This fixes many games that use the PSG, particuarly the noise generator.
It is very noticeable in explosion/collision sounds with Sonic and Kirby
games, where the noise channel is rapidly tweaked.
This is just responsible for a few cycles every frame (could be around 1
and 2% depending on the game usage) but makes emulation a bit more
accurate and potentially faster.
Let's see, this should fix issues on platforms that do not support
running the emu at 59.73 FPS. We run the emu at fake 60fps, which means
we produce more audio samples than the original device.
Instead of missing samples (which produce cracks in the audio) we should
be producing some extra samples, which will result in a frame drop every
now and then (like every minute or so, so it's not noticeable).
This uses BSON as savestate format, to allow external tools to parse it
(so that we can add proper test of the states). The BSON is not 100%
correct according to spec (no ordered keys) but can be parsed by most
libraries.
This fixes also a bug in the savestate palette color recalculation that
was wrongly overwritting the original palette (which could cause some
problems on some games).
Also fixes some potential issues by serializing some more stuff and
cleans up unused stuff.
Testing shows that states look good and there's only minor differences
in audio ticks, related to buffer sizes (since buffer flushes are
de-synced from video frames due to different frequency).
this also changes how direct sound channels are started and
sample step precision is increased to hopefully fix gbc + direct
channel desync that has been reported on the forums.
David Guillen Fandos
jdgleaver
twinaphex
aliaspider
notaz
notaz