1 files changed, 127 insertions, 0 deletions
diff --git a/src/audio_core/stream.cpp b/src/audio_core/stream.cpp
new file mode 100644
index 000000000..ad9e2915c
--- /dev/null
+++ b/src/audio_core/stream.cpp
@@ -0,0 +1,127 @@
+// Copyright 2018 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <cmath>
+
+#include "audio_core/sink.h"
+#include "audio_core/sink_details.h"
+#include "audio_core/stream.h"
+#include "common/assert.h"
+#include "common/logging/log.h"
+#include "core/core_timing.h"
+#include "core/core_timing_util.h"
+#include "core/settings.h"
+
+namespace AudioCore {
+
+constexpr size_t MaxAudioBufferCount{32};
+
+u32 Stream::GetNumChannels() const {
+    switch (format) {
+    case Format::Mono16:
+        return 1;
+    case Format::Stereo16:
+        return 2;
+    case Format::Multi51Channel16:
+        return 6;
+    }
+    LOG_CRITICAL(Audio, "Unimplemented format={}", static_cast<u32>(format));
+    UNREACHABLE();
+    return {};
+}
+
+Stream::Stream(u32 sample_rate, Format format, ReleaseCallback&& release_callback,
+               SinkStream& sink_stream, std::string&& name_)
+    : sample_rate{sample_rate}, format{format}, release_callback{std::move(release_callback)},
+      sink_stream{sink_stream}, name{std::move(name_)} {
+
+    release_event = CoreTiming::RegisterEvent(
+        name, [this](u64 userdata, int cycles_late) { ReleaseActiveBuffer(); });
+}
+
+void Stream::Play() {
+    state = State::Playing;
+    PlayNextBuffer();
+}
+
+void Stream::Stop() {
+    ASSERT_MSG(false, "Unimplemented");
+}
+
+s64 Stream::GetBufferReleaseCycles(const Buffer& buffer) const {
+    const size_t num_samples{buffer.GetSamples().size() / GetNumChannels()};
+    return CoreTiming::usToCycles((static_cast<u64>(num_samples) * 1000000) / sample_rate);
+}
+
+static void VolumeAdjustSamples(std::vector<s16>& samples) {
+    const float volume{std::clamp(Settings::values.volume, 0.0f, 1.0f)};
+
+    if (volume == 1.0f) {
+        return;
+    }
+
+    // Implementation of a volume slider with a dynamic range of 60 dB
+    const float volume_scale_factor{std::exp(6.90775f * volume) * 0.001f};
+    for (auto& sample : samples) {
+        sample = static_cast<s16>(sample * volume_scale_factor);
+    }
+}
+
+void Stream::PlayNextBuffer() {
+    if (!IsPlaying()) {
+        // Ensure we are in playing state before playing the next buffer
+        return;
+    }
+
+    if (active_buffer) {
+        // Do not queue a new buffer if we are already playing a buffer
+        return;
+    }
+
+    if (queued_buffers.empty()) {
+        // No queued buffers - we are effectively paused
+        return;
+    }
+
+    active_buffer = queued_buffers.front();
+    queued_buffers.pop();
+
+    VolumeAdjustSamples(active_buffer->Samples());
+    sink_stream.EnqueueSamples(GetNumChannels(), active_buffer->GetSamples());
+
+    CoreTiming::ScheduleEventThreadsafe(GetBufferReleaseCycles(*active_buffer), release_event, {});
+}
+
+void Stream::ReleaseActiveBuffer() {
+    ASSERT(active_buffer);
+    released_buffers.push(std::move(active_buffer));
+    release_callback();
+    PlayNextBuffer();
+}
+
+bool Stream::QueueBuffer(BufferPtr&& buffer) {
+    if (queued_buffers.size() < MaxAudioBufferCount) {
+        queued_buffers.push(std::move(buffer));
+        PlayNextBuffer();
+        return true;
+    }
+    return false;
+}
+
+bool Stream::ContainsBuffer(Buffer::Tag tag) const {
+    ASSERT_MSG(false, "Unimplemented");
+    return {};
+}
+
+std::vector<Buffer::Tag> Stream::GetTagsAndReleaseBuffers(size_t max_count) {
+    std::vector<Buffer::Tag> tags;
+    for (size_t count = 0; count < max_count && !released_buffers.empty(); ++count) {
+        tags.push_back(released_buffers.front()->GetTag());
+        released_buffers.pop();
+    }
+    return tags;
+}
+
+} // namespace AudioCore