View Full Version : Downconverting a sharper SD image


Daniel Larson
January 9th, 2010, 08:50 AM
I've been working on a few SD projects where I shoot with a F335 in 1080 30P and bring the footage into Final Cut Pro in real time by downconverting in-camera to FCP's log and capture. It has been working well. Now I want to get a sharper SD image using this same FCP input method and have been trying to adjust the settings in the F335. In the Paint menu under SD Detail I have it set to High and I can see a difference between High, Mid, and Low. I have also been adusting the SD Crispening setting in the Advanced menu under SD Detail but the image does not seem to change. The same goes for the other settings in the Advanced SD Detail menu. I must be missing something basic. Any ideas on how to get a sharper image into FCP via downconverting?

- Dan

Alister Chapman
January 9th, 2010, 01:32 PM
Changing the SD settings only effects the SD sharpness etc if you are shooting SD, not if you shoot SD and downconvert.

Daniel Epstein
January 9th, 2010, 01:33 PM
Daniel,
I think the camera settings only effect the camera for future recordings not previously shot footage. There would have to be some sort of sharpening in playback mode to help you and that may not happen on a firewire transfer but could show up on HDSDI or analog playback

Daniel Larson
January 9th, 2010, 04:29 PM
Thanks for the clarification. My thinking was off quite a bit for how downconverting works. I would think if I sharpened the 1080 30P image then the downconvert to SD would be sharper as well.

-Dan

Doug Jensen
January 9th, 2010, 04:43 PM
I've been working on a few SD projects where I shoot with a F335 in 1080 30P and bring the footage into Final Cut Pro in real time by downconverting in-camera to FCP's log and capture.

Dan, I understand everyone has their own workflow, but I really wonder why you are downconverting and capturing in real time? You're not only missing out on all the great features of having a tapeless workflow, your're also getting an inferior video image to work with.

Try importing the full-res HD clips properly and using HD clips on your SD timeline. You'll find all kinds of advantages with scanning, panning, and better down-converstion.

Just a suggestion. I'm been doing it that way for almost 4 years and I couldn't imagine going back to live capture.

Daniel Larson
January 9th, 2010, 09:16 PM
Hi Doug, Thanks for the reply. I'm stumbling along trying to determine a workflow to furture proof footage on XDCAM HD and edit for the SD present. Your suggestion to bring in HD clips to a SD sequence is what I needed to hear. I've done some experimenting tonight and tried some SD settings in FCP that are giving me a better quality output - as you predicted. Earlier attempts at trying to fit XDCAM HD and SD together would give me a lot of sequenes with red render lines and not very good images. I don't know if you edit with FCP, but here is a setting I'd like to run by in case you do. The footage is XDCAM HD 35mp/s shot at 1080 30P and imported via XDCAM transfer. I've set the Easy Setup to ProRes 422, the sequence is set to a frame size of 720x486 CCIR 601, the pixel aspect is CCIR 601, field is none, the compressor is Apple ProRes 422. The sequence has a green render bar above and plays back on the computer and the video monitor. When rendered the quality is very good and is better than what I was getting with my up convert method. Let me know if I'm headed in the right direction. Thanks again.

- Dan

Doug Jensen
January 9th, 2010, 10:14 PM
Hi Dan,

Yes, I edit exclusively with FCP. I also have an F350, EX1, EX1R, and F800. I use the exact same editing workflow for all of them.

Personally, I don't think there is any reason to use ProRes in a typical XDCAM workflow. Okay, if you want to render effects and stuff like that to ProRes, that's one thing, but other than that ProRes doesn't povide any benefits and just wastes time and hard drive space.

Although I don't consider myself to be a Final Cut Pro expert, I have found editing XDCAM to be very easy and simple with no special steps or unusual issues to deal with. I strongly believe it is very important to edit with Sequence settings that are as close as you can come to matching your final output. In other words, if you aren't going to author a Blu-ray disk or some other HD final product -- then don't edit in HD. Edit in SD. Choose sequence settings that match your output -- not the source footage.

Here are the steps I follow for Final Cut Pro for a project that will be released on DVD or the web.

1) I shoot most footage with the HQ1080/30P Video Format.

2) I open a new Sequence in FCP and use the "DV NTSC 48Khz Anamorphic" preset.

3) I change the Field Dominance to "NONE"

4) I edit the entire program within that Sequence.

5) When I'm done editing, I then Export a QuickTime movie of the Sequence. I choose "Current Settings" and I do NOT choose to "Make Movie Self-Contained".

6) I then take that QuickTime movie and bring it into Compressor.

7) I then choose the Compressor preset for DVD Best Quality and modify a few of the settings (such as bitrate), but nothing major.

8) After that file is finished rendering, I bring it into DVD Studio Pro and author the DVD normally

I found that this workflow is fast and easy, requires no extra software or plugins, and produces very nice results. Plus, I have not given up all the huge benefits of working tapeless.

Anton Strauss
January 10th, 2010, 12:27 AM
how does Final Cut handle HD to SD downscaling? do you get lots of artifacts or stairstep effects on diagonal detail?

Simon Denny
January 10th, 2010, 12:52 AM
I use the same workflow as Doug except for a self contained quicktime and I'm in Pal.
I think FCP does a great job converting HD to SD and I do this all the time.

Doug Jensen
January 10th, 2010, 06:26 AM
how does Final Cut handle HD to SD downscaling? do you get lots of artifacts or stairstep effects on diagonal detail?

Footage looks great with this workflow or I wouldn't use it.
Here's an example that has lots of diagonal detail and was edited using the above workflow. (Shot with an EX3)

2009 Rhode Island Air Show Highlights on Vimeo

Daniel Larson
January 10th, 2010, 09:44 AM
Doug, the Rhode Island Airshow video was great.

I'm up to speed on editing with the FCP settings determined by the final output. So for an SD project I shoot XDCAM HD, edit in FCP at DV NTSC 48Khz Anamorphic, with field dominance at none. But now I have to drop in a few 4x3 DVCAM shots from projects shot a few years ago. If I am going to stay with 16x9 I can distort the aspect ratio in the FCP Motion tab and increase the Scale to make the clip fit within the rastor. I loose resolution but the aspect ratio matches 16x9. Is that the way you would treat those 4x3 clips so they blend better with the XDCAM footage?

-Dan

Doug Jensen
January 10th, 2010, 10:51 AM
No, I would never stretch the footage. I cannot stand that when I see it on TV.
I'd either put black pillar boxes on the sides of the screen or add graphics to fill the empty space. Watch any of the nightly network news programs (CBS, NBC, ABC) and notice how they mix 4x3 footage by adding motion graphics to fill the space on the sides. I'd say it works pretty good and is much better than stretching stuff.

Another alternative would just be to produce your whole video in 4x3 and crop all the 16x9 footage. I nice thing about working with HD clips in an SD timeline is that you can change the Motion tab settings to a setting between 50% and 100%, and then slide the clip around within the canvas to get the framing that works best.

Anton Strauss
January 10th, 2010, 06:09 PM
Footage looks great with this workflow or I wouldn't use it.
Here's an example that has lots of diagonal detail and was edited using the above workflow. (Shot with an EX3)

2009 Rhode Island Air Show Highlights on Vimeo (http://vimeo.com/5425091)

I also get great results when exporting to web sizes

however, when you actually put it on a DVD, you can see artifacts when played on standalone DVD player connected to TV, Plasma or LCD

in order to avoid these artifacts, I use Virtual Dub as a downscaling tool
Using Virtual Dub and Edius to downscale HD to SD (http://www.videoproductions.com.au/html/virtualdub-hd-sd.html)

here is a typical troublesome shot taken of the sydney cricket ground, vertical tilt with lots of detail, shot with PDW-F335 1440x1080 Pal interlaced
Index of /HD (http://www.videoproductions.com.au/HD) (30mb)
if I downscale the above with Virtual Dub, the DVD looks great, but if I use my NLE, it looks not so great

if you have time on day, I would love to see a downconverted DVD compliant mpeg clip of the above, using FCP, then I could author a DVD from it and compare to my results

I would need the mpeg as elementary streams, 720x576 16:9 Pal interlaced (the clip has no audio)

Doug Jensen
January 10th, 2010, 09:26 PM
Hi Anton,
I would never, under any circumstances, shoot interlaced. That's your problem right there.
It's outdated, old fashioned technology that has no purpose in today's world.
I am not surprised the your DVDs are not turning out too well. Try 30P instead.

Also, you might want to try FCP and Compressor isntead of Edius.

Anton Strauss
January 11th, 2010, 12:24 AM
I tested my camera in 25p mode (Pal) but the resulting shots look like they have a strobe filter applied when there is a pan, tilt or zoom

I usually don't pan, tilt or zoom much. but sometimes it can't be avoided

if my camera could do 50p, I think it would look better

Greg Boston
January 11th, 2010, 06:38 AM
No, I would never stretch the footage. I cannot stand that when I see it on TV.
I'd either put black pillar boxes on the sides of the screen or add graphics to fill the empty space. Watch any of the nightly network news programs (CBS, NBC, ABC) and notice how they mix 4x3 footage by adding motion graphics to fill the space on the sides. I'd say it works pretty good and is much better than stretching stuff.

Another alternative would just be to produce your whole video in 4x3 and crop all the 16x9 footage. I nice thing about working with HD clips in an SD timeline is that you can change the Motion tab settings to a setting between 50% and 100%, and then slide the clip around within the canvas to get the framing that works best.

Personally, I am a fan of putting 4:3 into 16:9 using the same video on a lower track enlarged and blurred to fill the side pillars. It gives a great effect and IMO, is the least visually jarring. You'll see this on some of the networks also, especially in sports retrospective pieces where they have to mix older material with the new.

-gb-

Doug Jensen
January 11th, 2010, 06:59 AM
Greg, yes that is another good solution I forgot to mention. Good idea.


Anton, people have been shooting 24P and 25P for decades. If you're judging your footage on the camera's LCD or on a computer screen you are probably not getting a true picture of what the footage really looks like. Also, shutter speed is important.

Anton Strauss
January 11th, 2010, 07:18 AM
I would never judge anything on a PC monitor

when I edit, the component out of Edius SP hardware is connected to 42" full HD Plasma

I think the real problem is that the DVD spec is interlaced, I noticed that newer players perform better, especially Blu-ray players because they upscale the DVD and somehow manage to hide the artifacts

Kevin Walsh
December 18th, 2010, 08:00 PM
Hi Dan,

Yes, I edit exclusively with FCP. I also have an F350, EX1, EX1R, and F800. I use the exact same editing workflow for all of them.

Personally, I don't think there is any reason to use ProRes in a typical XDCAM workflow. Okay, if you want to render effects and stuff like that to ProRes, that's one thing, but other than that ProRes doesn't povide any benefits and just wastes time and hard drive space.

Although I don't consider myself to be a Final Cut Pro expert, I have found editing XDCAM to be very easy and simple with no special steps or unusual issues to deal with. I strongly believe it is very important to edit with Sequence settings that are as close as you can come to matching your final output. In other words, if you aren't going to author a Blu-ray disk or some other HD final product -- then don't edit in HD. Edit in SD. Choose sequence settings that match your output -- not the source footage.

Here are the steps I follow for Final Cut Pro for a project that will be released on DVD or the web.

1) I shoot most footage with the HQ1080/30P Video Format.

2) I open a new Sequence in FCP and use the "DV NTSC 48Khz Anamorphic" preset.

3) I change the Field Dominance to "NONE"

4) I edit the entire program within that Sequence.

5) When I'm done editing, I then Export a QuickTime movie of the Sequence. I choose "Current Settings" and I do NOT choose to "Make Movie Self-Contained".

6) I then take that QuickTime movie and bring it into Compressor.

7) I then choose the Compressor preset for DVD Best Quality and modify a few of the settings (such as bitrate), but nothing major.

8) After that file is finished rendering, I bring it into DVD Studio Pro and author the DVD normally

I found that this workflow is fast and easy, requires no extra software or plugins, and produces very nice results. Plus, I have not given up all the huge benefits of working tapeless.

This is what I do too. It works like a charm. Doug what do you do if you have to deliver both Blu-ray and DVD?

Doug Jensen
December 19th, 2010, 10:01 AM
Hi Kevin,

I've never had to deliver on Blu-ray. I thought I was going to have to once, so I bought Blu-ray burner in December 2008 and the box is still sitting on a shelf with the shrink wrap intact. By the time I ever use it, it will probably be as outdated as a floppy disc drive.

However, getting back to the intent of your question, when I have to deliver on other HD formats, I edit with an XDCAM HD 422 timeline that matches the majority of my raw footage. I would then downconvert the final edited video if a DVD version was also needed. That workflow also gets great results, but I still feel there's no reason to edit in HD if I'll never need any HD output. There are many advantages to editing on an SD time line if that's the only output I'll ever need.

Once again, ProRes would not be needed at all in my workflow. I don't think there's any benefit to using ProRes for people who are already working with XDCAM. ProRes is a great option for the "other guys", but I don't have any use for it.

Uli Mors
December 20th, 2010, 02:19 AM
Hi,

I really dont want to open the "p vs i" shooting discussion again, but here its part of the question.

My experience: If you shoot progressive (25p, 30p) , downconversion in NLEs is MUCH BETTER than shooting interlaced.
In both worlds, NLEs do a (deinterlacing if needed and) downscaling, of course.
Its a question of filtering "too high" detail frequencies to avoid aliasing and other artefacts - simply spoken: SD cant take as high frequencies as HD can.
Since most NLE Plugins do some simple downscaling, the results are different.

In case of deinterlacing, the process is even more complex. But there are software workflows that produce a good quality even with Interlaced footage.

What I found is that any hardware conversion (HD->SD, progressive or interlaced) is WAY better if done by hardware. I guess its a question of filtering high frequencies too.
I tried to copy my HD master back to camera (I used XDCAM F330, XDCAM 700 and HDV) and play the signal out in SD. ITīS FANTASTIC.
In case of F330 (aka 350, 355 etc.) you can benefit from 2 things:
a) use SD Detail to enhance your SD Signal to your taste
b) use Firewire AVC out (switch from FAM to AVC) to ingest the footage digitally. The SD Signal via Firewire is great (digital) quality with the same SD Detail enhancement

In case of PDW700 and others there is often no AVC stream out possible. In this case I ingest analog via component or composite outs.

Again, I found the hardware conversion to be the winner over most NLE conversions. Especially with interlaced material.

Have a try & compare!

Doug, I like your air show , but I am afraid this is not the problematic footage we are talking about.
Instead, have a try with slow pans or zooms over straight lined objects like brick-lined houses or walls, mega-detail city overviews etc. I assume these are the shots that get critical when converted to SD.

Regarding shooting P or I: Its right, dont jugde your P footage over an LCD screen or the viewfinder. If played correctly in the NLE or a BluRay /DVD Player the shutter impression is less.
For shooting: I dont like shooting (PAL...) 25p. I find it often too difficult to quick focus or follow a person.
To my opinion (an broadcast opinion in general) 1080i is a good compromise as long as you have a way to downconvert to SD (DVD etc.) in a high quality. I dont agree that 50i (60i) is an old fashioned method. Its a compromise for motion as long as we dont have 1080 50p.

I recently shot a comedian piano concert in 25p and my customer complained: "Whats wrong with the motion when the comedians jump an and run around?". And my 2nd cameramen complained: "it was so hard to be in focus". That was a test for me. And the reason why I will shoot most of my footage interlaced again (had an ice show yesterday - fantastic!).

ULI

Alister Chapman
December 20th, 2010, 09:26 AM
Downconverting progressive material is the least problematic because you can simply divide the vertical and horizontal pixels by a near symmetrical amount to get the smaller frame size you want. Interlace is much harder as first you must separate out the fields and then you have to divide each field by an asymmetric amount. In the case of NTSC you have to drop every other line, plus an additional line every 4 lines, for PAL you drop every other line for 3 lines then keep a line. This un even number of dropped lines can lead to stair stepping and artefacts. The problem is even worse if you convert to DV as the DV field order is reversed and many NLE's will make a complete hash of this.

The next problem is the need to include some form of low pass filtering in the down conversion process to reduce the high frequency components in the HD image. Just as a decent video camera will have an optical low pass filter to eliminate aliasing, we need to do the same with any video downconversion. I posted some examples of this on my web site.
XDCAM-USER.com Getting SD from HD and the problems of oversampling. (http://www.xdcam-user.com/?p=443)
One cure is to add a 3 pixel blur to the HD image before you down convert it. The difference in the final down converted image can be quite striking.

Les Wilson
September 8th, 2011, 03:48 PM
This is now the location of Alister's article:
Getting SD from HD and the problems of oversampling. | XDCAM-USER.COM (http://www.xdcam-user.com/2009/11/getting-sd-from-hd-and-the-problems-of-oversampling/)