AnimeSuki Forums

exedore · 2004-01-28, 04:26

Quote:

Originally Posted by Fntc

Also any hope of using DVD sources? The remastered video on the DVD box is great. ^_^

I hope not, the reanimated sequences stick out like a sore thumb. I watched a couple episodes of it and just sat there going "crappy cg pan, crappy cg pan, they changed that, what the hell happened to his character design, crappy cg pan..." etc. The whole reanimation thing is almost enough to make me not want to buy an R1 and just keep my LDs.

Fntc · 2004-01-28, 05:24

Quote:

Originally Posted by exedore

I hope not, the reanimated sequences stick out like a sore thumb. I watched a couple episodes of it and just sat there going "crappy cg pan, crappy cg pan, they changed that, what the hell happened to his character design, crappy cg pan..." etc. The whole reanimation thing is almost enough to make me not want to buy an R1 and just keep my LDs.

The problem with CG pans is that they move WAY smoother than the rest of the action... Coming from film the 24 fps framerate makes it not as jarring. I wish they'd stop doing 60-field-per-second (or even 30 fps) animation and stick with the 24fps paradigm, even if the pictures never touch actual film.

Unfortunately capturing stuff made for 30fps at 24fps doesn't work real well and makes the pans a bit uneven. =( You just can't win.

satsuke · 2004-01-28, 18:56

Quote:

Originally Posted by Fntc

I hope you're setting it to maximum quality encoding. Realtime MPEG-2 encoders can be pretty poor in the limited bandwidth that DVD allows (just under a measly 10Mbps max). The tiny artifacts that you get from this form generational artifacts when you go to the MPEG-4 encode. You're always going to lose something from the intermediate MPEG-2 step, but if you set it to the maximum possible quality you can mimize it pretty well.

LDs do indeed yield about 400 lines of square horizontal resolution without any filters, which works out to about 532 horizontal pixels on a 4:3 display... but these are not actually PIXELS. It's actually a gradual falloff. Good LD players have a high-frequency-gain circuit that boosts the falloff curve into more of a sudden cliff, and then applies noise reduction to compensate for the poorer SNR of those frequencies. It's basically the same thing as the "sharpness" control on your TV but it's tuned to only boost frequencies where there is actual information salvageable. (With the advent of pixel-based systems like DVD, high frequency gain has been much maligned since it just worsens image quality on DVDs... ...but the technique is there for a REASON because analog formats dynamic range falls off at high frequencies).

In short you can actually get something closer to 570 horizontal pixels of meaningful data. Most LD players with digital framebuffers output at the same resolution as DVD just to be on the safe side.

What's really killing the image quality though is the vertical scaling. It's REALLY messing up your chroma resolution hardcore. This is because you're doing TWO scalings of your chroma res. LDs do perfect vertical luma and chroma res at 525 scanlines (480 to 481 usable). By capturing to your DVD recorder, MPEG-2 is scaling your vertical chroma image to only 240 lines (MPEG-4 does this too!), and when you scale it in MPEG-4 to 384 you're actually only getting 192 vertical chroma pixels. What is also happening here is you are getting scaling artifacts from performing two scale operations on the chroma instead of one.

Coupled with the interlace artifacting (which is still happening, although it's heavily minimized due to what appears to be an EXCELLENT deinterlacer on your DVD recorder) and the lost vertical luma resolution, it's really hurting your image quality. ^^;

Well, I'm not seeing artifacts worse than really anything else in MPEG-4 at that resolution/bitrate. So it's not a problem. Really you should go to at least 640x480 though and jack up your bitrate to compensate though. The video is always going to suck somewhat since it has to be limited to the relatively-crummy bitrates that are transportable over the 'net (if I had my way everything would be lossless

) but you could be making it look a lot better.

Also any hope of using DVD sources? The remastered video on the DVD box is great. ^_^

While I have seen a DVD rip of the new R2 DVD, it also happens to have the new retouched animation that has caused a little controversy <We've played the game of "improved video" .. TokyoPop used <and credited> our subtitles on the commercial release of Initial D, but proceeded to mangle and mutilate the video with the "tricked out" version>.

As it is we have an entirely analog based capture mechanism and for this series, which for us is largely in the can <we have finished versions up through the 60s and scripts up into the 90s> .. don't see changing the source anytime soon.

There is also the issue of taking DVD rip / compressed once sources and recompressing them again .. which would be a minimum of 3 full recompressions and 1 RGB to YUV conversions. I am looking into using the Matroska container format, but at this point I don't see the granularity of control over font and placement available in MKV as we do using our current systems.

As far as the cumulative effect of filters and resolution, you are correct, DVD recorders / DVD in general only use 1/2 of the horizontal chroma information. At this point the end result of DVDr to AVI is an acceptable trade off, the reasons for scaling to 512/384 have been talked about elsewhere ,. for my intermediate runs for the next 4 episodes I've been scaling to 640 / 480 from 704/480, but still haven't decided on how to proceed.

The actual number of horizontal lines of chroma encoded is somewhere above 192 .. given that the decompression filter from DVD to AVI is going through the corresponding approximation of the dropped chroma phase.

As far as deinterlace filters, the DVD <i've learned> is encoding interlaced, it's the deinterlace filter built into a specific version of HuffYUV that we've been using .. if you care .. we've had a good deal of luck with huffy as a intermediate step up until recently .. a newer version was installed and hence generates a jumping effect seen in unreleased encoding runs internally>.

The eventualy point we want to get to is capturing directly to HuffyUV rather than DVDr .. but at present we are still identifying capture boards that are up to the task while maintaining color fidelity.

As far as artifacts with the scaling process .. I personally see more compression artifacts in space scenes and the like when using the larger sizes and thus the smaller resolution is better for this purpose.

The observation that bitrates are a bit low is correct .. the newer xvid builds I have used have a small applet that shows the bandwidth XVID wants to use .. for most video tasks it wants to use 3000+ kb/s for even simple sequences.

Fntc · 2004-01-29, 00:25

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