Handling Aspect Ratio when going from DVD sources to NLE?

[GMaq]

Hi VH folks, long time no post.. This was the first Web forum I joined early in the 2000's and I put my Video hobby on hold for a while and started an Audio Video Linux Distro called 'AV Linux' but that is another story..

I find I'm back to my roots and am kind of embarrassed to ask this question... In short I am revisiting my considerable Concert DVD collection and pulling together several sort of 'greatest hits' compilations destined for TV and projector viewing. These DVD's are from various sources including the dubious but seemingly legal err... uhm... 'import' market and some of this stuff is a real crapfest of multigenerational bounces and improperly digitized Video. That doesn't daunt me too much because I'm once again enjoying the magic of Virtualdub2 and my long unused NeatVideo plugin and I'm content with my abilities to clean up stuff while staying within the SD resolution. Although I have been dabbling with Topaz Labs VEAI I find with crappy footage I'm simply trading one kind of artifact for another, the AI models are constantly improving but I'm more happy with my results with cleaned-up SD sources leaning on the TV hardware upscaler than intermediate software upscaling to HD that gets upscaled on the TV to 4K anyway and I have zero interest in working with 4K Video, I can't believe the required resources, storage and processing time... insane!.

OK, to the point...

When I work with Video in Vdub at it's OG resolution (fullscreen either 704x480 or 720x480) I export a ProRes intermediate file and the aspect Ratio is shown to be 1:1. If I want to further work with the Video and do some blends and Titles etc in an NLE most Video Editors seem to have a variation of a 720x480 'NTSC' profile format that I assume is geared to creating DVDs and wants to enforce a 4:3 or 16:9 Aspect Ratio. If I import a 1:1 file that has been cropped and resized often 4:3 is incorrectly squeezed and of course this old material is fullscreen so 16:9 is out of the question, I do know that much at least..

What aspect ratio should I be editing and exporting from the NLE in? Just keep things 1:1 all the way through? I was quite stunned when I hit the NLE phase that I didn't really know what the proper way to handle this was after all these years..

Advice and time to give it much appreciated! TIA!

[Alwyn]

I gather I'm the only one here who does it and am scorned-upon for doing so, but as soon as I can, I go square pixels. That is, for an export out of VDub, I resize in VDub to 768x576 (for PAL) or in your NTSC case, 720x540, and Save Video. That's it. I then do not have any issues with DARs, SARs or PARs, squishes or stretches.

[DB83]

Actually, I see no issue with the above approach.

But do see an issue if the OP is exporting to ProRes before any other work. 1. There will be quality loss from mpeg2. 2. Does ProRes even have an Display Aspect Ratio flag so, yes, you simply get a 'Raw' result except that even that should be reported as 3:2 (5:4 for PAL)

[Alwyn]

Does ProRes even have an Display Aspect Ratio flag so, yes, you simply get a 'Raw' result except that even that should be reported as 3:2 (5:4 for PAL)

As far as I can see, the ProRes encoder in VDub2 doesn't have a flag-set feature, like the common AVIs, so if you "save video" in 4:3 ie 720x540, it'll display correctly in the NLE.

[GMaq]

Hi and thanks!

@Alwyn

Hmmm then I've already made a mess of some these, you're right and now I see it makes sense if there are no future AR flags coming down the line then keeping with the 720x480 NTSC DVD resolution (including new cropping) has been a recipe for trouble unless I export these from the NLE with an added 4:3 flag to correct things. 720x540 makes much more sense and actually that is a saner resized height for potential future upscaling to either 1080 or 2160. This was the kind of info I was looking for!

@DB83

You've mentioned quality loss, I thought (within VDub2) ProRes was my best option for retaining intermediate quality aside from uncompressed AVI?

[DB83]

^^ 'Quality Loss' is to some degree a controversial subject. Yet I hope that all can agree that a lossy format saved to even an uncompressed one looses 'real' quality from the original even if the end-user does not appreciate the actual loss with their own eyes.

[GMaq]

^^ 'Quality Loss' is to some degree a controversial subject. Yet I hope that all can agree that a lossy format saved to even an uncompressed one looses 'real' quality from the original even if the end-user does not appreciate the actual loss with their own eyes.

Ah, I see what you're saying... A necessary evil for some workflows, but of course the less steps in the process the better. The NLE situation complicates that too, ideally I'd pull the DVD sources into Davinci Resolve, make use of NeatVideo in there, color grade, resize and possibly even super scale from there, sadly it seems to not like importing MPG files, unless I've missed something...

[Sharc]

720x540 makes much more sense and actually that is a saner resized height for potential future upscaling to either 1080 or 2160. This was the kind of info I was looking for!

If upscaling to 1080 or 2160 is really in your plan, better do it right now in one step as every new re-size/re-encode of an already resized/re-encoded video (like your 720x540) adversely affects quality. Better avoid resizing of resizing and re-encoding of re-encoded stuff (exceptions confirm the rules).

[GMaq]

720x540 makes much more sense and actually that is a saner resized height for potential future upscaling to either 1080 or 2160. This was the kind of info I was looking for!

If upscaling to 1080 or 2160 is really in your plan, better do it right now in one step as every new re-size/re-encode of an already resized/re-encoded video (like your 720x540) adversely affects quality. Better avoid resizing of resizing and re-encoding of re-encoded stuff (exceptions confirm the rules).

The thing is it's not a definite and certainly not until Topaz VEAI etc. get better training for muddled sources like this and better optimized. My guess would be I really would only want to take very good or very rare unobtanium stuff to the next scaling level. For most things the TV (Bravia) is doing a surprisingly good job.

Speaking of scaling and understanding anything over 100% is a slippery slope what would you say is a safe zone for resizing cropped content in either dimension with Lanczos3? Like 115%?

[Sharc]

Speaking of scaling and understanding anything over 100% is a slippery slope .....

Where do you have this from? The point is that upscaling does not add any real details to the picture but upscales artifacts as well, so it's basically a futile exercise unless one has a specific reason why one needs to upscale. But yes, TV upscalers are very good these days and one can normally leave the uscaling to the native TV resolution to them.

Added:
You may know this already, but anyway: Before even thinking of vertical rescaling or resizing to square pixels make sure that your video is progressive, which means before rescaling/resizing:
- properly deinterlace interlaced video
- properly IVTC telecined stuff

[GMaq]

Actually for anyone following and doing DVD/VHS work..

I seem to be getting very good results taking the DVD/VHS content cropping and scaling to 640x480 in Vdub2 or Avidemux (unless deinterlacing is needed) exporting to FFV1/PCM and importing it into Davinci Resolve Studio and setting the timeline for 1280x960 and using super scale at x2 with the nVidia RTX setting. Running NeatVideo and color grading and other filters on the upscaled resolution seems to deliver better results than at 640x480. For interlaced content the Davinci Resolve neural deinterlacing is also excellent when used on the 720x480 DVD sources. No, not a free workflow but top shelf utilities for everything that is needed and a good quality upscaled final product. I want to do this once and be done with it..

[dellsam34]

Avoid low res to low res resizing at all cost, especially vertically, it degrades the video quality, Depends on your aspect ratio, resize to either 1920x1080 (16:9) or 1440x1080 (4:3) and work in this resolution.
I would strip the mpeg-2 codec into basic AVI 4:2:2, PCM 48KHz/16 audio, then de-interlace if needed, resize to HD, you can use HuffYUV a lossless compressor as a temporary format and import to your NLE for editing and special effects, once done export to h.264 in the same HD resolution with low CRF for better quality if storage is not an issue.

[GMaq]

Avoid low res to low res resizing at all cost, especially vertically, it degrades the video quality, Depends on your aspect ratio, resize to either 1920x1080 (16:9) or 1440x1080 (4:3) and work in this resolution.
I would strip the mpeg-2 codec into basic AVI 4:2:2, PCM 48KHz/16 audio, then de-interlace if needed, resize to HD, you can use HuffYUV a lossless compressor as a temporary format and import to your NLE for editing and special effects, once done export to h.264 in the same HD resolution with low CRF for better quality if storage is not an issue.

Hi,

I'm asking more questions to learn, not to counter what you're saying.. While I understand that adding vertical resolution is a very bad idea, isn't 4:3 flagged content from a DVD actually being resized 'visually' to 640x480? When you're looking at it in a 720x480 DVD resolution it's a/r is wrong so at some point it's going to have to be restored to either 4:3 or be forced to a 4:3 resolution ratio with square pixels so assuming it's progressive (I fully understand deinterlacing must be dealt with first at source resolution) what is the harm in cropping and squeezing pixels from improper 720 width to 640 before further processing?

[lollo]

I seem to be getting very good results taking the DVD/VHS content cropping and scaling to 640x480 in Vdub2 or Avidemux

Useless resizing applied here, keep original 720x480 4:3 DAR for further processing.

exporting to FFV1/PCM and importing it into Davinci Resolve Studio and setting the timeline for 1280x960 and using super scale at x2 with the nVidia RTX setting.

Useless step, upscale with AviSynth / nnedi3 to 1440x1080 (in specific cases Topaz VEAI may have an interest, but just as upscaler). Use Davinci only for its excellent color adjustement.

Running NeatVideo and color grading and other filters on the upscaled resolution seems to deliver better results than at 640x480.

In general is better to apply the denoise on the original capture/source prior to upscale, because you do not want to enhace the defects with the resizing. YMMV.

For interlaced content the Davinci Resolve neural deinterlacing is also excellent when used on the 720x480 DVD sources. No, not a free workflow but top shelf utilities for everything that is needed and a good quality upscaled final product. I want to do this once and be done with it..

If the content is really interlaced, another useless step. Use AviSynth and QTGMC.

what is the harm in cropping and squeezing pixels from improper 720 width to 640 before further processing

You won't use a 640x480 screen to exact pixel mapping, so any useless additional resizing you apply is degrading the quality. BTW, 720 is not improper; is the specification!!!

[dellsam34]

Yes, if you are going to apply some cleanup such as denoise, color correction ... etc. it is better to do it at the native resolution before you resize to HD.

[rgr]

Does ProRes even have an Display Aspect Ratio flag so, yes, you simply get a 'Raw' result except that even that should be reported as 3:2 (5:4 for PAL)

As far as I can see, the ProRes encoder in VDub2 doesn't have a flag-set feature, like the common AVIs, so if you "save video" in 4:3 ie 720x540, it'll display correctly in the NLE.

But you can set this flag later using MOVEdit.

[GMaq]

OK,

After trying a bunch of stuff and reading and re-reading the replies several times I'd like to thank all of the contributors for your time to answer and share your valuable knowledge. Since I already own the tools it seems following the wisdom here it is best to upscale now instead of staying in the SD realm and wreaking havoc with cropping and re-resizing in the SD resolution only to be sorry later when upscaling reveals all the losses incurred. Unfortunately Davinci Resolve Studio does not import MPEG-2 files but Topaz Labs VEAI does so I'm now doing DVD MPEG-2 directly into VEAI, deinterlacing, cropping and resizing to 1440x1080p square pixels and employing trial and error with the 'Proteus' model for careful denoising and sharpening. I'm exporting to ProRes with PCM Audio to minimize losses to get to the NLE and do final color grades, audio processing and titling etc. Even some pretty egregious Video is coming out surprisingly well so far... Will post some examples when they are finally edited and publishing-worthy..

While I appreciate the Avisynth suggestions and am often impressed with the results I've seen I've never gotten my head wrapped around it and VirtualDub w/frameserving is about as far down the rabbit hole as I ever got... I've never compared QTGMC directly with VEAI but I do know Topaz really upped their deinterlacing game in the last few VEAI releases and it is at least a significant improvement over YADIF..