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/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <signal.h>
#include <unistd.h>
#include <pthread.h>
#include <errno.h>
#include <string.h>
#include <tinyalsa/asoundlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include "accessory.h"
#define BUFFER_COUNT 2
#define BUFFER_SIZE 16384
#define BUFFER_EMPTY 0
#define BUFFER_BUSY 1
#define BUFFER_FULL 2
static char* buffers[BUFFER_COUNT];
static int buffer_states[BUFFER_COUNT];
static int empty_index = 0;
static int full_index = -1;
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t empty_cond = PTHREAD_COND_INITIALIZER;
static pthread_cond_t full_cond = PTHREAD_COND_INITIALIZER;
static unsigned int input_card;
static unsigned int input_device;
static int get_empty()
{
int index, other;
pthread_mutex_lock(&mutex);
while (empty_index == -1)
pthread_cond_wait(&empty_cond, &mutex);
index = empty_index;
other = (index == 0 ? 1 : 0);
buffer_states[index] = BUFFER_BUSY;
if (buffer_states[other] == BUFFER_EMPTY)
empty_index = other;
else
empty_index = -1;
pthread_mutex_unlock(&mutex);
return index;
}
static void put_empty(int index)
{
pthread_mutex_lock(&mutex);
buffer_states[index] = BUFFER_EMPTY;
if (empty_index == -1) {
empty_index = index;
pthread_cond_signal(&empty_cond);
}
pthread_mutex_unlock(&mutex);
}
static int get_full()
{
int index, other;
pthread_mutex_lock(&mutex);
while (full_index == -1)
pthread_cond_wait(&full_cond, &mutex);
index = full_index;
other = (index == 0 ? 1 : 0);
buffer_states[index] = BUFFER_BUSY;
if (buffer_states[other] == BUFFER_FULL)
full_index = other;
else
full_index = -1;
pthread_mutex_unlock(&mutex);
return index;
}
static void put_full(int index)
{
pthread_mutex_lock(&mutex);
buffer_states[index] = BUFFER_FULL;
if (full_index == -1) {
full_index = index;
pthread_cond_signal(&full_cond);
}
pthread_mutex_unlock(&mutex);
}
static void* capture_thread(void* arg)
{
struct pcm_config config;
struct pcm *pcm = NULL;
fprintf(stderr, "capture_thread start\n");
memset(&config, 0, sizeof(config));
config.channels = 2;
config.rate = 44100;
config.period_size = 1024;
config.period_count = 4;
config.format = PCM_FORMAT_S16_LE;
while (1) {
while (!pcm) {
pcm = pcm_open(input_card, input_device, PCM_IN, &config);
if (pcm && !pcm_is_ready(pcm)) {
pcm_close(pcm);
pcm = NULL;
}
if (!pcm)
sleep(1);
}
while (pcm) {
int index = get_empty();
if (pcm_read(pcm, buffers[index], BUFFER_SIZE)) {
put_empty(index);
pcm_close(pcm);
pcm = NULL;
} else {
put_full(index);
}
}
}
fprintf(stderr, "capture_thread done\n");
return NULL;
}
static void* play_thread(void* arg)
{
struct pcm *pcm = arg;
char *buffer;
int index, err;
fprintf(stderr, "play_thread start\n");
while (1) {
index = get_full();
err = pcm_write(pcm, buffers[index], BUFFER_SIZE);
if (err)
fprintf(stderr, "pcm_write err: %d\n", err);
put_empty(index);
}
fprintf(stderr, "play_thread done\n");
pcm_close(pcm);
free(buffer);
return NULL;
}
int init_audio(unsigned int ic, unsigned int id, unsigned int oc, unsigned int od)
{
pthread_t tid;
struct pcm_config config;
struct pcm *pcm;
int i;
input_card = ic;
input_device = id;
for (i = 0; i < BUFFER_COUNT; i++) {
buffers[i] = malloc(BUFFER_SIZE);
buffer_states[i] = BUFFER_EMPTY;
}
memset(&config, 0, sizeof(config));
config.channels = 2;
config.rate = 44100;
config.period_size = 1024;
config.period_count = 4;
config.format = PCM_FORMAT_S16_LE;
pcm = pcm_open(oc, od, PCM_OUT, &config);
if (!pcm || !pcm_is_ready(pcm)) {
fprintf(stderr, "Unable to open PCM device %d/%d for output (%s)\n",
oc, od, pcm_get_error(pcm));
return -1;
}
pthread_create(&tid, NULL, capture_thread, NULL);
pthread_create(&tid, NULL, play_thread, pcm);
return 0;
}
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