regarding resizing and some things in the resolution window..

[cogd115]

I somehow have to spend some time on resizing to get the right aspect ratio (that is as close to the original dvd as possible). I am not sure whether or not this is the case for everyone. In my case, I often find that specifying Input Resolution and Input Pixel Aspect Ratio, and auto/smart cropping it do not get the right aspect ratio. Hence, I have to check "other" and diddle with aspect ratio manually to get it as close (it gets even more tedious to get it right when I try to put subtitles in the dark area below the pic screen). Is there a more precise, more efficient way to resize such as typing in values for resolution, etc.?

Another question: what happens if w-zoom and/or h-zoom go well over 100% (therefore creeping into the "red" territory), and I go ahead encoding it? Does that affect the quality of encoding adversely? It seems to me -- intuitively of course -- by going over 100%, the encoded movie gets lager in megabites, yet should produce better qualities.. Am I right to assume this?

One more question: Let's say a movie is encoded in same pixels and bitrates.. However, suppose that I encoded it in 640x240 and then again in 704x384. Then, should the latter produce better video qualities when played in full screen thoug the filesize is bigger? If so, should I aim to get a highest width/height?

Hmm, being a newbie, I often suspect if I put the question in a manner so that people understand me what I am talking about. :) Sue me if I didn't. :D

Thanks in advance...

[Tuning]

For 1&2 Q,U don't require to follow 100% correct aspect ratios,these errors will not affect quality.The errorreneuos resolution is approximated by choosing a nearer resolution by skewing/streaching,and then it is used for encoding.Thus making little difference in width/height of ppls on-screen.:D
Thus for a particular aspect ratio,a specific frame size is presented and every thing cropped is filled to this width/height.



One more question: Let's say a movie is encoded in same pixels and bitrates.. However, suppose that I encoded it in 640x240 and then again in 704x384. Then, should the latter produce better video qualities when played in full screen thoug the filesize is bigger? If so, should I aim to get a highest width/height?

It is obvious that higher the resolution higher the quality,but if u re-encode an existing low resolution avi to larger one,no quality will increase as the details(sharpness/texture) was lost in first

[len0x]

Originally posted by cogd115
In my case, I often find that specifying Input Resolution and Input Pixel Aspect Ratio, and auto/smart cropping it do not get the right aspect ratio. Hence, I have to check "other" and diddle with aspect ratio manually...

How can you be so sure that you're not getting right aspect ratio?
I recommend you reading this sticky:

http://forum.doom9.org/showthread.php?s=&threadid=42708

It might not be an explanation to all you problems, but it will give you an idea on why sometimes you get not what you expect...

[cogd115]

Thanks for the replies, guys..

Tuning, so I take it that I can go ahead and encode mah movies from dvd in higher resolution like 800x400, which should produce better video qualities without any adverse effects.. I personally hold you responsible if anything goes wrong. :D Kidding.. I was wondering if or not encoding in, say, 800x400 is alright..

len0x, I compare the dvd screen with either .d2v screen or preview. If they match closely in size of the pic screen (width/height), I know I got the aspect ratio right -- it has been true so far. I am sure that the approach I take is not fool-proof, and there is a better way to figure out if or not I get the right aspect ratio.

I often wanna put subtitles in the dark area below the pic screen. That seems to change the aspect ratio of the pic screen when I crop the dark area and readjust the dark area below the screen and therefore make it a bit more complicated. Still, the simplistic see-if-match approach has been working for it, as well.. So far, at least..

Hey, thanks for the link. I will investigate..

[piscator]

+ 800x400 is way to much, since the DVD is at max 720x576. Make
sure to do a compressability check to get your quality right
(check guides). I recommend using 640 by whatever. That's what
a lot of people use.

+ And as tuning said. don't reencode existing files at higher
resolution: no quality improvements. Don't reencode existing
files ever, since you always loose quality with lossy file
formats.

greetz,
Piscator

[cogd115]

I got your point, piscator. The reason I was asking the question is that I am finding it quite difficult to get quality encoding out of full screen movies of the 4:3 aspect ratio, older ones usually. It seems to me that information losses of the movies far exceed those of the more recent ones even in the same aspect ratio. And, I was wondering if increasing width/height would produce better video quality. Thanks for your reply and the one to the other thread, as well.

[piscator]

Older 4:3 movies can be interlaced. If you don't de-interlace the movies are really bad compressable. Check thread forum.doom9.org/showthread.php?s=&threadid=34696 on de-interlacing. I prefer TomsMoComp.

And increasing the resolution is opposite what you want. That gives less quality, because a higher resolution needs more information to encode giving less space to encode the details. Decreasing the resolution is what you want. That's why you want to do a compressability check. It gives feedback about this. Check also the other thread you posted. There are a lot of things you can do to increase quality.

greetz,
Piscator

[Soulhunter]

And increasing the resolution is opposite what you want. That gives less quality, because a higher resolution needs more information to encode giving less space to encode the details.
But using a higher res. as the source, is still nice when you use a high bitrate too...

Maybe try mf's "SharpTools/SharpResize" ! ;)

Bye

[piscator]

@soulhunter
I meant a lower resolution in respect to targetted file size. The discussion in the other thread forum.doom9.org/showthread.php?s=&threadid=63228 seems to converge a bit with this.

And yes, the nice thing about so many standards, is also that it gives a lot to discuss. Otherwise, what would we be talking about in the forum? :p

greetz,
Piscator

[cogd115]

Thanks for the explanation, piscator. One more question. It seems that you are assuming bitrates fixed (or holding everything else fixed) when you said higher resolution will decrease encoding quality? What if I increase bitrates, pixels, and resolution in the same ratio, would the higher resolution produce inferior qualty? I am getting lost here... :D At least, I see that higher resolution does not necessarily produce better video quality. :)

[piscator]

Originally posted by cogd115
Thanks for the explanation, piscator. One more question. It seems that you are assuming bitrates fixed (or holding everything else fixed) when you said higher resolution will decrease encoding quality? What if I increase bitrates, pixels, and resolution in the same ratio, would the higher resolution produce inferior qualty? I am getting lost here... :D At least, I see that higher resolution does not necessarily produce better video quality. :)

I always target a specific filesize (which depends on the compressability check and on how much I like a movie. Crappy movies don't deserve high bit-rates :D )

So with a fixed filesize, the bitrates for the video are more or less fixed. But you can always decrease the bitrate for the audio a bit in favor for the video.

E.g., if your compressability check would return 60%, it would make no sense to increase your resolution: meaning less bits(pixel*frame). Effectively meaning you would get more macro blocking in high motion scenes.

E.g. if your compressability check would return 110%, you would get an undersized file. So in this case, it's really good to increase resolution (but not more than the max of the source).

Hitting at 80%, as the guides tell you, gets you max quality. But there's a lot you can do using the proper filters (especially resize and IVTC/deinterlace when the source requires it).

In my case, I playback movies on my TV set and resolutions higher than 640 by whatever don't have effect anyway. TV's generally have quite bad resolutions (unless of course you've a really expensive one)