XA audio improvements - Githubissues

dmitrysmagin / pcsx4all

Pcsx4all v2.4 with mips-to-mips recompiler by Ulrich Hecht https://github.com/uli/psx4all-dingoo/

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XA audio improvements #6

Closed senquack closed 8 years ago

senquack commented 8 years ago

XA audio (music/speech) on slow devices was suffering dropouts. It turns out the problem was two-fold:

CDREAD_INT interrupts were being issued at same or slower rate than it would take to keep buffer filled. If a game cannot run 100% fullspeed, dropouts were inevitable.
Even when said interrupts were issued sooner when buffer wasn't full, XA buffer in spu_pcsxrearmed would never fill more than one frame of audio.

Fix:

Added new function SPU_getADPCMBufferRoom() and XABufferRoom variable, used to determine if XA buffer isn't full and to issue a CDREAD_INT twice as soon as normal to keep it full. 'Config.ForcedXAUpdates' option can be set to 0 if original behavior is desired, set through the new commandline '-noforcedxaupdates' flag.
FeedXA() in spu_pcsxrearmed/xa.c uses new method of determining available buffer space