VobSub subtitles not rendered correctly when subtitle dimensions differ from video dimensions
When playing a video file which has embbed vobsub subtitles from a DVD the subtitles are squashed. The subtitles were embbed to the file with a passthrough method, so no dimension information on them was changed. The video however was cropped to remove letterboxing so the video dimensions were changed from the original.
The same behavior was observed on two different versions: 2.1.6 on Linux and 2.2.1 on Windows.
How the subtitles look on the original DVD.
How VLC is expected to render the subtitles when they're embbed in the cropped video. VLC cannot currently render subtitles outside the video dimensions so this approach would be the most correct one. This screenshot was taken by exporting the subtitles to external .idx and .sub files and changing the video dimensions in the .idx to match those of the video (from 720x576 to 718x426).
How VLC actually renders the subtitles (as of version 2.2.1).
Expected behavior would be VLC figuring out that cropping (and possibly scaling) happened and figuring out the correct way to render the subtitles based on the video's dimensions, the video's aspect ratio and the original dimensions stored in the idx.
How to reproduce
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Download a transcoder that can rip DVDs and do subtitle passthrough (such as Handbrake).
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Rip an anamorphic widescreen DVD, crop the black bars above and under the picture. Enable subtitle passthrough and embbed at least 1 subtitle track of any language.
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Play the produced file with VLC and observe the phenomenon described above.
I can also provide an example file with embbed subtitles and external .idx and .sub files, but the package would end up being rather large (~1.5 GB).
Moved sample file to: http://streams.videolan.org/issues/14847/