code940 now plays mp3s

git-svn-id: file:///home/notaz/opt/svn/PicoDrive@22 be3aeb3a-fb24-0410-a615-afba39da0efa

platform/gp2x/code940/940shared.h

@@ -0,0 +1,42 @@
+#include "../../../Pico/sound/ym2612.h"
+#include "../helix/pub/mp3dec.h"
+
+enum _940_job_t {
+	JOB940_INITALL = 1,
+	JOB940_YM2612RESETCHIP,
+	JOB940_YM2612UPDATEONE,
+	JOB940_PICOSTATELOAD,
+	JOB940_MP3DECODE,
+	JOB940_NUMJOBS
+};
+
+#define MAX_940JOBS	2
+
+typedef struct
+{
+	YM2612  ym2612;					/* current state of the emulated YM2612 */
+	HMP3Decoder mp3dec;			/* mp3 decoder's handle */
+	int     mix_buffer[44100/50*2];		/* this is where the YM2612 samples will be mixed to */
+	short   mp3_buffer[2][1152*2];		/* buffers for mp3 decoder's output */
+} _940_data_t;
+
+
+typedef struct
+{
+	int		jobs[MAX_940JOBS];			/* jobs for second core */
+	int		busy;					/* busy status of the 940 core */
+	int		length;					/* number of samples to mix (882 max) */
+	int		stereo;					/* mix samples as stereo, doubles sample count automatically */
+	int		baseclock;				/* ym2612 settings */
+	int		rate;
+	int		writebuffsel;			/* which write buffer to use (from 940 side) */
+	UINT16  writebuff0[2048];			/* list of writes to ym2612, 1024 for savestates, 1024 extra */
+	UINT16  writebuff1[2048];
+	int		mp3_len;			/* data len of loaded mp3 */
+	int		mp3_offs;			/* current playback offset (just after last decoded frame) */
+	int		mp3_buffsel;			/* which output buffer to decode to */
+	int		vstarts[8];				/* debug: number of starts from each of 8 vectors */
+	int		loopc;					/* debug: main loop counter */
+	int		mp3_errors;			/* debug: mp3 decoder's error counter */
+	int		mp3_lasterr;			/* debug: mp3 decoder's last error */
+} _940_ctl_t;