HD>SD downconversion Mac/FCP only

[Perrone Ford]

Originally Posted by Dominik Seibold

I used XDCAM-EX-source for testing. I attached an 100%-crop-example. The left side is avid with 36mbit/s, the right unaltered XDCAM. There are clearly more artifacts on the left side.

Ok,

So here is a screen shot of my editing space. Essentially, I took 5 seconds of a closeup of water on a fountain. So organic movement, and unpredictable by the codec for the most part. I stacked the original, and uncompressed, a jpeg2000, and the DNxHD175 on the timeline.

I then did a difference composite for each one. I have highlighted the Avid against the original source. I have histograms (Luma, R,G,B), Waveform, Vectorscope, and RGB Parade open as well as the preview window.

You can see from this that there is nearly NOTHING. For all intents and purposes, DNxHD at this bit rate is lossless when presented with an XDCamEX image.

[Edit]
Oh, file sizes for 5 seconds of 1080/24p:

Uncompressed: 972,008
Jpeg2000: 114,882
DnxHD 175: 107,522

[Arthur Hancock]

Interesting results, Perrone, thanks for posting.

OT: I notice you're from Tallahassee. Have you done any shooting down at Wakulla Springs? I lived there as a kid.

[Steve Shovlar]

Ok here's the two TIFs I made.

First one is using Cinema Craft Encoder MP, 15 pass VBR.

http://www.steveshovlar.com/cinemacraft_encode/CCE_.tif

Second one is using prores422 into Compressor then out using Cinema Craft Encoder MP, 15 pass VBR.

http://www.steveshovlar.com/cinemacr...tprores422.tif

Pretty sure I have captured the wrong way. The tifs don't looks as smooth as the video.

[Dominik Seibold]

Originally Posted by Mitchell Lewis

When you have the time, can you pretty please tell me exactly what setting you used in Compressor.

I didn't do anything more than I showed in this video except for selecting QuickTime/DV as output-format:
YouTube - high-quality HD to SD-DVD conversion with FCP

Originally Posted by Steve Shovlar

How do you get a tif from an M2V file?

You can get PNGs with MPEG Streamclip. PNG is better than TIFF for web-use, because it's lossless compressed (vs. uncompressed TIFF) and well supported by web-browsers.

Originally Posted by Perrone Ford

DNxHD175

I was talking about the 36mbit/s-variant not 175mbit/s. The 175mbit/s-variant will of course look very good.
I attached a screen-shot to show you what I mean.

[Perrone Ford]

Steve you've done something very wrong there my friend!

[Perrone Ford]

I completely misundderstood you! So for grins, I'll try a 36mbps render now.

Originally Posted by Dominik Seibold;984743I

was talking about the 36mbit/s-variant not 175mbit/s. The 175mbit/s-variant will of course look very good.
I attached a screen-shot to show you what I mean.

New difference attached...

File size: 22,082

[Matt Davis]

Originally Posted by Perrone Ford

I think Dominik, and myself to a degree, get in these semantic arguments for no purpose. <snip> DVCPro50 is nice, but not full raster. So you'll take your 1920x1080 and shring it to 1280x1080. better than DV, but still a terrible thing to do if you don't have to.

If I am not much mistaken, DVCPro50 is Panasonic's souped up version of DVCPro (Panny's 'DVCAM'), which uses 2.5:1 compression rather than 5:1, therefore getting pret-ty close to DigiBeta. I used it a lot for sucking in and laying off to DigiBeta/BetaSP with my Aja IO. Useful format for stuff with lots of motion graphics 'pre-ProRes'.

I believe you were referring to DVCPro-HD? Or more specifically the 720p variant at 50 mbps? If so, would that be 960x720? ... Does anyone care?

With that and a penchant for PhotoJPEG, I feel like a 'Dead Codec Preservation Society' - "Anoraks Up!"

[Perrone Ford]

Originally Posted by Matt Daviss

I believe you were referring to DVCPro-HD? Or more specifically the 720p variant at 50 mbps? If so, would that be 960x720? ... Does anyone care?

Yep. Always forget the SD variant because I never used it. Went from VHS to SVHS to DV. I trade DVCam with the local PBS folks and that's about the extent of it. No Digibeta for me! Couldn't afford the VTRs!

Originally Posted by Matt Daviss

With that and a penchant for PhotoJPEG, I feel like a 'Dead Codec Preservation Society' - "Anoraks Up!"

O Captain my Captain! LOL!

[Steve Shovlar]

OK last night I completely messed up the images of the clips I was trying to show. Downloaded and installed Mpegstreamclip and it was very easy to grab a frame.

Here are the results of using Compressor with a two pass VBR, and using Compressor plugin Cinema Craft Encoder MP.

Now this is how I got the footage to Compressor.

I dropped the 720P50 footage on its own timeline, then exported it to prores422 720P50, self contained movie.

I then made a new sd timeline , PAL and dropped the prores422 file onto it. FCP asked if I should change the timeline. No is the answer. Then I rendered the timeline. I now have a nice SD timeline with the 720P50 footage converted down to SD PAL. It looks lovely and clean, no aliasing.

I then export this timeline to Compressor, and did a two pass VBR on the 90 minute DVD setting, and then did it again using Cinema Craft Encoder MP, do a 10 pass VBR.

First thumb is the original footage, second is compressor, and third is Cinema Craft Encoder MP.

http://www.steveshovlar.com/cinemacr...e/original.png
http://www.steveshovlar.com/cinemacr...compressor.png
http://www.steveshovlar.com/cinemacraft_encode/CCE1.png

Thoughts?

[Dominik Seibold]

Originally Posted by Steve Shovlar

I then made a new sd timeline , PAL and dropped the prores422 file onto it.

I tested this method and I figured out that this method gives the same result as using Compressors "better" rescaling method, but much faster than doing it with Compressor. The quality is great, but if you want the absolute highest quality and you have enough time then use Compressor with its "best" rescaling.

Originally Posted by Steve Shovlar

http://www.steveshovlar.com/cinemacr...e/original.png

You should really check the detail-settings in your ex1. The sharpening looks really ugly. I always recommend to turn the detail-function entirely off.

Btw, you're not converting to interlaced SD, so you're effectively converting 50fps to 25fps. Do you intend to do that? If yes, then I would recommend not to shoot with 720p/50 but with 1080p/25.

[Sverker Hahn]

Originally Posted by Steve Shovlar

I dropped the 720P50 footage on its own timeline, then exported it to prores422 720P50, self contained movie.

I then made a new sd timeline , PAL and dropped the prores422 file onto it. FCP asked if I should change the timeline. No is the answer. Then I rendered the timeline. I now have a nice SD timeline with the 720P50 footage converted down to SD PAL. It looks lovely and clean, no aliasing.

It is not necessary to to export to anything. Just drop the HD sequence on the DV timeline. Did you test that workflow?

[Sverker Hahn]

Originally Posted by Steve Shovlar

OK
http://www.steveshovlar.com/cinemacr...e/original.png
http://www.steveshovlar.com/cinemacr...compressor.png
http://www.steveshovlar.com/cinemacraft_encode/CCE1.png
Thoughts?

The CCE1 comes out a little better than compressor.

[Steve Shovlar]

Originally Posted by Sverker Hahn

The CCE1 comes out a little better than compressor.

I agree. Cinema Craft Encoder MP is better than Compressor. But then it should be for 800 bucks.

[Steve Shovlar]

Originally Posted by Sverker Hahn

It is not necessary to to export to anything. Just drop the HD sequence on the DV timeline. Did you test that workflow?

I haven't but I will certainly try this out.
Thanks
Steve

[Steve Shovlar]

Originally Posted by Dominik Seibold

I tested this method and I figured out that this method gives the same result as using Compressors "better" rescaling method, but much faster than doing it with Compressor. The quality is great, but if you want the absolute highest quality and you have enough time then use Compressor with its "best" rescaling.

You should really check the detail-settings in your ex1. The sharpening looks really ugly. I always recommend to turn the detail-function entirely off.

Btw, you're not converting to interlaced SD, so you're effectively converting 50fps to 25fps. Do you intend to do that? If yes, then I would recommend not to shoot with 720p/50 but with 1080p/25.

Good point on the detail. As I shoot 95% weddings the client mostly wants the video look, so that's what they get. I wil shoot some footage tomorrow morning and compare detail on and off.

I shoot 720P50 because its much better for slo mo in the snogging musical interlude. 50% of 50 frames = 25P.