HD>SD downconversion Mac/FCP only

[Peter Kraft]

Is there a compatible codec to QT PNG in Winworld?
BTW, we are testing Avid Meridien uncompressed for file exchange between Macs and Wins (Liquid, Avid).

[Perrone Ford]

Originally Posted by Peter Kraft

Yes sir, I am. Which apps are you talking about? Would love to test them on my Mac turned WinMachine;-)

The program you want is Virtualdub. Its just a framework. You extend it by dropping "filters" into its folder. No install necessary. Just close the program and restart. The lanczos rescaler is built-in though. Just open your video, select the resize filter, type in the new size, choose lanczos, and convert.

It's pretty fast too.

[Perrone Ford]

Originally Posted by Peter Kraft

Is there a compatible codec to QT PNG in Winworld?
BTW, we are testing Avid Meridien uncompressed for file exchange between Macs and Wins (Liquid, Avid).

I hadn't done a Jpeg2000 test in HD, so I tried it just now.

Basically, what I've tried are the following codecs

Uncompressed
BlackMagic 10 bit - Largest file besides uncompressed
Aja Kona 10 bit
Jpeg2000 (best quality) - Small files, performance not so great on timeline
HuffYUV - YUV so loses Chroma
Lagarith - Similar performance to HuffYUV
PNG Paeth - Nice encode but takes FOREVER to encode
Avid DNxHD 220 - Small files, good timeline performance.

I did not test DVCProHD because I wanted full raster
I did not test ProRes because I don't have a Mac.

For my money, the Avid Codec wins. Good performance, reasonably fast encode time, available on Mac and PC for FREE. I'm glad I have this solved as I have a huge project I am currently working on and needed something I could work with. But now I have to go back and remaster all the bit's I've done already!

[Steve Shovlar]

Originally Posted by Perrone Ford

Based on my results tonight, and over the past few months of testing, Avi's DNxHD is giving results darn near equal to uncompressed at a fraction of the size. ProRes isn't close since it cannot do RGB with Alpha channels (unless someone know's sommething I don't).

Looks like this is my new mastering format! Sweet!

And it comes in Mac and PC versions, and the codec is free. Can't beat that.

But don't you have to edit in AVID to use it? How can you go from FCP to this codec?

[Perrone Ford]

Originally Posted by Steve Shovlar

But don't you have to edit in AVID to use it? How can you go from FCP to this codec?

Absolutely not. I edit in Vegas. If you install the quicktime Avid Codec, you should be able to render to it from FCP just like any quicktime file.

[Steve Shovlar]

Ok thanks for that. I will try it later today.

[Steve Shovlar]

OK it installed perfectly. Stuck a 720P50 clip on the FCP timeline, went export, Quicktime Conversion, chose DNxHD codec, and it made the same sized file. A 20 second clip came out at 283Mb in size.


But. The clip looks washed out. The contrast is shot. However I have chosen one of the other Avid codecs and got stunning results downconverted to Pal DV. I am now importing that into compressor and out with Cinema craft Encoder MP.

[Matt Davis]

Originally Posted by Peter Kraft

Fraunhofer Institut suggests JPEG2000 for a comparable task. Any comments on that?

I've been using PhotoJPEG at 80-100% (I believe 100% is 4:4:4 RGB and virtually lossless) for over a decade, mostly for archiving motion graphics final renders, though I also used it for downsampled HDV and DV50 work. With more compression (75% to 85%), it makes for a great real-time playback format in Apple's Keynote - especially 1280x720.

Great legacy format.

[Andy Nickless]

Originally Posted by Dominik Seibold

Compressor is doing exactly the same than lanczos. I posted an example to show that, but who realizes it?

I realise it, Dominik.
You proved your method to me and you are obviously an expert in this field but sadly, despite your best efforts, some others don't seem to want to learn from you.

I hope you won't give up.
People like you are just what these forums need.

[Dominik Seibold]

Originally Posted by Andy Nickless

I hope you won't give up.
People like you are just what these forums need.

Can't help, but you sound a bit ironic to me. ;)

Originally Posted by Peter Kraft

I have so far not found any hint about Compresor and Lanczos.

This one was posted by Perrone done with lanczos in virtualdub:
http://www.dvinfo.net/conf/attachmen...test_small.png
This one was posted by me done with Compressor:
http://www.dvinfo.net/conf/attachmen...compressor.png
They are almost 100% identical. Hence Compressor is doing something equal to lanczos.

Originally Posted by Perrone Ford

HuffYUV - YUV so loses Chroma

HuffYUV can do RGB, but it is a lossless codec, so it produces very large files. About 50-60% file-size of uncompressed, similar to rar-compression.

Originally Posted by Perrone Ford

Based on my results tonight, and over the past few months of testing, Avi's DNxHD is giving results darn near equal to uncompressed at a fraction of the size. ProRes isn't close since it cannot do RGB with Alpha channels (unless someone know's sommething I don't).

That sounds very interesting, especially for pre-rendering of green-screen work because of the alpha-channel-capability. Earlier I used HuffYUV for that, now I've got a faster computer. ;)

Yes, there are some other great intermediate codecs, which are capable of 4:4:4YUV/RGB. They're especially useful for special-effects-work. But I think that with 4:4:4 you don't gain any advantage for pure editing/grading, because the end-consumer/release-formats are at most 4:2:2, so using 4:4:4 is just a waste of harddisk-space.

[Perrone Ford]

Originally Posted by Dominik Seibold

Yes, there are some other great intermediate codecs, which are capable of 4:4:4YUV/RGB. They're especially useful for special-effects-work. But I think that with 4:4:4 you don't gain any advantage for pure editing/grading, because the end-consumer/release-formats are at most 4:2:2, so using 4:4:4 is just a waste of harddisk-space.

The codec has a number of options. One preset (DNxHD 36) is specifically for intermmediate work. I am about to try it now.

More info here:

Avid DNxHD Codec

Cool article about Iron Man being cut in this HD proxy Format:

DNxHD Marvel | Behind the DNxHD 36 workflow for Iron Man

[Steve Shovlar]

Ok I have had a few plays with it now and it does give off a very good video file which I boought into Compressor and then out again via Cinema craft Encoder MP. I did a 10 pass VBR with a max of 9000, min of 2000 and average of 6000.

Quite a good clip to use as it has plenty going on with all that confetti. Plus the bride ain't bad looking either!

Original untouched file is here. Shot with EX1.
Right mouse click and "save target as"
http://www.steveshovlar.com/cinemacr...44_1441_01.mov

The finished file is here.
Right mouse click and "save target as"
http://www.steveshovlar.com/cinemacr...tEncoderMP.m2v

Can anyone improve on that finished file?

[Dominik Seibold]

I tried DNxHD and my impressions are:
-it is 4:2:2, not 4:4:4
-the 36mbit/s-variant has much more artifacts than 35mbit/s-XDCAM-EX
-at all bitrates (and without alpha-channel) it needs for playback about 2 times as much CPU than ProResHQ and about 3 times as much CPU than XDCAM-EX
-it doesn't support 1080p/29.97

So I can't see any advantages using it except the alpha-channel-capability.

[Andy Nickless]

Originally Posted by Dominik Seibold

Can't help, but you sound a bit ironic to me.

Maybe something got lost in translation.
(I was saying you do a good job - I meant it).

[Mitchell Lewis]

Originally Posted by Dominik Seibold

Mitchell, I will say it one more time, but if you don't listen to me I can't help you:
if you compress with a YUV-format like DV, then there's chroma-subsampling going on, so features with strong saturation-jumps + hue-jumps + luma-jumps will look pixelated or blurred. There's nothing you can do against it but using a non-YUV-format or decreasing saturation.
Try to use QTs uncompressed setting and you'll see the difference.

Sorry Dominik, I am listening, but I'm not understanding. You (and others in this thread) talk over my head quite a bit.

So what your saying is that because I compressed to standard DV codec (YUV), it's going to look crappy. Sorry but this doesn't make any sense to me, because the commercial was originally produced and broadcast in DV codec. I rendered the project in AfterEffects directly to a DV codec file (Quicktime mov). I've seen it on the air and it looks fine. By my logic this tells me that it should be possible to convert HD to SD - DV codec, but that the tools I'm using (Compressor) arn't working very well.

Compressor does offer conversion to DVCPRO50. Isn't that a 4:2:2 codec? I can't remember. I think it also will convert to the Uncompressed codec.

My problem is all the local broadcasters in my market broadcast their commercials using the DV codec. When I send them copies of my work (dubs) I have to send them as Standard Def DV codec mov files. Another option is to send them as a DV Stream, but that's basically the same thing as a DV codec mov.

On January 5th (when all our new equipment arrives) I'm especially looking forward to installing our new AJA Io HD device. Supposedly I does a great job converting HD to SD using hardware based conversion. Once it's all hooked up, I will have an SD monitor connected alongside our HD monitor so I will be able to instantly see what an AJA IoHD SD conversion looks like. But I agree with you, I not very optimistic that it will look better than the best software based conversion.

Still looking for a simple HD to SD (DV codec) solution on a Mac..... (hopefully you now understand why I keep wanting to transcode to DV)