godot/drivers/alsa/audio_driver_alsa.cpp
Pedro J. Estébanez 99fe462452 Modernize Thread
- Based on C++11's `thread` and `thread_local`
- No more need to allocate-deallocate or check for null
- No pointer anymore, just a member variable
- Platform-specific implementations no longer needed (except for the few cases of non-portable functions)
- Simpler for `NO_THREADS`
- Thread ids are now the same across platforms (main is 1; others follow)
2021-01-29 12:02:13 +01:00

315 lines
9 KiB
C++

/*************************************************************************/
/* audio_driver_alsa.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "audio_driver_alsa.h"
#ifdef ALSA_ENABLED
#include "core/config/project_settings.h"
#include "core/os/os.h"
#include <errno.h>
Error AudioDriverALSA::init_device() {
mix_rate = GLOBAL_GET("audio/mix_rate");
speaker_mode = SPEAKER_MODE_STEREO;
channels = 2;
// If there is a specified device check that it is really present
if (device_name != "Default") {
Array list = get_device_list();
if (list.find(device_name) == -1) {
device_name = "Default";
new_device = "Default";
}
}
int status;
snd_pcm_hw_params_t *hwparams;
snd_pcm_sw_params_t *swparams;
#define CHECK_FAIL(m_cond) \
if (m_cond) { \
fprintf(stderr, "ALSA ERR: %s\n", snd_strerror(status)); \
if (pcm_handle) { \
snd_pcm_close(pcm_handle); \
pcm_handle = nullptr; \
} \
ERR_FAIL_COND_V(m_cond, ERR_CANT_OPEN); \
}
//todo, add
//6 chans - "plug:surround51"
//4 chans - "plug:surround40";
if (device_name == "Default") {
status = snd_pcm_open(&pcm_handle, "default", SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
} else {
String device = device_name;
int pos = device.find(";");
if (pos != -1) {
device = device.substr(0, pos);
}
status = snd_pcm_open(&pcm_handle, device.utf8().get_data(), SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
}
ERR_FAIL_COND_V(status < 0, ERR_CANT_OPEN);
snd_pcm_hw_params_alloca(&hwparams);
status = snd_pcm_hw_params_any(pcm_handle, hwparams);
CHECK_FAIL(status < 0);
status = snd_pcm_hw_params_set_access(pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED);
CHECK_FAIL(status < 0);
//not interested in anything else
status = snd_pcm_hw_params_set_format(pcm_handle, hwparams, SND_PCM_FORMAT_S16_LE);
CHECK_FAIL(status < 0);
//todo: support 4 and 6
status = snd_pcm_hw_params_set_channels(pcm_handle, hwparams, 2);
CHECK_FAIL(status < 0);
status = snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, &mix_rate, nullptr);
CHECK_FAIL(status < 0);
// In ALSA the period size seems to be the one that will determine the actual latency
// Ref: https://www.alsa-project.org/main/index.php/FramesPeriods
unsigned int periods = 2;
int latency = GLOBAL_GET("audio/output_latency");
buffer_frames = closest_power_of_2(latency * mix_rate / 1000);
buffer_size = buffer_frames * periods;
period_size = buffer_frames;
// set buffer size from project settings
status = snd_pcm_hw_params_set_buffer_size_near(pcm_handle, hwparams, &buffer_size);
CHECK_FAIL(status < 0);
status = snd_pcm_hw_params_set_period_size_near(pcm_handle, hwparams, &period_size, nullptr);
CHECK_FAIL(status < 0);
print_verbose("Audio buffer frames: " + itos(period_size) + " calculated latency: " + itos(period_size * 1000 / mix_rate) + "ms");
status = snd_pcm_hw_params_set_periods_near(pcm_handle, hwparams, &periods, nullptr);
CHECK_FAIL(status < 0);
status = snd_pcm_hw_params(pcm_handle, hwparams);
CHECK_FAIL(status < 0);
//snd_pcm_hw_params_free(&hwparams);
snd_pcm_sw_params_alloca(&swparams);
status = snd_pcm_sw_params_current(pcm_handle, swparams);
CHECK_FAIL(status < 0);
status = snd_pcm_sw_params_set_avail_min(pcm_handle, swparams, period_size);
CHECK_FAIL(status < 0);
status = snd_pcm_sw_params_set_start_threshold(pcm_handle, swparams, 1);
CHECK_FAIL(status < 0);
status = snd_pcm_sw_params(pcm_handle, swparams);
CHECK_FAIL(status < 0);
samples_in.resize(period_size * channels);
samples_out.resize(period_size * channels);
return OK;
}
Error AudioDriverALSA::init() {
active = false;
thread_exited = false;
exit_thread = false;
Error err = init_device();
if (err == OK) {
thread.start(AudioDriverALSA::thread_func, this);
}
return err;
}
void AudioDriverALSA::thread_func(void *p_udata) {
AudioDriverALSA *ad = (AudioDriverALSA *)p_udata;
while (!ad->exit_thread) {
ad->lock();
ad->start_counting_ticks();
if (!ad->active) {
for (uint64_t i = 0; i < ad->period_size * ad->channels; i++) {
ad->samples_out.write[i] = 0;
}
} else {
ad->audio_server_process(ad->period_size, ad->samples_in.ptrw());
for (uint64_t i = 0; i < ad->period_size * ad->channels; i++) {
ad->samples_out.write[i] = ad->samples_in[i] >> 16;
}
}
int todo = ad->period_size;
int total = 0;
while (todo && !ad->exit_thread) {
int16_t *src = (int16_t *)ad->samples_out.ptr();
int wrote = snd_pcm_writei(ad->pcm_handle, (void *)(src + (total * ad->channels)), todo);
if (wrote > 0) {
total += wrote;
todo -= wrote;
} else if (wrote == -EAGAIN) {
ad->stop_counting_ticks();
ad->unlock();
OS::get_singleton()->delay_usec(1000);
ad->lock();
ad->start_counting_ticks();
} else {
wrote = snd_pcm_recover(ad->pcm_handle, wrote, 0);
if (wrote < 0) {
ERR_PRINT("ALSA: Failed and can't recover: " + String(snd_strerror(wrote)));
ad->active = false;
ad->exit_thread = true;
}
}
}
// User selected a new device, finish the current one so we'll init the new device
if (ad->device_name != ad->new_device) {
ad->device_name = ad->new_device;
ad->finish_device();
Error err = ad->init_device();
if (err != OK) {
ERR_PRINT("ALSA: init_device error");
ad->device_name = "Default";
ad->new_device = "Default";
err = ad->init_device();
if (err != OK) {
ad->active = false;
ad->exit_thread = true;
}
}
}
ad->stop_counting_ticks();
ad->unlock();
}
ad->thread_exited = true;
}
void AudioDriverALSA::start() {
active = true;
}
int AudioDriverALSA::get_mix_rate() const {
return mix_rate;
}
AudioDriver::SpeakerMode AudioDriverALSA::get_speaker_mode() const {
return speaker_mode;
}
Array AudioDriverALSA::get_device_list() {
Array list;
list.push_back("Default");
void **hints;
if (snd_device_name_hint(-1, "pcm", &hints) < 0) {
return list;
}
for (void **n = hints; *n != nullptr; n++) {
char *name = snd_device_name_get_hint(*n, "NAME");
char *desc = snd_device_name_get_hint(*n, "DESC");
if (name != nullptr && !strncmp(name, "plughw", 6)) {
if (desc) {
list.push_back(String(name) + ";" + String(desc));
} else {
list.push_back(String(name));
}
}
if (desc != nullptr) {
free(desc);
}
if (name != nullptr) {
free(name);
}
}
snd_device_name_free_hint(hints);
return list;
}
String AudioDriverALSA::get_device() {
return device_name;
}
void AudioDriverALSA::set_device(String device) {
lock();
new_device = device;
unlock();
}
void AudioDriverALSA::lock() {
mutex.lock();
}
void AudioDriverALSA::unlock() {
mutex.unlock();
}
void AudioDriverALSA::finish_device() {
if (pcm_handle) {
snd_pcm_close(pcm_handle);
pcm_handle = nullptr;
}
}
void AudioDriverALSA::finish() {
exit_thread = true;
thread.wait_to_finish();
finish_device();
}
#endif // ALSA_ENABLED