![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to dmaSnd.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [HATARI the Atari ST Emulator] / hatari / src|
Return to dmaSnd.c CVS log | Up to [HATARI the Atari ST Emulator] / hatari / src |
1.1 root 1: /*
2: Hatari - dmaSnd.c
3:
1.1.1.11 root 4: This file is distributed under the GNU General Public License, version 2
5: or at your option any later version. Read the file gpl.txt for details.
1.1 root 6:
7: STE DMA sound emulation. Does not seem to be very hard at first glance,
8: but since the DMA sound has to be mixed together with the PSG sound and
9: the output frequency of the host computer differs from the DMA sound
10: frequency, the copy function is a little bit complicated.
1.1.1.7 root 11: The update function also triggers the ST interrupts (Timer A and MFP-i7)
12: which are often used in ST programs for setting a new sound frame after
13: the old one has finished.
14:
1.1.1.8 root 15: To support programs that write into the frame buffer while it's played,
16: we should update dma sound on each video HBL.
17: This is also how it works on a real STE : bytes are read by the DMA
18: at the end of each HBL and stored in a small FIFO (8 bytes) that is sent
19: to the DAC depending on the chosen DMA output freq.
20:
1.1.1.7 root 21: Falcon sound emulation is all taken into account in crossbar.c
1.1 root 22:
23:
24: Hardware I/O registers:
25:
26: $FF8900 (word) : DMA sound control register
27: $FF8903 (byte) : Frame Start Hi
28: $FF8905 (byte) : Frame Start Mi
29: $FF8907 (byte) : Frame Start Lo
30: $FF8909 (byte) : Frame Count Hi
31: $FF890B (byte) : Frame Count Mi
32: $FF890D (byte) : Frame Count Lo
33: $FF890F (byte) : Frame End Hi
34: $FF8911 (byte) : Frame End Mi
35: $FF8913 (byte) : Frame End Lo
36: $FF8920 (word) : Sound Mode Control (frequency, mono/stereo)
37: $FF8922 (byte) : Microwire Data Register
38: $FF8924 (byte) : Microwire Mask Register
1.1.1.7 root 39:
40:
41: The Microwire and LMC 1992 commands :
42:
43: a command looks like: 10 CCC DDD DDD
44:
45: chipset address : 10
46: command :
47: 000 XXX XDD Mixing
1.1.1.12! root 48: 00 : DMA sound only
! 49: 01 : DMA sound + input 1 (YM2149 + AUDIOI, full frequency range)
! 50: 10 : DMA sound + input 2 (YM2149 + AUDIOI, Low Pass Filter) -> DMA sound only
! 51: 11 : DMA sound + input 3 (not connected) -> DMA sound only
1.1.1.7 root 52:
53: 001 XXD DDD Bass
54: 0 000 : -12 dB
55: 0 110 : 0 dB
56: 1 100 : +12 dB
57:
58: 002 XXD DDD Treble
59: 0 000 : -12 dB
60: 0 110 : 0 dB
61: 1 100 : +12 dB
62:
63: 003 DDD DDD Master volume
64: 000 000 : -80 dB
65: 010 100 : -40 dB
66: 101 XXX : 0 dB
67:
68: 004 XDD DDD Right channel volume
69: 00 000 : -40 dB
70: 01 010 : -20 dB
71: 10 1XX : 0 dB
72:
73: 005 XDD DDD Left channel volume
74: 00 000 : -40 dB
75: 01 010 : -20 dB
76: 10 1XX : 0 dB
77:
78: Other : undefined
79:
80: LMC1992 IIR code Copyright by David Savinkoff 2010
81:
82: A first order bass filter is multiplied with a
83: first order treble filter to make a single
84: second order IIR shelf filter.
85:
86: Sound is stereo filtered by Boosting or Cutting
87: the Bass and Treble by +/-12dB in 2dB steps.
88:
89: This filter sounds exactly as the Atari TT or STE.
90: Sampling frequency = selectable
91: Bass turnover = 118.276Hz (8.2nF on LM1992 bass)
92: Treble turnover = 8438.756Hz (8.2nF on LM1992 treble)
1.1 root 93: */
1.1.1.7 root 94:
95:
1.1.1.5 root 96: const char DmaSnd_fileid[] = "Hatari dmaSnd.c : " __DATE__ " " __TIME__;
1.1 root 97:
98: #include "main.h"
99: #include "audio.h"
1.1.1.3 root 100: #include "configuration.h"
1.1 root 101: #include "dmaSnd.h"
1.1.1.7 root 102: #include "cycInt.h"
1.1 root 103: #include "ioMem.h"
1.1.1.6 root 104: #include "log.h"
1.1 root 105: #include "memorySnapShot.h"
106: #include "mfp.h"
107: #include "sound.h"
1.1.1.3 root 108: #include "stMemory.h"
1.1.1.10 root 109: #include "crossbar.h"
1.1.1.11 root 110: #include "screen.h"
111: #include "video.h"
112: #include "m68000.h"
1.1.1.7 root 113:
114: #define TONE_STEPS 13
115:
1.1.1.8 root 116: #define DMASND_FIFO_SIZE 8 /* 8 bytes : size of the DMA Audio's FIFO, filled on every HBL */
117: #define DMASND_FIFO_SIZE_MASK (DMASND_FIFO_SIZE-1) /* mask to keep FIFO_pos in 0-7 range */
118:
1.1.1.7 root 119:
120: /* Global variables that can be changed/read from other parts of Hatari */
121:
1.1.1.8 root 122: static void DmaSnd_Apply_LMC(int nMixBufIdx, int nSamplesToGenerate);
1.1.1.7 root 123: static void DmaSnd_Set_Tone_Level(int set_bass, int set_treb);
124: static float DmaSnd_IIRfilterL(float xn);
125: static float DmaSnd_IIRfilterR(float xn);
126: static struct first_order_s *DmaSnd_Treble_Shelf(float g, float fc, float Fs);
127: static struct first_order_s *DmaSnd_Bass_Shelf(float g, float fc, float Fs);
1.1.1.8 root 128: static Sint16 DmaSnd_LowPassFilterLeft(Sint16 in);
129: static Sint16 DmaSnd_LowPassFilterRight(Sint16 in);
130: static bool DmaSnd_LowPass;
1.1 root 131:
132:
133: Uint16 nDmaSoundControl; /* Sound control register */
134:
1.1.1.7 root 135: struct first_order_s { float a1, b0, b1; };
136: struct second_order_s { float a1, a2, b0, b1, b2; };
137:
138: struct dma_s {
139: Uint16 soundMode; /* Sound mode register */
140: Uint32 frameStartAddr; /* Sound frame start */
141: Uint32 frameEndAddr; /* Sound frame end */
1.1.1.8 root 142: Uint32 frameCounterAddr; /* Sound frame current address counter */
143:
144: /* Internal 8 byte FIFO */
145: Sint8 FIFO[ DMASND_FIFO_SIZE ];
146: Uint16 FIFO_Pos; /* from 0 to DMASND_FIFO_SIZE-1 */
147: Uint16 FIFO_NbBytes; /* from 0 to DMASND_FIFO_SIZE */
148:
1.1.1.9 root 149: Sint16 FrameLeft; /* latest values read from the FIFO */
1.1.1.8 root 150: Sint16 FrameRight;
1.1.1.7 root 151: };
152:
1.1.1.8 root 153: Sint64 frameCounter_float = 0;
154: bool DmaInitSample = false;
155:
156:
1.1.1.7 root 157: struct microwire_s {
158: Uint16 data; /* Microwire Data register */
159: Uint16 mask; /* Microwire Mask register */
1.1.1.9 root 160: Uint16 mwTransferSteps; /* Microwire shifting counter */
161: Uint16 pendingCyclesOver; /* Number of delayed cycles for the interrupt */
1.1.1.7 root 162: Uint16 mixing; /* Mixing command */
163: Uint16 bass; /* Bass command */
164: Uint16 treble; /* Treble command */
165: Uint16 masterVolume; /* Master volume command */
166: Uint16 leftVolume; /* Left channel volume command */
167: Uint16 rightVolume; /* Right channel volume command */
168: };
169:
170: struct lmc1992_s {
171: struct first_order_s bass_table[TONE_STEPS];
172: struct first_order_s treb_table[TONE_STEPS];
1.1.1.8 root 173: float coef[5]; /* IIR coefficients */
174: float left_gain;
175: float right_gain;
1.1.1.7 root 176: };
177:
178: static struct dma_s dma;
179: static struct microwire_s microwire;
180: static struct lmc1992_s lmc1992;
181:
182: /* dB = 20log(gain) : gain = antilog(dB/20) */
183: /* Table gain values = (int)(powf(10.0, dB/20.0)*65536.0 + 0.5) 2dB steps */
184:
185: /* Values for LMC1992 Master volume control (*65536) */
186: static const Uint16 LMC1992_Master_Volume_Table[64] =
187: {
188: 7, 8, 10, 13, 16, 21, 26, 33, 41, 52, /* -80dB */
189: 66, 83, 104, 131, 165, 207, 261, 328, 414, 521, /* -60dB */
190: 655, 825, 1039, 1308, 1646, 2072, 2609, 3285, 4135, 5206, /* -40dB */
191: 6554, 8250, 10387, 13076, 16462, 20724, 26090, 32846, 41350, 52057, /* -20dB */
192: 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, /* 0dB */
193: 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, /* 0dB */
194: 65535, 65535, 65535, 65535 /* 0dB */
195: };
1.1.1.6 root 196:
1.1.1.7 root 197: /* Values for LMC1992 Left and right volume control (*65536) */
198: static const Uint16 LMC1992_LeftRight_Volume_Table[32] =
199: {
200: 655, 825, 1039, 1308, 1646, 2072, 2609, 3285, 4135, 5206, /* -40dB */
201: 6554, 8250, 10387, 13076, 16462, 20724, 26090, 32846, 41350, 52057, /* -20dB */
202: 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, 65535, /* 0dB */
203: 65535, 65535 /* 0dB */
1.1 root 204: };
205:
1.1.1.7 root 206: /* Values for LMC1992 BASS and TREBLE */
207: static const Sint16 LMC1992_Bass_Treble_Table[16] =
208: {
209: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 12, 12, 12
210: };
1.1 root 211:
1.1.1.7 root 212: static const int DmaSndSampleRates[4] =
1.1.1.3 root 213: {
1.1.1.8 root 214: 6258, 12517, 25033, 50066
1.1.1.3 root 215: };
216:
217:
1.1.1.8 root 218:
219: /*--------------------------------------------------------------*/
220: /* Local functions prototypes */
221: /*--------------------------------------------------------------*/
222:
223: static void DmaSnd_FIFO_Refill(void);
224: static Sint8 DmaSnd_FIFO_PullByte(void);
225: static void DmaSnd_FIFO_SetStereo(void);
226:
227: static int DmaSnd_DetectSampleRate(void);
228: static void DmaSnd_StartNewFrame(void);
229: static inline int DmaSnd_EndOfFrameReached(void);
230:
231:
1.1.1.7 root 232: /**
1.1.1.3 root 233: * Reset DMA sound variables.
234: */
1.1.1.4 root 235: void DmaSnd_Reset(bool bCold)
1.1 root 236: {
237: nDmaSoundControl = 0;
1.1.1.8 root 238: dma.soundMode = 0;
239:
240: /* [NP] Set start/end to 0 even on warm reset ? (fix 'Brace' by Diamond Design) */
241: IoMem[0xff8903] = 0; /* frame start addr = 0 */
242: IoMem[0xff8905] = 0;
243: IoMem[0xff8907] = 0;
244: IoMem[0xff890f] = 0; /* frame end addr = 0 */
245: IoMem[0xff8911] = 0;
246: IoMem[0xff8913] = 0;
247:
248: dma.FIFO_Pos = 0;
249: dma.FIFO_NbBytes = 0;
250: dma.FrameLeft = 0;
251: dma.FrameRight = 0;
1.1 root 252:
1.1.1.8 root 253: if ( bCold )
1.1 root 254: {
1.1.1.8 root 255: /* Microwire has no reset signal, it will keep its values on warm reset */
256: microwire.masterVolume = 7; /* -80 dB ; TOS 1.62 will put 0x28 (ie 65535) = 0 dB (max volume) */
257: microwire.leftVolume = 655; /* -40 dB ; TOS 1.62 will put 0x14 (ie 65535) = 0 dB (max volume) */
258: microwire.rightVolume = 655; /* -40 db ; TOS 1.62 will put 0x14 (ie 65535) = 0 dB (max volume) */
1.1.1.7 root 259: microwire.mixing = 0;
1.1.1.8 root 260: microwire.bass = 6; /* 0 dB (flat) */
261: microwire.treble = 6; /* 0 dB (flat) */
1.1 root 262: }
1.1.1.4 root 263:
1.1.1.7 root 264: /* Initialise microwire LMC1992 IIR filter parameters */
265: DmaSnd_Init_Bass_and_Treble_Tables();
1.1.1.6 root 266:
1.1.1.7 root 267: microwire.mwTransferSteps = 0;
1.1.1.9 root 268: microwire.pendingCyclesOver = 8;
1.1 root 269: }
270:
271: /*-----------------------------------------------------------------------*/
1.1.1.3 root 272: /**
273: * Save/Restore snapshot of local variables ('MemorySnapShot_Store' handles type)
274: */
1.1.1.4 root 275: void DmaSnd_MemorySnapShot_Capture(bool bSave)
1.1 root 276: {
277: /* Save/Restore details */
278: MemorySnapShot_Store(&nDmaSoundControl, sizeof(nDmaSoundControl));
1.1.1.7 root 279: MemorySnapShot_Store(&dma, sizeof(dma));
280: MemorySnapShot_Store(µwire, sizeof(microwire));
281: MemorySnapShot_Store(&lmc1992, sizeof(lmc1992));
1.1 root 282: }
283:
284:
1.1.1.8 root 285: /*-----------------------------------------------------------------------*/
286: /**
287: * This function is called on every HBL to ensure the DMA Audio's FIFO
288: * is kept full.
289: * In Hatari, the FIFO is handled like a ring buffer (to avoid memcopying bytes
290: * inside the FIFO when a byte is pushed/pulled).
291: * Note that the DMA fetches words, not bytes, so we read new data only
292: * when 2 bytes or more are missing.
293: * When end of frame is reached, we continue with a new frame if loop mode
294: * is on, else we stop DMA Audio.
295: */
296: static void DmaSnd_FIFO_Refill(void)
297: {
298: /* If DMA sound is OFF, don't update the FIFO */
299: if ( ( nDmaSoundControl & DMASNDCTRL_PLAY ) == 0)
300: return;
301:
302: /* If End Address == Start Address, don't update the FIFO */
303: if (dma.frameEndAddr == dma.frameStartAddr)
304: {
305: DmaSnd_EndOfFrameReached(); /* Stop dma audio if loop mode is off */
306: return;
307: }
308:
309: /* Refill the whole FIFO */
310: while ( DMASND_FIFO_SIZE - dma.FIFO_NbBytes >= 2 )
311: {
312: /* Add one word to the FIFO */
313: LOG_TRACE(TRACE_DMASND, "DMA snd fifo refill adr=%x pos %d nb %d %x %x\n", dma.frameCounterAddr , dma.FIFO_Pos , dma.FIFO_NbBytes ,
314: STRam[ dma.frameCounterAddr ] , STRam[ dma.frameCounterAddr+1 ] );
315:
316: dma.FIFO[ ( dma.FIFO_Pos+dma.FIFO_NbBytes+0 ) & DMASND_FIFO_SIZE_MASK ] = (Sint8)STRam[ dma.frameCounterAddr ]; /* add upper byte of the word */
317: dma.FIFO[ ( dma.FIFO_Pos+dma.FIFO_NbBytes+1 ) & DMASND_FIFO_SIZE_MASK ] = (Sint8)STRam[ dma.frameCounterAddr+1 ]; /* add lower byte of the word */
318:
319: dma.FIFO_NbBytes += 2; /* One word more in the FIFO */
320:
321: /* Increase current frame address and check if we reached frame's end */
322: dma.frameCounterAddr += 2;
323: if ( dma.frameCounterAddr == dma.frameEndAddr ) /* end of frame reached, should we loop or stop dma ? */
324: {
325: if ( DmaSnd_EndOfFrameReached() )
326: break; /* Loop mode off, dma audio is now turned off */
327: }
328: }
329: }
330:
331:
332: /*-----------------------------------------------------------------------*/
333: /**
334: * Pull one sample/byte from the DMA Audio's FIFO and decrease the number of
335: * remaining bytes.
336: * If the FIFO is empty, return 0 (empty sample)
337: * Note : on a real STE, the 8 bytes FIFO is refilled on each HBL, which gives
1.1.1.11 root 338: * a total of 313*8*VBL_PER_SEC=125326 bytes per sec read by the DMA. As the max freq
1.1.1.8 root 339: * is 50066 Hz, the STE can play 100132 bytes per sec in stereo ; so on a real STE
340: * the FIFO can never be empty while DMA is ON.
341: * But on Hatari, if the user chooses an audio's output frequency that is much
342: * lower than the current DMA freq, audio will be updated less frequently than
343: * on each HBL and it could require to process more than DMASND_FIFO_SIZE in one
344: * call to DmaSnd_GenerateSamples(). This is why we allow DmaSnd_FIFO_Refill()
345: * to be called if FIFO is empty but DMA sound is still ON.
346: * This way, sound remains correct even if the user uses very low output freq.
347: */
348: static Sint8 DmaSnd_FIFO_PullByte(void)
349: {
350: Sint8 sample;
351:
352: if ( dma.FIFO_NbBytes == 0 )
353: {
354: DmaSnd_FIFO_Refill();
355: if ( dma.FIFO_NbBytes == 0 ) /* Refill didn't add any new bytes */
356: {
357: LOG_TRACE(TRACE_DMASND, "DMA snd fifo empty for pull\n" );
358: return 0;
359: }
360: }
361:
362:
363: LOG_TRACE(TRACE_DMASND, "DMA snd fifo pull pos %d nb %d %02x\n", dma.FIFO_Pos , dma.FIFO_NbBytes , (Uint8)dma.FIFO[ dma.FIFO_Pos ] );
364:
365: sample = dma.FIFO[ dma.FIFO_Pos ]; /* Get oldest byte from the FIFO */
366: dma.FIFO_Pos = (dma.FIFO_Pos+1) & DMASND_FIFO_SIZE_MASK;/* Pos to be pulled on next call */
367: dma.FIFO_NbBytes--; /* One byte less in the FIFO */
368:
369: return sample;
370: }
371:
372:
373: /*-----------------------------------------------------------------------*/
374: /**
375: * In case a program switches from mono to stereo, we must ensure that
376: * FIFO_pos is on even boundary to keep Left/Right bytes in the correct
377: * order (Left byte should be on even addresses and Right byte on odd ones).
378: * If this is not the case, we skip one byte.
379: */
380: static void DmaSnd_FIFO_SetStereo(void)
381: {
382: Uint16 NewPos;
383:
384: if ( dma.FIFO_Pos & 1 )
385: {
386: NewPos = (dma.FIFO_Pos+1) & DMASND_FIFO_SIZE_MASK; /* skip the byte on odd address */
387:
388: if ( nDmaSoundControl & DMASNDCTRL_PLAY ) /* print a log if we change while playing */
389: { LOG_TRACE(TRACE_DMASND, "DMA snd switching to stereo mode while playing mono FIFO_pos %d->%d\n", dma.FIFO_Pos , NewPos ); }
390: else
391: { LOG_TRACE(TRACE_DMASND, "DMA snd switching to stereo mode FIFO_pos %d->%d\n", dma.FIFO_Pos , NewPos ); }
392:
393: dma.FIFO_Pos = NewPos;
394:
395: if ( dma.FIFO_NbBytes > 0 )
396: dma.FIFO_NbBytes--; /* remove one byte if FIFO was not already empty */
397: }
398:
399: }
400:
401:
402: /*-----------------------------------------------------------------------*/
403: /**
404: * Returns the frequency corresponding to the 2 lower bits of dma.soundMode
405: */
1.1.1.7 root 406: static int DmaSnd_DetectSampleRate(void)
1.1.1.3 root 407: {
1.1.1.7 root 408: return DmaSndSampleRates[dma.soundMode & 3];
1.1.1.3 root 409: }
410:
411:
1.1 root 412: /*-----------------------------------------------------------------------*/
1.1.1.3 root 413: /**
414: * This function is called when a new sound frame is started.
1.1.1.8 root 415: * It copies the start and end address from the I/O registers and set
416: * the frame counter addr to the start of this new frame.
1.1.1.3 root 417: */
1.1 root 418: static void DmaSnd_StartNewFrame(void)
419: {
1.1.1.7 root 420: dma.frameStartAddr = (IoMem[0xff8903] << 16) | (IoMem[0xff8905] << 8) | (IoMem[0xff8907] & ~1);
421: dma.frameEndAddr = (IoMem[0xff890f] << 16) | (IoMem[0xff8911] << 8) | (IoMem[0xff8913] & ~1);
1.1 root 422:
1.1.1.8 root 423: dma.frameCounterAddr = dma.frameStartAddr;
1.1.1.6 root 424:
1.1.1.8 root 425: LOG_TRACE(TRACE_DMASND, "DMA snd new frame start=%x end=%x\n", dma.frameStartAddr, dma.frameEndAddr);
1.1 root 426: }
427:
428:
429: /*-----------------------------------------------------------------------*/
1.1.1.3 root 430: /**
1.1.1.7 root 431: * End-of-frame has been reached. Raise interrupts if needed.
1.1.1.6 root 432: * Returns true if DMA sound processing should be stopped now and false
1.1.1.7 root 433: * if it continues (DMA PLAYLOOP mode).
1.1.1.3 root 434: */
1.1.1.7 root 435: static inline int DmaSnd_EndOfFrameReached(void)
1.1 root 436: {
1.1.1.8 root 437: LOG_TRACE(TRACE_DMASND, "DMA snd end of frame\n");
438:
1.1.1.7 root 439: /* Raise end-of-frame interrupts (MFP-i7 and Time-A) */
1.1.1.11 root 440: MFP_InputOnChannel ( MFP_INT_GPIP7 , 0 );
1.1.1.7 root 441: if (MFP_TACR == 0x08) /* Is timer A in Event Count mode? */
442: MFP_TimerA_EventCount_Interrupt();
1.1 root 443:
1.1.1.7 root 444: if (nDmaSoundControl & DMASNDCTRL_PLAYLOOP)
445: {
446: DmaSnd_StartNewFrame();
1.1 root 447: }
1.1.1.7 root 448: else
1.1.1.6 root 449: {
1.1.1.7 root 450: nDmaSoundControl &= ~DMASNDCTRL_PLAY;
451: return true;
1.1.1.6 root 452: }
453:
1.1.1.7 root 454: return false;
1.1 root 455: }
456:
457:
458: /*-----------------------------------------------------------------------*/
1.1.1.3 root 459: /**
460: * Mix DMA sound sample with the normal PSG sound samples.
1.1.1.6 root 461: * Note: We adjust the volume level of the 8-bit DMA samples to factor
1.1.1.7 root 462: * 0.75 compared to the PSG sound samples.
1.1.1.8 root 463: *
1.1.1.11 root 464: * The following formula: -((256*3/4)/4)/4
1.1.1.8 root 465: *
466: * Multiply by 256 to convert 8 to 16 bits;
467: * DMA sound is 3/4 level of YM sound;
1.1.1.11 root 468: * Divide by 4 to account for the STe YM volume table level;
469: * ( STe sound at 1/2 amplitude to avoid overflow. )
470: * ( lmc1992.right_gain and lmc1992.left_gain are )
471: * ( doubled to compensate. )
1.1.1.8 root 472: * Divide by 4 to account for DmaSnd_LowPassFilter;
473: * Multiply DMA sound by -1 because the LMC1992 inverts the signal
474: * ( YM sign is +1 :: -1(op-amp) * -1(Lmc1992) ).
1.1.1.3 root 475: */
1.1.1.8 root 476:
477:
1.1 root 478: void DmaSnd_GenerateSamples(int nMixBufIdx, int nSamplesToGenerate)
479: {
1.1.1.8 root 480: int i;
1.1.1.7 root 481: int nBufIdx;
1.1.1.10 root 482: Sint8 MonoByte , LeftByte , RightByte;
1.1.1.7 root 483: unsigned n;
1.1.1.8 root 484: Sint64 FreqRatio;
485:
486:
487: /* DMA Audio OFF and FIFO empty : process YM2149's output */
488: if ( !(nDmaSoundControl & DMASNDCTRL_PLAY) && ( dma.FIFO_NbBytes == 0 ) )
489: {
490: for (i = 0; i < nSamplesToGenerate; i++)
491: {
492: nBufIdx = (nMixBufIdx + i) % MIXBUFFER_SIZE;
1.1.1.6 root 493:
1.1.1.8 root 494: switch (microwire.mixing) {
495: case 1:
1.1.1.12! root 496: /* DMA and YM2149 mixing */
! 497: MixBuffer[nBufIdx][0] = MixBuffer[nBufIdx][0] + dma.FrameLeft * -((256*3/4)/4)/4;
! 498: MixBuffer[nBufIdx][1] = MixBuffer[nBufIdx][1] + dma.FrameRight * -((256*3/4)/4)/4;
1.1.1.8 root 499: break;
500: default:
1.1.1.12! root 501: /* mixing=0 DMA only */
! 502: /* mixing=2 DMA and input 2 (YM2149 LPF) -> DMA */
! 503: /* mixing=3 DMA and input 3 -> DMA */
! 504: MixBuffer[nBufIdx][0] = dma.FrameLeft * -((256*3/4)/4)/4;
! 505: MixBuffer[nBufIdx][1] = dma.FrameRight * -((256*3/4)/4)/4;
1.1.1.8 root 506: break;
507: }
508: }
509:
510: /* Apply LMC1992 sound modifications (Bass and Treble) */
511: DmaSnd_Apply_LMC ( nMixBufIdx , nSamplesToGenerate );
1.1.1.10 root 512:
1.1 root 513: return;
1.1.1.8 root 514: }
515:
1.1 root 516:
1.1.1.8 root 517: /* DMA Audio ON or FIFO not empty yet */
1.1 root 518:
1.1.1.8 root 519: /* Compute ratio between DMA's sound frequency and host computer's sound frequency, */
520: /* use << 32 to simulate floating point precision */
521: FreqRatio = ( ((Sint64)DmaSnd_DetectSampleRate()) << 32 ) / nAudioFrequency;
1.1.1.7 root 522:
523: if (dma.soundMode & DMASNDMODE_MONO)
1.1.1.3 root 524: {
525: /* Mono 8-bit */
1.1 root 526: for (i = 0; i < nSamplesToGenerate; i++)
527: {
1.1.1.8 root 528: if ( DmaInitSample )
529: {
530: MonoByte = DmaSnd_FIFO_PullByte ();
1.1.1.9 root 531: dma.FrameLeft = DmaSnd_LowPassFilterLeft( (Sint16)MonoByte );
532: dma.FrameRight = DmaSnd_LowPassFilterRight( (Sint16)MonoByte );
1.1.1.8 root 533: DmaInitSample = false;
1.1.1.7 root 534: }
535:
1.1 root 536: nBufIdx = (nMixBufIdx + i) % MIXBUFFER_SIZE;
1.1.1.7 root 537:
538: switch (microwire.mixing) {
539: case 1:
1.1.1.12! root 540: /* DMA and YM2149 mixing */
1.1.1.11 root 541: MixBuffer[nBufIdx][0] = MixBuffer[nBufIdx][0] + dma.FrameLeft * -((256*3/4)/4)/4;
1.1.1.7 root 542: break;
543: default:
1.1.1.12! root 544: /* mixing=0 DMA only */
! 545: /* mixing=2 DMA and input 2 (YM2149 LPF) -> DMA */
! 546: /* mixing=3 DMA and input 3 -> DMA */
! 547: MixBuffer[nBufIdx][0] = dma.FrameLeft * -((256*3/4)/4)/4;
1.1.1.7 root 548: break;
549: }
550:
1.1.1.8 root 551: MixBuffer[nBufIdx][1] = MixBuffer[nBufIdx][0]; /* right = left */
552:
553: /* Increase freq counter */
554: frameCounter_float += FreqRatio;
555: n = frameCounter_float >> 32; /* number of samples to skip */
556: while ( n > 0 ) /* pull as many bytes from the FIFO as needed */
557: {
558: MonoByte = DmaSnd_FIFO_PullByte ();
1.1.1.9 root 559: dma.FrameLeft = DmaSnd_LowPassFilterLeft( (Sint16)MonoByte );
560: dma.FrameRight = DmaSnd_LowPassFilterRight( (Sint16)MonoByte );
1.1.1.8 root 561: n--;
1.1.1.7 root 562: }
1.1.1.8 root 563: frameCounter_float &= 0xffffffff; /* only keep the fractional part */
1.1 root 564: }
565: }
566: else
567: {
1.1.1.3 root 568: /* Stereo 8-bit */
1.1 root 569: for (i = 0; i < nSamplesToGenerate; i++)
570: {
1.1.1.8 root 571: if ( DmaInitSample )
572: {
573: LeftByte = DmaSnd_FIFO_PullByte ();
574: RightByte = DmaSnd_FIFO_PullByte ();
575: dma.FrameLeft = DmaSnd_LowPassFilterLeft( (Sint16)LeftByte );
576: dma.FrameRight = DmaSnd_LowPassFilterRight( (Sint16)RightByte );
577: DmaInitSample = false;
1.1.1.7 root 578: }
579:
1.1 root 580: nBufIdx = (nMixBufIdx + i) % MIXBUFFER_SIZE;
1.1.1.8 root 581:
1.1.1.7 root 582: switch (microwire.mixing) {
583: case 1:
1.1.1.12! root 584: /* DMA and YM2149 mixing */
1.1.1.11 root 585: MixBuffer[nBufIdx][0] = MixBuffer[nBufIdx][0] + dma.FrameLeft * -((256*3/4)/4)/4;
586: MixBuffer[nBufIdx][1] = MixBuffer[nBufIdx][1] + dma.FrameRight * -((256*3/4)/4)/4;
1.1.1.7 root 587: break;
1.1.1.12! root 588: default:
! 589: /* mixing=0 DMA only */
! 590: /* mixing=2 DMA and input 2 (YM2149 LPF) -> DMA */
! 591: /* mixing=3 DMA and input 3 -> DMA */
1.1.1.11 root 592: MixBuffer[nBufIdx][0] = dma.FrameLeft * -((256*3/4)/4)/4;
593: MixBuffer[nBufIdx][1] = dma.FrameRight * -((256*3/4)/4)/4;
1.1.1.7 root 594: break;
595: }
596:
1.1.1.8 root 597: /* Increase freq counter */
598: frameCounter_float += FreqRatio;
599: n = frameCounter_float >> 32; /* number of samples to skip */
600: while ( n > 0 ) /* pull as many bytes from the FIFO as needed */
601: {
602: LeftByte = DmaSnd_FIFO_PullByte ();
603: RightByte = DmaSnd_FIFO_PullByte ();
604: dma.FrameLeft = DmaSnd_LowPassFilterLeft( (Sint16)LeftByte );
605: dma.FrameRight = DmaSnd_LowPassFilterRight( (Sint16)RightByte );
606: n--;
1.1.1.7 root 607: }
1.1.1.8 root 608: frameCounter_float &= 0xffffffff; /* only keep the fractional part */
1.1 root 609: }
610: }
1.1.1.7 root 611:
1.1.1.8 root 612: /* Apply LMC1992 sound modifications (Bass and Treble) */
613: DmaSnd_Apply_LMC ( nMixBufIdx , nSamplesToGenerate );
614: }
615:
616:
617: /*-----------------------------------------------------------------------*/
618: /**
619: * Apply LMC1992 sound modifications (Bass and Treble)
620: * The Bass and Treble get samples at nAudioFrequency rate.
621: * The tone control's sampling frequency must be at least 22050 Hz to sound good.
622: */
623: static void DmaSnd_Apply_LMC(int nMixBufIdx, int nSamplesToGenerate)
624: {
625: int nBufIdx;
626: int i;
1.1.1.11 root 627: Sint32 sample;
1.1.1.7 root 628:
629: /* Apply LMC1992 sound modifications (Left, Right and Master Volume) */
630: for (i = 0; i < nSamplesToGenerate; i++) {
631: nBufIdx = (nMixBufIdx + i) % MIXBUFFER_SIZE;
1.1.1.11 root 632:
633: sample = DmaSnd_IIRfilterL( Subsonic_IIR_HPF_Left( MixBuffer[nBufIdx][0]));
634: if (sample<-32767) /* check for overflow to clip waveform */
635: sample = -32767;
636: else if (sample>32767)
637: sample = 32767;
638: MixBuffer[nBufIdx][0] = sample;
639:
640: sample = DmaSnd_IIRfilterR( Subsonic_IIR_HPF_Right(MixBuffer[nBufIdx][1]));
641: if (sample<-32767) /* check for overflow to clip waveform */
642: sample = -32767;
643: else if (sample>32767)
644: sample = 32767;
645: MixBuffer[nBufIdx][1] = sample;
1.1.1.8 root 646: }
1.1 root 647: }
648:
649:
650: /*-----------------------------------------------------------------------*/
1.1.1.3 root 651: /**
1.1.1.8 root 652: * STE DMA sound is using an 8 bytes FIFO that is checked and filled on each HBL
653: * (at 50066 Hz 8 bit stereo, the DMA requires approx 6.5 new bytes per HBL)
654: * Calling Sound_Update on each HBL allows to emulate some programs that modify
655: * the data between FrameStart and FrameEnd while DMA sound is ON
656: * (eg the demo 'Mental Hangover' or the game 'Power Up Plus')
657: * We first check if the FIFO needs to be refilled, then we call Sound_Update.
658: * This function should be called from the HBL's handler (in video.c)
1.1.1.3 root 659: */
1.1.1.8 root 660: void DmaSnd_STE_HBL_Update(void)
1.1 root 661: {
1.1.1.8 root 662: if ( ( ConfigureParams.System.nMachineType != MACHINE_STE )
663: && ( ConfigureParams.System.nMachineType != MACHINE_MEGA_STE ) )
664: return;
1.1 root 665:
1.1.1.8 root 666:
667: /* The DMA starts refilling the FIFO when display is OFF (eg cycle 376 in low res 50 Hz) */
668: DmaSnd_FIFO_Refill ();
669:
670: /* If DMA sound is ON or FIFO is not empty, update sound */
671: if ( (nDmaSoundControl & DMASNDCTRL_PLAY) || ( dma.FIFO_NbBytes > 0 ) )
672: Sound_Update(false);
673:
674: /* As long as display is OFF, the DMA will refill the FIFO after playing some samples during the HBL */
675: DmaSnd_FIFO_Refill ();
1.1 root 676: }
677:
678:
679: /*-----------------------------------------------------------------------*/
1.1.1.3 root 680: /**
1.1.1.8 root 681: * Return current frame counter address (value is always even)
1.1.1.3 root 682: */
1.1 root 683: static Uint32 DmaSnd_GetFrameCount(void)
684: {
685: Uint32 nActCount;
686:
1.1.1.8 root 687: /* Update sound to get the current DMA frame address */
688: Sound_Update(false);
689:
1.1 root 690: if (nDmaSoundControl & DMASNDCTRL_PLAY)
1.1.1.8 root 691: nActCount = dma.frameCounterAddr;
1.1 root 692: else
1.1.1.8 root 693: nActCount = (IoMem[0xff8903] << 16) | (IoMem[0xff8905] << 8) | (IoMem[0xff8907] & ~1);
1.1 root 694:
695: return nActCount;
696: }
697:
698:
699: /*-----------------------------------------------------------------------*/
1.1.1.3 root 700: /**
701: * Read word from sound control register (0xff8900).
702: */
1.1 root 703: void DmaSnd_SoundControl_ReadWord(void)
704: {
705: IoMem_WriteWord(0xff8900, nDmaSoundControl);
1.1.1.6 root 706:
1.1.1.11 root 707: if(LOG_TRACE_LEVEL(TRACE_DMASND))
708: {
709: int FrameCycles, HblCounterVideo, LineCycles;
710: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
711: LOG_TRACE_PRINT("DMA snd control read: 0x%04x video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
712: nDmaSoundControl,
713: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
714: }
1.1 root 715: }
716:
717:
718: /*-----------------------------------------------------------------------*/
1.1.1.3 root 719: /**
1.1.1.8 root 720: * Write word to sound control register (0xff8900).
721: */
722: void DmaSnd_SoundControl_WriteWord(void)
723: {
724: Uint16 nNewSndCtrl;
725:
1.1.1.11 root 726: if(LOG_TRACE_LEVEL(TRACE_DMASND))
727: {
728: int FrameCycles, HblCounterVideo, LineCycles;
729: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
730: LOG_TRACE_PRINT("DMA snd control write: 0x%04x video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
731: IoMem_ReadWord(0xff8900),
732: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
733: }
1.1.1.8 root 734:
735: /* Before starting/stopping DMA sound, create samples up until this point with current values */
736: Sound_Update(false);
737:
738: nNewSndCtrl = IoMem_ReadWord(0xff8900) & 3;
739:
740: if (!(nDmaSoundControl & DMASNDCTRL_PLAY) && (nNewSndCtrl & DMASNDCTRL_PLAY))
741: {
742: LOG_TRACE(TRACE_DMASND, "DMA snd control write: starting dma sound output\n");
743: DmaInitSample = true;
744: frameCounter_float = 0;
745: DmaSnd_StartNewFrame();
746: }
747: else if ((nDmaSoundControl & DMASNDCTRL_PLAY) && !(nNewSndCtrl & DMASNDCTRL_PLAY))
748: {
749: LOG_TRACE(TRACE_DMASND, "DMA snd control write: stopping dma sound output\n");
750: }
751:
752: nDmaSoundControl = nNewSndCtrl;
753: }
754:
755:
756: /*-----------------------------------------------------------------------*/
757: /**
1.1.1.3 root 758: * Read word from sound frame count high register (0xff8909).
759: */
1.1 root 760: void DmaSnd_FrameCountHigh_ReadByte(void)
761: {
762: IoMem_WriteByte(0xff8909, DmaSnd_GetFrameCount() >> 16);
763: }
764:
765:
766: /*-----------------------------------------------------------------------*/
1.1.1.3 root 767: /**
768: * Read word from sound frame count medium register (0xff890b).
769: */
1.1 root 770: void DmaSnd_FrameCountMed_ReadByte(void)
771: {
772: IoMem_WriteByte(0xff890b, DmaSnd_GetFrameCount() >> 8);
773: }
774:
775:
776: /*-----------------------------------------------------------------------*/
1.1.1.3 root 777: /**
778: * Read word from sound frame count low register (0xff890d).
779: */
1.1 root 780: void DmaSnd_FrameCountLow_ReadByte(void)
781: {
782: IoMem_WriteByte(0xff890d, DmaSnd_GetFrameCount());
783: }
784:
785:
786: /*-----------------------------------------------------------------------*/
1.1.1.3 root 787: /**
1.1.1.8 root 788: * Write bytes to various registers with no action.
789: */
790: void DmaSnd_FrameStartHigh_WriteByte(void)
791: {
1.1.1.11 root 792: if(LOG_TRACE_LEVEL(TRACE_DMASND))
793: {
794: int FrameCycles, HblCounterVideo, LineCycles;
795: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
796: LOG_TRACE_PRINT("DMA snd frame start high: 0x%02x at pos %d/%d video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
797: IoMem_ReadByte(0xff8903) , dma.frameCounterAddr - dma.frameStartAddr , dma.frameEndAddr - dma.frameStartAddr ,
798: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
799: }
1.1.1.8 root 800: }
801:
802: void DmaSnd_FrameStartMed_WriteByte(void)
803: {
1.1.1.11 root 804: if(LOG_TRACE_LEVEL(TRACE_DMASND))
805: {
806: int FrameCycles, HblCounterVideo, LineCycles;
807: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
808: LOG_TRACE_PRINT("DMA snd frame start med: 0x%02x at pos %d/%d video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
809: IoMem_ReadByte(0xff8905) , dma.frameCounterAddr - dma.frameStartAddr , dma.frameEndAddr - dma.frameStartAddr ,
810: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
811: }
1.1.1.8 root 812: }
813:
814: void DmaSnd_FrameStartLow_WriteByte(void)
815: {
1.1.1.11 root 816: if(LOG_TRACE_LEVEL(TRACE_DMASND))
817: {
818: int FrameCycles, HblCounterVideo, LineCycles;
819: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
820: LOG_TRACE_PRINT("DMA snd frame start low: 0x%02x at pos %d/%d video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
821: IoMem_ReadByte(0xff8907) , dma.frameCounterAddr - dma.frameStartAddr , dma.frameEndAddr - dma.frameStartAddr ,
822: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
823: }
1.1.1.8 root 824: }
825:
826: void DmaSnd_FrameCountHigh_WriteByte(void)
827: {
1.1.1.11 root 828: if(LOG_TRACE_LEVEL(TRACE_DMASND))
829: {
830: int FrameCycles, HblCounterVideo, LineCycles;
831: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
832: LOG_TRACE_PRINT("DMA snd frame count high: 0x%02x at pos %d/%d video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
833: IoMem_ReadByte(0xff8909) , dma.frameCounterAddr - dma.frameStartAddr , dma.frameEndAddr - dma.frameStartAddr ,
834: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
835: }
1.1.1.8 root 836: }
837:
838: void DmaSnd_FrameCountMed_WriteByte(void)
839: {
1.1.1.11 root 840: if(LOG_TRACE_LEVEL(TRACE_DMASND))
841: {
842: int FrameCycles, HblCounterVideo, LineCycles;
843: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
844: LOG_TRACE_PRINT("DMA snd frame count med: 0x%02x at pos %d/%d video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
845: IoMem_ReadByte(0xff890b) , dma.frameCounterAddr - dma.frameStartAddr , dma.frameEndAddr - dma.frameStartAddr ,
846: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
847: }
1.1.1.8 root 848: }
849:
850: void DmaSnd_FrameCountLow_WriteByte(void)
851: {
1.1.1.11 root 852: if(LOG_TRACE_LEVEL(TRACE_DMASND))
853: {
854: int FrameCycles, HblCounterVideo, LineCycles;
855: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
856: LOG_TRACE_PRINT("DMA snd frame count low: 0x%02x at pos %d/%d video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
857: IoMem_ReadByte(0xff890d) , dma.frameCounterAddr - dma.frameStartAddr , dma.frameEndAddr - dma.frameStartAddr ,
858: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
859: }
1.1.1.8 root 860: }
861:
862: void DmaSnd_FrameEndHigh_WriteByte(void)
863: {
1.1.1.11 root 864: if(LOG_TRACE_LEVEL(TRACE_DMASND))
865: {
866: int FrameCycles, HblCounterVideo, LineCycles;
867: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
868: LOG_TRACE_PRINT("DMA snd frame end high: 0x%02x at pos %d/%d video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
869: IoMem_ReadByte(0xff890f) , dma.frameCounterAddr - dma.frameStartAddr , dma.frameEndAddr - dma.frameStartAddr ,
870: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
871: }
1.1.1.8 root 872: }
873:
874: void DmaSnd_FrameEndMed_WriteByte(void)
875: {
1.1.1.11 root 876: if(LOG_TRACE_LEVEL(TRACE_DMASND))
877: {
878: int FrameCycles, HblCounterVideo, LineCycles;
879: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
880: LOG_TRACE_PRINT("DMA snd frame end med: 0x%02x at pos %d/%d video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
881: IoMem_ReadByte(0xff8911) , dma.frameCounterAddr - dma.frameStartAddr , dma.frameEndAddr - dma.frameStartAddr ,
882: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
883: }
1.1.1.8 root 884: }
885:
886: void DmaSnd_FrameEndLow_WriteByte(void)
887: {
1.1.1.11 root 888: if(LOG_TRACE_LEVEL(TRACE_DMASND))
889: {
890: int FrameCycles, HblCounterVideo, LineCycles;
891: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
892: LOG_TRACE_PRINT("DMA snd frame end low: 0x%02x at pos %d/%d video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
893: IoMem_ReadByte(0xff8913) , dma.frameCounterAddr - dma.frameStartAddr , dma.frameEndAddr - dma.frameStartAddr ,
894: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
895: }
1.1.1.8 root 896: }
897:
898:
899: /*-----------------------------------------------------------------------*/
900: /**
1.1.1.7 root 901: * Read word from sound mode register (0xff8921).
1.1.1.3 root 902: */
1.1.1.7 root 903: void DmaSnd_SoundModeCtrl_ReadByte(void)
1.1 root 904: {
1.1.1.7 root 905: IoMem_WriteByte(0xff8921, dma.soundMode);
1.1.1.6 root 906:
1.1.1.11 root 907: if(LOG_TRACE_LEVEL(TRACE_DMASND))
908: {
909: int FrameCycles, HblCounterVideo, LineCycles;
910: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
911: LOG_TRACE_PRINT("DMA snd mode read: 0x%02x video_cyc=%d %d@%d pc=%x instr_cycle %d\n", dma.soundMode,
912: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
913: }
1.1 root 914: }
915:
916:
917: /*-----------------------------------------------------------------------*/
1.1.1.3 root 918: /**
1.1.1.7 root 919: * Write word to sound mode register (0xff8921).
1.1.1.3 root 920: */
1.1.1.7 root 921: void DmaSnd_SoundModeCtrl_WriteByte(void)
1.1 root 922: {
1.1.1.8 root 923: Uint16 SoundModeNew;
924:
925: SoundModeNew = IoMem_ReadByte(0xff8921);
926:
1.1.1.11 root 927: if(LOG_TRACE_LEVEL(TRACE_DMASND))
928: {
929: int FrameCycles, HblCounterVideo, LineCycles;
930: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
931: LOG_TRACE_PRINT("DMA snd mode write: 0x%02x mode=%s freq=%d video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
932: SoundModeNew, SoundModeNew & DMASNDMODE_MONO ? "mono" : "stereo" , DmaSndSampleRates[ SoundModeNew & 3 ],
933: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
934: }
1.1.1.8 root 935:
936: /* We maskout to only bits that exist on a real STE */
937: SoundModeNew &= 0x8f;
1.1.1.3 root 938:
1.1.1.8 root 939: /* Are we switching from mono to stereo ? */
940: if ( ( dma.soundMode & DMASNDMODE_MONO ) && ( ( SoundModeNew & DMASNDMODE_MONO ) == 0 ) )
941: DmaSnd_FIFO_SetStereo ();
942:
943: dma.soundMode = SoundModeNew;
944: /* We also write the masked value back into the emulated hw registers so we have a correct value there */
1.1.1.7 root 945: IoMem_WriteByte(0xff8921, dma.soundMode);
1.1 root 946: }
947:
1.1.1.8 root 948:
1.1.1.6 root 949: /* ---------------------- Microwire / LMC 1992 ---------------------- */
950:
1.1.1.3 root 951: /**
1.1.1.4 root 952: * Handle the shifting/rotating of the microwire registers
953: * The microwire regs should be done after 16 usec = 32 NOPs = 128 cycles.
954: * That means we have to shift 16 times with a delay of 8 cycles.
1.1.1.12! root 955: * Microwire uses the MWK clock signal at 1 Mhz
1.1.1.3 root 956: */
1.1.1.4 root 957: void DmaSnd_InterruptHandler_Microwire(void)
1.1 root 958: {
1.1.1.12! root 959: int i;
! 960: Uint16 cmd;
! 961: int cmd_len;
1.1.1.10 root 962:
963: /* If emulated computer is the Falcon, let's the crossbar Microwire code do the job. */
964: if (ConfigureParams.System.nMachineType == MACHINE_FALCON) {
965: Crossbar_InterruptHandler_Microwire();
966: return;
967: }
1.1.1.7 root 968:
1.1.1.9 root 969: /* How many cycle was this sound interrupt delayed (>= 0) */
970: microwire.pendingCyclesOver += -INT_CONVERT_FROM_INTERNAL ( PendingInterruptCount , INT_CPU_CYCLE );
1.1.1.4 root 971: /* Remove this interrupt from list and re-order */
1.1.1.7 root 972: CycInt_AcknowledgeInterrupt();
1.1.1.4 root 973:
1.1.1.9 root 974: /* Shift the mask and data according to the number of cycles (8 cycles for a shift) */
975: do
1.1 root 976: {
1.1.1.9 root 977: --microwire.mwTransferSteps;
978: /* Shift data register until it becomes zero. */
1.1.1.7 root 979: IoMem_WriteWord(0xff8922, microwire.data<<(16-microwire.mwTransferSteps));
1.1.1.9 root 980: /* Rotate mask register */
981: IoMem_WriteWord(0xff8924, (microwire.mask<<(16-microwire.mwTransferSteps))
982: |(microwire.mask>>microwire.mwTransferSteps));
983: /* 8 cycles for 1 shift */
984: microwire.pendingCyclesOver -= 8;
1.1 root 985: }
1.1.1.9 root 986: while ((microwire.mwTransferSteps != 0) && (microwire.pendingCyclesOver >= 8) );
1.1.1.4 root 987:
1.1.1.9 root 988: /* Is the transfer finished ? */
1.1.1.7 root 989: if (microwire.mwTransferSteps > 0)
1.1.1.4 root 990: {
1.1.1.11 root 991: /* No ==> start a new internal interrupt to continue to transfer the data */
1.1.1.9 root 992: microwire.pendingCyclesOver = 8 - microwire.pendingCyclesOver;
993: CycInt_AddRelativeInterrupt(microwire.pendingCyclesOver, INT_CPU_CYCLE, INTERRUPT_DMASOUND_MICROWIRE);
1.1.1.4 root 994: }
1.1.1.9 root 995: else
996: {
997: /* Yes : decode the address + command word according to the binary mask */
1.1.1.12! root 998: /* According to LMC1992 doc, command starts with the first '1' bit in the mask */
! 999: /* and ends when a '0' bits is received in the mask */
! 1000: /* If we get a bad command, we must scan the rest of the mask in case there's a valid */
! 1001: /* command in the remaining bits */
! 1002: /* TODO [NP] : to be really cycle accurate, we should decode the command at the same */
! 1003: /* time as we rotate mask/data, instead of doing it when 16 rotations were made. */
! 1004: /* But this would not be noticeable, so leave it like this for now */
! 1005: cmd = 0;
! 1006: cmd_len = 0;
! 1007: for ( i=15 ; i>=0 ; i-- )
! 1008: if ( microwire.mask & ( 1 << i ) )
! 1009: {
! 1010: /* Start of command found, wait for next '0' bit or end of mask */
! 1011: do
! 1012: {
! 1013: cmd <<= 1;
! 1014: cmd_len++;
! 1015: if ( microwire.data & ( 1 << i ) )
! 1016: cmd |= 1;
! 1017: i--;
! 1018: }
! 1019: while ( ( i >= 0 ) && ( microwire.mask & ( 1 << i ) ) );
! 1020:
! 1021: if ( ( cmd_len >= 11 )
! 1022: && ( ( cmd >> ( cmd_len-2 ) ) & 0x03 ) == 0x02 )
! 1023: break; /* We found a valid command */
! 1024:
! 1025: LOG_TRACE ( TRACE_DMASND, "Microwire bad command=0x%x len=%d ignored mask=0x%x data=0x%x\n", cmd , cmd_len , microwire.mask , microwire.data );
! 1026: if ( i < 0 )
! 1027: return; /* All bits were tested, stop here */
! 1028:
! 1029: /* Check remaining bits for a possible command */
! 1030: cmd = 0;
! 1031: cmd_len = 0;
1.1.1.7 root 1032: }
1.1.1.12! root 1033: //fprintf ( stderr , "mwire cmd=%x len=%d mask=%x data=%x\n" , cmd , cmd_len , microwire.mask , microwire.data );
1.1.1.4 root 1034:
1.1.1.12! root 1035: /* The LMC 1992 address (first 2 bits) should be "10", else we ignore the command */
! 1036: /* The address should be followed by at least 9 bits ; if more bits were received, */
! 1037: /* then only the latest 9 ones should be kept */
! 1038: if ( ( cmd_len < 11 )
! 1039: || ( ( cmd >> ( cmd_len-2 ) ) & 0x03 ) != 0x02 )
! 1040: {
! 1041: LOG_TRACE ( TRACE_DMASND, "Microwire bad command=0x%x len=%d ignored mask=0x%x data=0x%x\n", cmd , cmd_len , microwire.mask , microwire.data );
1.1.1.7 root 1042: return;
1.1.1.12! root 1043: }
1.1.1.7 root 1044:
1045: /* Update the LMC 1992 commands */
1.1.1.12! root 1046: switch ( ( cmd >> 6 ) & 0x7 ) {
1.1.1.7 root 1047: case 0:
1048: /* Mixing command */
1.1.1.12! root 1049: LOG_TRACE ( TRACE_DMASND, "Microwire new mixing=0x%x\n", cmd & 0x3 );
! 1050: microwire.mixing = cmd & 0x3;
1.1.1.7 root 1051: break;
1052: case 1:
1053: /* Bass command */
1.1.1.12! root 1054: LOG_TRACE ( TRACE_DMASND, "Microwire new bass=0x%x\n", cmd & 0xf );
! 1055: microwire.bass = cmd & 0xf;
1.1.1.7 root 1056: DmaSnd_Set_Tone_Level(LMC1992_Bass_Treble_Table[microwire.bass],
1057: LMC1992_Bass_Treble_Table[microwire.treble]);
1058: break;
1059: case 2:
1060: /* Treble command */
1.1.1.12! root 1061: LOG_TRACE ( TRACE_DMASND, "Microwire new trebble=0x%x\n", cmd & 0xf );
! 1062: microwire.treble = cmd & 0xf;
1.1.1.7 root 1063: DmaSnd_Set_Tone_Level(LMC1992_Bass_Treble_Table[microwire.bass],
1064: LMC1992_Bass_Treble_Table[microwire.treble]);
1065: break;
1066: case 3:
1067: /* Master volume command */
1.1.1.12! root 1068: LOG_TRACE ( TRACE_DMASND, "Microwire new master volume=0x%x\n", cmd & 0x3f );
! 1069: microwire.masterVolume = LMC1992_Master_Volume_Table[ cmd & 0x3f ];
1.1.1.11 root 1070: lmc1992.left_gain = (microwire.leftVolume * (Uint32)microwire.masterVolume) * (2.0/(65536.0*65536.0));
1071: lmc1992.right_gain = (microwire.rightVolume * (Uint32)microwire.masterVolume) * (2.0/(65536.0*65536.0));
1.1.1.7 root 1072: break;
1073: case 4:
1074: /* Right channel volume */
1.1.1.12! root 1075: LOG_TRACE ( TRACE_DMASND, "Microwire new right volume=0x%x\n", cmd & 0x1f );
! 1076: microwire.rightVolume = LMC1992_LeftRight_Volume_Table[ cmd & 0x1f ];
1.1.1.11 root 1077: lmc1992.right_gain = (microwire.rightVolume * (Uint32)microwire.masterVolume) * (2.0/(65536.0*65536.0));
1.1.1.7 root 1078: break;
1079: case 5:
1080: /* Left channel volume */
1.1.1.12! root 1081: LOG_TRACE ( TRACE_DMASND, "Microwire new left volume=0x%x\n", cmd & 0x1f );
! 1082: microwire.leftVolume = LMC1992_LeftRight_Volume_Table[ cmd & 0x1f ];
1.1.1.11 root 1083: lmc1992.left_gain = (microwire.leftVolume * (Uint32)microwire.masterVolume) * (2.0/(65536.0*65536.0));
1.1.1.7 root 1084: break;
1085: default:
1086: /* Do nothing */
1.1.1.12! root 1087: LOG_TRACE ( TRACE_DMASND, "Microwire unknown command=0x%x len=%d ignored mask=0x%x data=0x%x\n", cmd , cmd_len , microwire.mask , microwire.data );
1.1.1.7 root 1088: break;
1089: }
1090: }
1091: }
1.1.1.4 root 1092:
1093: /**
1094: * Read word from microwire data register (0xff8922).
1095: */
1096: void DmaSnd_MicrowireData_ReadWord(void)
1097: {
1098: /* Shifting is done in DmaSnd_InterruptHandler_Microwire! */
1.1.1.11 root 1099: if(LOG_TRACE_LEVEL(TRACE_DMASND))
1100: {
1101: int FrameCycles, HblCounterVideo, LineCycles;
1102: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
1103: LOG_TRACE_PRINT("Microwire data read: 0x%x video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
1104: IoMem_ReadWord(0xff8922),
1105: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
1106: }
1.1 root 1107: }
1108:
1109:
1.1.1.3 root 1110: /**
1111: * Write word to microwire data register (0xff8922).
1112: */
1.1 root 1113: void DmaSnd_MicrowireData_WriteWord(void)
1114: {
1.1.1.4 root 1115: /* Only update, if no shift is in progress */
1.1.1.7 root 1116: if (!microwire.mwTransferSteps)
1.1.1.4 root 1117: {
1.1.1.7 root 1118: microwire.data = IoMem_ReadWord(0xff8922);
1.1.1.4 root 1119: /* Start shifting events to simulate a microwire transfer */
1.1.1.7 root 1120: microwire.mwTransferSteps = 16;
1.1.1.9 root 1121: microwire.pendingCyclesOver = 8;
1122: CycInt_AddRelativeInterrupt(microwire.pendingCyclesOver, INT_CPU_CYCLE, INTERRUPT_DMASOUND_MICROWIRE);
1.1.1.4 root 1123: }
1124:
1.1.1.11 root 1125: if(LOG_TRACE_LEVEL(TRACE_DMASND))
1126: {
1127: int FrameCycles, HblCounterVideo, LineCycles;
1128: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
1129: LOG_TRACE_PRINT("Microwire data write: 0x%x video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
1130: IoMem_ReadWord(0xff8922),
1131: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
1132: }
1.1 root 1133: }
1134:
1135:
1.1.1.3 root 1136: /**
1137: * Read word from microwire mask register (0xff8924).
1138: */
1.1 root 1139: void DmaSnd_MicrowireMask_ReadWord(void)
1140: {
1.1.1.4 root 1141: /* Same as with data register, but mask is rotated, not shifted. */
1.1.1.11 root 1142: if(LOG_TRACE_LEVEL(TRACE_DMASND))
1143: {
1144: int FrameCycles, HblCounterVideo, LineCycles;
1145: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
1146: LOG_TRACE_PRINT("Microwire mask read: 0x%x video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
1147: IoMem_ReadWord(0xff8924),
1148: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
1149: }
1.1 root 1150: }
1151:
1152:
1.1.1.3 root 1153: /**
1154: * Write word to microwire mask register (0xff8924).
1155: */
1.1 root 1156: void DmaSnd_MicrowireMask_WriteWord(void)
1157: {
1.1.1.4 root 1158: /* Only update, if no shift is in progress */
1.1.1.7 root 1159: if (!microwire.mwTransferSteps)
1.1.1.4 root 1160: {
1.1.1.7 root 1161: microwire.mask = IoMem_ReadWord(0xff8924);
1.1.1.4 root 1162: }
1163:
1.1.1.11 root 1164: if(LOG_TRACE_LEVEL(TRACE_DMASND))
1165: {
1166: int FrameCycles, HblCounterVideo, LineCycles;
1167: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
1168: LOG_TRACE_PRINT("Microwire mask write: 0x%x video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
1169: IoMem_ReadWord(0xff8924),
1170: FrameCycles, LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
1171: }
1.1.1.6 root 1172: }
1173:
1174:
1.1.1.7 root 1175: /*-------------------Bass / Treble filter ---------------------------*/
1.1.1.6 root 1176:
1.1.1.7 root 1177: /**
1178: * Left voice Filter for Bass/Treble.
1179: */
1180: static float DmaSnd_IIRfilterL(float xn)
1181: {
1182: static float data[2] = { 0.0, 0.0 };
1183: float a, yn;
1.1.1.6 root 1184:
1.1.1.7 root 1185: /* Input coefficients */
1186: /* biquad1 Note: 'a' coefficients are subtracted */
1.1.1.8 root 1187: a = lmc1992.left_gain * xn; /* a=g*xn; */
1.1.1.7 root 1188: a -= lmc1992.coef[0] * data[0]; /* a1; wn-1 */
1189: a -= lmc1992.coef[1] * data[1]; /* a2; wn-2 */
1190: /* If coefficient scale */
1191: /* factor = 0.5 then */
1192: /* multiply by 2 */
1193: /* Output coefficients */
1194: yn = lmc1992.coef[2] * a; /* b0; */
1195: yn += lmc1992.coef[3] * data[0]; /* b1; */
1196: yn += lmc1992.coef[4] * data[1]; /* b2; */
1.1.1.6 root 1197:
1.1.1.7 root 1198: data[1] = data[0]; /* wn-1 -> wn-2; */
1199: data[0] = a; /* wn -> wn-1 */
1200: return yn;
1.1.1.6 root 1201: }
1202:
1203:
1204: /**
1.1.1.7 root 1205: * Right voice Filter for Bass/Treble.
1.1.1.6 root 1206: */
1.1.1.7 root 1207: static float DmaSnd_IIRfilterR(float xn)
1.1.1.6 root 1208: {
1.1.1.7 root 1209: static float data[2] = { 0.0, 0.0 };
1210: float a, yn;
1211:
1212: /* Input coefficients */
1213: /* biquad1 Note: 'a' coefficients are subtracted */
1.1.1.8 root 1214: a = lmc1992.right_gain * xn; /* a=g*xn; */
1.1.1.7 root 1215: a -= lmc1992.coef[0]*data[0]; /* a1; wn-1 */
1216: a -= lmc1992.coef[1]*data[1]; /* a2; wn-2 */
1217: /* If coefficient scale */
1218: /* factor = 0.5 then */
1219: /* multiply by 2 */
1220: /* Output coefficients */
1221: yn = lmc1992.coef[2]*a; /* b0; */
1222: yn += lmc1992.coef[3]*data[0]; /* b1; */
1223: yn += lmc1992.coef[4]*data[1]; /* b2; */
1224:
1225: data[1] = data[0]; /* wn-1 -> wn-2; */
1226: data[0] = a; /* wn -> wn-1 */
1227: return yn;
1.1.1.6 root 1228: }
1229:
1230: /**
1.1.1.7 root 1231: * LowPass Filter Left
1.1.1.6 root 1232: */
1.1.1.8 root 1233: static Sint16 DmaSnd_LowPassFilterLeft(Sint16 in)
1.1.1.6 root 1234: {
1.1.1.8 root 1235: static Sint16 lowPassFilter[2] = { 0, 0 };
1236: static Sint16 out = 0;
1.1.1.6 root 1237:
1.1.1.8 root 1238: if (DmaSnd_LowPass)
1239: {
1240: out = lowPassFilter[0] + (lowPassFilter[1]<<1) + in;
1241: lowPassFilter[0] = lowPassFilter[1];
1242: lowPassFilter[1] = in;
1.1.1.6 root 1243:
1.1.1.8 root 1244: return out; /* Filter Gain = 4 */
1245: }else
1246: {
1247: return in << 2;
1248: }
1.1.1.6 root 1249: }
1250:
1251: /**
1.1.1.7 root 1252: * LowPass Filter Right
1.1.1.6 root 1253: */
1.1.1.8 root 1254: static Sint16 DmaSnd_LowPassFilterRight(Sint16 in)
1.1.1.6 root 1255: {
1.1.1.8 root 1256: static Sint16 lowPassFilter[2] = { 0, 0 };
1257: static Sint16 out = 0;
1.1.1.6 root 1258:
1.1.1.8 root 1259: if (DmaSnd_LowPass)
1260: {
1261: out = lowPassFilter[0] + (lowPassFilter[1]<<1) + in;
1262: lowPassFilter[0] = lowPassFilter[1];
1263: lowPassFilter[1] = in;
1.1.1.6 root 1264:
1.1.1.8 root 1265: return out; /* Filter Gain = 4 */
1266: }else
1267: {
1268: return in << 2;
1269: }
1.1.1.6 root 1270: }
1271:
1272: /**
1.1.1.7 root 1273: * Set Bass and Treble tone level
1.1.1.6 root 1274: */
1.1.1.7 root 1275: static void DmaSnd_Set_Tone_Level(int set_bass, int set_treb)
1276: {
1277: /* 13 levels; 0 through 12 correspond with -12dB to 12dB in 2dB steps */
1278: lmc1992.coef[0] = lmc1992.treb_table[set_treb].a1 + lmc1992.bass_table[set_bass].a1;
1279: lmc1992.coef[1] = lmc1992.treb_table[set_treb].a1 * lmc1992.bass_table[set_bass].a1;
1280: lmc1992.coef[2] = lmc1992.treb_table[set_treb].b0 * lmc1992.bass_table[set_bass].b0;
1281: lmc1992.coef[3] = lmc1992.treb_table[set_treb].b0 * lmc1992.bass_table[set_bass].b1 +
1282: lmc1992.treb_table[set_treb].b1 * lmc1992.bass_table[set_bass].b0;
1283: lmc1992.coef[4] = lmc1992.treb_table[set_treb].b1 * lmc1992.bass_table[set_bass].b1;
1.1.1.6 root 1284: }
1285:
1286:
1287: /**
1.1.1.7 root 1288: * Compute the first order bass shelf
1.1.1.6 root 1289: */
1.1.1.7 root 1290: static struct first_order_s *DmaSnd_Bass_Shelf(float g, float fc, float Fs)
1.1.1.6 root 1291: {
1.1.1.7 root 1292: static struct first_order_s bass;
1293: float a1;
1.1.1.6 root 1294:
1.1.1.7 root 1295: /* g, fc, Fs must be positve real numbers > 0.0 */
1296: if (g < 1.0)
1297: bass.a1 = a1 = (tanf(M_PI*fc/Fs) - g ) / (tanf(M_PI*fc/Fs) + g );
1298: else
1299: bass.a1 = a1 = (tanf(M_PI*fc/Fs) - 1.0) / (tanf(M_PI*fc/Fs) + 1.0);
1.1.1.6 root 1300:
1.1.1.7 root 1301: bass.b0 = (1.0 + a1) * (g - 1.0) / 2.0 + 1.0;
1302: bass.b1 = (1.0 + a1) * (g - 1.0) / 2.0 + a1;
1.1.1.6 root 1303:
1.1.1.7 root 1304: return &bass;
1.1.1.6 root 1305: }
1306:
1307:
1308: /**
1.1.1.7 root 1309: * Compute the first order treble shelf
1.1.1.6 root 1310: */
1.1.1.7 root 1311: static struct first_order_s *DmaSnd_Treble_Shelf(float g, float fc, float Fs)
1.1.1.6 root 1312: {
1.1.1.7 root 1313: static struct first_order_s treb;
1314: float a1;
1.1.1.6 root 1315:
1.1.1.7 root 1316: /* g, fc, Fs must be positve real numbers > 0.0 */
1317: if (g < 1.0)
1318: treb.a1 = a1 = (g*tanf(M_PI*fc/Fs) - 1.0) / (g*tanf(M_PI*fc/Fs) + 1.0);
1319: else
1320: treb.a1 = a1 = (tanf(M_PI*fc/Fs) - 1.0) / (tanf(M_PI*fc/Fs) + 1.0);
1.1.1.6 root 1321:
1.1.1.7 root 1322: treb.b0 = 1.0 + (1.0 - a1) * (g - 1.0) / 2.0;
1323: treb.b1 = a1 + (a1 - 1.0) * (g - 1.0) / 2.0;
1324:
1325: return &treb;
1.1.1.6 root 1326: }
1327:
1.1.1.7 root 1328:
1.1.1.6 root 1329: /**
1.1.1.7 root 1330: * Compute the bass and treble tables (nAudioFrequency)
1.1.1.6 root 1331: */
1.1.1.7 root 1332: void DmaSnd_Init_Bass_and_Treble_Tables(void)
1.1.1.6 root 1333: {
1.1.1.7 root 1334: struct first_order_s *bass;
1335: struct first_order_s *treb;
1336:
1.1.1.8 root 1337: float dB_adjusted, dB, g, fc_bt, fc_tt, Fs;
1.1.1.7 root 1338: int n;
1339:
1340: fc_bt = 118.2763;
1341: fc_tt = 8438.756;
1342: Fs = (float)nAudioFrequency;
1343:
1344: if ((Fs < 8000.0) || (Fs > 96000.0))
1345: Fs = 44100.0;
1346:
1.1.1.8 root 1347: if (fc_tt > 0.5*0.8*Fs)
1348: {
1349: fc_tt = 0.5*0.8*Fs;
1350: dB_adjusted = 2.0 * 0.5*0.8*Fs/fc_tt;
1351: }else
1352: {
1353: dB_adjusted = 2.0;
1354: }
1355:
1356: for (dB = dB_adjusted*(TONE_STEPS-1)/2, n = TONE_STEPS; n--; dB -= dB_adjusted)
1357: {
1358: g = powf(10.0, dB/20.0); /* 12dB to -12dB */
1359:
1360: treb = DmaSnd_Treble_Shelf(g, fc_tt, Fs);
1361:
1362: lmc1992.treb_table[n].a1 = treb->a1;
1363: lmc1992.treb_table[n].b0 = treb->b0;
1364: lmc1992.treb_table[n].b1 = treb->b1;
1365: }
1366:
1.1.1.7 root 1367: for (dB = 12.0, n = TONE_STEPS; n--; dB -= 2.0)
1368: {
1369: g = powf(10.0, dB/20.0); /* 12dB to -12dB */
1370:
1371: bass = DmaSnd_Bass_Shelf(g, fc_bt, Fs);
1372:
1373: lmc1992.bass_table[n].a1 = bass->a1;
1374: lmc1992.bass_table[n].b0 = bass->b0;
1375: lmc1992.bass_table[n].b1 = bass->b1;
1376: }
1377:
1378: DmaSnd_Set_Tone_Level(LMC1992_Bass_Treble_Table[microwire.bass & 0xf],
1379: LMC1992_Bass_Treble_Table[microwire.treble & 0xf]);
1.1.1.8 root 1380:
1381: /* Initialize IIR Filter Gain and use as a Volume Control */
1.1.1.11 root 1382: lmc1992.left_gain = (microwire.leftVolume * (Uint32)microwire.masterVolume) * (2.0/(65536.0*65536.0));
1383: lmc1992.right_gain = (microwire.rightVolume * (Uint32)microwire.masterVolume) * (2.0/(65536.0*65536.0));
1.1.1.8 root 1384:
1385: /* Anti-alias filter is not required when nAudioFrequency == 50066 Hz */
1386: if (nAudioFrequency>50000 && nAudioFrequency<50100)
1387: DmaSnd_LowPass = false;
1388: else
1389: DmaSnd_LowPass = true;
1.1 root 1390: }
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.