Cropping with Avisynth in Hybrid?

[RolledJoel]

Hello. I would appreciate some feedback on my hybrid crop settings? I am new to this but eager to learn. The source is a VHS PAL tape. If I force 4:3 output without 5:4 input the picture squeezes in a lot. 12 pixels is enough to take out the head switching noise at the bottom. I have taken 16 off the right as there is some color distortion which I would like to mask further but not sure if it's feasible.

I have attached a photo with my settings.

Thanks, Joel

[Selur]

Those settings make no sense.
4:3 is a DAR(=display aspect ratio) not a PAR (pixel aspect ratio).
=> read up on what those mean and how they interact
I'm not really sure what you want to achieve. Best share a small sample of your unprocessed source.

Cu Selur

[RolledJoel]

Quote:

Originally Posted by Selur

Those settings make no sense.
4:3 is a DAR(=display aspect ratio) not a PAR (pixel aspect ratio).
=> read up on what those mean and how they interact
I'm not really sure what you want to achieve. Best share a small sample of your unprocessed source.

Cu Selur

I will look into this and post a sample of the uncompressed footage when I'm at the PC in a few hours.
Thanks for the feedback.

Joel

[RolledJoel]

Quote:

Originally Posted by Selur

Those settings make no sense.
4:3 is a DAR(=display aspect ratio) not a PAR (pixel aspect ratio).
=> read up on what those mean and how they interact
I'm not really sure what you want to achieve. Best share a small sample of your unprocessed source.

Cu Selur

Here is a quick sample of the source. It's late here now and I haven't managed to get time to look into what you suggested. Any information you may pass over in the meantime will be appreciated.

The goal is to play on a modern TV/Monitor. Ideally, I would like to focus on getting my brain around cropping at the moment before moving on to implementing filters.

Cheers,

Joel

[Selur]

Modern TVs should have no problem with correctly interpreting PAR flags.
What I would do, looking at the file as a basic start:

• it is flagged with a 1:1 PAR (PAL DV usually has a PAR of 1.066 <>533:500 (=> overwriting Filtering->Crop/Resize->Base->Pixel Aspect Ratio (PAR)->Input PAR to 533:500)
• Not knowing what output resolution and output PAR you are aiming (=> setting 'Filtering->Crop/Resize->Base->Pixel Aspect Ratio (PAR)->Convert output to PAR' to '1:1')
• Cropping black bars and noise at the bottom (using: 0:0:26:10)
• Optionally I would adjust the outpur resolutoion by setting 'Filtering->Crop/Resize->Base->Picture Resize->Target resolution->Width' to '704'. (height is automatically adjusted to 540)
• Source is only flagged as interlaced without scan order info, Hybrid assumed 'bff', but for the source 'tff' is correct. (=> enabling Filtering->(De-)Interlace/Telecine->Deinterlace/Telecine Settings->Overwrite input scan type' and setting it to 'top field first')

Additionally, I would:

• use Balanced Borders to lessen the yellow stain on the right side. (I would also move the 'Balanced Borders' filter below the 'Crop' filter, so that it's easier to get the BalancedBorder-values.)
• test different denoise/degrain/dehalo/sharpening/.. filters to see what works well with the source
• last but not least, I would tweak the colors&gamma a bit

Depending on what your MediaPlayer is capable of I would at the end convert the content to H.264/H.265 or AV-1.
Normal MediaPlayers should automatically add black borders and resize during playback to match to target device.
Letterboxing and using a specific output PAR other than 1:1 usually only is required if you want to create DVD, Blu-Rays or similar, but then you should know what you need.

Cu Selur

[RolledJoel]

Thank you for your analysis.

A few questions. Why would the PAR not be set correctly in the source? Is it something I'm doing wrong in capture? I live in the UK and set the filter to PAL I. If I aim for 1:1 Square PAR am I right in thinking this will have less issues playing on modern screens? And if I'm wrong what is the best use case for implementing 1:1 PAR vs not. I was originally planning to keep the resolution the same. I am interested to see how 720p/1080p looks. How would I scale to adjust for this?

For reference I'm using a Thomson VSH 2080 which is based on one of the JVCs with a TBC. I'm going to send you another sample with filters off, it does say to do this for further editing in the manual. I don't have much of an eye for color accuracy. I would be interested to see what your thoughts are. I have a Panasonic HS-1000 I bought serviced which is currently being repaired in Germany under warranty which I can't wait to get back. The audio is not great on the Thomson.

Thanks

Joel

[Selur]

Quote:

Why would the PAR not be set correctly in the source? Is it something I'm doing wrong in capture?

I don't think you are doing anything wrong, analog capturing usually comes without that info. Other here probably can elaborate on that.

Quote:

If I aim for 1:1 Square PAR am I right in thinking this will have less issues playing on modern screens?

Modern (and old) consumer screens are all 1:1 only and any decent player from the last 20 years should handle anamorphic pixels, but yes 1:1 PAR should be more compatible.

Quote:

I am interested to see how 720p/1080p looks. How would I scale to adjust for this?

Denoise&filter then use whatever upscaler produces the base result, but given the lack of details, I doubt there is much to gain compared to the normal upscalers the screen or player uses.

Got no thoughts about the capturing, since my last capture was 25+ years ago, but I'm sure other users here in the forum can chime in on that.

Cu Selur

[RolledJoel]

Quote:

Originally Posted by Selur

I don't think you are doing anything wrong, analog capturing usually comes without that info. Other here probably can elaborate on that.

Modern (and old) consumer screens are all 1:1 only and any decent player from the last 20 years should handle anamorphic pixels, but yes 1:1 PAR should be more compatible.

Denoise&filter then use whatever upscaler produces the base result, but given the lack of details, I doubt there is much to gain compared to the normal upscalers the screen or player uses.

Got no thoughts about the capturing, since my last capture was 25+ years ago, but I'm sure other users here in the forum can chime in on that.

Cu Selur

Great stuff. It's nice to see developers who dedicate time to their users.

One last question and I'll leave you to enjoy your weekend. I think I'm being blind, where is crop/resizing in filtering?

[Selur]

Quote:

I'm being blind, where is crop/resizing in filtering?

"Filtering->Crop/Resize" should be "Crop/Resize".

Cu Selur

[RolledJoel]

Haha fair enough. You had me on a roundabout lol. Have a great weekend.

[lordsmurf]

Lossless captures exist in a fairly raw and basic form. No flags for AR, no flags for interlacing. And that's by design. You must set the correct values when using the files. That means you must also know the values. So, for example, for analog videotape captures from anything other than DV, it's TFF. And the SAR is always 1:1, 720x480 PAR is 3:2, and the eventual DAR should be 4:3 (minus the 16px pillars).

[RolledJoel]

Quote:

Originally Posted by lordsmurf

Lossless captures exist in a fairly raw and basic form. No flags for AR, no flags for interlacing. And that's by design. You must set the correct values when using the files. That means you must also know the values. So, for example, for analog videotape captures from anything other than DV, it's TFF. And the SAR is always 1:1, 720x480 PAR is 3:2, and the eventual DAR should be 4:3 (minus the 16px pillars).

Does it have to be 16 pixels exact or within? If I crop 2 more pixels from the bottom I can eliminate the head switching noise entirely. Which gets me to a final resolution of 708x540. I'm assuming by pillars you mean within.

[Selur]

ignore the DAR, simply set the PAR and crop,...

[RolledJoel]

Quote:

Originally Posted by Selur

ignore the DAR, simply set the PAR and crop,...

Where is the balanced borders filter in vapoursynth? I see it in avisynth under ‘other’

Also, is it possible to utilise the GPU with M.264 or is this only a feature with AV-1?

[Selur]

Depends on whether your graphic card has an encoder chip for it.
There is QSVEncC (for Intel cards), VCEEncC (for AMD cards) and NVEncC (for NVIDIA cards) which all offer support for different hardware encoders.