Newbie questions after working through tutorial

[Housepiglet]

Hi,

I'm new to Avisynth and although I've worked through the v. helpful tutorial and searched around to try to understand what I'm doing I'm still confused about a few basic aspects of using Avisynth to produce a vid. If anyone can help I'd be very grateful. I'm no techy, but I'm trying hard to get to grips with the necessary info and terminology.

1. The tutorial (on here) explained how to make a script loading my files and applying various filters. It suggested doing some cleaning up of the files even before importing (not sure whether that's the right word) the script into Ulead (my video editor). It also suggested doing some post-producing cleaning too, though. My probably idiotic question here is: presumably I then make a new script which loads the AVI I've produced in Ulead into VirtualDubMod, and apply the cleaning filters to that?

2. I followed the directions in the tutorial for compressing to H.264 MPEG-4 for upload to YouTube. (If that was a bad choice then please don't hesitate to say so.) The tutorial recommends using Zarx264gui for that process. When I tried to open my *.avs in that prog, though, it put up a message telling me that I needed to add ConvertToYV12() to the end of the script. That confused me because earlier in the tutorial process I'd made a choice to 'compress RGB with huffyuv', and so I had the line ConvertToRGB24() in my script. Am I right in thinking that ConvertToYV12() somehow conflicts with or negates that choice?

3. Is there a place where I can go to look at suggested scripts? Because I'm totally new to this I just adopted a few of the cleaning up suggestions made in the tutorial, but in browsing through here I've already seen people discussing all sorts of (to me) complex and confusing things they might include in scripts.

Many thanks for any help. I have many other questions but I'm trying hard to work it all out. These seem fundamental, though, and despite a lot of looking I've not been able to work out the answers

[BasharOfTheAges]

1) Yes, you seem to understand the concept of post-production correctly. However, It's often best to do your filtering and cleaning all at once in preproduction.

2) A script is a series of steps. Yes, you assert the video is in RGB color space in the beginning of the script, but that's because most of the cleaning filters need it to be for it to work, not to mention most editing software wants it that way. H264 encoding needs the video to be in another color space, so you need to change it to YUV to be able to encode that way. You don't negate anything you did previously - that was all setup for editing, and this (the color space conversion to YUV) is all setup for encoding.

3) There used to be one, but it disappeared - I think due to lack of use or over-dependence depending on who you ask.

[Zarxrax]

As for 2), heres how it breaks down:
Your source (dvd or whatever) starts out as YV12, and your final video (x264, xvid or whatever) ends up as YV12. The only reason that it ever goes to RGB is because videos editors work in RGB.

[Housepiglet]

1) Yes, you seem to understand the concept of post-production correctly. However, It's often best to do your filtering and cleaning all at once in preproduction.

2) A script is a series of steps. Yes, you assert the video is in RGB color space in the beginning of the script, but that's because most of the cleaning filters need it to be for it to work, not to mention most editing software wants it that way. H264 encoding needs the video to be in another color space, so you need to change it to YUV to be able to encode that way. You don't negate anything you did previously - that was all setup for editing, and this (the color space conversion to YUV) is all setup for encoding.

Ahaa! Thanks so much for explaining It's much clearer now. I'll keep at it, then

[Housepiglet]

As for 2), heres how it breaks down:
Your source (dvd or whatever) starts out as YV12, and your final video (x264, xvid or whatever) ends up as YV12. The only reason that it ever goes to RGB is because videos editors work in RGB.

Thanks for explaining It's all a bit head-spin to me at the moment, but it's beginning to make a bit more sense

[Mosc]

3. The problem with recommending plugins and scripts is that people automatically assume these can all be used at once for every single video they encounter. This community is an excellent example of this phenomenon: a huge number of videos are an over-smoothed mess with rough, dark lines because everyone here seems to love Deen, aWarpSharp and vmToon. Some of the scripts posted by users make me cringe. This is not really a problem with the guide though; it clearly states that these filters should be used with caution.

Some general hints:

• Do a lot of experimenting. This is the only way to really know what filters to use on what material.
• Stay clear of aWarpSharp and vmToon unless you're absolutely certain they improve the subjective quality.
• Don't use Deen. It was a decent denoiser at a certain point in time, but there are better filters now. Deen can still be surprisingly effective on older material, though.
• You might want to try RemoveGrain (note that RemoveGrain(1) is actually the same as Undot(), but RemoveGrain is faster and less buggy), TTempSmooth, dfttest, fft3dfilter and hqdn3d. The latter three are very powerful even on their default settings, so be careful!
• Make sure you know the difference between spatial and temporal smoothing, and more importantly, the consequences of over-using them.
• LimitedSharpenFaster is pretty safe to use as a general purpose sharpener, but again, don't use it unless it really improves the overall quality.
• If you have more than three filters in your AviSynth script (excluding IVTC, cropping, resizing, etc.) you're probably doing something wrong.

[BasharOfTheAges]

As a note. The listings i mentioned before were for the "best" filters on a series by series basis. I'm all for experimentation, but most people don't want to spend the time which is why you get over-filtered stuff everywhere. With enough people contributing to a master series-by-series list everyone wins - because most editors aren't going to spend the time perfecting their filter chains otherwise.

[Housepiglet]

3. The problem with recommending plugins and scripts is that people automatically assume these can all be used at once for every single video they encounter. This community is an excellent example of this phenomenon: a huge number of videos are an over-smoothed mess with rough, dark lines because everyone here seems to love Deen, aWarpSharp and vmToon. Some of the scripts posted by users make me cringe. This is not really a problem with the guide though; it clearly states that these filters should be used with caution.

Some general hints:

• Do a lot of experimenting. This is the only way to really know what filters to use on what material.
• Stay clear of aWarpSharp and vmToon unless you're absolutely certain they improve the subjective quality.
• Don't use Deen. It was a decent denoiser at a certain point in time, but there are better filters now. Deen can still be surprisingly effective on older material, though.
• You might want to try RemoveGrain (note that RemoveGrain(1) is actually the same as Undot(), but RemoveGrain is faster and less buggy), TTempSmooth, dfttest, fft3dfilter and hqdn3d. The latter three are very powerful even on their default settings, so be careful!
• Make sure you know the difference between spatial and temporal smoothing, and more importantly, the consequences of over-using them.
• LimitedSharpenFaster is pretty safe to use as a general purpose sharpener, but again, don't use it unless it really improves the overall quality.
• If you have more than three filters in your AviSynth script (excluding IVTC, cropping, resizing, etc.) you're probably doing something wrong.

This is enormously helpful. Thank you very much indeed

I noted from the tutorial that I should be careful not to apply too many filters. I had a little go last night, and I included Deen with teh suggested settings to see how it would work out. I was very struck, though, when I watched the results, by how over-smoothed the picture seemed to me to be. (Well, I'm assuming that I'm applying the right term, here. Everyone seemed to have flawless, porcelain complexions: I'm assuming that's smoothing.) Today I had a second go but I reduced the Deen settings. I'll leave it out altogether next time, though, and see how that works.

I'm relieved to read what you say about not being likely to need more than 3 filters in a script!

Thanks once again for all the v. helpful info. I'll go and read up on those things