[FFmpeg-devel] DVB Subtitles

Reimar Döffinger Reimar.Doeffinger at gmx.de
Tue Jun 17 09:42:19 CEST 2014

On 17.06.2014, at 09:19, JULIAN GARDNER <joolzg at btinternet.com> wrote:
> Now a question for the list.
> If we take a HD stream, 1280x720 and have subtitles which are based on 720x576, what should we do if we have resized the video to 640x360, should we remap the subtitles to be in the same place or just leave them as is?

Without rescaling, remapping will improve things only minimally.
In containers like MKV this is solved by storing the original video size as dimensions of the subtitle stream, and we should do that.
For formats where this information can't be stored it might make sense to just refuse muxing if the subtitle dimensions do not match any of the video streams.

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