mirror of
https://github.com/ZLMediaKit/ZLMediaKit.git
synced 2026-07-07 12:18:12 +08:00
121 lines
4.0 KiB
C++
121 lines
4.0 KiB
C++
/*
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* Copyright (c) 2016-present The ZLMediaKit project authors. All Rights Reserved.
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*
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* This file is part of ZLMediaKit(https://github.com/ZLMediaKit/ZLMediaKit).
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*
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* Use of this source code is governed by MIT-like license that can be found in the
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* LICENSE file in the root of the source tree. All contributing project authors
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* may be found in the AUTHORS file in the root of the source tree.
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*/
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#include "Util/logger.h"
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#include "AudioSRC.h"
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#include "SDLAudioDevice.h"
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using namespace std;
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using namespace toolkit;
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INSTANCE_IMP(SDLAudioDevice);
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SDLAudioDevice::~SDLAudioDevice() {
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if (_init_thread.joinable()) {
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_init_thread.join();
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}
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auto dev = _device.load();
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if (dev) {
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SDL_CloseAudioDevice(dev);
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_device = 0;
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}
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}
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SDLAudioDevice::SDLAudioDevice() {
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// 将 SDL_OpenAudioDevice 放到后台线程异步执行, 防止主线程(SDL事件循环)和 event poller 线程阻塞
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// 在Windows下没声卡/设备异常时，SDL_OpenAudioDevice()会阻塞
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// 在 Linux(PulseAudio/ALSA) 和 macOS(CoreAudio) 上通常秒回，几乎无开销
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_init_thread = std::thread([this]() {
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SDL_AudioSpec wanted_spec;
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wanted_spec.freq = DEFAULT_SAMPLERATE;
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wanted_spec.format = DEFAULT_FORMAT;
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wanted_spec.channels = DEFAULT_CHANNEL;
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wanted_spec.silence = 0;
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wanted_spec.samples = DEFAULT_SAMPLES;
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wanted_spec.userdata = this;
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wanted_spec.callback = [](void *userdata, Uint8 *stream, int len) {
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SDLAudioDevice *_this = (SDLAudioDevice *)userdata;
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_this->onReqPCM((char *)stream, len);
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};
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SDL_AudioSpec audio_config;
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auto dev = SDL_OpenAudioDevice(NULL, 0, &wanted_spec, &audio_config, 0);
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if (dev <= 0)
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dev = SDL_OpenAudioDevice(NULL, 0, &wanted_spec, &audio_config, SDL_AUDIO_ALLOW_ANY_CHANGE);
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if (dev <= 0) {
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WarnL << "SDL_OpenAudioDevice failed, audio output disabled: " << SDL_GetError();
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return;
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}
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InfoL << "actual audioSpec, " << "freq:" << audio_config.freq
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<< ", format:" << hex << audio_config.format << dec
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<< ", channels:" << (int)audio_config.channels
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<< ", samples:" << audio_config.samples
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<< ", pcm size:" << audio_config.size;
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// 先设置 _audio_config 和 _play_buf，再设置 _device (release)
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// 这样 addChannel 读到 _device != 0 时，_audio_config 和 _play_buf 已就绪
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_audio_config = audio_config;
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_play_buf.reset(new char[audio_config.size], [](char *ptr) {
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delete[] ptr;
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});
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_device.store(dev, std::memory_order_release);
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});
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}
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void SDLAudioDevice::addChannel(AudioSRC *chn) {
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auto dev = _device.load(std::memory_order_acquire);
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if (dev == 0) {
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throw std::runtime_error("SDL audio device not available (not ready or no audio device)");
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}
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lock_guard<recursive_mutex> lck(_channel_mtx);
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if (_channels.empty()) {
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SDL_PauseAudioDevice(dev, false);
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}
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chn->setOutputAudioConfig(_audio_config);
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_channels.emplace(chn);
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}
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void SDLAudioDevice::delChannel(AudioSRC *chn) {
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lock_guard<recursive_mutex> lck(_channel_mtx);
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_channels.erase(chn);
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auto dev = _device.load();
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if (_channels.empty() && dev) {
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SDL_PauseAudioDevice(dev, true);
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}
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}
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void SDLAudioDevice::onReqPCM(char *stream, int len) {
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lock_guard<recursive_mutex> lck(_channel_mtx);
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int size;
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int channel = 0;
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for (auto &chn : _channels) {
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if (channel == 0) {
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size = chn->getPCMData(_play_buf.get(), len);
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if (size) {
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memcpy(stream, _play_buf.get(), size);
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}
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} else {
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size = chn->getPCMData(_play_buf.get(), len);
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if (size) {
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SDL_MixAudio((Uint8 *) stream, (Uint8 *) _play_buf.get(), size, SDL_MIX_MAXVOLUME);
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}
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}
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if (size) {
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channel++;
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}
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}
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if (!channel) {
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memset(stream, 0, len);
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}
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}
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