summaryrefslogtreecommitdiffstats
path: root/src/audio_core/sdl2_sink.cpp
blob: 933c5f16d1a150057e45e6ba4284a065747b5f42 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
// Copyright 2016 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#include <list>
#include <numeric>
#include <SDL.h>
#include "audio_core/audio_core.h"
#include "audio_core/sdl2_sink.h"
#include "common/assert.h"
#include "common/logging/log.h"
#include "core/settings.h"

namespace AudioCore {

struct SDL2Sink::Impl {
    unsigned int sample_rate = 0;

    SDL_AudioDeviceID audio_device_id = 0;

    std::list<std::vector<s16>> queue;

    static void Callback(void* impl_, u8* buffer, int buffer_size_in_bytes);
};

SDL2Sink::SDL2Sink() : impl(std::make_unique<Impl>()) {
    if (SDL_Init(SDL_INIT_AUDIO) < 0) {
        LOG_CRITICAL(Audio_Sink, "SDL_Init(SDL_INIT_AUDIO) failed with: %s", SDL_GetError());
        impl->audio_device_id = 0;
        return;
    }

    SDL_AudioSpec desired_audiospec;
    SDL_zero(desired_audiospec);
    desired_audiospec.format = AUDIO_S16;
    desired_audiospec.channels = 2;
    desired_audiospec.freq = native_sample_rate;
    desired_audiospec.samples = 512;
    desired_audiospec.userdata = impl.get();
    desired_audiospec.callback = &Impl::Callback;

    SDL_AudioSpec obtained_audiospec;
    SDL_zero(obtained_audiospec);

    int device_count = SDL_GetNumAudioDevices(0);
    device_list.clear();
    for (int i = 0; i < device_count; ++i) {
        device_list.push_back(SDL_GetAudioDeviceName(i, 0));
    }

    const char* device = nullptr;

    if (device_count >= 1 && Settings::values.audio_device_id != "auto" &&
        !Settings::values.audio_device_id.empty()) {
        device = Settings::values.audio_device_id.c_str();
    }

    impl->audio_device_id = SDL_OpenAudioDevice(device, false, &desired_audiospec,
                                                &obtained_audiospec, SDL_AUDIO_ALLOW_ANY_CHANGE);
    if (impl->audio_device_id <= 0) {
        LOG_CRITICAL(Audio_Sink, "SDL_OpenAudioDevice failed with code %d for device \"%s\"",
                     impl->audio_device_id, Settings::values.audio_device_id.c_str());
        return;
    }

    impl->sample_rate = obtained_audiospec.freq;

    // SDL2 audio devices start out paused, unpause it:
    SDL_PauseAudioDevice(impl->audio_device_id, 0);
}

SDL2Sink::~SDL2Sink() {
    if (impl->audio_device_id <= 0)
        return;

    SDL_CloseAudioDevice(impl->audio_device_id);
}

unsigned int SDL2Sink::GetNativeSampleRate() const {
    if (impl->audio_device_id <= 0)
        return native_sample_rate;

    return impl->sample_rate;
}

std::vector<std::string> SDL2Sink::GetDeviceList() const {
    return device_list;
}

void SDL2Sink::EnqueueSamples(const s16* samples, size_t sample_count) {
    if (impl->audio_device_id <= 0)
        return;

    SDL_LockAudioDevice(impl->audio_device_id);
    impl->queue.emplace_back(samples, samples + sample_count * 2);
    SDL_UnlockAudioDevice(impl->audio_device_id);
}

size_t SDL2Sink::SamplesInQueue() const {
    if (impl->audio_device_id <= 0)
        return 0;

    SDL_LockAudioDevice(impl->audio_device_id);

    size_t total_size = std::accumulate(impl->queue.begin(), impl->queue.end(),
                                        static_cast<size_t>(0), [](size_t sum, const auto& buffer) {
                                            // Division by two because each stereo sample is made of
                                            // two s16.
                                            return sum + buffer.size() / 2;
                                        });

    SDL_UnlockAudioDevice(impl->audio_device_id);

    return total_size;
}

void SDL2Sink::SetDevice(int device_id) {
    this->device_id = device_id;
}

void SDL2Sink::Impl::Callback(void* impl_, u8* buffer, int buffer_size_in_bytes) {
    Impl* impl = reinterpret_cast<Impl*>(impl_);

    size_t remaining_size = static_cast<size_t>(buffer_size_in_bytes) /
                            sizeof(s16); // Keep track of size in 16-bit increments.

    while (remaining_size > 0 && !impl->queue.empty()) {
        if (impl->queue.front().size() <= remaining_size) {
            memcpy(buffer, impl->queue.front().data(), impl->queue.front().size() * sizeof(s16));
            buffer += impl->queue.front().size() * sizeof(s16);
            remaining_size -= impl->queue.front().size();
            impl->queue.pop_front();
        } else {
            memcpy(buffer, impl->queue.front().data(), remaining_size * sizeof(s16));
            buffer += remaining_size * sizeof(s16);
            impl->queue.front().erase(impl->queue.front().begin(),
                                      impl->queue.front().begin() + remaining_size);
            remaining_size = 0;
        }
    }

    if (remaining_size > 0) {
        memset(buffer, 0, remaining_size * sizeof(s16));
    }
}

} // namespace AudioCore