@xcxz-a - Many thanks! And what does the abbreviation actually stand for?: S o 4

So we need to careful about sync yeah? And is this meant to replace QT as we go down the road?

It's a decoder ("plug-in") for AVC (H.264) formats, that mostly replaces compoundplug.dll.

But something I read (that I now can't find) makes me think it's not just a self-contained decoder. I think it has the ability to pass streams off to other decoders depending on their specific content.

It doesn't replace QT but it does decode AVC streams within QT .mov containers.

My GUESS is that compoundplug may entail costs (e.g. from MainConcept?) in terms of royalties/on-going licensing and that so4compoundplug.dll avoids these costs because it has been developed in house? This is speculation and might be nonsense. Or it might be that compoundplug was somehow terminally limited, for example in terms of hardware acceleration.

Would love someone from the VEGAS team to confirm or deny that speculation, and also tell us what "so4" stands for, cuz I have no idea either.

@xcxz-a - Many thanks! And what does the abbreviation actually stand for?: S o 4

It may just be a funny name, means Sulfate compound,something like FeSO4.

So we need to careful about sync yeah?

If encounter sync problem, we can turn so4 off in inner settings.

 

And is this meant to replace QT as we go down the road?

QT is abandoned but not replaced.

personal opinion .

@xcxz-a & @NickHope Thank you! I have more questions, of course:

Q1 : I’ve been using QT Animation to produce ALPHA. What’s the “informed” thinking, going forward?

Q2 : The Audio sync issue, will this be cured? How will I notice an issue?

Q3 : If I were to Transcode, yuck, what do you recommend?

TIA - G

If you have an established, successful workflow using QT Animation then for an easy life you could just enable Quicktime in VEGAS File I/O preferences and carry on. I doubt VEGAS will produce another native decoder that will read that format like they did for Quicktime AVC and ProRes (and HEVC?).

If you want to use a different codec for alpha, I'm afraid I'm not sure which to recommend. I rarely use alpha and can't remember which intermediate-worthy codecs support it in VEGAS.

Personally, I've not experienced audio sync issues with so4compoundplug.

@NickHope - As always, your replies are both full some and easy for me to understand.

Doesn't Magic YUV have an alpha option?

@RogerS - It would appear so. But only, my brain is starting to ache, in a compressed state: https://www.magicyuv.com/

It's compressed but isn't it lossless? If so seems like a valid replacement for old QT-based codecs.

Yes, MagicYUV is always compressed - and it's lossless. There are two (RGBA and YUVA) MagicYUV codec choices which support alpha channels.

AVI supports uncompressed with alpha channel.

So4 also enables better GPU acceleration and the ability to decode 10 bit media.

There are fewer and fewer reasons to disable it with each update, and because of the above mentioned aspects, it's best not to.

Q1 : I’ve been using QT Animation to produce ALPHA. What’s the “informed” thinking, going forward?

I'm not a big fan. I tested QT Animation thoroughly back when I ran these tests in 2011, and panned it quickly as a candidate for true lossless encoders.

1. The RLE compression is terribly inefficient, except with low/no motion source. With full motion scenes, it is essentially no more efficient than uncompressed.
2. The encode is full of rounding errors, making the blue ramp vectorscope line "fat," meaning noisy with increased small-scale banding.

As an early attempt at "lossless" compression, it was a good idea in its day, but has been obsoleted by advanced intraframe encoders such as Magic (RGB), UT, and even Huffy. And of course it is no match for interframe encoders, although they usually don't support Alpha.

So in my workflow, it sits on the shelf as a dusty but well-earned trophy. No charge for the editorial.

@Musicvid - Thanks 🙏

I like the animation codec, but mostly because I use it for graphic animation, so rounding errors and fat vectorscopes don't show. Usually it is a text graphic or manipulating a logo. So don't write it off completely. The file size is small relatively, but the quality, especially text, holds up very well.

@Former user - Yes, me too. Unless @Musicvid has some concerning input regarding this too, I shall keep using it. No, my initial concerns was to do with the Windows 10 and QT support falling away and what alternatives I could use - easily 😉 .

I always use AVI uncompressed for my alpha stuff, it gets rid of the QT headache all together.

@Former user - Yes, me too. Unless @Musicvid has some concerning input regarding this too, I shall keep using it. No, my initial concerns was to do with the Windows 10 and QT support falling away and what alternatives I could use - easily 😉 .

@Grazie @Former user

I got to thinking this morning (a rarity), and decided to rerun my tests that were almost a decade old. Using my generated banding test media, I was only able to see a little of the rounding errors I reported before. Certainly not enough to compromise the output in any significant way. So until I've had a chance to dive deeper, I hope you'll take those earlier observations with a grain of salt.

My personal choices for RGBA intermediates are either Magic or UT AVI, and when encoding camera video, UT 422, which comes in at only 1-2% of uncompressed size. Thanks for cueing me to take a second look.

My personal choices for RGBA intermediates are either Magic

@Musicvid - Erm? Where he be? Looked through my List of Render Options, can't find RGBA . . . ?

Just did a Quick 'n Dirty Transparency Test QT > MP4 - HEVC:

You can get Alpha in Magic and UT in HOS, or Wayne made a custom aviplug.dll for Vegas. You could ask him if he has one for your VP18.

In VP18 you don't need workarounds to use the alpha channel of AVI files. VP18 supports it natively (if the codec itself supports it).