DVD Image Compression

ReconFive · Post by **ReconFive** » 05 Aug 2005, 23:51

Ok, i'm just trying to figure out if i'm going crazy here.
Has anyone ever seen a dvd image where the motion seems to be alittle 'rough', and not perfectly smooth and fluid? I don't mean ghosting, where there is a trail left behind the motion...but just a little hint of roughness/choppyness due to poor quality video compression.

My girlfriend has absolutly no idea what i'm talking about and says i'm crazy, and everyone else i ask don't seem to notice it either.

This is a very rare artifact, but i just got another dvd that has it so i'm just wondering if anyone has any idea what i'm talking about.

Thanks.

tom2681 · Post by **tom2681** » 06 Aug 2005, 00:07

Has anyone ever seen a dvd image where the motion seems to be alittle 'rough', and not perfectly smooth and fluid?

Not very often. It's more likely to be a problem with your dvd-player than with the disc.
My Pioneer standalone is suffering from this problem.

just a little hint of roughness/choppyness due to poor quality video compression.

While losing frames is possible with Mpeg-4 codecs, it can't happen with DVD.
Maybe it could, but the bitrate would have to be extremely low (less than 3 mbits/s).

I've seen it happen once with a Lord of The Rings bootleg DVD.

On which dvds do you notice this problem ?

BTW: I guess it could also happen with "constant bitrate" dvds. Farscape R2UK dvds have this problem for example.

ReconFive · Post by **ReconFive** » 06 Aug 2005, 00:32

Well, i know its not my dvd player because i always test them in my PC as well, and there is no change. As i said, this is very rare and i only own a few that seem to have it. The ones i can think of are..
-Someone Special R3 (the one i just got

)
-Princess Blade R4 (I think its a poor PAL conversion, but it does not quite seem like ghosting)
-The Eye (Kr R3)
-Musa Uk R2 (this one is not too bad)
-Ong-Bak bootleg (understandably so)
I think there are a few more but i can't remember off hand.

Its probably just me going insane, but it drives me crazy and makes the film pretty much unwatchable. I'm just glad its so rare.

tom2681 · Post by **tom2681** » 06 Aug 2005, 00:47

Princess Blade R4

That one I can check.
I'll tell you if I find something wrong with it.

ReconFive · Post by **ReconFive** » 06 Aug 2005, 01:10

ok thanks

I actually just figured out what causes it. There are very very short little pauses in the transfer, i think just a single frame, and that's what makes the motion seem rough. If you pause the dvd and go forward frame by frame, every few frames there is a point where you press the button and the image doesn't change at all, which indicates the little pause in the transfer.

I have no idea why this would happen, but that's deffintly what it is.

tom2681 · Post by **tom2681** » 06 Aug 2005, 01:14

That's a side effect from the NTSC->PAL conversion.
You either get ghosting or pauses (jerky motion).

ReconFive · Post by **ReconFive** » 06 Aug 2005, 01:28

hmm..
Well Someone Special is an NTSC dvd of a Korean NTSC film, being played on NTSC equipment. It has no ghosting at all, but just the rough transfer caused by these frame pauses.
I know its not a PAL issue, and that its not my dvd player. Who knows

Its a shame though because i really like this film

bradavon · Post by **bradavon** » 06 Aug 2005, 12:02

It's funny how some people notice the smallest problem but others have no idea what you're talking about and can't see any problem at all.

My Dad can't see the difference between Composite and RGB, which I find am

ReconFive wrote:-Princess Blade R4 (I think its a poor PAL conversion, but it does not quite seem like ghosting)

Off topic how does this DVD fare? I'm guessing while not perfect it's still better than the woeful R1 and UK R2?

What are the extras like?

ReconFive wrote:-Musa Uk R2 (this one is not too bad)

OMG I thought this had outstanding PQ right through. I'm sure it's a proper PAL DVD (not that you didn't say it wasn't).

Tom2681 wrote:
Princess Blade R4
That one I can check.
I'll tell you if I find something wrong with it.

Same questions as Recon please? I was hoping someone would post in the Eastern Eye thread

Tom2681 wrote:That's a side effect from the NTSC->PAL conversion.
You either get ghosting or pauses (jerky motion).

And do most companies fix it? If they use an NTSC Master.

tom2681 · Post by **tom2681** » 06 Aug 2005, 12:40

Brad wrote:-side effect from the NTSC->PAL conversion.
You either get ghosting or pauses (jerky motion).
-And do most companies fix it? If they use an NTSC Master.

Of course. It's an easy fix.

You get a NTSC transfer with 24 progressive frames.
What do you do with it ?

Option 1 (Tartan):
You take the 24 full frames and try to fit them into 25 frames.
You end up with ghosting (3 out of 4 frames aren't progressive anymore).

Option 2 :
You take the 24 full frames and duplicate frame 24.
You get a slight pause every second.

Option 3 :
You get the 24 frames and accelerate the video so that "the first frame" from "second number 2" becomes "frame 25" from "second number 1".
It's called PAL speed-up.
All you have to do then is correct the pitch so the voices don't seem too high-pitched (lots of TV shows released in the UK have this problem).

-----------------------

-Princess Blade R4
-how does this DVD fare?
-What are the extras like?

I haven't watched it in full yet so I can't really comment on picture, sound and subs but:

I haven't noticed any pauses as Recon describes, although that DVD suffers from heavy ghosting and it seems to be incorrectly flagged.
It looks like a weird hybrid transfer.
Putting my progressive DVD-Player in video mode makes the jerkyness disappear.

Sound:
Japanese 5.1 and 2.0

Extras:
Donnie Yen fighting-scenes audio commentary.
Fairly uninteresting because Donnie doesn't seem to know what to say.

Theatrical Trailer.

Trailers for:
Volcano High
Bichunmoo
The Grudge
Infernal Affairs

ReconFive · Post by **ReconFive** » 06 Aug 2005, 13:56

In regards to Princess Blade, i think Tom is right about the problem being ghosting and not the rough/jerky motion. Other then that, the dvd is pretty good, but i myself cannot tolerate even a hint of ghosting. Its pretty ridiculous how sensitive i am.
I only got it because i wanted an anamorphic transfer, but i'd take ADV's non-anamorphic NTSC over Madman's poorly converted PAL anyday.

About the rough montion issue..I'm just glad i figured out what was causing it. There is no doubt in my mind that its the little frame pause i described. I think that problem is worse on the Someone Special R3 then any other i've seen.

Also there is nothing wrong with Musa R2, I was mistaken.

tom2681 · Post by **tom2681** » 06 Aug 2005, 14:03

Its pretty ridiculous how sensitive i am.

Nah, I'm allergic to ghosting too.
I gotta be, considering the size of my screen.

romerojpg · Post by **romerojpg** » 06 Aug 2005, 14:36

Is that the lovley Andrea

ahhhh

tom2681 · Post by **tom2681** » 06 Aug 2005, 14:41

Obviously

From the Live In London concert. 8)

romerojpg · Post by **romerojpg** » 06 Aug 2005, 15:26

I have that

crap picture if I remember.

tom2681 · Post by **tom2681** » 06 Aug 2005, 15:29

No. Crap picture was Live at Lansdowne Road and Live at the Royal Albert Hall.
Live in London (2000) is fine.

romerojpg · Post by **romerojpg** » 06 Aug 2005, 15:31

Ahh I have them all I think

gets confusing, I like MTV Unplugged best.

bradavon · Post by **bradavon** » 06 Aug 2005, 15:50

Tom2681 wrote:I haven't watched it in full yet so I can't really comment on picture, sound and subs

Can you comment on the parts you have seen?

Tom2681 wrote:It looks like a weird hybrid transfer.

What do you mean?

Tom2681 wrote:Japanese 5.1 and 2.0

Is the 5.1 decent?

Tom2681 wrote:Live at the Royal Albert Hall

That's the best one IMO. MTV Unplugged is great also.

I'm talking from a concert point of view. Why they decided to dual side it is beyond me. With PCM Stereo on one side and DD5.1 on the other.

I have them all also except the video DVD (the one with all the videos).

tom2681 · Post by **tom2681** » 06 Aug 2005, 16:01

-It looks like a weird hybrid transfer.
-What do you mean?

I mean it reminds me of those hybrid NTSC transfers that are half-interlaced half-progressive (which look crap on low-end DVD-Players).
Which is nonsense since we're talking about a R4 PAL DVD.

Can you comment on the parts you have seen?

It's difficult coz I have nothing to compare it to.
-It looks soft and grainy, downright blurry when there's motion.
-Subs are yellow.
-Picture is true anamorphic 1:85 (hasn't been cropped to 1:778).
-Blacks are deep, shadow detail is low (it was probably meant to look that way).
-Skin tones are good, so are the colors.

Is the 5.1 decent?

I don't have a 5.1 setup on my PC so I can't comment on that.
You'll know more when I watch it on my super-dooper Home-Cinema system.

sky75 · Post by **sky75** » 10 Nov 2005, 12:00

I can't comment on the picture quality but my Korean region 3 copy of Princess Blade has quite a good Japanese 5.1 soundtrack, which was much, much better than the region 2 stereo soundtrack I had rented previously.