pokeysnd.c

wince下著名的视频播放器源码

				/* if the output is pure or the output is poly5 and the poly5 bit */
				/* is set */
				if ((audc & NOTPOLY5) || bit5[P5]) {
					/* if the PURETONE bit is set */
					if (audc & PURETONE) {
						/* then simply toggle the output */
						toggle = TRUE;
					}
					/* otherwise if POLY4 is selected */
					else if (audc & POLY4) {
						/* then compare to the poly4 bit */
						toggle = (bit4[P4] == !(*out_ptr));
					}
					else {
						/* if 9-bit poly is selected on this chip */
						if (AUDCTL[next_event >> 2] & POLY9) {
							/* compare to the poly9 bit */
							toggle = ((poly9_lookup[P9] & 1) == !(*out_ptr));
						}
						else {
							/* otherwise compare to the poly17 bit */
							toggle = (((poly17_lookup[P17 >> 3] >> (P17 & 7)) & 1) == !(*out_ptr));
						}
					}
				}
			}

			/* check channel 1 filter (clocked by channel 3) */
			if ( AUDCTL[next_event >> 2] & CH1_FILTER) {
				/* if we're processing channel 3 */
				if ((next_event & 0x03) == CHAN3) {
					/* check output of channel 1 on same chip */
					if (Outvol[next_event & 0xfd]) {
						/* if on, turn it off */
						Outvol[next_event & 0xfd] = 0;
#ifdef STEREO_SOUND
#ifdef __PLUS
						if (stereo_enabled && (next_event & 0x04))
#else
						if ((next_event & 0x04))
#endif
							cur_val2 -= AUDV[next_event & 0xfd];
						else
#endif /* STEREO_SOUND */
							cur_val -= AUDV[next_event & 0xfd];
					}
				}
			}

			/* check channel 2 filter (clocked by channel 4) */
			if ( AUDCTL[next_event >> 2] & CH2_FILTER) {
				/* if we're processing channel 4 */
				if ((next_event & 0x03) == CHAN4) {
					/* check output of channel 2 on same chip */
					if (Outvol[next_event & 0xfd]) {
						/* if on, turn it off */
						Outvol[next_event & 0xfd] = 0;
#ifdef STEREO_SOUND
#ifdef __PLUS
						if (stereo_enabled && (next_event & 0x04))
#else
						if ((next_event & 0x04))
#endif
							cur_val2 -= AUDV[next_event & 0xfd];
						else
#endif /* STEREO_SOUND */
							cur_val -= AUDV[next_event & 0xfd];
					}
				}
			}

			/* if the current output bit has changed */
			if (toggle) {
				if (*out_ptr) {
					/* remove this channel from the signal */
#ifdef STEREO_SOUND
#ifdef __PLUS
					if (stereo_enabled && (next_event & 0x04))
#else
					if ((next_event & 0x04))
#endif
						cur_val2 -= AUDV[next_event];
					else
#endif /* STEREO_SOUND */
						cur_val -= AUDV[next_event];

					/* and turn the output off */
					*out_ptr = 0;
				}
				else {
					/* turn the output on */
					*out_ptr = 1;

					/* and add it to the output signal */
#ifdef STEREO_SOUND
#ifdef __PLUS
					if (stereo_enabled && (next_event & 0x04))
#else
					if ((next_event & 0x04))
#endif
						cur_val2 += AUDV[next_event];
					else
#endif /* STEREO_SOUND */
						cur_val += AUDV[next_event];
				}
			}
		}
		else {					/* otherwise we're processing a sample */
			/* adjust the sample counter - note we're using the 24.8 integer
			   which includes an 8 bit fraction for accuracy */

			int iout;
#ifdef STEREO_SOUND
			int iout2;
#endif
#ifdef INTERPOLATE_SOUND
			if (cur_val != last_val) {
				if (*Samp_n_cnt < Samp_n_max) {		/* need interpolation */
					iout = (cur_val * (*Samp_n_cnt) +
							last_val * (Samp_n_max - *Samp_n_cnt))
						/ Samp_n_max;
				}
				else
					iout = cur_val;
				last_val = cur_val;
			}
			else
				iout = cur_val;
#ifdef STEREO_SOUND
#ifdef __PLUS
		if (stereo_enabled)
#endif
			if (cur_val2 != last_val2) {
				if (*Samp_n_cnt < Samp_n_max) {		/* need interpolation */
					iout2 = (cur_val2 * (*Samp_n_cnt) +
							last_val2 * (Samp_n_max - *Samp_n_cnt))
						/ Samp_n_max;
				}
				else
					iout2 = cur_val2;
				last_val2 = cur_val2;
			}
			else
				iout2 = cur_val2;
#endif  /* STEREO_SOUND */
#else   /* INTERPOLATE_SOUND */
			iout = cur_val;
#ifdef STEREO_SOUND
#ifdef __PLUS
		if (stereo_enabled)
#endif
			iout2 = cur_val2;
#endif  /* STEREO_SOUND */
#endif  /* INTERPOLATE_SOUND */

#ifdef VOL_ONLY_SOUND
#ifdef __PLUS
			if (g_Sound.nDigitized)
#endif
			{
				if (sampbuf_rptr != sampbuf_ptr) {
					int l;
					if (sampbuf_cnt[sampbuf_rptr] > 0)
						sampbuf_cnt[sampbuf_rptr] -= 1280;
					while ((l = sampbuf_cnt[sampbuf_rptr]) <= 0) {
						sampout = sampbuf_val[sampbuf_rptr];
						sampbuf_rptr++;
						if (sampbuf_rptr >= SAMPBUF_MAX)
							sampbuf_rptr = 0;
						if (sampbuf_rptr != sampbuf_ptr)
							sampbuf_cnt[sampbuf_rptr] += l;
						else
							break;
					}
				}
				iout += sampout;
#ifdef STEREO_SOUND
#ifdef __PLUS
				if (stereo_enabled)
#endif
				{
					if (sampbuf_rptr2 != sampbuf_ptr2) {
						int l;
						if (sampbuf_cnt2[sampbuf_rptr2] > 0)
							sampbuf_cnt2[sampbuf_rptr2] -= 1280;
						while ((l = sampbuf_cnt2[sampbuf_rptr2]) <= 0) {
							sampout2 = sampbuf_val2[sampbuf_rptr2];
							sampbuf_rptr2++;
							if (sampbuf_rptr2 >= SAMPBUF_MAX)
								sampbuf_rptr2 = 0;
							if (sampbuf_rptr2 != sampbuf_ptr2)
								sampbuf_cnt2[sampbuf_rptr2] += l;
							else
								break;
						}
					}
					iout2 += sampout2;
				}
#endif  /* STEREO_SOUND */
			}
#endif  /* VOL_ONLY_SOUND */

#ifdef CLIP_SOUND
			if (iout > SAMP_MAX) {	/* then check high limit */
				*buffer++ = (uint8) SAMP_MAX;	/* and limit if greater */
			}
			else if (iout < SAMP_MIN) {		/* else check low limit */
				*buffer++ = (uint8) SAMP_MIN;	/* and limit if less */
			}
			else {				/* otherwise use raw value */
				*buffer++ = (uint8) iout;
			}
#ifdef STEREO_SOUND
#ifdef __PLUS
			if (stereo_enabled) {
				if (iout2 > SAMP_MAX)
					*buffer++ = (uint8) SAMP_MAX;
				else if (iout2 < SAMP_MIN)
					*buffer++ = (uint8) SAMP_MIN;
				else
					*buffer++ = (uint8) iout2;
			}
#else /* __PLUS */
			if (Num_pokeys > 1) {
				if ((stereo_enabled ? iout2 : iout) > SAMP_MAX) {	/* then check high limit */
					*buffer++ = (uint8) SAMP_MAX;	/* and limit if greater */
				}
				else if ((stereo_enabled ? iout2 : iout) < SAMP_MIN) {		/* else check low limit */
					*buffer++ = (uint8) SAMP_MIN;	/* and limit if less */
				}
				else {				/* otherwise use raw value */
					*buffer++ = (uint8) (stereo_enabled ? iout2 : iout);
				}
			}
#endif /* __PLUS */
#endif /* STEREO_SOUND */
#else /* CLIP_SOUND */
			*buffer++ = (uint8) iout;	/* clipping not selected, use value */
#ifdef STEREO_SOUND
			if (Num_pokeys > 1)
#ifdef ASAP
				*buffer++ = (uint8) iout2;
#else
				*buffer++ = (uint8) (stereo_enabled ? iout2 : iout);
#endif
#endif /* STEREO_SOUND */
#endif /* CLIP_SOUND */

#ifdef WORDS_BIGENDIAN
			*(Samp_n_cnt + 1) += Samp_n_max;
#else
			*Samp_n_cnt += Samp_n_max;
#endif
			/* and indicate one less byte in the buffer */
			n--;
#ifdef STEREO_SOUND
#ifdef __PLUS
			if (stereo_enabled)
#endif
			if (Num_pokeys > 1)
				n--;
#endif
		}
	}
#ifdef VOL_ONLY_SOUND
#ifdef __PLUS
	if (g_Sound.nDigitized)
#endif
	{
		if (sampbuf_rptr == sampbuf_ptr)
			sampbuf_last = cpu_clock;
#ifdef STEREO_SOUND
#ifdef __PLUS
	if (stereo_enabled)
#endif
		if (sampbuf_rptr2 == sampbuf_ptr2)
			sampbuf_last2 = cpu_clock;
#endif /* STEREO_SOUND */
	}
#endif  /* VOL_ONLY_SOUND */
}

#ifdef SERIO_SOUND
static void Update_serio_sound_rf(int out, UBYTE data)
{
#ifdef VOL_ONLY_SOUND
#ifdef __PLUS
	if (g_Sound.nDigitized) {
#endif
	int bits, pv, future;
	if (!serio_sound_enabled) return;

	pv = 0;
	future = 0;
	bits = (data << 1) | 0x200;
	while (bits)
	{
		sampbuf_lastval -= pv;
		pv = (bits & 0x01) * AUDV[3];	/* FIXME!!! - set volume from AUDV */
		sampbuf_lastval += pv;

	sampbuf_val[sampbuf_ptr] = sampbuf_lastval;
	sampbuf_cnt[sampbuf_ptr] =
		(cpu_clock + future-sampbuf_last) * 128 * samp_freq / 178979;
	sampbuf_last = cpu_clock + future;
	sampbuf_ptr++;
	if (sampbuf_ptr >= SAMPBUF_MAX )
		sampbuf_ptr = 0;
	if (sampbuf_ptr == sampbuf_rptr ) {
		sampbuf_rptr++;
		if (sampbuf_rptr >= SAMPBUF_MAX)
			sampbuf_rptr = 0;
	}
		/* 1789790/19200 = 93 */
		future += 93;	/* ~ 19200 bit/s - FIXME!!! set speed form AUDF [2] ??? */
		bits >>= 1;
	}
	sampbuf_lastval -= pv;
#ifdef __PLUS
	}
#endif
#endif  /* VOL_ONLY_SOUND */
}
#endif /* SERIO_SOUND */

static void Pokey_process_16(void *sndbuffer, unsigned sndn)
{
	uint16 *buffer = (uint16 *) sndbuffer;
	int i;

	Pokey_process_8(buffer, sndn);

	for (i = sndn - 1; i >= 0; i--) {
		int smp = ((int) (((uint8 *) buffer)[i]) - 0x80) * 0x100;

		if (smp > 32767)
			smp = 32767;
		else if (smp < -32768)
			smp = -32768;

		buffer[i] = smp;
	}
}

#ifdef CONSOLE_SOUND
static void Update_consol_sound_rf(int set)
{
#ifdef VOL_ONLY_SOUND
	static int prev_atari_speaker = 0;
	static unsigned int prev_cpu_clock = 0;
	int d;
#ifdef __PLUS
	if (!g_Sound.nDigitized)
		return;
#endif
	if (!console_sound_enabled)
		return;

	if (!set && samp_consol_val == 0)
		return;
	sampbuf_lastval -= samp_consol_val;
	if (prev_atari_speaker != atari_speaker) {
		samp_consol_val = atari_speaker * 8 * 4;	/* gain */
		prev_cpu_clock = cpu_clock;
	}
	else if (!set) {
		d = cpu_clock - prev_cpu_clock;
		if (d < 114) {
			sampbuf_lastval += samp_consol_val;
			return;
		}
		while (d >= 114 /* CPUL */) {
			samp_consol_val = samp_consol_val * 99 / 100;
			d -= 114;
		}
		prev_cpu_clock = cpu_clock - d;
	}
	sampbuf_lastval += samp_consol_val;
	prev_atari_speaker = atari_speaker;

	sampbuf_val[sampbuf_ptr] = sampbuf_lastval;
	sampbuf_cnt[sampbuf_ptr] =
		(cpu_clock - sampbuf_last) * 128 * samp_freq / 178979;
	sampbuf_last = cpu_clock;
	sampbuf_ptr++;
	if (sampbuf_ptr >= SAMPBUF_MAX)
		sampbuf_ptr = 0;
	if (sampbuf_ptr == sampbuf_rptr) {
		sampbuf_rptr++;
		if (sampbuf_rptr >= SAMPBUF_MAX)
			sampbuf_rptr = 0;
	}
#endif  /* VOL_ONLY_SOUND */
}
#endif /* CONSOLE_SOUND */

#ifdef VOL_ONLY_SOUND
static void Update_vol_only_sound_rf(void)
{
#ifdef CONSOLE_SOUND
	Update_consol_sound(0);	/* mmm */
#endif /* CONSOLE_SOUND */
}
#endif  /* VOL_ONLY_SOUND */