HD to SD Challenge

amendegw wrote on 11/24/2010, 1:24 PM

All,

There's been much discussion recently about how to downrez HD source for SD DVD production. I propose a challenge (I'd call it a contest, but there's no prizes).

I shot a short, 10 sec clip under (what I thought) were the worst conditions for downrezzing HD to SD: a stationary figure with a a moving, high contrast, fine detailed background. The clip is 1920x1080 60i AVCHD. The Challenge is to get the best balance of sharpness while eliminating the flicker in the background.

I tried to downrez this clip and got good sharpness, but horrible flicker/moire patterns by adding the Sharpen FX = zero. Adding a Vertical Gaussian Blur of .002 minimized the flicker/moire, but caused too much loss of resolution in the central figure. I uprezzed the results to 720p and sent them to YouTube:

So, here's the rules of the Challenge:

1) Download and start with the clip in this link: AVCHD.zip
2) Render the clip to an NTSC 720x480 Widescreen format for import to DVDA.
3) All work must be done within Vegas.
4) Render to an intermediate format is okay.
5) Masking and/or keyframing are not allowed.
6) The objective is to get the best resolution while eliminating the flicker.
7) If you are tempted to post, "Can't be done" or "start with a different format" or something similar, please don't post a reply.
8) Uprez the results of your efforts to the web and post the link in this thread (YouTube is nice because it can be embedded, but any web link is okay).
9) Tell us how you accomplished the results - Workflow, FX's applied, Project Settings, Render settings, etc.

Any takers?
...Jerry

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Comments

PeterDuke wrote on 11/26/2010, 3:04 AM

I find the use of Cineform HDlink to be a fairly straightforward procedure and gives good results in resizing down without too much moire or other artefacts.

The only nuisance seems to be that the AVI file is not flagged widescreen (regardless of whether the "Keep source aspect ratio" is ticked or not), necessitating a subsequent fix to the clip properties in Vegas.

amendegw wrote on 11/26/2010, 3:36 AM

[I]"{Dan} uploaded 720p video to YouTube.

What this means is that the video is not 720x480 but instead is 1280x720. The less the video is subsampled, the fewer problems you'll have with the artifacts we've been talking about. As another poster said, I'd like to see the 720x480 MPEG-2 file rather than something that has been changed to a high resolution, deinterlaced and changed to progressive, uploaded to YouTube, resampled by YouTube, and then displayed on my computer screen. All those extra steps create a completely different workflow than what was initially asked for in the original post."[/i]Yeah, I probably should not have made the "YouTube" request in the original post - hence my request to Dan (David) to post an ftp download link to his SD interlaced clip.

When I made the original post, my testing suggested that we could get "a close-enough comparison" by uprezzing the SD and uploading to YouTube - and forum participlants could view the results by merely reading this thread. In other words, I viewed my render (to 780x480 60i) referenced in my original post and comparied it to the uprezzed progressive that was set to YouTube and they looked pretty close. Actually, if I was descerning, the YouTube video was worse - some fringe artifacts around the edges of the figurine. I think we have now gone beyond that point and the only meaningful comparisons are apples-to-apples/side-by-side SD interlaced clips. My bad.

...Jerry

PeterDuke wrote on 11/26/2010, 3:46 AM

Yes, but it still begs my question earlier, "how do we compare interlaced mpg files on progressive gear" (such as computers and flat panel TVs, which may have different ways of deinterlacing).

amendegw wrote on 11/26/2010, 4:02 AM

@PerroneFord: "...the discussion has morphed."That's okay - let's keep this discussion going it's very educational.

"Neither Squeeze nor Avid support MTS files, so I did the initial conversion in Vegas and created a DNxHD 220x 60i file. I took that file into Squeeze, selected Mpeg2 16x9, and set VBR of 9.5k/9.2k/9.0k for my Max/Avg/Min respectively. That process created this file:That's very, very good. I just wish we didn't have to spend $600 for Squeeze or $500 for HD Link to get this kind of quality. That might not be expensive for folks who regularly produce Standard DVD's, but for those of us who mostly do web work, and only make less than a half dozen DVD's per year, it pretty steep.

...Jerry

amendegw wrote on 11/26/2010, 4:15 AM

@musicvid: "On another note (you knew this one was coming, Jerry), here is the same thing rendered to 480p in Handbrake."Yeah, as with my reply to Perronford... "Let's keep this discussion going" it's very educational.

Here's a thought (and I haven't thought it through, so go ahead and throw tomatoes). What if you were to use Handbrake to to downrez the source to high bitrate progressive and then use Vegas to render this to MainConcept NTSC DVD Widescreen?

...Jerry

Edit: Whoa! I did my own test and the results are here: FromHandBrake.zip To my eyes, when compairing to Perroneford's Sorenson Squeeze, the Handbrake result appears to be sharper (I added Sharpen=0 in Vegas), however there are more residual (though minor) moire. However, I'm concerned over the 60i -> 30p -> 60i process. Motion is low here. Will this cause problems if there was more movement?

PeterDuke wrote on 11/26/2010, 5:10 AM

" I just wish we didn't have to spend $600 for Squeeze or $500 for HD Link to get this kind of quality"

I don't think you need HD Link. Neoscene ($99 at VideoGuys) may do just as well.

I loaded our AVCHD.MTS into Vegas with matching project and deinterlace set to none. I then rendered it to Cineform 720x480 with deinterlace set to none. I also tried setting the same info in Cineform codec properties or leaving the settings at automatic. The file sizes were slightly different but the quality seemed the same.

Somebody with better eyesight and who is more experienced in looking for artefacts may see a difference between these methods but they were as good as the same to me.

One thing you get with HD Link though is batch processing. This may not be missed if you edit your project in HD and output the lot as a Cineform SD AVI. Then load it back into a Vegas SD project to make your DVD mpeg.

This load back in and rerender is a bit of a nuisance but in my case wouldn't take much of my time compared to the time to do the main editing.

amendegw wrote on 11/26/2010, 5:29 AM

@PeterDuke:

Any chance you could post an download link to you final .mpg file?

Cost of Neoscene is certainly do-able. I downloaded the trial a year or two ago, but looked at it from the perspective of ease of editing, and found that direct editing of AVCHD was not that problematic for me (on my Desktop/Q9950). Also, concerned that I would need two licenses - one for my laptop on one for my desktop. However, the whole subject of HD to SD may put a new light on this subject.

...Jerry

farss wrote on 11/26/2010, 5:50 AM

Seeing as how this discussion has drifted off into spending money buying 3rd party tools etc I feel I really must ask what to me is a very obvious question.

How did you manage to shoot such bad HD in the first place. If you'd done something deliberate just for the challenge then fine, you don't have to let the cat out of the bag. If not then I have to say you've managed to create a problem that I've never had to wrange shooting with a number of HDV cameras. I haven't really tried to 'break something' by deliberately waving fine patterned cloth in front of any of them but I've just never seen a hint of such a problem happening either and I do shoot a fair amount of content with lots of detail in front of the camera.

Bob.

ECB wrote on 11/26/2010, 5:56 AM

Caution! NeoScene HDLink does *not* have the resize option. NeoHD and above, support the resize option.

-Ed B

musicvid10 wrote on 11/26/2010, 6:33 AM

"Here's a thought (and I haven't thought it through, so go ahead and throw tomatoes). What if you were to use Handbrake to to downrez the source to high bitrate progressive and then use Vegas to render this to MainConcept NTSC DVD Widescreen?"

Not throwing tomatoes here (they're too expensive), but that was actually the first thing I tried. My attempts to go from x264 to MainConcept MPEG-2 were frustrating, as they have been in the past, even at 8Mbs CBR. Lots of pixel clumping and other junk. I have much better luck going from say, HDV to x264, but the return trip is a bumpy flight.

I also have to run my HB encodes through AVIDemux to get them to open in Vegas.

@Perrone -- Thanks for the comment on Vimeo!

amendegw wrote on 11/26/2010, 6:35 AM

@farss: "How did you manage to shoot such bad HD in the first place. If you'd done something deliberate just for the challenge then fine, you don't have to let the cat out of the bag"Yes, that's exactly the case. I attempted to shoot a clip that would be the toughest HD to SD I could conceive. Yeah, if I wanted to shoot a clip of a hula dancer figurine for a real project, I would never have chosen that background. Not only is it a mess to downrez, but it's pretty awful from an artistic prespective.

It seems like (almost) weekly we see a post that asks the question, "Why does my HD to SD conversion look like crap?" I may be dreaming, but if we reach consensus re: how to take a really terrible clip and do a great job of this conversion, then we can tell the next poster... do A, B, then C. Or maybe: for the bulk of your project, you should do A, B then C, but for especially troublesome clips you should do D, E & F. Ideally, this would be a Vegas only solution, but it's starting to look like third-party products are required. As an aside, I want to educate myself (as well as others?) on this entire subject, and I'll speak for myself - I am becoming educated.

And finally, I produce a few DVD's each year and I'd like to apply best techniques to each project.

...Jerry

musicvid10 wrote on 11/26/2010, 6:45 AM

I've seen the assumption raised that the finished DVD should be interlaced. They can be progressive, in my workflow it seems to be an advantage.

amendegw wrote on 11/26/2010, 7:09 AM

@musicvid: "I also have to run my HB encodes through AVIDemux to get them to open in Vegas."Hmmm... the HB encode dropped into Vegas nicely for me. Wonder why? I did have to install some extra codec packages for Mercalli V2 SAL - MatroskaSplitter & ffdshow - could that be the reason?

Also, I may have been editing while you were posting. Did you have a chance to look at my FromHandBrake.zip referenced a few posts up?

...Jerry

PerroneFord wrote on 11/26/2010, 7:43 AM

I'm up for that. So do this:

Start a new thread and let's toss this up as a re-scale challenge.

Last night I created a clean center cut from the ISO 12233 chart. It has more than enough detail to push any codec we throw at it. It is available for download here:

http://exposureroom.com/members/PerroneFord/b8c1559a3775485c9bffa23a5dc1953b/

The file is 4096 x 4096 to fit within the constraints of Vegas.

I suggest we set some parameters like testing a specific codec (h.264, mpeg2, wmv, etc.), I also suggest we set parameters on finished size (NTSC/PAL SD, 1080p, 720p, 2k, etc.

I'll let you sort out the details. I'll be glad to participate once you figure out how you want to run it.

amendegw wrote on 11/26/2010, 11:56 AM

PerroneFord,

I love this type of testing and banter back & forth in efforts to figure out the best way of doing things. However, my mind is fried - just from attempting to moderate this thread.

Furthermore, I'm not sure I have the technical expertise to do a good job of "sort{ing} out the details" Virtually everyone in this thread knows more about this subject than I - that's why I proposed this challenge to the experts!

So... if someone would like to start a thread based on PerroneFord's ISO 12333, I say "go for it, great idea!".

...Jerry

amendegw wrote on 11/26/2010, 12:23 PM

@dan: "I did not follow the rules as I convert and scaled in HDLink to CineForm AVI first"

@PeterDuke: "I don't think you need HD Link. Neoscene ($99 at VideoGuys) may do just as well.

@ECB: "Caution! NeoScene HDLink does *not* have the resize option. NeoHD and above, support the resize option."I just spent about 2 hrs downloading the trial NeoScene and attempted to create a good NTSC 720x480 Widescreen .mpg - and failed miserably. I tried three different scenarios.

First, I used the Cineform app convert AVCHD.mts to a 1920x1080 .avi file. I did not see a re-size option (which agrees with ECB's comment).

Next (trial #1), I loaded the Cineform .avi into Vegas and rendered to MainConcept DVDA MainConcept NTSC Widescreen template. - No Joy!

Next (trial #2), I rendered the same project to Cineform 720x480 NTSC Widescreen .avi. Loaded that into a new project (matching the 720x480 file), and rendered to MainConcept - still No Joy!

Next (trial #3), I rendered to 720x405, Pixel Aspect Ration=1.000, Cineform .avi. Re-rendered that to MainConcept - still No Joy!

Am I doing something wrong? Or do I indeed need the HD Link with the resize option?

...Jerry (who is being to think he needs a life! {grin})

farss wrote on 11/26/2010, 12:38 PM

"I've seen the assumption raised that the finished DVD should be interlaced. They can be progressive, in my workflow it seems to be an advantage."

You can put progressive material into a SD DVD however it still gets played out as interlaced. Whilst some DVD players / TVs may avoid this you need to be quite careful how the content is edited and mastered to get it to work. As far as I know this only works for 24p which also means your content has to be 720x480. If nothing else you kind of exclude half the planet sighting that as a viable solution.

Bob.

PerroneFord wrote on 11/26/2010, 12:40 PM

In those steps, how did the .avi file look? Where are you losing the quality? Is it at the .avi creation step, or at the mpeg2 step?

amendegw wrote on 11/26/2010, 1:00 PM

"In those steps, how did the .avi file look? Where are you losing the quality? Is it at the .avi creation step, or at the mpeg2 step?"Pretty crappy in the .avi's, even worse in the .mpg's. It's interesting that when I played the 720x480; 1.212 Pixel Aspect Ratio Cineform .avi in WMP, it played as 4:3. I double and triple checked all my render settings and they looked fine. Also, dropped it in the Vegas timeline all was okay (but I guess it would have in a 16:9 project). The .avi wouldn't play at all in VLC.

...Jerry

PerroneFord wrote on 11/26/2010, 1:12 PM

That was meant for Bob, not for you man, since he came up with the idea of that test... :)

amendegw wrote on 11/26/2010, 1:16 PM

"That was meant for Bob, not for you man, since he came up with the idea of that test... :)"phew!! relief! {grin}

...Jerry

farss wrote on 11/26/2010, 1:33 PM

OK, but.
That would then become a thread about handling high resolution stills and producing a SD DVD from them. To the best of my knowledge no video camera on the planet can resolve 4K with that MTF. Over the years I have tried exactly this kind of thing using that chart and you do end up with a mess.
What I'll try to find the time to do is shoot a chart with a good HD camera (PMW-350) in interlace and upload a short file of it. I can record to either ProRes or I frame only mpeg-2 @ 220Mbps. I can obviously do this at 25fps and 30fps in both I and P. Might be interesting for people to have access to both.

Bob.

PeterDuke wrote on 11/26/2010, 2:14 PM

I see, it is not HD Link that is different between Neo Scene abd Neo HD, it is the cineform codec that both both Vegas and HD Link use.

I realise that what I have done is convert 60i to 30p and in the final step, the MPEG is still 30p, but flagged as 60i. (What's the proper name for that?) In the challenge video, there is no significant fast moving stuff to take advantage of 60 fields per second, so that didn't matter.

By the way, how do flat panel TVs handle 50i or 60i? Do they always convert to 50p (60p) or do at least some convert to 25p (30p) while throwing away a field?

musicvid10 wrote on 11/26/2010, 2:33 PM

"You can put progressive material into a SD DVD however it still gets played out as interlaced."
If it is being played through composite or svhs outputs, yes. A progressive DVD would be interlaced for playback, not such a difficult task.
A progressive player can output progressive video through HDMI, DVI, Component, or VGA, so why let the player deinterlace, which is basically a crapshoot?

"As far as I know this only works for 24p which also means your content has to be 720x480."
While 24p is commonly put on DVD movies, it is always flagged as 29.97 w/pulldown (for NTSC), because 24p is not part of the DVD spec, nor would it play smoothly on most sets.

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