Avisynth has better Scalers built in?

[demistate]

I was at NAB 2010 this year, a show for professional broadcasters and asked Adobe, Telestream, and Mainconcept about the pre-processing abilities in their encoding software.

Grain removal was almost non existent in their products. They recommended a simple gaussian blur to help smooth it out.

All three of the pay applications I described above use Blinear as their "highest quality" scale. There were no other scaling methods. I personally find Spline36 and Lancos4 blows bilinear out of the water.

Adobe Media Encoder, Telestream Episode Pro, and Mainconcept encoders are $1000+ encoding softwares, and Avisynth does a better job pre-processing than these "all in one" software packages do.

Pair it with a free encoder like x264 and you're outperforming the most trusted software packages in the industry. In my experience, pre-processing is 80% of the encode quality.

I'm still going to stick to Avisynth for pre-processing even if I do use pay encoders to make the final crunch.

Most broadcasters don't even know about Avisynth or x264. Most of the posters here would be able to net really good jobs at professional post houses that compress films/tv shows for places like iTunes and other digital distribution networks just from their avisynth skills.

I'm just amazed that the free tools are better than the expensive, supported, pay tools.

[Lyris]

Grain removal was almost non existent in their products. They recommended a simple gaussian blur to help smooth it out.

Seriously?



I'm not surprised that a lot of people haven't heard of AVISynth. From what I've seen and heard, the industry seems to operate on a "time is money" basis and doesn't really have time to write scripts or experiment with different filter chains. They like all-in-one hardware solutions, though.

However, there is an area where I think that may be changing. Since there are no hardware AVC encoders for Blu-ray production, a host of people who previously used hardware encoders to produce DVDs (directly from VTR playback I believe) are getting into the habit of capturing files from tape then encoding via software. I explained what AVISynth could do with that captured file to some other DVD/BD authors at a Sonic Solutions training event I attended in London last year, and got a few nodding heads. Sonic's people certainly knew of it

[Dark Shikari]

Originally Posted by demistate

I was at NAB 2010 this year, a show for professional broadcasters and asked Adobe, Telestream, and Mainconcept about the pre-processing abilities in their encoding software.

Grain removal was almost non existent in their products. They recommended a simple gaussian blur to help smooth it out.

All three of the pay applications I described above use Blinear as their "highest quality" scale. There were no other scaling methods. I personally find Spline36 and Lancos4 blows bilinear out of the water.

I don't believe this. Maybe bicubic, but bilinear is practically the worst you can possibly do for scalers besides point scaling. Even Photoshop offers bicubic.

[Blue_MiSfit]

Yes. All the encoding packages I'm personally familiar with can do bicubic or bilinear. More exotic options like lanczos and spline etc are not frequently encountered.

If you go to Snell or Terranex, you will find powerful algorithms backed by FPGAs for high quality upconversion. This is real time, but very expensive.

Avisynth is awesome, and free, but not real time

~MiSfit

[lych_necross]

Originally Posted by Dark Shikari

I don't believe this. Maybe bicubic, but bilinear is practically the worst you can possibly do for scalers besides point scaling. Even Photoshop offers bicubic.

Now thats not true about bilinear. It is a perfectly fine scaler (especially for down scaling). In fact, depending on the source material, bilinear scaling might be better because of the smoother images it tends to produce where as a bicubic scaler might over sharpen the image. It just depends on a person's preferences.

[Dark Shikari]

Originally Posted by lych_necross

Now thats not true about bilinear. It is a perfectly fine scaler (especially for down scaling). In fact, depending on the source material, bilinear scaling might be better because of the smoother images it tends to produce where as a bicubic scaler might over sharpen the image.

The sharpness of a bicubic scaler is adjustable.

[demistate]

Originally Posted by Dark Shikari

I don't believe this. Maybe bicubic, but bilinear is practically the worst you can possibly do for scalers besides point scaling. Even Photoshop offers bicubic.

A huge misconception about Adobe apps is that they share some sort of common code. In reality the After Effects guys don't know what the Premiere Guys are doing. I had to ask separate engineers what kind of scaling was going on for each product. The After Effects engineer was reluctant to tell me probably because he knows that bilinear isn't the greatest in the world.

So while Photoshop does have bicubic scaling, After Effects and Premiere Pro DON'T. I don't know of many people using Photoshop to pre-process videos (even though it is possible).

I almost threw up when the Telestream pro told me that I should scale a video twice with their high quality bilinear to get a "super high-quality" HD to SD downscale. (Scale by half once, and scale that output by half again)

I wonder if these professional compression software companies are worried about licensing other scaling methods someone could have a claim to it. Crazy US patent laws.

[wonkey_monkey]

I almost threw up when the Telestream pro told me that I should scale a video twice with their high quality bilinear to get a "super high-quality" HD to SD downscale. (Scale by half once, and scale that output by half again)

That sounds pretty reasonable for a standard bilinear filter

David

[Keiyakusha]

Originally Posted by demistate

So while Photoshop does have bicubic scaling, After Effects and Premiere Pro DON'T. I don't know of many people using Photoshop to pre-process videos (even though it is possible).

Speaking about scalers... the one in AE is so crappy so its sometimes impossible to work with it. Especially when you working with sharp CG footage, when camera flies through some raster object which is equal to 4x and more upscaling... It looks very bad.

[NerdWithNoLife]

Originally Posted by demistate

Most broadcasters don't even know about Avisynth or x264. Most of the posters here would be able to net really good jobs at professional post houses that compress films/tv shows for places like iTunes and other digital distribution networks just from their avisynth skills.

I'm just amazed that the free tools are better than the expensive, supported, pay tools.

Absolutely! I'm one of the dummies here and I just went from being a postman to being chief engineer for a video production company. AviSynth has been more valuable than my college education in this field - seriously. (I just TGMC'd a Justin Bieber concert. That's probably a first.)

I also agree that in the business there's not always time, so you have to pay to let an expensive program think for you. But it's still good to have an idea of how to configure the stuff.

There was once a thread discussing the possibility of integrating AviSynth with hardware, and I would LOVE to see that. It is possible to run scripts live through ffdshow, and with live input. How neat it would be to have LiveVideoSource, or something like that to pull live video from a camera. I'd use it.

[demistate]

Originally Posted by NerdWithNoLife

Absolutely! I'm one of the dummies here and I just went from being a postman to being chief engineer for a video production company. AviSynth has been more valuable than my college education in this field - seriously. (I just TGMC'd a Justin Bieber concert. That's probably a first.)

I also agree that in the business there's not always time, so you have to pay to let an expensive program think for you. But it's still good to have an idea of how to configure the stuff.

There was once a thread discussing the possibility of integrating AviSynth with hardware, and I would LOVE to see that. It is possible to run scripts live through ffdshow, and with live input. How neat it would be to have LiveVideoSource, or something like that to pull live video from a camera. I'd use it.

Avisynth hardware? That would be amazing.

I will admit that Avisynth's weakness is sometimes it's lack of speed. It's not very efficent when you parse AviSynth scrips through Premiere Pro, but the results do look nice

[SynchronousArts]

Originally Posted by demistate

Avisynth hardware? That would be amazing.

I will admit that Avisynth's weakness is sometimes it's lack of speed. It's not very efficent when you parse AviSynth scrips through Premiere Pro, but the results do look nice

I've found AVISynth to be faster on a per process comparison, especially with MT based scripts.

The 8 bit limit is what stops many from using it in professional environments. Most of my use is for downconversions for web videos so I don't worry much.

SA

[Blue_MiSfit]

Lack of 10 bit only really hurts while in the post chain. After the media is finished up, you're good to go.

I take 10 bit ProRes files ALL DAY LONG into AviSynth, and it just chops off the extra data

You'd think it would look horrible, but most of the time it looks fine. Would I be a happy nerd with nice 10->8 dithering? Absolutely!!

Still, an AviSynth (and x264 / HC) powered encoder a-la Rhozet Carbon Coder / Telestream Episode Pro / Flip Factory would be absolutely revolutionary to the "professionals" that use said products.

Show them a 480i -> 1080i upconvert from their Rhozet farm, and then show them a 480i -> 1080i upconvert using TGMC (plus maybe NNEDI2 for the scaling). Bricks will be shat. Then show them a 4mbps 1080p H.264 file generated by MainConcept, and the same video generated by x264. Larger bricks will be shat.

I've done it

~MiSfit

[NerdWithNoLife]

8bpc may be a hit for compositing in RGB, but for live hardware deinterlacing (i.e. live web streaming from interlaced input), I must quote Blue_MiSfit: "Bricks will be shat."

[roozhou]

Originally Posted by Dark Shikari

I don't believe this. Maybe bicubic, but bilinear is practically the worst you can possibly do for scalers besides point scaling. Even Photoshop offers bicubic.

IIRC MainConcept's SDK also provides a bicubic resizer that smartly picks number of taps based on source and target resolution. It also provides a way of doing resizing and color space conversion in the same time, similar to what swscale does.

[Dogway]

Except a bit of aliasing I find bilinear near perfect, it preserves detail, and doesnt create halo. Better indeed if used in float point.
Please compare spline64 vs PS float bilinear downsize by 2.

Spline64


Bilinear



The automttap3 function by *.mp4 guy deals with details quite well through adaptive multitap but in the other hand has severe halo issues on high contrasts areas.

Another question is about why bilinear in Avisynth is so different than Photoshop's.
I made a layer comparison in photoshop:

13Mb Mediafire
http://www.mediafire.com/?3jlyiz94au3v2w8

[poisondeathray]

Originally Posted by Dogway

Another question is about why bilinear in Avisynth is so different than Photoshop's.
I made a layer comparison in photoshop:

13Mb Mediafire
http://www.mediafire.com/?3jlyiz94au3v2w8

If I'm understanding what you did correctly, your avisynth bilinear resize was done in YV12, not RGB (less color information). There might be other reasons

EDIT: Yes, I can confirm what you are seeing. It's almost as if avisynth's bilinear is shifting pixels to the left, making it look softer

There seem to be differences in the other algorithms as well... PS's bicubic looks similar to avisynths' spline36

[Dogway]

Originally Posted by poisondeathray

If I'm understanding what you did correctly, your avisynth bilinear resize was done in YV12, not RGB (less color information)

true, I didnt realise, but only that doesnt make such differencies :/
and yes bicubic was really similar to spline36, I thought this kind of algorithms were somewhat universal.
Now having a second look, looks like avisynth's bilinear is just as photoshop's but happy antialiased.

[Gavino]

Originally Posted by poisondeathray

It's almost as if avisynth's bilinear is shifting pixels to the left, making it look softer

Avisynth's resizers preserve the centre of the image.
I don't know what Photoshop does, but if it instead preserves the top left corner, Avisynth's image will be relatively shifted left (on downsizing).

Also, as Dogway says, Avisynth downsizing includes antialiasing (by extending filter width).

[poisondeathray]

ok thanks that would explain it

is there anyway to adjust the AA during downsizing in avisynth ? I couldn't find it in the docs