[Graeme Nattress]

DV50 over SDI would be a double compression, so probably not worth doing.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Graeme Nattress]

Thanks. ProRes should be included too!

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Graeme Nattress]

I’ve never had problems playing out 480 lines over hardware. Never a dropped frame warning.

For the test, just capture the same source clip thrice, once over SDI to uncompressed 10bit, and another to uncompressed 8bit, and finally over FW. If you can do that on a small, colourful clip, that’s probably best.

Different 4:2:2 codecs are handled differrently by FCP, some will be chroma smoothed, some not, so you still have to analyse what the chroma is doing. That can significantly effect a key, so if you’re noticing better keying, it’s vital that the methods of chroma subsampling reconstruction are verified. If you have time to capture stuff, I’ll take a look and see.

Well, you don’t try to measure subjectivity – what we’d look for is any mathematical differences first, both in bit depth, resolution, chroma sampling, compression artifacts etc. That might be enough to explain what you’re seeing.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Graeme Nattress]

Well, as the camera codec only records 480 lines, where are the other 6 coming from? And of course, an uncompressed timeline need not be 486 lines, but can be 480.

What it comes back to, is not that such a flow makes you happy in the edit suite, but have you checked with, rigorous experimentation, the output of the SDI port on the deck compared to the Apple DV50 decode? When the same question was asked about DV that’s what I did. I spent a lot of time and enlisted some good help to perform that experimentation as best as I could. Would you care to do the same with your DV50 gear and write an article on the results?

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Graeme Nattress]

I’m sorry, but that’s just twaddle. When you do an effect on a clip in FCP, if you have the timeline set to high precision rendering, the clip us “upped” on the fly to 4:4:4 32bit float. When it’s rendered back, it can be set to render back to uncompressed or whatever.

Think of it like this, with DV50 footage on an uncompressed 10bit timeline:

DV50 -> 32 float 4:4:4 -> effects -> back to 10bit uncompressed.

or if you capture DV50 to uncompressed it goes like:

DV50 -> UC10bit 4:2:2 0> 32 float 4:4:4 -> effects -> back to 10bit uncompressed.

And that’s why it only just wastes disk space. As for the SDI feed on a deck doing a better job than the software codec, I’ve not seen that – you’d have to show some evidence for that.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Graeme Nattress]

I think you’ve got to look at everything on a time / results basis. I don’t think there’s a hard and fast rule you can make. There’s good computer software that’s fast, and some that’s slow, and sometimes the slowest makes the best image. In hardware, it’s either realtime or it doesn’t work, and depending upon cost and hardware, it might not be currently possible to do the best current algorithm in realtime, and therefore software, albeit slower, might be better. You pays your money, you takes your choice!

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Graeme Nattress]

Capturing an 8bit compressed format to a 10bit uncompressed format is just wasting hard drive space for no real benefit.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Graeme Nattress]

AFAIK, FCP only ever applies correct pulldown on playout to tape of 23.98fps media, either over Firewire, or via, say, a Kona card.

I’ve got a plugin that helps do pulldown as a render in my conversion pack, but that takes time to render.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Graeme Nattress]

Just make a movie of the timeline, then convert that movie. We lost of the ability to convert sequences back with FCP5….

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Graeme Nattress]

I’ve got a long dissolve plugin that uses dither to try and extend the range of a good looking dissolve out further: https://www.nattress.com/Products/BigBox/Transitions/GLongDiss.htm

It might work for you!

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP