Use a common function since most parsers did the same thing with minor
config params.
Also add extra validations to Cabela's DSP since it was hijacking other
DSPs.
Used to play separate intro+loop files, mask channels, play subsongs in
single files without having to demux, etc.
Also a channel mask parsing during main render_vgmstream.
It's not the easiest thing to follow so here is what's going on with
STREAMFILEs:
- external player opens base-streamfile, with a base FILE
- meta scd parses stuff, then per DSP channel/layer:
- open temp-streamfile, which does custom IO with base-streamfile
(doesn't open any FILE)
- pass temp-streamfile to init_vgmstream_ngc_dsp_std
- init parses ok, and re-opens temp-streamfile (with custom IO) as its
own dsp-vgmstream-streamfile; internally it does fopen/fdopen the
original FILE from base-streamfile
- scd_int_layout stores the newly created VGMSTREAM (internally has
the dsp-vgmstream-streamfile too)
- close temp-streamfile, that doesn't close base-streamfile as it's
wrapped to avoid doing so, nor affects dsp-vgmstream-streamfile in any
way.
- meta parsing is done, so external player closes base-streamfile (but
the re-fopen'ed dsp-vgmstream-streamfile FILE remains)
- vgmstream renders pcm buffers, etc
- finally player calls close_vgmstream
- scd_int_layout calls close_vgmstream for each stored VGMSTREAM
- the VGMSTREAM internally closes the dsp-vgmstream-streamfile, which
in turn closes its own FILE
So ultimately all FILEs, STREAMFILEs and their clones should be properly
handled and closed.
Remove layout_interleave_shortblock for clarity as the value is enough
to signal its use. Also fix .snd last block calculation, and clean some
metas since I was testing changes anyway.
