| 1 | /** |
| 2 | * Copyright (C) 2011-2012 Juho Vähä-Herttua |
| 3 | * |
| 4 | * This library is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU Lesser General Public |
| 6 | * License as published by the Free Software Foundation; either |
| 7 | * version 2.1 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * This library is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | * Lesser General Public License for more details. |
| 13 | */ |
| 14 | |
| 15 | #include "audiooutput.h" |
| 16 | |
| 17 | #include <QDebug> |
| 18 | #include <QtEndian> |
| 19 | #include <math.h> |
| 20 | |
| 21 | #define BUFFER_SIZE (64*1024) |
| 22 | |
| 23 | AudioOutput::AudioOutput(QObject *parent) : |
| 24 | QIODevice(parent), |
| 25 | m_initialized(false), |
| 26 | m_output(0), |
| 27 | m_volume(0.0f) |
| 28 | { |
| 29 | } |
| 30 | |
| 31 | bool AudioOutput::init(int bits, int channels, int samplerate) |
| 32 | { |
| 33 | if (m_initialized) { |
| 34 | return false; |
| 35 | } |
| 36 | if (bits != 16) { |
| 37 | return false; |
| 38 | } |
| 39 | |
| 40 | m_format.setSampleSize(bits); |
| 41 | m_format.setChannels(channels); |
| 42 | m_format.setFrequency(samplerate); |
| 43 | m_format.setCodec("audio/pcm"); |
| 44 | m_format.setByteOrder(QAudioFormat::LittleEndian); |
| 45 | m_format.setSampleType(QAudioFormat::SignedInt); |
| 46 | |
| 47 | m_initialized = setDevice(QAudioDeviceInfo::defaultOutputDevice()); |
| 48 | return m_initialized; |
| 49 | } |
| 50 | |
| 51 | bool AudioOutput::setDevice(QAudioDeviceInfo deviceInfo) |
| 52 | { |
| 53 | if (!deviceInfo.isFormatSupported(m_format)) { |
| 54 | qDebug() << "Format not supported!"; |
| 55 | return false; |
| 56 | } |
| 57 | m_deviceInfo = deviceInfo; |
| 58 | this->reinit(); |
| 59 | return true; |
| 60 | } |
| 61 | |
| 62 | void AudioOutput::reinit() |
| 63 | { |
| 64 | bool running = false; |
| 65 | if (m_output && m_output->state() != QAudio::StoppedState) { |
| 66 | running = true; |
| 67 | } |
| 68 | this->stop(); |
| 69 | |
| 70 | // Reinitialize audio output |
| 71 | delete m_output; |
| 72 | m_output = 0; |
| 73 | m_output = new QAudioOutput(m_deviceInfo, m_format, this); |
| 74 | |
| 75 | // Set constant values to new audio output |
| 76 | connect(m_output, SIGNAL(notify()), SLOT(notified())); |
| 77 | connect(m_output, SIGNAL(stateChanged(QAudio::State)), SLOT(stateChanged(QAudio::State))); |
| 78 | if (running) { |
| 79 | this->start(); |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | void AudioOutput::start() |
| 84 | { |
| 85 | if (m_output == 0 || m_output->state() != QAudio::StoppedState) { |
| 86 | return; |
| 87 | } |
| 88 | this->open(QIODevice::ReadOnly); |
| 89 | m_buffer.clear(); |
| 90 | m_output->start(this); |
| 91 | m_output->suspend(); |
| 92 | } |
| 93 | |
| 94 | void AudioOutput::setVolume(float volume) |
| 95 | { |
| 96 | m_volume = volume; |
| 97 | } |
| 98 | |
| 99 | void AudioOutput::output(const QByteArray & data) |
| 100 | { |
| 101 | if (m_output && m_output->state() != QAudio::StoppedState) { |
| 102 | // Append input data to the end of buffer |
| 103 | m_buffer.append(data); |
| 104 | |
| 105 | // Check if our buffer has grown too large |
| 106 | if (m_buffer.length() > 2*BUFFER_SIZE) { |
| 107 | // There could be a better way to handle this |
| 108 | this->flush(); |
| 109 | } |
| 110 | |
| 111 | // If audio is suspended and buffer is full, resume |
| 112 | if (m_output->state() == QAudio::SuspendedState) { |
| 113 | if (m_buffer.length() >= BUFFER_SIZE) { |
| 114 | qDebug() << "Resuming..."; |
| 115 | m_output->resume(); |
| 116 | } |
| 117 | } |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | void AudioOutput::flush() |
| 122 | { |
| 123 | // Flushing buffers is a bit tricky... |
| 124 | // Don't modify this unless you're sure |
| 125 | this->stop(); |
| 126 | m_output->reset(); |
| 127 | this->start(); |
| 128 | } |
| 129 | |
| 130 | void AudioOutput::stop() |
| 131 | { |
| 132 | if (m_output && m_output->state() != QAudio::StoppedState) { |
| 133 | // Stop audio output |
| 134 | m_output->stop(); |
| 135 | m_buffer.clear(); |
| 136 | this->close(); |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | static void apply_s16le_volume(float volume, uchar *data, int datalen) |
| 141 | { |
| 142 | int samples = datalen/2; |
| 143 | float mult = pow(10.0,0.05*volume); |
| 144 | |
| 145 | for (int i=0; i<samples; i++) { |
| 146 | qint16 val = qFromLittleEndian<qint16>(data+i*2)*mult; |
| 147 | qToLittleEndian<qint16>(val, data+i*2); |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | qint64 AudioOutput::readData(char *data, qint64 maxlen) |
| 152 | { |
| 153 | // Calculate output length, always full samples |
| 154 | int outlen = qMin(m_buffer.length(), (int)maxlen); |
| 155 | if (outlen%2 != 0) { |
| 156 | outlen += 1; |
| 157 | } |
| 158 | |
| 159 | memcpy(data, m_buffer.data(), outlen); |
| 160 | apply_s16le_volume(m_volume, (uchar *)data, outlen); |
| 161 | m_buffer.remove(0, outlen); |
| 162 | return outlen; |
| 163 | } |
| 164 | |
| 165 | qint64 AudioOutput::writeData(const char *data, qint64 len) |
| 166 | { |
| 167 | Q_UNUSED(data); |
| 168 | Q_UNUSED(len); |
| 169 | |
| 170 | return 0; |
| 171 | } |
| 172 | |
| 173 | qint64 AudioOutput::bytesAvailable() const |
| 174 | { |
| 175 | return m_buffer.length() + QIODevice::bytesAvailable(); |
| 176 | } |
| 177 | |
| 178 | bool AudioOutput::isSequential() const |
| 179 | { |
| 180 | return true; |
| 181 | } |
| 182 | |
| 183 | void AudioOutput::notified() |
| 184 | { |
| 185 | } |
| 186 | |
| 187 | void AudioOutput::stateChanged(QAudio::State state) |
| 188 | { |
| 189 | // Start buffering again in case of underrun... |
| 190 | // Required on Windows, otherwise it stalls idle |
| 191 | if (state == QAudio::IdleState && m_output->error() == QAudio::UnderrunError) { |
| 192 | // This check is required, because Mac OS X underruns often |
| 193 | if (m_buffer.length() < BUFFER_SIZE) { |
| 194 | m_output->suspend(); |
| 195 | } |
| 196 | } |
| 197 | qWarning() << "state = " << state; |
| 198 | } |