ladybird/Ladybird/AudioThread.h
Andrew Kaster 2a4f2110b9 Ladybird: Move the AudioThread class into its own file
This implementation detail of audio support in ladybird is a QObject
that needs moc'd by the moc tools. Putting it in its own file follows
the pattern we have for all the other QObjects in Ladybird.
2023-07-07 06:41:51 -04:00

104 lines
2.7 KiB
C++

/*
* Copyright (c) 2023, Tim Flynn <trflynn89@serenityos.org>
* Copyright (c) 2023, Andrew Kaster <akaster@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Endian.h>
#include <AK/MemoryStream.h>
#include <AK/Optional.h>
#include <AK/Types.h>
#include <LibAudio/Loader.h>
#include <LibAudio/Sample.h>
#include <LibCore/SharedCircularQueue.h>
#include <QAudioFormat>
#include <QAudioSink>
#include <QByteArray>
#include <QMediaDevices>
#include <QThread>
namespace Ladybird {
static constexpr u32 UPDATE_RATE_MS = 10;
struct AudioTask {
enum class Type {
Stop,
Play,
Pause,
Seek,
Volume,
RecreateAudioDevice,
};
Type type;
Optional<double> data {};
};
using AudioTaskQueue = Core::SharedSingleProducerCircularQueue<AudioTask>;
class AudioThread final : public QThread { // We have to use QThread, otherwise internal Qt media QTimer objects do not work.
Q_OBJECT
public:
static ErrorOr<NonnullOwnPtr<AudioThread>> create(NonnullRefPtr<Audio::Loader> loader);
ErrorOr<void> stop();
Duration duration() const { return m_duration; }
ErrorOr<void> queue_task(AudioTask task);
Q_SIGNALS:
void playback_position_updated(Duration);
private:
AudioThread(NonnullRefPtr<Audio::Loader> loader, AudioTaskQueue task_queue);
enum class Paused {
Yes,
No,
};
void run() override;
ErrorOr<Paused> play_next_samples(QAudioSink& audio_output, QIODevice& io_device);
void enqueue_samples(QAudioSink const& audio_output, QIODevice& io_device, FixedArray<Audio::Sample> samples);
template<typename T>
void write_sample(FixedMemoryStream& stream, float sample)
{
// The values that need to be written to the stream vary depending on the output channel format, and isn't
// particularly well documented. The value derivations performed below were adapted from a Qt example:
// https://code.qt.io/cgit/qt/qtmultimedia.git/tree/examples/multimedia/audiooutput/audiooutput.cpp?h=6.4.2#n46
LittleEndian<T> pcm;
if constexpr (IsSame<T, u8>)
pcm = static_cast<u8>((sample + 1.0f) / 2 * NumericLimits<u8>::max());
else if constexpr (IsSame<T, i16>)
pcm = static_cast<i16>(sample * NumericLimits<i16>::max());
else if constexpr (IsSame<T, i32>)
pcm = static_cast<i32>(sample * NumericLimits<i32>::max());
else if constexpr (IsSame<T, float>)
pcm = sample;
else
static_assert(DependentFalse<T>);
MUST(stream.write_value(pcm));
}
NonnullRefPtr<Audio::Loader> m_loader;
AudioTaskQueue m_task_queue;
QByteArray m_sample_buffer;
Duration m_duration;
Duration m_position;
};
}