Cropped Blu-ray/DVD rips, graphics-based subtitles squished or stretched
Posted: 16 Nov 2018 16:34
I'm not sure if this a bug per se or just a certain way of doing things, all I know is - with regards to graphics-based subtitles - Kodi and VLC do things differently and I think Kodi handles it better.
VobSub or PGS (graphics-based) subtitles have video dimensions encoded into them.
Most people who rip blurays or DVDs with horizontal or vertical black bars, crop these out.
The graphical subtitles however, usually remain untouched.
So if it's a blu-ray, the subtitles will say 1920x1080, but the video once it's been ripped might be around 1920x800 if it's a film shot in 2:35 ratio.
Herein lies the problem - the way VLC handles this mismatch, or rather, doesn't handle at all.
Kodi seems clever enough to notice this mismatch of subtitle dimensions and video dimensions, assumes the video has been cropped and renders the subtitles so they look no different to how they were originally.
Kodi however is intended to be run fullscreen.
VLC on the other hand, often running inside an adjustable window, does things differently.
It assumes nothing, and when given a graphics based subtitle with a mismatching video, VLC forces it into the video-space anyway.
I understand why this might be the default behaviour, some subtitles may be positioned in a cropped area of the video - if it's a widescreen 2:35 film, that subttitle might be in one of the black bars, but if the window is not fullscreen or is tightly hugging the video frame (ie, no black bars) some subtitles could appear partially or fully outside of the frame.
However, it is extremely rare for blu-ray and DVD graphics-based subtitles to render outside the frame of the picture (ie, in the black bars), so this default behaviour in the majority of cases will get it wrong.
I think Kodi has the right idea, and I'd like to see it implemented in VLC as the default behaviour.
At the very least there should be an option to handle graphics-based subtitles the way Kodi does.
VobSub or PGS (graphics-based) subtitles have video dimensions encoded into them.
Most people who rip blurays or DVDs with horizontal or vertical black bars, crop these out.
The graphical subtitles however, usually remain untouched.
So if it's a blu-ray, the subtitles will say 1920x1080, but the video once it's been ripped might be around 1920x800 if it's a film shot in 2:35 ratio.
Herein lies the problem - the way VLC handles this mismatch, or rather, doesn't handle at all.
Kodi seems clever enough to notice this mismatch of subtitle dimensions and video dimensions, assumes the video has been cropped and renders the subtitles so they look no different to how they were originally.
Kodi however is intended to be run fullscreen.
VLC on the other hand, often running inside an adjustable window, does things differently.
It assumes nothing, and when given a graphics based subtitle with a mismatching video, VLC forces it into the video-space anyway.
I understand why this might be the default behaviour, some subtitles may be positioned in a cropped area of the video - if it's a widescreen 2:35 film, that subttitle might be in one of the black bars, but if the window is not fullscreen or is tightly hugging the video frame (ie, no black bars) some subtitles could appear partially or fully outside of the frame.
However, it is extremely rare for blu-ray and DVD graphics-based subtitles to render outside the frame of the picture (ie, in the black bars), so this default behaviour in the majority of cases will get it wrong.
I think Kodi has the right idea, and I'd like to see it implemented in VLC as the default behaviour.
At the very least there should be an option to handle graphics-based subtitles the way Kodi does.