Fix cid #1048765

This test is always true. Moreover, strrchr does handle empty strings.

This no longer assumes that planes are contiguous. It should help with
libav reference counting, and also avoids interleaving unused padding.

Regression from 5989169a and ticket #7558

Close #9124

Yeah, yeah, such a clever idea, thx...
Let' not use TRACKTOTAL or TOTALTRACKS or TOTALTRACK or TRACKSTOTAL,
because you know, there is not enough options...
Oh, and let's not make ANY of the above official in the spec, because
then, people could follow the spec...
https://www.xiph.org/vorbis/doc/v-comment.html

Next time, please use mkv...

(regression from 46f782a9)

(since the callbacks do not know the actual offsets)

closes #8981
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Currently, the period time is more critical, so constrain it first.
Both values are interdependant with some drivers.

This is not fool proof, as the run-time version is not checked.
But versions 0.4/0.5 crash due to a bug in the libvdpau DRI2 code.

This reverts commit a08cf819.