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#include "encoder/encoderopus.h"
#include <stdlib.h>
#include <QByteArray>
#include <QMapIterator>
#if (QT_VERSION >= QT_VERSION_CHECK(5, 10, 0))
#include <QRandomGenerator>
#endif
#include <QtGlobal>
#include "encoder/encoderopussettings.h"
#include "engine/sidechain/enginesidechain.h"
#include "util/logger.h"
namespace {
// From libjitsi's Opus encoder:
// 1 byte TOC + maximum frame size (1275)
// See https://tools.ietf.org/html/rfc6716#section-3.2
constexpr int kMaxOpusBufferSize = 1+1275;
// Opus frame duration in milliseconds. Fixed to 60ms
constexpr int kOpusFrameMs = 60;
constexpr int kOpusChannelCount = 2;
// Opus only supports 48 and 96 kHz samplerates
constexpr int kMasterSamplerate = 48000;
const mixxx::Logger kLogger("EncoderOpus");
QString opusErrorString(int error) {
QString errorString = "";
switch (error) {
case OPUS_OK:
errorString = "OPUS_OK";
break;
case OPUS_BAD_ARG:
errorString = "OPUS_BAD_ARG";
break;
case OPUS_BUFFER_TOO_SMALL:
errorString = "OPUS_BUFFER_TOO_SMALL";
break;
case OPUS_INTERNAL_ERROR:
errorString = "OPUS_INTERNAL_ERROR";
break;
case OPUS_INVALID_PACKET:
errorString = "OPUS_INVALID_PACKET";
break;
case OPUS_UNIMPLEMENTED:
errorString = "OPUS_UNIMPLEMENTED";
break;
case OPUS_INVALID_STATE:
errorString = "OPUS_INVALID_STATE";
break;
case OPUS_ALLOC_FAIL:
errorString = "OPUS_ALLOC_FAIL";
break;
default:
return "Unknown error";
}
return errorString + (QString(" (%1)").arg(error));
}
int getSerial() {
static int prevSerial = 0;
int serial;
do {
#if (QT_VERSION >= QT_VERSION_CHECK(5, 10, 0))
serial = static_cast<int>(QRandomGenerator::global()->generate());
#else
serial = qrand();
#endif
} while (prevSerial == serial);
prevSerial = serial;
kLogger.debug() << "RETURNING SERIAL " << serial;
return serial;
}
} // namespace
//static
int EncoderOpus::getMasterSamplerate() {
return kMasterSamplerate;
}
//static
QString EncoderOpus::getInvalidSamplerateMessage() {
return QObject::tr(
"Using Opus at samplerates other than 48 kHz "
"is not supported by the Opus encoder. Please use "
"48000 Hz in \"Sound Hardware\" preferences "
"or switch to a different encoding.");
};
EncoderOpus::EncoderOpus(EncoderCallback* pCallback)
: m_bitrate(0),
m_bitrateMode(0),
m_channels(0),
m_samplerate(0),
m_readRequired(0),
m_pCallback(pCallback),
m_fifoBuffer(EngineSideChain::SIDECHAIN_BUFFER_SIZE * kOpusChannelCount),
m_pFifoChunkBuffer(),
m_pOpus(nullptr),
m_opusDataBuffer(kMaxOpusBufferSize),
m_header_write(false),
m_packetNumber(0),
m_granulePos(0)
{
// Regarding m_pFifoBuffer:
// Size the input FIFO buffer with twice the maximum possible sample count that can be
// processed at once, to avoid skipping frames or waiting for the required sample count
// and encode at a regular pace.
// This is set to the buffer size of the sidechain engine because
// Recording (which uses this engine) sends more samples at once to the encoder than
// the Live Broadcasting implementation
m_opusComments.insert("ENCODER", "mixxx/libopus");
#if (QT_VERSION >= QT_VERSION_CHECK(5, 10, 0))
int serial = static_cast<int>(QRandomGenerator::global()->generate());
#else
int serial = qrand();
#endif
ogg_stream_init(&m_oggStream, serial);
}
EncoderOpus::~EncoderOpus() {
if (m_pOpus) {
opus_encoder_destroy(m_pOpus);
}
ogg_stream_clear(&m_oggStream);
}
void EncoderOpus::setEncoderSettings(const EncoderSettings& settings) {
m_bitrate = settings.getQuality();
m_bitrateMode = settings.getSelectedOption(EncoderOpusSettings::BITRATE_MODE_GROUP);
switch (settings.getChannelMode()) {
case EncoderSettings::ChannelMode::MONO:
m_channels = 1;
break;
case EncoderSettings::ChannelMode::STEREO:
m_channels = 2;
break;
case EncoderSettings::ChannelMode::AUTOMATIC:
m_channels = 2;
break;
}
}
int EncoderOpus::initEncoder(int samplerate, QString& errorMessage) {
Q_UNUSED(errorMessage);
if (samplerate != kMasterSamplerate) {
kLogger.warning() << "initEncoder failed: samplerate not supported by Opus";
const QString invalidSamplerateMessage = getInvalidSamplerateMessage();
ErrorDialogProperties* props = ErrorDialogHandler::instance()->newDialogProperties();
props->setType(DLG_WARNING);
props->setTitle(QObject::tr("Encoder"));
props->setText(invalidSamplerateMessage);
props->setKey(invalidSamplerateMessage);
ErrorDialogHandler::instance()->requestErrorDialog(props);
return -1;
}
m_samplerate = samplerate;
DEBUG_ASSERT(m_samplerate == 8000 || m_samplerate == 12000 ||
m_samplerate == 16000 || m_samplerate == 24000 ||
m_samplerate == 48000);
int createResult = 0;
m_pOpus = opus_encoder_create(m_samplerate, m_channels, OPUS_APPLICATION_AUDIO, &createResult);
if (createResult != OPUS_OK) {
kLogger.warning() << "opus_encoder_create failed:" << opusErrorString(createResult);
return -1;
}
// Optimize encoding for high-quality music
opus_encoder_ctl(m_pOpus, OPUS_SET_COMPLEXITY(10)); // Highest setting
opus_encoder_ctl(m_pOpus, OPUS_SET_SIGNAL(OPUS_SIGNAL_MUSIC));
if(m_bitrateMode == OPUS_BITRATE_CONSTRAINED_VBR) {
// == Constrained VBR ==
// Default mode, gives the best quality/bitrate compromise
opus_encoder_ctl(m_pOpus, OPUS_SET_BITRATE(m_bitrate * 1000)); // convert to bits/second
opus_encoder_ctl(m_pOpus, OPUS_SET_VBR(1)); // default value in libopus
opus_encoder_ctl(m_pOpus, OPUS_SET_VBR_CONSTRAINT(1)); // Constrained VBR
} else if(m_bitrateMode == OPUS_BITRATE_CBR) {
// == CBR (quality loss at low bitrates) ==
opus_encoder_ctl(m_pOpus, OPUS_SET_BITRATE(m_bitrate * 1000)); // convert to bits/second
opus_encoder_ctl(m_pOpus, OPUS_SET_VBR(0));
} else if(m_bitrateMode == OPUS_BITRATE_VBR) {
// == Full VBR ==
opus_encoder_ctl(m_pOpus, OPUS_SET_VBR(1));
opus_encoder_ctl(m_pOpus, OPUS_SET_VBR_CONSTRAINT(0)); // Unconstrained VBR
}
m_readRequired = m_samplerate * kOpusFrameMs;
m_pFifoChunkBuffer = std::make_unique<mixxx::SampleBuffer>(m_readRequired);
initStream();
return 0;
}
void EncoderOpus::initStream() {
ogg_stream_clear(&m_oggStream);
ogg_stream_init(&m_oggStream, getSerial());
m_header_write = true;
m_granulePos = 0;
m_packetNumber = 0;
pushHeaderPacket();
pushTagsPacket();
}
// Binary header construction is done manually to properly
// handle endianness of multi-byte number fields
void EncoderOpus::pushHeaderPacket() {
// Opus identification header
// Format from https://tools.ietf.org/html/rfc7845.html#section-5.1
// Header buffer size:
// - Magic signature: 8 bytes
// - Version: 1 byte
// - Channel count: 1 byte
// - Pre-skip: 2 bytes
// - Samplerate: 4 bytes
// - Output Gain: 2 bytes
// - Mapping family: 1 byte
// - Channel mapping table: ignored
// Total: 19 bytes
const int frameSize = 19;
QByteArray frame;
// Magic signature (8 bytes)
frame.append("OpusHead", 8);
// Version number (1 byte, fixed to 1)
frame.append(0x01);
// Channel count (1 byte)
frame.append(static_cast<unsigned char>(m_channels));
// Pre-skip (2 bytes, little-endian)
int preskip = 0;
opus_encoder_ctl(m_pOpus, OPUS_GET_LOOKAHEAD(&preskip));
for (int x = 0; x < 2; x++) {
unsigned char preskipByte = (preskip >> (x*8)) & 0xFF;
frame.append(preskipByte);
}
// Sample rate (4 bytes, little endian)
for (int x =
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