion different ways (length, style, bitrate, and so on), the only common factor being TMPGEnc and that particular setting

cheers

[vitualis]

Great work!

So you think it maybe due to the matrix settings (in this version of TMPGEnc at least)?

Regards.

[EddyH]

DEFINATELY the matrix setting.

After testing, I've gone back and re-encoded my movie in EXACTLY the same manner except for changing the compression matrix thingee (just what does it do anyway? ) from Animation/CG to Default.

After literally fifteen tries to get the computer to go through with it - many odd and novel problems as if I was fated not to make the disc - it now works beautifully! Not a hint of the previous bizarre bugs.

What did become evident was a strange change in sound sync half way through (that is, from being about 1/8th second "late" in the first half to fully synched in the second; never noticed before because the video bug distracted me), but that was quickly tracked down to how the movie originally came from two divxs i joined, and was fixed easily.

Now, I'm just wondering if this is worthy of a bug report to the TMPGEnc programmers, or if it's just something odd that's arisen with certain new encoding in the program and my particular (cheap-ass) DVD player...
And also where to get reliable 90+ minute discs, because 790kbits looks perfectly fine for the most part, but slaughters certain scenes even with VBR.. the occasional hard edge that the matrix might actually have helped on!

((another tangent - i dont know quite what where or how, but through looking at the live encode log from time to time, i think i changed something to do with the VBR somewhere and don't know how to put it back. with one particularly encode run, a lot more information was being passed - things that were normally streams of zeroes actually having numbers, like motion count, CQ adjustment and the like - and the bitrate was far more 'variable' than usual. output was sweet. now it's gone back to 'normal', a lot of the advanced stuff has reverted to zeroes, output is passably good for a 120m singledisc but not fantastic, and bitrate is varying to maybe 400 - 1500 at best, rather than 50 - 2400.. wtf?!))