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/*
* Copyright (C) 2014 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.
*/
#define LOG_TAG "alsa_device_proxy"
/*#define LOG_NDEBUG 0*/
/*#define LOG_PCM_PARAMS 0*/
#include <log/log.h>
#include <errno.h>
#include "include/alsa_device_proxy.h"
#include "include/alsa_logging.h"
#define DEFAULT_PERIOD_SIZE 1024
#define DEFAULT_PERIOD_COUNT 2
#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
static const unsigned format_byte_size_map[] = {
2, /* PCM_FORMAT_S16_LE */
4, /* PCM_FORMAT_S32_LE */
1, /* PCM_FORMAT_S8 */
4, /* PCM_FORMAT_S24_LE */
3, /* PCM_FORMAT_S24_3LE */
};
void proxy_prepare(alsa_device_proxy * proxy, alsa_device_profile* profile,
struct pcm_config * config)
{
ALOGV("proxy_prepare(c:%d, d:%d)", profile->card, profile->device);
proxy->profile = profile;
#ifdef LOG_PCM_PARAMS
log_pcm_config(config, "proxy_setup()");
#endif
proxy->alsa_config.format =
config->format != PCM_FORMAT_INVALID && profile_is_format_valid(profile, config->format)
? config->format : profile->default_config.format;
proxy->alsa_config.rate =
config->rate != 0 && profile_is_sample_rate_valid(profile, config->rate)
? config->rate : profile->default_config.rate;
proxy->alsa_config.channels =
config->channels != 0 && profile_is_channel_count_valid(profile, config->channels)
? config->channels : profile->default_config.channels;
proxy->alsa_config.period_count = profile->default_config.period_count;
proxy->alsa_config.period_size =
profile_get_period_size(proxy->profile, proxy->alsa_config.rate);
// Hack for USB accessory audio.
// Here we set the correct value for period_count if tinyalsa fails to get it from the
// f_audio_source driver.
if (proxy->alsa_config.period_count == 0) {
proxy->alsa_config.period_count = 4;
}
proxy->pcm = NULL;
// config format should be checked earlier against profile.
if (config->format >= 0 && (size_t)config->format < ARRAY_SIZE(format_byte_size_map)) {
proxy->frame_size = format_byte_size_map[config->format] * proxy->alsa_config.channels;
} else {
proxy->frame_size = 1;
}
}
int proxy_open(alsa_device_proxy * proxy)
{
alsa_device_profile* profile = proxy->profile;
ALOGV("proxy_open(card:%d device:%d %s)", profile->card, profile->device,
profile->direction == PCM_OUT ? "PCM_OUT" : "PCM_IN");
if (profile->card < 0 || profile->device < 0) {
return -EINVAL;
}
proxy->pcm = pcm_open(profile->card, profile->device,
profile->direction | PCM_MONOTONIC, &proxy->alsa_config);
if (proxy->pcm == NULL) {
return -ENOMEM;
}
if (!pcm_is_ready(proxy->pcm)) {
ALOGE(" proxy_open() pcm_open() failed: %s", pcm_get_error(proxy->pcm));
#if defined(LOG_PCM_PARAMS)
log_pcm_config(&proxy->alsa_config, "config");
#endif
pcm_close(proxy->pcm);
proxy->pcm = NULL;
return -ENOMEM;
}
return 0;
}
void proxy_close(alsa_device_proxy * proxy)
{
ALOGV("proxy_close() [pcm:%p]", proxy->pcm);
if (proxy->pcm != NULL) {
pcm_close(proxy->pcm);
proxy->pcm = NULL;
}
}
/*
* Sample Rate
*/
unsigned proxy_get_sample_rate(const alsa_device_proxy * proxy)
{
return proxy->alsa_config.rate;
}
/*
* Format
*/
enum pcm_format proxy_get_format(const alsa_device_proxy * proxy)
{
return proxy->alsa_config.format;
}
/*
* Channel Count
*/
unsigned proxy_get_channel_count(const alsa_device_proxy * proxy)
{
return proxy->alsa_config.channels;
}
/*
* Other
*/
unsigned int proxy_get_period_size(const alsa_device_proxy * proxy)
{
return proxy->alsa_config.period_size;
}
unsigned int proxy_get_period_count(const alsa_device_proxy * proxy)
{
return proxy->alsa_config.period_count;
}
unsigned proxy_get_latency(const alsa_device_proxy * proxy)
{
return (proxy_get_period_size(proxy) * proxy_get_period_count(proxy) * 1000)
/ proxy_get_sample_rate(proxy);
}
int proxy_get_presentation_position(const alsa_device_proxy * proxy,
uint64_t *frames, struct timespec *timestamp)
{
int ret = -EPERM; // -1
unsigned int avail;
if (proxy->pcm != NULL
&& pcm_get_htimestamp(proxy->pcm, &avail, timestamp) == 0) {
const size_t kernel_buffer_size =
proxy->alsa_config.period_size * proxy->alsa_config.period_count;
if (avail > kernel_buffer_size) {
ALOGE("available frames(%u) > buffer size(%zu)", avail, kernel_buffer_size);
} else {
int64_t signed_frames = proxy->transferred - kernel_buffer_size + avail;
// It is possible to compensate for additional driver and device delay
// by changing signed_frames. Example:
// signed_frames -= 20 /* ms */ * proxy->alsa_config.rate / 1000;
if (signed_frames >= 0) {
*frames = signed_frames;
ret = 0;
}
}
}
return ret;
}
/*
* I/O
*/
int proxy_write(alsa_device_proxy * proxy, const void *data, unsigned int count)
{
int ret = pcm_write(proxy->pcm, data, count);
if (ret == 0) {
proxy->transferred += count / proxy->frame_size;
}
return ret;
}
int proxy_read(const alsa_device_proxy * proxy, void *data, unsigned int count)
{
return pcm_read(proxy->pcm, data, count);
}
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