Amazing discovery in capture resolutions (IMHO)

[lordsmurf]

at this res 720x576 (x288 resized remember, it saves deinterlacing which usualy makes things worse not better, in my experience),

What? Huh? Cane you try to explain this again?

If you're saying deinterlaced looks better than interlaced on a tv, then you've got problems with your equipment and/or tv set.

If you're using Divx and watching on the PC, you're in the wrong thread. This is about MPEG for TV here.

[lacywest]

I didn't read all the posts but I read somewhere ...

First I will post some links

http://www.divx-digest.com/articles/dvd2ogm.html

https://www.videohelp.com/forum/archive/t54478.html

http://nickyguides.digital-digest.com/bilinear-vs-bicubic.htm

If you capture at a size that is reasonable large and ... can handle the bitrate without dropping frames .... clarity and sharpness can be obtain by re-editing at a smaller size.

Ok I read somewhere ... capture at large resolutions and then downsize ... picture sharpness improves.

Term called ... downsizing ... I think.

I tried to find the exact article but ... it's been too long ... almost a year ago.

[Northstar]

at this res 720x576 (x288 resized remember, it saves deinterlacing which usualy makes things worse not better, in my experience),

What? Huh? Cane you try to explain this again?

If you're saying deinterlaced looks better than interlaced on a tv, then you've got problems with your equipment and/or tv set.

If you're using Divx and watching on the PC, you're in the wrong thread. This is about MPEG for TV here.

Ok yet again i resize up from x288 so i dont have to deinterlace... how many more times does it need explaining?

Deinterlaced looks better on pc, on tv it dosent make a lot of difference whether its deinterlaced or not, as the tv will interlace it if its deinterlaced, and i most assuredly do not have a problem with my equipment and/or tv set.

Im using divx on my tv AND pc, i have a standalone divx player, nowhere in this thread does it say in this thread is ONLY MPEG for tv, and i presumed this was a thread about resolutions (silly me).

Last but not least... the way i do things dosent make it the right or wrong way to do things, and your method isnt right or wrong either, they are just different ways of doing things, i am just giving my views and experience in this thread of the way i do things, which are the best way for me.

[trevlac]

@Northstar

I can't say much about your experience because I don't know much about divx. As you go thru your process, many things may change the source. I did not understand that you watched DivX on your TV, when you 1st posted.

I do know:

1) Interlaced ?x576 source has twice as much vertical resolution as ?x288.
If you watch interlaced source on a progressive display, it will not look good. The player will most likely need to deinterlace it to display it correctly. There are fancy ways to do this and keep most of the info. Dropping 1/2 the lines is not fancy. For expensive progressive HD tv's, there are expensive deinterlacers.

2) Any analog source has a limited resolution. A digital frame size of 640x? can support almost any analog you can get (short of DVD or DV). Going higher gets no more detail, because there isn't any. VHS limits at about 360 wide max.

So, if you think 720x288 is better than 640x576, I disagree. Especially, if the source was interlaced (like most any analog input), and you will watch it on a TV. If the latter is made into mpeg4 by de-interlacing the source, then the test is not good.

And I welcome you here. DivX is still a mystery to me.

[Northstar]

Yes your right x576 is twice the vertical resolution of x288, 288 doubled is 576, i may only be capturing half the frames at x288 but when its resized it looks great (to me anyway). DivX encodes a progressive output if thats what you want to do, it also deinterlaces, but in my opinion it works better doing it my way rather than deinterlacing, i do understand that a lot of people dont deinterlace because they are going to watch it on tv only, i actually do both. 640x576 also looks great, its one of the other capture res' i have been trying on and off, i just stick to what i know works for me mainly. All in all its what people are happy with, if people get good results with lower res then thats great, i just know im not happy when i compare the quality of a higher res of the same bitrate with a low res one. We are all different and without those differences what a boring place the world would be. Im not trying to anger or upset anyone here with my views on this resolution subject. Ok i'll shut up now :P

Thanks for the welcome too

[SatStorm]

OK, I did some tests with 368x576
On my asus 7700 (Nvidia WDM 1.08, the only working drivers for this card when you have w2k or winXP), 352 vs 368 gains nothing. I love this card, best quality from all I tested so far for that price

On my Hauppauge win tv primio fm, with the official (broken...) vfm drivers for win2k, also 352 vs 368 gain nothing.
But after I installed the latest tweaked bt878 drivers, the difference between 368 vs 352 was noticable.
Comparing frames from caps from the same source with old and latest drivers, conclude that:
With the old drivers, there was no dfference. With the new drivers, there is a big difference at all resolutions. Overall, better picture (and not more wrong field orders...). And, 368 x 576 is the most sharp from all! Even 704 x 576.
The problem now, is that if I don't cropp 368 to make it 352, any kind of resizing I tried fail to keep that quality in the picture. The best I succeed was 368 x 576 resizing lanczos @344x576 and add borders with virtualdub to make it 352 x 576. But the difference from a direct cap @ 352 x 576 isn't that huge this way. Almost unoticable...
Resizing 368 x 576 to 352 x 576, f*ck up the picture for good, using any kind of resizing.

I repait my tests with my kworld bt8x8a card. About the same story here, but the difference between 368 vs 352 is much with this card. Seems like 8x8a is the different older 8x8 on this...

So, the problem now is to find the best way to resize 368 x 576. The most loseless method. Personally, beyond the cropping, I can't find a way...

[FulciLives]

The problem now, is that if I don't cropp 368 to make it 352, any kind of resizing I tried fail to keep that quality in the picture. The best I succeed was 368 x 576 resizing lanczos @344x576 and add borders with virtualdub to make it 352 x 576. But the difference from a direct cap @ 352 x 576 isn't that huge this way. Almost unoticable...
Resizing 368 x 576 to 352 x 576, f*ck up the picture for good, using any kind of resizing.

So, the problem now is to find the best way to resize 368 x 576. The most loseless method. Personally, beyond the cropping, I can't find a way...

This is exactly why I posted the pics that I did. I wanted to show that when you capture at 368x480/576 that the only way to get a (mostly) correct aspect ratio is to resize from 368x480/576 to 344x480/576 and add borders to make it 352x480/576

The problem is the resizing.

Although if you ask me I see little to no difference between 704x480 (I'm NTSC) padded to 720 and then resized to 352x480 VS resizing 368x480 to 344x480 and padding to 352x480

When I say that I see no difference what I mean is that both methods seem to be about the same level of sharpness. So for me this is a good thing because my system ... both speed wise and HDD size wise ... cannot really handle HuffyUV at 704x480 forcing me to use the PICVideo MJPEG codec BUT since 368x480 is less CPU intensive I can now use HuffyUV which also takes up less space when doing 368x480 than 704x480

So for me this has been a good thing

- John "FulciLives" Coleman

P.S.
I also noticed that my MPEG-2 encoding time was much faster with the 368x480 file (with resizing and padding to 352x480) than when I capture at 704x480 (with padding and resizing to 352x480) so hey that is another BIG plus. Although I did use HuffyUV whereas I normally use PICVideo MJPEG so maybe that made the speed difference?

[lordsmurf]

Although if you ask me I see little to no difference between 704x480 (I'm NTSC) padded to 720 and then resized to 352x480 VS

Why would you pad 704 to 720 prior to converting to 352 .. I must have missed something ... that makes no sense to me, not numerically or video-wise.

[FulciLives]

Although if you ask me I see little to no difference between 704x480 (I'm NTSC) padded to 720 and then resized to 352x480 VS

Why would you pad 704 to 720 prior to converting to 352 .. I must have missed something ... that makes no sense to me, not numerically or video-wise.

I thought we have gone through this before but it boild down to the fact that with my AverTV Stereo PCI capture card (which is BT based i.e., what we are talking about) I have to capture at 704x480 to get a proper aspect ratio because of the internal scaling that the card does or the fact that it does not ... unlike the ATI or the Canopus ADVC-100 ... does NOT capture the full frame. 720x480 does not give a proper aspect ratio. 704x480 does and since DVD is 720x480 I padd it up to 720x480 with equal amounts of black on the side (I use AviSynth for this but it can be done a variety of ways such as using VirtualDub).

So you need to pad 704x480 to 720x480 before you resize to 352x480 or you get an aspect ratio error.

Of course trevlac says to use 712x480 instead of 704x480 but I've tried 712x480 and I really think the aspect ratio is not correct using that. 704x480 looks "about" right.

So for you LordSmurf ... using ATI ... it is proper to capture at 720x480 or 352x480 but this is not so with BT based cards. At least not for the AverTV Stereo and since it is BT based I think all BT based cards share this "strangeness".

- John "FulciLives" Coleman

P.S.
Using the same math I could capture direct at 344x480 and padd it up to 352x480 and get a proper aspect ratio but as we know the BT based cards capture "too soft" at that low of a resolution.

[lordsmurf]

I remember this now. Bad aspect. Gotcha. Thanks.

[FulciLives]

I remember this now. Bad aspect. Gotcha. Thanks.

Well you CAN get a proper nearly 100% correct aspect ratio but you have to "work" at it hehehe

The BT cards don't capture the full frame. If there is black on the left/right sides somehow it doesn't "see" it. The capture is picture from left side to right side. There is never any black on the sides.

Somehow it manages not to cut off the black from the top/bottom of widescreen material which is short of a miracle if you ask me hehehe

Basically the "resizing" that it does is limited to horizontal resizing hence no black on the sides of captures.

So yes it makes getting a 100% correct aspect ratio a bit tricky

- John "FulciLives" Coleman

[trevlac]

I'm sorry, but I have to but in.

The AR is due to the driver. If you use the BTwincap driver, you will get 712 pixels when you capture. Most others do 688. ATI does 704 (i believe).

A full frame of NTSC analog is 711, so the BTwincap gets real close. A full frame of DV is 720. Hence, you get black borders when you use a dv device to capture analog.

So, if you are caping at 720 or 704, on a BT8x8, you are getting a bad AR. (At least different than the source). Cap at 368 on the BTwincap is in fact closer to the source AR than cap at 720 resize to 352 on other BT8x8 drivers.

I just have to say this I read the BT878 spec. Then I found some tools that read the registers on the chip. Then I wrote a calculator that tells you exactly what is going on with your driver. I know exactly what is happening for AR on the BT. If you read the links I gave, you will see. It covers all chips.

Then again, your source could have a weird AR. So could your TV.


PS: 368 is not as good for PAL. For PAL, 704/352 is dead on for the BTWincap driver, so you are indead cropping 16 real pixels.

[SatStorm]

With my hauppauge card the difference is just noticable, to tell the truth direct cap to 352 vs 368 cropped to 352 after the encoding to mpeg, is about the same (slightly, almost unoticable difference...)

But with the kworld card the difference is huge! 368 x 576 looks better all other framesizes.
And just imagine: Both cards are using the same drivers...

Today, I gonna test something even more extreme: PAL60 capture at 368 x 480.

But the question remains: Which is the best resizing method from 368 to 352? All my tests on this issue fail...

[fmctm1sw]

With my hauppauge card the difference is just noticable, to tell the truth direct cap to 352 vs 368 cropped to 352 after the encoding to mpeg, is about the same (slightly, almost unoticable difference...)

But with the kworld card the difference is huge! 368 x 576 looks better all other framesizes.
And just imagine: Both cards are using the same drivers...

Today, I gonna test something even more extreme: PAL60 capture at 368 x 480.

But the question remains: Which is the best resizing method from 368 to 352? All my tests on this issue fail...

Wow, this turned out to be a great thread.

1] I know someone mentioned using pictures. anyone is more than welcome to use any of mine. I even have (all I think) of the original BMP files in case anyone wants to use some other fporm of compression on them. I simply ask credit be given to me. It may somehow legitimize my otherwise feeble attempts at capturing

2] My first real attempt with 368 resized to 352 was horrible. Probably more due to the fact I tried to cram 3 hours and 20 minutes of my kids' basketball games on one DVD. I used something like 2700CBR .

3] I too am struggling with aspect ratios. I think the answer may be in this thread already but I seen to have an issue when I resize to 352. It just looks little different to me. I may try the "crop" method someone else mentioned earlier.

4] I really wouldn't mind doing any specific testing for anyone. Most of my specs should be under my profile. The one channel I used for the pictures I posted has some good items for comparing resolution (IMHO).

[holistic]

Excellent methodology. Well done on this topic.
Looks like I am going to reinstall my old AverMedia TV/FM and try some of these theories out for myself.
Keep it coming .

[trevlac]

With my hauppauge card the difference is just noticable, to tell the truth direct cap to 352 vs 368 cropped to 352 after the encoding to mpeg, is about the same (slightly, almost unoticable difference...)

But with the kworld card the difference is huge! 368 x 576 looks better all other framesizes.
And just imagine: Both cards are using the same drivers...

Today, I gonna test something even more extreme: PAL60 capture at 368 x 480.

But the question remains: Which is the best resizing method from 368 to 352? All my tests on this issue fail...

You are doing some great tests here. It is very interesting that you get different results from different cards (same driver). They'd have to be different chips. What is kworld BT878a ?

You can resize from 368->352 by throwing out every 23rd column. This would skew the picture a bit. A better method is to use a complex filter to move the pixels about. I'll write an avisynth plugin to do the 1st tonight. I'm not sure if such a crappy method exists in a current filter. I would think this is what point resize does, but I'm not sure.

[SatStorm]

Pay attention boy:
Full spec, I say, full specifics of my Kworld card

KW TV878RF-PRO (878TV Rev: D)

Conexant Fussion 878A
25878 - 13
E349773-1
0316 Taiwan

Just for the info, the built in tuner is a philips all pal compatible. My tests show me that it is also Secam and PAL60 compatible.

I mostly interest on virtualdub resizing methods... I know basic avisynth, but I simply hate it.... Don't know why, can't explain it... It is a mystery of life if you ask me....

[SLK001]

...he mentions a filter in the TV tuner driver that cuts in at apparantly 365 lines of vertical resolution...

352x480
364x480
365x480
366x480
367x480
368x480

He talks about the vertical resolution, and you are testing the horizontal resolution?

I think that the problems are in the capture card, and not in your files. Some cards require resolutions with multiples of 16. This is why the horizontal resolution of 1/2 D1 is 352 and NOT 360 (which is half of 720).

Also, some color spaces require resolutions in multiples of 4, which most of your capture resolutions violate. Your software may be interpolating your captures and not doing a very good job.

[trevlac]

...he mentions a filter in the TV tuner driver that cuts in at apparantly 365 lines of vertical resolution...

352x480
364x480
365x480
366x480
367x480
368x480

He talks about the vertical resolution, and you are testing the horizontal resolution?

A typeo. We are talking about the width of the screen.

I think that the problems are in the capture card, and not in your files. Some cards require resolutions with multiples of 16. This is why the horizontal resolution of 1/2 D1 is 352 and NOT 360 (which is half of 720).

Also, some color spaces require resolutions in multiples of 4, which most of your capture resolutions violate. Your software may be interpolating your captures and not doing a very good job.

Well, I thought multiples were more a function of the subsampling and codec. YCbCr 4:2:2 would require 2 pixels since data is stored in 2 pixel blocks Y1UY2V as an example. MPeg codecs would indeed require 16 pixel blocks. I believe Pic MJPeg will let you go to 2 pixel intervals with YUY2. I'm not sure about Huffyuv. Anyway, a test of uncompressed YUY2 should let you see some results. Some drivers may also limit your options. BTWincap lets you have an amazing number of options. He probably had to do RGB to get the odd sizes to work correctly.

Overall, I'm not sure what 'problems' you are talking about.



@Satstorm

Virtualdub it is, then.

Also, if you use virtualdub for capture, there is a tool called BTtweak (i think). It allows you to change the 'capture window' of the driver. This may allow you to cap some black border to crop. I'll take a look to see if I can figure it out. It does not work for timed captures.

trev

[SatStorm]

This fuction based on some old dscaler dlls I don't have (from the time dscaler called dtv...)

Thanks for the idea, I almost forgot that fuction. Now, where are those dlls...
When I can, I use virtualdub. On all other cases, I use virtualvcr.

[trevlac]

Here is your resizer. You need to copy the url into a new browser window. My provider does not allow direct links.

http://trevlac.us/throwAwy.vdf

It basically throws away every X pixel on the horizontal.

For example:

1) If X is a factor of Input width (divide with no remainder)

Input = 368, x=23 will output 368/23 = 16 * 22 = 352 out


2) If Input / X has a remainder

Input = 366, x=4 will output 366/4 = 91 * 3 = 273 + 2 (remainder) = 275 out

[SatStorm]

It doesn't support Opera also.... :P

Thanks for the filter, I'll test later in my house!

[SatStorm]

OK, have you ever read the chaos Theory?

Well, it snows in Athens after years, and my duron based PC (the one with the Hauppauge card, the one stable as a rock for about 3 years), total crashed, exactly the time I installed your plug in to test it!
Of course it is not your filter's fault, I think it is a conspiracy from the ATI users against me! I blame them for anything!!!
I seek revenge: Give Lord Snumf to Gargamel! Now!!!

Anyway, the next hours I have to re-install this PC, so no video tests today! It seems that the suplier unit, after five years, went to suplier's heaven... Took also all the data of my HDs...

[FulciLives]

@Trevlac

I am curious if you ... or anyone else ... can describe why I get the results I get in the pictures below:

PIC A is a screen grab of the original DVD of BATTLE ROYALE ripped to my HDD so this is at the native 720x480 DVD resolution:

PIC A


PIC B is a screen grab of a CAPTURE done direct from the DVD player hooked up to my AverTV Stereo BT based PCI capture card. The resolution is 720x480

PIC B


PIC C is a screen grab like PIC B but this time the capture was done at 704x480. I then padded it to 720x480 but I used the color RED for the padding so you can see exactly what is the capture (the middle 704 of the 720 width) and what is the padding (the red pixels on either side which total 8 per side for 16 total)

PIC C


As you can see my AverTV Stereo PCI capture card does not capture the full width of the screen. I used the BATTLE ROYALE DVD (this is the HK NTSC REGION 3 release) since it has more black on either side of it than the normal DVD. This DVD is 4:3 widescreen in case you were wondering.

- John "FulciLives" Coleman

P.S.
I guess I should point out that I am using drivers by AverMedia for my AverTV Stereo PCI capture card which is BT based.

[FulciLives]

OK well I did it again ...

This time I picked GODZILLA VS MECHAGODZILLA 2003

This is another HK NTSC REGION 3 DVD release that is widescreen but 4:3 (not 16x9 enhanced).

The reason I'm doing this second test is that this DVD has almost no black on the left/right sides of the image. There is MAYBE like 1 or 2 pixels of black otherwise it is image from left to right. As you recall BATTLE ROYAL had A LOT of black on either side of the image.

PIC A is a screen grab of the DVD after ripping it to my HDD

PIC B is the AverTV Stereo PCI card (BT based) capture done direct from my DVD player. This was captured at 720x480

PIC C is like PIC B a capture but this time done at 704x480 then padded to 720x480 by adding 8 pixels of RED (so you can tell what is the actual capture and what is padding) on either side of the image so this image is 720x480

PIC A


PIC B


PIC C


As you can tell this is VERY discouraging as the captures cut off picture information from either side of the image.

Again this is using the AverMedia drivers. I might redo these tests over the weekend using the BTwincap drivers ... assuming I can get it to install A-OK

- John "FulciLives" Coleman

[trevlac]

None of your pictures match.

This is because your driver does not capture the entire frame width. The width captured is based upon the driver. I'd guess the driver you are using does 688. You can read all about it in the link I keep posting. It even tells how to find what any driver for any card does. BTs are easier.

The BTwincap driver does 712. If you cap at 712 and pad to 720, it will match what is on the dvd.

-----
A little more detail. Your Pic may start at 720. When you play this in your dvd player, it gets converted to an NTSC signal. The frame size of this signal is 711x486. The xtra on the sides are overlaid with other signal info. The xtra 6 height is probably set as black. When you capture, your card grabs 688x480 of the signal your dvd player sent out. The BTwincap grabs 712x480. So with the aver driver, you lose a little more. How much you lose is not the issue. It is knowing what goes on. If you ask for 704, you will get the 688 stretched to 704. If you cap at 688 and pad to 720, it will match (xcept for the padded edges, but the middle will line up).

Please read me.

[BrainStorm69]

trevlac is absolutely right. The Avermedia drivers for the AverTV Stereo have a capture screen that is 688 pixels wide. I checked it myself last night using the link he's provided.

I then installed the BTwincap drivers, and immediately noticed on the test captures I was doing from my Star Wars VHS tape that I was capturing the entire width of the video frame plus a little black on each side, when the Avermedia drivers showed no black on the sides and in fact cut off a smidgen of the video on the sides.

[FulciLives]

Well that sure sucks donkey balls

Who the hell thought that capturing 688x480 made any sense!

Oh well I downloaded the BTwincap driver so I will try that and then recapture BATTLE ROYALE and G VS MECHA G and see how it compares to the DVD rip screen grabs.

THIS REALLY PISSES ME OFF TO NO END !!!

I will report back after I test ...

- John "FulciLives" Coleman

[BrainStorm69]

Let us know how things go for you. Also, you may find that your color is all screwed up after you install the BTwincap drivers. Mine was. Just had to adjust it in Virtual VCR (something I couldn't do with the Avermedia drivers).

[FulciLives]

Let us know how things go for you. Also, you may find that your color is all screwed up after you install the BTwincap drivers. Mine was. Just had to adjust it in Virtual VCR (something I couldn't do with the Avermedia drivers).

Yeah the colors were all screwed up ... mostly red and green. I finally figured out how to change that back to normal but when I start a capture it goes back to that red/green look and I have to set the default AGAIN after I start capturing. Maybe it's just a quirk with TheFlyDS but that capture program ... at least in the past ... gave me the best A/V sync compared to iuVCR or VirtualVCR.

I captured BATTLE ROYAL at 712x480 and yeah it gets the whole frame and yes it matches up aspect wise nearly 100%

I say nearly 100% because althogh the aspect ratio is 100% the image appears to be every-so-slightly shifted to the right (I padded it with 4 on each side to get from 712 to 720) and it is also every-so-slightly higher as well. I haven't done G VS MECHA G yet but I think I will try something that is 4:3 full frame next.

All this time I thought trevlac always made sense except for that 712 thing but now I see the light.

Stupid fucked up Aver drivers. I mean that is so stupid! Why set the capture to 688 blah

- John "FulciLives" Coleman

P.S.
So when I capture at 368x480 should I resize that to 352x480 to get a proper aspect ratio?