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-   -   Upsampling software (https://www.dvinfo.net/forum/non-linear-editing-pc/481705-upsampling-software.html)

Paul Nixon July 11th, 2010 10:47 AM

Upsampling software
 
I've been pretty impressed with the upsampling results of my DVD player - obviously not going to reproduce data that's not there, but the image quality is very good.

I'm curious if there is upsampling software that I can apply to some video clips - upsample to HD and then crop and downsample.

Much of what I've found thus far is for playback only. I've seen ffdshow suggested but others say it's been dead since 2004 and to use ffdshow-tryouts. But much of the discussion seems to be aimed at upsampling audio for playback in Media Center.

I'm looking for something that will take DV mpg, output to HD mpg/mov/avi/etc that I can crop/downsample, then output to DVD.

Thanks.

Randall Leong July 11th, 2010 12:01 PM

Unfortunately, since SD MPG is already lossy-compressed, you will degrade image quality every time you convert formats. What complicates the matter more is the fact that standard-definition DV is interlaced - and most converters can only resize progressive-scan footage properly (they deinterlace and sometimes resize using the wrong alogarithm). Trying to resize interlaced footage with most video transcoders will result in severe artifacting.

To properly convert 480i SD DV or MPEG to an HD requires a good deinterlacer (such as YADIF), a bob/weave deinterlacer and a Lanczos resizer. You will have to know all of the command-line language for the particular program (such as the AVISynth/VirtualDub combo) in order to use this stuff correctly. Otherwise, your results will be no better than the already poor job most "simple" transcoders do.

The worst thing to do is to upconvert SD to HD and then downconvert back to SD. This will severely degrade image quality (because upconverting SD to HD will not regain the information lost in the original encode, and then downconverting that back to SD will remove even more information)! Simply put, if you upsample 480-line video to 1080 lines and then downconvert that back to 480 lines, you will end up with the image quality of a video that has only 213 lines (you will effectively end up with only a 213i video as the end result). Instead, SD footage should be handled only in SD if the final output is to be SD DVD. The only time that SD footage should be upconverted to HD is if you're trying to make an HD compilation in HD (for authoring on a Blu-ray disc) and you need all of your footage to exactly match one another in terms of resolution (image size).

In other words, there is no way at all whatsoever for you to do what you were asking in the original post (which is upconverting SD to HD and then downconverting that upconverted HD back down to SD) without SEVERE loss in image quality. Doing it your way will end up producing an effective 213i or 320i video (and not the original 480i video) because downconverting will always degrade resolution.

Paul Nixon July 11th, 2010 05:05 PM

Thanks very much for the detailed reply Randall,

There are two things I'm hoping to accomplish in this. 1) to get rid of the onscreen time/date/battery condition that was used during the recording and 2) to try to zoom in on the person of interest. The footage is of high school football games shot from the stands so not much focus on the person with the ball.

I know the quality will degrade some, but this article got me thinking: Autumn 2007 Video Processing Face Off

I'd like to output the 1080p upsampled content to a file rather than a display, then import that file into an editor, then apply a moving DV resolution crop and output that footage to DVD. Unfortunately it sounds like there are some major issues.

I guess I could simply connect the HDMI output from the DVD player to an HDMI recorder to get the 1080p files, but that sure sounds like doing it the hard way, and I don't even know if that would work.

Randall Leong July 11th, 2010 05:38 PM

Quote:

Originally Posted by Paul Nixon (Post 1547508)
Thanks very much for the detailed reply Randall,

There are two things I'm hoping to accomplish in this. 1) to get rid of the onscreen time/date/battery condition that was used during the recording and 2) to try to zoom in on the person of interest. The footage is of high school football games shot from the stands so not much focus on the person with the ball.

I know the quality will degrade some, but this article got me thinking: Autumn 2007 Video Processing Face Off

I'd like to output the 1080p upsampled content to a file rather than a display, then import that file into an editor, then apply a moving DV resolution crop and output that footage to DVD. Unfortunately it sounds like there are some major issues.

I guess I could simply connect the HDMI output from the DVD player to an HDMI recorder to get the 1080p files, but that sure sounds like doing it the hard way, and I don't even know if that would work.

Oh, yes, you were trying to crop an image that had been shot with a zoom lens that could not optically reach all the way out there. In that case, then, you will need AVISynth, VirtualDub and the YADIF deinterlace filter for AVISynth. Upsizing interlaced footage to anything will almost always result in artifacts. In other words, you cannot resize interlaced footage without deinterlacing first.

Craig Coston July 11th, 2010 06:11 PM

I won't write a thousand word essay on why it IS possible. Instead, I'll just post a link to a reputable software company that has a solution for you. There are other companies that have this capacity in software as well.

Red Giant Software: Magic Bullet Instant HD 1.1

If you want to deinterlace first, try their Frames software too. This is the same company that makes Magic Bullet Looks.

Paul Nixon July 12th, 2010 11:14 AM

I do believe that is exactly what I'm looking for. Thank you. I'll check the trial version and see how it looks.

Have you any idea if this is similar to what Premier CS5 does? I don't have that package but saw a reference to its "upsample" tool.

Paul Nixon July 12th, 2010 11:19 AM

Quote:

Originally Posted by Randall Leong (Post 1547517)
Oh, yes, you were trying to crop an image that had been shot with a zoom lens that could not optically reach all the way out there. In that case, then, you will need AVISynth, VirtualDub and the YADIF deinterlace filter for AVISynth. Upsizing interlaced footage to anything will almost always result in artifacts. In other words, you cannot resize interlaced footage without deinterlacing first.

Thanks Randall,

Unfortunately, the source footage wasn't even zoomed most of the time. I'm hoping that by upsampling to a higher resolution and then only using a DV size crop will produce at least some zoom.

I'm going to take a look at Craig's suggestion because, thus far with the tools I have, I'm seeing a lot of what you've been saying. My last try was with Neo - the resize actually looks pretty good *on screen* (i.e. on my computer monitor) prior to rendering it out to m2t (I think it's using HDV compressor), but the m2t file looks pretty mushy. I am going to continue experimenting to get a feel for it, but the Magic Bullet Instant HD looks like a good option.


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