[vlc-devel] Seeking opinions

tony hugh1234 at mail.ustc.edu.cn
Wed Sep 9 06:41:27 CEST 2015

First, all the subtitle tracks already exists,
which is taken care of by the input.c file.

My goal is, the user is allowed to choose a 2nd
subtitle from the same list of the 1st subtitle.
And the user should be allowed to set a style for
each one, for example, 1st on bottom, 2st on top.

Currently, I set a special flag to indicate
the order of the subtitle,
so that the decoder render it differently,
according to the user setting. Therefore,
the overlapping problem is solved.

As for how that helps:
Normally, I select two SPU ES at the same time,
with one decoder for each SPU ES.
if the user did choose the the same
track for the 2nd as the 1st, then shouldn't we
display it?
In this case, I assign two decoders
to the same track, but the two decoders are
not the same!
Because they may place the sub at different
location with different style.

As the Unix philosophy says:
"mechanism, not policy."
I think it's very possible that
one track should be decoded in multiple different
ways with multiple style.

For example, with this feature implemented,
a user is able to play the same audio twice
with a certain delay to acquire
a “Duet" like effect,
without writing a new decoder!

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