Changing a file name requires this change, usually...

Results in wrong position if only one track has bitrate info.

Limits memory size allocation that could have been triggered by
a file, due to chapters array for reordering.

Lowercase or mixed case identifier are legit.
reverts 03c69b44

This fixes memory leaks when seeking or dropping frames for other reasons.

close #8927

This should make 100% 3dB lower

Should close #9371

Also rename dirac to diracsys to disambiguate from the encoder.

If you missed the fact that recursive makefiles are harmful, there is
plenty of documentation online (try "Recursive makefiles considered
harmful"), or ask the libav developers for the more concise version.

This change and the previous ones, are particularly boring though. The
main motivation is to eventually address #9397, after the same change is
applied to codec/, demux/ and possibly a few other subdirectories.

Note that some more simplification between Makefile.am files and
configure.ac is definitely possible - if someone is bored.

This is just a step toward less recursion.

libasound2 seem to cause spurious test suite failures.

On Windows, it seems people expect volume keys to control the master
volume...
I'm not going to fight this fight with our users during support...

Ref #9373

Should close #9375
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>