[HELP] how to crop 720×480 to 1920×1080 without stretch?

[ssdde]

to keep original ratio, if i set 1920, it will set height to 1280 automaticly,




if i uncheck "Auto ajust", set 1920×1080 manually, the encoded picture is stretched, so how to crop 720×480 to 1920×1080 without stretch?

and what's the mod value for in the Auto ajust?

i using Vapoursynth , nnedi3 16×6 spline64, thanks.

[Selur]

Your input has a resolution of 720x480, with a PAR of 8:9 and you probably want to resize to 1920x1080 with a PAR of 1:1.

So first, Enable "Crop/Resize->Base->Pixel Aspect Ratio (PAR)->Convert Output to PAR" and select 'Square Pixel (1:1)'.
This will then automatically enable "Crop/Resize->Base->Resize" and should show a target resolution of 720x540 which happens if the height is adjusted according to the PAR change.
If you now change the width value of "Crop/Resize->Base->Picture Resize->Target resolution" to 1920 you see that resizing the width to 1920 would require the height to have a value of 1440 to avoid distortions.
So to get to the output resolution of 1920x1080 without distortions you got two options:
1. crop parts from the top and bottom of the image so that the resolution after the cropping is 720x360 (cropping 60 from the top and bottom)
or
2. tell Hybrid to resize to an output height of 1080 and then letterbox to archive the resolution, for this you
2.1 change "Crop/Resize->Base->Picture Resize->Auto adjust" to "width" and enter 1080 as target width (now the output resolution would be 1440x1080)
2.2 enable "Crop/Resize->Base->Letterbox" and set the width to 1920 and the height to 1080.

Cu Selur

Ps.: you should read up on stuff like what aspect ratio of videos mean.

[ssdde]

Your input has a resolution of 720x480, with a PAR of 8:9 and you probably want to resize to 1920x1080 with a PAR of 1:1.

So first, Enable "Crop/Resize->Base->Pixel Aspect Ratio (PAR)->Convert Output to PAR" and select 'Square Pixel (1:1)'.
This will then automatically enable "Crop/Resize->Base->Resize" and should show a target resolution of 720x540 which happens if the height is adjusted according to the PAR change.
If you now change the width value of "Crop/Resize->Base->Picture Resize->Target resolution" to 1920 you see that resizing the width to 1920 would require the height to have a value of 1440 to avoid distortions.
So to get to the output resolution of 1920x1080 without distortions you got two options:
1. crop parts from the top and bottom of the image so that the resolution after the cropping is 720x360 (cropping 60 from the top and bottom)
or
2. tell Hybrid to resize to an output height of 1080 and then letterbox to archive the resolution, for this you
2.1 change "Crop/Resize->Base->Picture Resize->Auto adjust" to "width" and enter 1080 as target width (now the output resolution would be 1440x1080)
2.2 enable "Crop/Resize->Base->Letterbox" and set the width to 1920 and the height to 1080.

Cu Selur

Ps.: you should read up on stuff like what aspect ratio of videos mean.

thanks. so in option1, the picture quality will loss some effective coverage? because 720x480 crop to 720x360, in especial it will crop top and bottom, not left and right black side.

in option2, is it need to check "Custom" in letterbox?  and letterbox is used for some custom crop?

[Selur]

so in option1, the picture quality will loss some effective coverage? because 720x480 crop to 720x360, in especial it will crop top and bottom, not left and right black side.

yes, but if your input image has black bars crop all of them and if you want to archive a resolution add back black bars using letterbox.

in option2, is it need to check "Custom" in letterbox? and letterbox is used for some custom crop?

Letterbox does not crop. It adds borders to the active image to archive a given resolution.
read: https://en.wikipedia.org/wiki/Letterboxi...filming%29
By default Hybrids letterbox the source to center the active image, if you want to have a centered image use 'custom' otherwise don't.

Cu Selur

[ssdde]

so in option1, the picture quality will loss some effective coverage? because 720x480 crop to 720x360, in especial it will crop top and bottom, not left and right black side.

yes, but if your input image has black bars crop all of them and if you want to archive a resolution add back black bars using letterbox.

in option2, is it need to check "Custom" in letterbox?  and letterbox is used for some custom crop?

Letterbox does not crop. It adds borders to the active image to archive a given resolution.
read: https://en.wikipedia.org/wiki/Letterboxi...filming%29
By default Hybrids letterbox the source to center the active image, if you want to have a centered image use 'custom' otherwise don't.

Cu Selur

OK, thank you. and what's the mod value stand for in the Auto ajust? there are many digital values.

[Selur]

The mod value tells Hybrid through which number the output resolution should be evenly dividable by.
Usually 2 is fine. (You get a bit more compressibility when higher values are used, but that gain in compressibility is usually neglectable.)

Cu Selur

[ssdde]

The mod value tells Hybrid through which number the output resolution should be evenly dividable by.
Usually 2 is fine. (You get a bit more compressibility when higher values are used, but that gain in compressibility is usually neglectable.)

Cu Selur

yeah. i tried the option2 way, the encoded file is nice, no picture quality loss. is it equal to set 1440×1080, then set letterbox to add black area to both left and right? to get 1920×1080? thank you very much.

[Selur]

then set letterbox to crop left and right black area to 1920×1080?

Letterbox does not crop it adds borders.

But, happy it worked like you wanted.

Cu Selur

[ssdde]

then set letterbox to crop left and right black area to 1920×1080?

Letterbox does not crop it adds borders.

But, happy it worked like you wanted.

Cu Selur

thank you, Hybrid is so powerful, it helps a lot, if i can master all the setting it will be great.

---

but i feel the auto adjust way result 1920×1280 quality is a little better than the 1920×1080 through letterbox,

is it because using the 1920×1080 way, the real picture is 1440×1080, and i using NNEDI3 to scale to 1920×1280, it gets over the FullHD quality, but 1440×1080 way is not reach the FullHD standard? is it right?