activegs-ios/kegs/Src/sound_driver.cpp

/*
 ActiveGS, Copyright 2004-2016 Olivier Goguel, https://github.com/ogoguel/ActiveGS
 Based on Kegs, Copyright 2004 Kent Dickey, https://kegs.sourceforge.net
 This code is covered by the GNU GPL licence
*/

#include "defc.h"
#include "sound.h"

#ifndef UNDER_CE
#include <errno.h>
#endif

extern int Verbose;

#define ZERO_PAUSE_SAFETY_SAMPS		(g_sound.g_audio_rate >> 5)
#define ZERO_PAUSE_NUM_SAMPS		(4*g_sound.g_audio_rate)



/*
int	g_bytes_written = 0;

#define ZERO_BUF_SIZE		2048

word32 g_snd_zero_buf[ZERO_BUF_SIZE];

#define ZERO_PAUSE_SAFETY_SAMPS		(g_sound.g_audio_rate >> 5)
#define ZERO_PAUSE_NUM_SAMPS		(4*g_sound.g_audio_rate)

int	g_zeroes_buffered = 0;
int	g_zeroes_seen = 0;
int	g_sound_paused = 0;
int	g_childsnd_vbl = 0;
int	g_childsnd_pos = 0;


*/

word32 *g_childsnd_shm_addr = 0;


void
reliable_buf_write(word32 *shm_addr, int pos, int size)
{
	byte	*ptr;
	int	ret;

	if(size < 1 || pos < 0 || pos > SOUND_SHM_SAMP_SIZE ||
				size > SOUND_SHM_SAMP_SIZE ||
				(pos + size) > SOUND_SHM_SAMP_SIZE) {
		printf("reliable_buf_write: pos: %04x, size: %04x\n",
			pos, size);
		x_exit(1);
	}

	ptr = (byte *)&(shm_addr[pos]);
	size = size * 4;

	while(size > 0) 
	{
		
		ret = x_snd_send_audio(ptr, size);

		if(ret < 0) {
			printf("audio write, errno: %d\n", errno);
			x_exit(1);
		}
		size = size - ret;
		ptr += ret;
		g_sound.g_bytes_written += ret;
	}

}

void
reliable_zero_write(int amt)
{
	int	len;

	while(amt > 0) {
		len = MIN(amt, ZERO_BUF_SIZE);
		reliable_buf_write(g_sound.g_snd_zero_buf, 0, len);
		amt -= len;
	}
}


void
child_sound_loop(int read_fd, int write_fd, word32 *shm_addr)
{


	doc_printf("Child pipe fd: %d\n", read_fd);

//	g_audio_rate = g_preferred_rate;

	g_sound.g_zeroes_buffered = 0;
	g_sound.g_zeroes_seen = 0;
	g_sound.g_sound_paused = 0;

	g_sound.g_childsnd_pos = 0;
	g_sound.g_childsnd_vbl = 0;
	g_childsnd_shm_addr = shm_addr;

	x_snd_child_init();

}

void
child_sound_playit(word32 tmp)
{
	int	size;

	size = tmp & 0xffffff;

	//printf("child_sound_playit: %08x\n", tmp);

	if((tmp >> 24) == 0xa2) {
		/* play sound here */


#if 0
		g_childsnd_pos += g_zeroes_buffered;
		while(g_childsnd_pos >= SOUND_SHM_SAMP_SIZE) {
			g_childsnd_pos -= SOUND_SHM_SAMP_SIZE;
		}
#endif

		if(g_sound.g_zeroes_buffered) {
			reliable_zero_write(g_sound.g_zeroes_buffered);
		}

		g_sound.g_zeroes_buffered = 0;
		g_sound.g_zeroes_seen = 0;

		if((size + g_sound.g_childsnd_pos) > SOUND_SHM_SAMP_SIZE) {
			reliable_buf_write(g_childsnd_shm_addr, g_sound.g_childsnd_pos,
					SOUND_SHM_SAMP_SIZE - g_sound.g_childsnd_pos);
			size = (g_sound.g_childsnd_pos + size) - SOUND_SHM_SAMP_SIZE;
			g_sound.g_childsnd_pos = 0;
		}

		reliable_buf_write(g_childsnd_shm_addr, g_sound.g_childsnd_pos, size);

		if(g_sound.g_sound_paused) {
			printf("Unpausing sound, zb: %d\n", g_sound.g_zeroes_buffered);
			g_sound.g_sound_paused = 0;
		}

	} else if((tmp >> 24) == 0xa1) {
		if(g_sound.g_sound_paused) {
			if(g_sound.g_zeroes_buffered < ZERO_PAUSE_SAFETY_SAMPS) {
				g_sound.g_zeroes_buffered += size;
			}
		} else {
			/* not paused, send it through */
			g_sound.g_zeroes_seen += size;

			reliable_zero_write(size);

			if(g_sound.g_zeroes_seen >= ZERO_PAUSE_NUM_SAMPS) {
				printf("Pausing sound\n");
				g_sound.g_sound_paused = 1;
			}
		}
	} else {
		printf("tmp received bad: %08x\n", tmp);
		x_exit(3);
	}

	g_sound.g_childsnd_pos += size;
	while(g_sound.g_childsnd_pos >= SOUND_SHM_SAMP_SIZE) {
		g_sound.g_childsnd_pos -= SOUND_SHM_SAMP_SIZE;
	}

	g_sound.g_childsnd_vbl++;
	if(g_sound.g_childsnd_vbl >= 60) {
		g_sound.g_childsnd_vbl = 0;
#if 0
		printf("sound bytes written: %06x\n", g_bytes_written);
		printf("Sample samples[0]: %08x %08x %08x %08x\n",
			g_childsnd_shm_addr[0], g_childsnd_shm_addr[1],
			g_childsnd_shm_addr[2], g_childsnd_shm_addr[3]);
		printf("Sample samples[100]: %08x %08x %08x %08x\n",
			g_childsnd_shm_addr[100], g_childsnd_shm_addr[101],
			g_childsnd_shm_addr[102], g_childsnd_shm_addr[103]);
#endif
		g_sound.g_bytes_written = 0;
	}
}