Rework PCM buffer
* Linked list instead of static array buffer pointers
* Variable sized chunks
* Improved mix handling
* Reduction in duplicated code
* Reduced IRAM usage w/o sacrificing performance
* Converted to almost entirely unsigned math
* Add pause function to reduce pcm_* exposure to playback.

This WILL break playback on the iPod until linuxstb makes a followup commit.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8612 a1c6a512-1295-4272-9138-f99709370657
13 files changed