Resolution vs Quality

[lpvtech]

People say that Higher Resolution loses quality in your encodes... But I don't understand... Resolution brings in finer details..Doesn't more details mean more quality?
Why are they kind of inversely propertional?

Also, what is the best resolution to encode "The Lord Of The Rings"
I need excellent quality... Each movie is on an 8GB DVD. My preference would be to put all the three on a single 4 GB DVD-R or an 8 GB Dual Layer if 1490MB Encodes are going to loose quality...Because,as you know, each movie is about 4 hrs long...

Thanks in advance...

[aabxx]

Just choose a high one and you'll be a happy camper, if you go for the dual layer DVD. High resolution and 3 x LOTR on single layer DVD won't work out well.

[check]

The idea when people say "high resolutino = low quality" is just that higher resolution means more information to encode. If your resolution is too high, you will end up with a blocky mess. If your reso is too low, you'll end up with a blurfest. There's a happy medium somewhere for your chosen bitrate.

[DarkZell666]

Well, there is "high" resolution, and there is "HD" resolution. Not quite the same thing ;)

"HD" resolution makes artefacts look so small compared to the rest of the picture that the bitrate increase isn't proportionnal to the resolution increase (nor is it to the diagonal size increase) for a given visual quality. Actually "mid" resolutions (DVD-resolutions ?) are the worst of all imho (I'll be frowned for saying this xD), since the artefacts are "in average quantity" and "of average size", which makes this "average-watchable" (:p) if you're trying to fit your video to a "smallest-possible-target-size" (which not everyone tries to do).

Downsizing gets rid of more macroblocks but blurs the picture a bit, upsizing doesn't create more detail but makes the artefacts proportionnally smaller to the information actually on the picture.
I prefer downsizing myself and have voted in that direction, and another cause for this (other than my visual preference) is that my hardware doesn't handle HD-resolutions very well :)

[Sharro]

My Star Wars Ep I to III and Matrix I to III on a DL-DVD.

They were all anamorphic encodings (just cropped black bars) and I used Teegedeck's >90%HQ preset.

I used Enc as suggested in Teegedeck's Xvid Presets thread and adjusted the filesize to have a balanced % between the 3 movies.

If you're talking of the Theatrical versions I would make a guess that they will fall within the >58% Preset that for an anamorphic encoding will have a very pleasing result, depending on how it compresses you may also try a different cqm. You'll find many interesting tests and opinions in the Xvid forum.

This is one of the "3 on a DL" that I want to play with next.

Just my 5 cents.

Sharro

[aabxx]

Anyway, you're asking beginners questions. As such, you should be testing/should already have tested the basics, because that's how you'll learn the basics. Within minutes, you could've seen for yourself what high resolution/low bitrate does, and the opposite, and with enough testing you would've established for yourself what balance is right for you.

[shon3i]

I prefer to keep original resolution, only crop black bars if is need (2.35:1 movies). From my testing lowering resolution not help much to encode looks much better, because resizers destroys and smooth picture very much, but mid resolutions (640x) are acceptable

[Blue_MiSfit]

Indeed. I despise resizers, and try to not use them when encoding. I will over-crop to MOD16 and encode anamorphic most of the time.

Of course, my backups fall into two categories, 1/4 DVD+R (~1100MB), or 1/2 DVD+R(~2200MB).

If you do 1CD (700mb) encodes (why????), then it's frequently difficult to keep full resolution and avoid bad artifacting. Of course, "bad" is highly subjective. I'm a quality nut.

In your case, you are trying to fit about 9 hours of complex video in 4 GB (or 8GB possibly). That's a tough bill.

I'm a big fan of keeping AC3 audio whenever possible, but you can save 100-200mb by re-encoding to multichannel AAC, if you don't plan on using a home theater reciever to decode your audio.

It also depends a lot on what codec you use. XviD (in my opinion) is better suited to high bitrate, high quality encodes, and x264 works better on low to medium bitrate. Not to say that x264 cannot do high quality, high bitrate encodes, but it's inherent denoising characteristics can make grain preservation difficult (which is usually a priority of mine, since I like film grain). These characteristics can be avoided or disabled by the usage of specialized parameters, careful avisynth filtering, and CQMs, but these methods require lots of testing and tuning. I find it usually easier to splurge on extra bitrate, and just use XviD with a good CQM :)

I bet with some good filtering, you could put all 3 LOTR movies on a DVD5, with AAC audio and x264 at full resolution. It would look great on an SDTV no doubt about it, but on a good PC LCD or CRT, you're not going to love it. This could be helped by having ffdshow in your filter chain, with it configured to resize to your screen resolution and add grain to mask any artifacts and fake details (a GREAT trick that I use all the time with my old encodes that I'm too lazy to re-do :D)

If you really want to preserve the full cinematic impact of these magnificent films, then splurge on a DVD9, keep the AC3 audio, and do high bitrate, with either XviD or x264. It would probably fall in the mid to high bitrate category, and both codecs are very good.

Of course, you could always just be absurd about it, and dedicate a full DVD5 to each movie, filter them with LSF or SeeSaw, and use XviD with 6of9 :D

What a fun project. I've got to try it some time!

~MiSfit

[lpvtech]

I agree with your Suggestion on XviD and x264.. I have also tested it and XviD works excellent at about 1500 Kbps(better than x264).
I have decided to go with DVD9 (Dual-Layer)... Also,
if I have to avoid the resizers, I end up in streaching.... So I have to stick to Lanczos or Spline( I'm not sure about that yet)...
Also, why AC3? I could use an MP3 VBR at 144 and save much more room for the video. Right? When there is going to be no difference in a non-home theatre system and on my computer....Right?
So I think I can stick to MP3 VBR since I'll be using AVI where I can't use AAC. Also, about using x264 and encoding all of it to one DVD5.. Will it look good? I wan't the max quality... So I think XviD with MP3 VBR on DVD9 is te best choice... Since the extended editions are each almost 4 hrs long..

[Sharro]

You don't have to resize if you crop the black bars and set the aspect ratio flag on Xvid decoder, AC3 will give you 5.1 audio and that's the reason to use it.

You should test first before anything else, again I repeat, this forum has a lot of valid advices :search:.

All the best,

Sharro

[Blue_MiSfit]

Ouch. 4 hours per movie? That means 12 hours for the whole series. Ouch indeed. Consider the MP4/MKV containers, as they will let you use AAC. This is only an issue if you have a 5.1 speaker system. If you have a 2.0 or headphones, then by all means use LAME MP3.

[lpvtech]

Hey, Thanks a lot for all the advice.. Now I have finally decided the way to go and one of my encode it already over.. It has excellent quality.. I could only differentiate from the original by checking the intensity of the grain... It is so hardly noticable...

Used Options:
Codec: XviD
Unrestricted Profile..
Q-Pix, No GMC, No Adaptive, No Interlacing, No Packed Bitstream, Trellis, Keyframe Int : 240, Others left to default..
with Lame MP3 VBR Q4. Excellent overallstuff with no resizing and set aspect ratio to 16:9 in XviD.. Thanks a lot to all, and special thanks to Sharro and Blue_MiSfit... But one more question... is 60% Quality Ok.. when using compressiblity test.. Or should I resize to increase the quality..

[Sharro]

Did you get those 60% with Enc ?

You did crop the blackbars didn't you ?

I can't remember the defaults for MSP and VHQ.

You should have also used Chroma Optimizer and Chroma Motion Estimation.

But...if you're happy with your results...why bother :cool:

All the best,

Sharro

[lpvtech]

Oohh... I'm sorry... I provided you with a wrong encode info of waht I did.. I actually had the LanczosResize on my AVS Script..
To 720x304..And I also had VHQ for B Frames.. I also had my AutoCrop in my script..
Anyway here is a summary of what I did..

Q-Pix, No GMC, No Adaptive, No Interlacing, No Packed Bitstream, Trellis, Chroma Motion, VHQ for B-frames, VHQ-1, MSP-6 Also, Keyframe Int : 240,
Others left to default..
with Lame MP3 VBR Q4.. LanczosResize(720,304) ..

The thing I did without cropping or resizing was another test script.. Just a few frames that I did.. Sorry.. I had too much of test clips to remember the exact settings... The above are my exact settings which made it look exactly like the original except for grain.

Also, I got the 60% Quality for this.. But the final encode looks excellent...Isn't 60% quality not so good one...Should I re-encode with more downsizing although I wouldn't go lower than 704?

Also in one of Test Clips , I did crop ( without using any resize) but then I got some problem.. It was not a 16:9 after I cropeed it...It still streated even after adjusting it in the XviD Encoder Options. So I had the blackbars which gave me the correct ratio without streching... Isn't it a bad way to encode without cropping....Also, I would like to know why... Does it afftect the quality of my final encode?

Thanks in advance.. There are a lot of questions popping up in my mind...

[Sharro]

All the questions popping have already been asked.

:search: :search: :search: :search: :search: :search:

Sharro

[Blue_MiSfit]

I always enable adaptive quantization. I find it improves overall quality a lot, but if your movie is very dark or foggy I wouldn't use it. Use VHQ4 if you can afford the time. It helps a lot. Also, if you're not going to resize, then don't resize at all. Don't allow a lanczosresize(...) to be anywhere in your script, even if it's not doing anything.

Your questions about cropping are common ones, but I'm feeling helpful. If you leave black bars in the encode it doesn't really hurt things. There are a few components to this issue
1) cropping pixels away always improves compressibility
2) black compresses very well, but not if a macroblock partially contains black bars and a thin piece of the actual video
3) not touching the video at all maintains macroblock alignment, theoretically making motion estimation better

*shrug* it doesn't make all that much difference... I usually just crop everything :)

Basically, if you don't want to use a resizer, and want to encode anamorphically, you need to do two things

1) crop the black bars away, resulting in a mod16 resolution. This may be difficult with autocrop.

I ususally use MeGUI to setup the basics of my scripts (loading source, cropping, resizing etc), and it has some nice options to automatically overcrop to achieve to mod16

2) Set 16x9 in the encoder, and in your muxing tool. If you use VirtualDub, it may or may not actually apply that aspect ratio flag to the AVI container. I use Matroska because (among other reasons) the MKVMergeGUI allows you to specify aspect ratios for each video track, as either a PAR or a display resolution

See, when you play the final video (AVI, MP4, OGM, or MKV), the player has to know what the correct pixel aspect ratio is, otherwise it will just assume 1:1. This information is stored in the container, and has to be specified (I think it's in the container, it might actually be in the MPEG-4 bitstream... Not sure). Once it's in there, the player (and directshow) can figure out how to properly display the video. Without this information, they cannot, and your video will look stretched.

Also, you should really consider adding some basic denoising like I suggested earlier. It will boost compressibility a lot. I like fft3dfilter/fft3dgpu on gentle settings. Example (good starting place:

fft3dfilter(plane=3, sigma=2) #basic chroma denoising
fft3dfilter(plane=0, sigma=.5, sharpen=.2) #light luma denoising and sharpening


Good luck.

~MiSfit

[lpvtech]

Well... That answers a lot... Thank You so much.. Anyway I have completed my encodes with a 720x304 resolution and it looks really good... Thanks for all your help.. Doom9 is truly the source of great people waiting to help.. Thanks again.. All the 3 in one DVD9.. Apparently indifferentiable from the original.

[Slitheen]

I'd rather see more detail and a few artifacts than less detail and no artifacts.

[Sharro]

I prefer details and no artifacts :D

Sharro

[satanius]

I did the same project, all three LOTR movies, extended editions, on one single layer DVD. I used x264, megui HQ-slow profile @ resolution 640x272. For audio I used vorbis q2, and , obviously, container is mkv. They look great on my 17" CRT, but i never tested them on bigger screen. I did that a year ago, now I prefer your idea, with full resolution and DVD9, but i would use x264 without resizing(anamorphic) and keep original ac3 sound.

[Blue_MiSfit]

Yeah... MPEG-4 is incredible.

I get all warm and fuzzy thinking about how cool it is that we can do the things we do :D

~MiSfit

[lpvtech]

Satanius, I would strongly recommend XviD over x264 for high bitrates... x264 overcomes XviD at low bitrates... But above 1100 or 1200 XviD is the best. It preserves more details and grain. x264 causes smoothening and results in lesser detailed pic than XviD.
So I would strongly recommend you to go with XviD.. It also has a better standalone compatibility. So its easier to get them on the bigger screens.

[check]

@iptech: there is no 'best', per forum rules.

[satanius]

Satanius, I would strongly recommend XviD over x264 for high bitrates... x264 overcomes XviD at low bitrates... But above 1100 or 1200 XviD is the best. It preserves more details and grain. x264 causes smoothening and results in lesser detailed pic than XviD.
So I would strongly recommend you to go with XviD.. It also has a better standalone compatibility. So its easier to get them on the bigger screens.

Standalone compatibility is no issue for me, i do all my backups to watch them on my computer. About the bitrate, well probably 1100-1200 is good enough for 640x272 encodings, but i prefer x264 for for full resolution @ 720x304. And if i'm not mistaken, avi doesn't support anamorphic and i try not to resize, just crop.

[lpvtech]

Well...As you wish... Good Luck.. But I would certainly recommend to check encoding with a 5-10 minute clip with both XviD and x264 and find what's the best for your eyes..
Also, you could go with a MKV container as an alternative..

[Sharro]

... And if i'm not mistaken, avi doesn't support anamorphic and i try not to resize, just crop.

You're completely wrong :).

All the best,

Sharro

[HeadBangeR77]

And if i'm not mistaken, avi doesn't support anamorphic and i try not to resize, just crop.

You're completely wrong :).

Well, partially only. :p
AVI as a container doesn't support PAR or DAR, yet the PAR flags are in the video stream, so it's up to decoder/player to read them and resize properly during playback.

Much more in this thread (http://forum.doom9.org/showthread.php?t=123113), and especially here... (http://forum.doom9.org/showthread.php?p=969271#post969271)

cheers,
HDBR77

[mkwin2k7]

I've read a few posts here and I have to say a firm understanding of bitrate and resolution is a must. The best tool I can think of to bring people up to speed on this is the "Gordian Knot". This app started as a bitrate calculator, but evolved into a all-in-one encoding solution. This app will show you the standards and the bounds of video your trying to code. Ultimately it depends on what you want to achieve, whether it be a Media server or jamming as many movies as you can on one DVD-R. Here's a link below to my Gordian Knot tutorial site.

http://gknot-tutorial.bravehost.com/

If you have any more questions, please post them.

This site is best viewed with Firefox, Mozilla or SeaMonkey.

[Blue_MiSfit]

Sure, I learned a lot with Gordian Knot, but I think it's a good idea to recommend a newer tool that's frequently updated to people learning about video. Hence MeGUI :)

~MiSfit

[Sharro]

I don't think the word "best" should fit to anything on this forum :D .

I started many years ago with gordian knot, today I hardly use any GUI.

Let the users choose what "truth" they will believe. Use "I prefer", "my eyes like", "I feel better using..." :D :D

Just my beginning of the day 5 cents.

All the best,

Sharro

[ToS_Maverick]

with HD-sources it's quite different

on my lcd with 1280x1024, an xvid encode 1080@q4 looks more detailed than 720@q3. of course both encodes are the same size.

[lpvtech]

Well... There are a lot other stuff to be taken into consideration.

1. The Resizer you used plays a major role. Lanczos4 or Lanczos would make the pic much more sharper at 1080p, which would seem like a more detailed encode.. You should rather try with Spline36 which is quite neutral.

2. The next factor is the LCD Moniter itself. LCDs deliver the exact picture with its full sharpness only at their native resolution. Since 1080p is quite closer to your LCD native resoultion, it might look to be a little more detailed than 720p.

3. The HD Source.. Since you use a HD Source, it should naturally look much better at a higher resolution... Since q4 and q3 doesn't make too much difference.. You should lose mch quality shifting from q3 to q4.. So naturally a higher resolution would bring you finer details..

[DarkZell666]

3. The HD Source.. Since you use a HD Source, it should naturally look much better at a higher resolution... Since q4 and q3 doesn't make too much difference.. You should lose mch quality shifting from q3 to q4.. So naturally a higher resolution would bring you finer details..Would you mind making this statement more understandable ? I sense a misconception right here ... (unless you didn't write down what you intended of course :))

[lpvtech]

I'm terribly sorry.... I missed the "NOT"
Originally Posted by lpvtech
3. The HD Source.. Since you use a HD Source, it should naturally look much better at a higher resolution... Since q4 and q3 doesn't make too much difference.. You should NOT lose much quality shifting from q3 to q4.. So naturally a higher resolution would bring you finer details..