[Jay M]

Ok, I read this in the FAQ
Quote:

First what is it? Ffdshow is a filter used with your DVD, Mpeg2, Mpeg1 and most Mpeg4 codec�s. Ffdshow allows you to make changes to the video stream real-time digitally, like sharpening and denoising. It�s sort of like digitally enhancing the video, to perfectly match your system, while playing it back, real time.

It seems to me that this sort of artificial sharpening and manipulation can only degrade the quality.


Faroudja is often criticized for adding such features to there scalers. Why would we want that on our HTPCs? Is this really a videophile thing to do? It seems to me more like those audio sound settings that I never use on my Receiver like "arena", "church", "hall", "Theater"


If only a few people used it I wouldn't bother asking...but ther are many here who can't live without it!


How does FFDshow help you image?


thanks,

~Jay

 

[Murilo]

Resize is probably my main reason.

 

[ProofTech]

On my system, ffdshow makes video look more detailed than it really is. I'm definitely one of the many people who couldn't live without it.

 

[mnn1265]

Quote:

It seems to me that this sort of artificial sharpening and manipulation can only degrade the quality.

Were not just talking about your typical "sharpening" here... it may seem like it would degrade the quality but I assure you it does the opposite. Well, I won't argue the technical nuances of whether or not filters and sharpeners "degrade" signal quality or not but can only say that my eye perceives the picture as much better - to me that's what counts anyway.


I use resize (which has nothing to do with sharpening), "unsharp mask" which is a different type of sharpening, and a Lanczos4 filter (you'll have to read about that one since it's more advanced than just "sharpen" that you typically use).


You have to try it to see the difference.

 

[madpoet]

Remember that you're using it on an image with source properties of (for NTSC) 720x480. And typically you're using it in conjunction with a larger display. So there's going to be image scaling involved somewhere whether you like it or not. Taking that into account, you want the best possible scaling you can get. And you also want to be able to do things like clean noise out of poor sources, or sharpen the image after scaling, or whatever. Unless you are displaying a 480p image at 480p, you're already messing with it

 

[Jay M]

Thanks, that is helpful.


I may give it a try!

Quote:

Unless you are displaying a 480p image at 480p, you're already messing with it

So I suppose with FFDshow, I am able to define how I mess with it?


~Jay

 

[madpoet]

Precisely

 

[mnn1265]

That's the best description I've heard of ffdshow yet...

 

[Kram Sacul]

The resize option is invaluable for getting as much quality from a dvd possible. The sharpening stuff will rot your eyes.

 

[madpoet]

As always, it's a matter of opinion

 

[Bryan withaY]

I wouldn't be using a HTPC if it wasn't for ffdshow. I wouldn't want to be without it now.

 

[SicteR]

Quote:

Originally posted by Bryan withaY I wouldn't be using a HTPC if it wasn't for ffdshow. I wouldn't want to be without it now.

I agree.

What puzzles me is why do we know so little about Milan. I saw a post of his over at sourceforge forums where he said he wished he had a P4 3.2Ghz to test some stuff on. I understand the opensource concept but this man has deserved NASA's computers being handed to him.

 

[Karnis]

I use it because everyone else around here does, and I'd get called bad names if I didnt.

 

[Sergei Esenin]

Milan does take donations for his projects, if anyone's inclined. Hook the man up with faster hardware, and maybe he'd add even more intensive features.

 

[Bob Sorel]

I've never quite understood the fascination with ffdShow, and with the CPU overhead it adds, I don't know why people aren't searching for a way to do without it. Isn't resizing the same thing as scaling? What is so special about ffdShow's resizing?


Q: Any filter that is used in the processing of video signals is altering the original signal (obviously), so why would you want to do that?

A: Because it makes the video look "better".


In the audio world, equalizers have been around for years, but people try to avoid them like the plague, despite the fact that they can be used to make the sound quality "better" and more appealing. Why are equalizers so frowned upon with audiophiles, yet video post processing is considered essential by videophiles?

 

[JinMTVT]

Maybe to start with, audio has almost always been in analogue where

any type of filters will have benefits and cons ...


now with the digital aera, even in audio we are starting to see more and more DSP processors with digital crossovers without limitations, digital filters, and all that, without degrading the source

( as u will always need some kind of room corrections to get the best sound, and it now can be done without almost degrading the quality of the sound )


wich video, the same applies.


Yes everytime you use some kind of filters u loose the base quality of the source, but now at least we have control on how we are loosing that quality ahha


with the resizing, the point is to bypass the cheap hardware resizers from the video cards, and use completly controllable software for this operation.

It usually equals to better quality as the end result.

+ u can introduce some add on filters such as sharpening while doing the resizing ( scaling or whatever u want to call it )



Resize is a MUST for peple driving digital displays , when u can get 1:1 mapping with the HTPC ..


And of course removing some noise and such can be done with software good enough not to loose much other information !

 

[Bob Sorel]

Thanks for the info, JinMTVT. What tests have been run or evidence discovered to prove that the resizing function of ffdShow is in fact any better than "the cheap hardware resizers"? And how about when the hardware resizers are used in conjunction with PowerStrip? It seems to me that PowerStrip has much more refined control over "resizing" than is available in ffdShow, so why not go that route? I'm not trying to give you a hard time - I'm just trying to understand.


BTW, I have used ffdShow, like a lot of others here, but I just don't see the huge improvements that others notice. Maybe it's because I have an analog display device (9" CRT front projector), and not a digital display?

 

[ferrisg]

Read posts by Blight in his Inmatrix forums or in the doom9 forums by many of the developers working on avisynth filters (which ffdshow now supports an uses some of their technology).


Generally, the video scaling done by overlay or vmr9 is of quite poor quality, and vmr9 is especially prone to bugs in its resizing algorithm. FFDShow allows you to chose the resizing algorithm (more complex = more overhead. . . ) so you can get the best possible quality of the scaling process. You can also try to sharpen excessively blurry transfers, or smooth out transfers with bad ringing (such as T2). There are some other options such as digital keystoning, but this is fairly buggy (at least the last time I tried it was). It allows for level correction to prevent white/black crush due to improper video level output from a video card, and it also allows for using any deinterlacing plugin you desire (most of which are better than those generally available with DVD decoders).


Those are the reasons I've experimented with ffdshow.

 

[Sergei Esenin]

Quote:

It seems to me that PowerStrip has much more refined control over "resizing"

Powerstrip doesn't resize anything, it just sets resolutions. Your video card and/or software is what scales the video to that resolution, and the algorithms used are more simple than what's available from ffdshow. For a quick and simplified overview of the most common methods, click on the picture here:

http://www.videophile.info/Editorial...EE/Page_01.htm


The most common scaling used when you don't tinker at all with display settings that affect it is closest to bilinear, which as you can see isn't the most appealing. Ffdshow allows you to choose even better, more customized forms of scaling than even the "simple" Lanczos or bicubic scaling shown in the image. You can choose with fine-grained control.


The issue is even more complicated for digital displays than it is for versatile CRTs, because if you don't feed the display its native resolution then the display will further use its own simplistic scaling. So, scaling to the display's native res using ffdshow sometimes substitutes one high-quality scaling step for two low-quality scaling steps.


And that's just the scaling issue. Ffdshow also has options for many further image processing filters which will appeal to different people based on personal preference. Some people may like slight denoisers to reduce grain or background noise, while others might prefer a filter to reduce the appearance of EE, while others may like a slight unsharp mask. Possibilities for fine-tuning to one's tastes are endless.

 

[madpoet]

And Bob, there have been some A/B comparison posts in the past as well. Certainly there is a definable difference with FFDShow and without. It's really all about control.