oak-editor/app/dialog/export/codec/h264section.cpp

#include "h264section.h"

#include <QCheckBox>
#include <QComboBox>
#include <QGridLayout>
#include <QLabel>

#include "common/qtutils.h"
#include "widget/slider/integerslider.h"

H264Section::H264Section(QWidget *parent) :
  CodecSection(parent)
{
  QGridLayout* layout = new QGridLayout(this);
  layout->setMargin(0);

  int row = 0;

  layout->addWidget(new QLabel(tr("Compression Method:")), row, 0);

  QComboBox* compression_box = new QComboBox();

  // These items must correspond to the CompressionMethod enum
  compression_box->addItem(tr("Constant Rate Factor"));
  compression_box->addItem(tr("Target Bit Rate"));
  compression_box->addItem(tr("Target File Size"));

  layout->addWidget(compression_box, row, 1);

  row++;

  compression_method_stack_ = new QStackedWidget();
  layout->addWidget(compression_method_stack_, row, 0, 1, 2);

  crf_section_ = new H264CRFSection();
  compression_method_stack_->addWidget(crf_section_);

  bitrate_section_ = new H264BitRateSection();
  compression_method_stack_->addWidget(bitrate_section_);

  filesize_section_ = new H264FileSizeSection();
  compression_method_stack_->addWidget(filesize_section_);

  connect(compression_box,
          static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
          compression_method_stack_,
          &QStackedWidget::setCurrentIndex);
}

void H264Section::AddOpts(EncodingParams *params)
{
  // FIXME: Implement two-pass

  CompressionMethod method = static_cast<CompressionMethod>(compression_method_stack_->currentIndex());

  if (method == kConstantRateFactor) {

    // Simply set CRF value
    params->SetVideoOption(QStringLiteral("crf"), QString::number(crf_section_->GetValue()));

  } else {

    int64_t target_rate, max_rate;

    if (method == kTargetBitRate) {
      // Use user-supplied values for the bit rate
      target_rate = bitrate_section_->GetTargetBitRate();
      max_rate = bitrate_section_->GetMaximumBitRate();
    } else {
      // Calculate the bit rate from the file size divided by the sequence length in seconds (bits per second)
      target_rate = qRound64(static_cast<double>(filesize_section_->GetFileSize()) / params->GetExportLength().toDouble());
      max_rate = target_rate;
    }

    // Disable CRF encoding
    params->SetVideoOption(QStringLiteral("crf"), QStringLiteral("-1"));

    params->SetVideoBitRate(target_rate);
    params->SetVideoMaxBitRate(max_rate);
    params->SetVideoBufferSize(2000000);

  }
}

H264CRFSection::H264CRFSection(QWidget *parent) :
  QWidget(parent)
{
  QHBoxLayout* layout = new QHBoxLayout(this);
  layout->setMargin(0);

  crf_slider_ = new QSlider(Qt::Horizontal);
  crf_slider_->setMinimum(kMinimumCRF);
  crf_slider_->setMaximum(kMaximumCRF);
  crf_slider_->setValue(kDefaultCRF);
  layout->addWidget(crf_slider_);

  IntegerSlider* crf_input = new IntegerSlider();
  crf_input->setMaximumWidth(QFontMetricsWidth(crf_input->fontMetrics(), QStringLiteral("HHHH")));
  crf_input->SetMinimum(kMinimumCRF);
  crf_input->SetMaximum(kMaximumCRF);
  crf_input->SetValue(kDefaultCRF);
  layout->addWidget(crf_input);

  connect(crf_slider_, &QSlider::valueChanged, crf_input, &IntegerSlider::SetValue);
  connect(crf_input, &IntegerSlider::ValueChanged, crf_slider_, &QSlider::setValue);
}

int H264CRFSection::GetValue() const
{
  return crf_slider_->value();
}

H264BitRateSection::H264BitRateSection(QWidget *parent) :
  QWidget(parent)
{
  QGridLayout* layout = new QGridLayout(this);
  layout->setMargin(0);

  int row = 0;

  layout->addWidget(new QLabel(tr("Target Bit Rate (Mbps):")), row, 0);

  target_rate_ = new FloatSlider();
  target_rate_->SetMinimum(0);
  layout->addWidget(target_rate_, row, 1);

  row++;

  layout->addWidget(new QLabel(tr("Maximum Bit Rate (Mbps):")), row, 0);

  max_rate_ = new FloatSlider();
  max_rate_->SetMinimum(0);
  layout->addWidget(max_rate_, row, 1);

  row++;

  layout->addWidget(new QLabel(tr("Two-Pass")), row, 0);

  QCheckBox* two_pass_box = new QCheckBox();
  layout->addWidget(two_pass_box, row, 1);

  // Bit rate defaults
  target_rate_->SetValue(16.0);
  max_rate_->SetValue(32.0);
}

int64_t H264BitRateSection::GetTargetBitRate() const
{
  return qRound64(target_rate_->GetValue() * 1000000.0);
}

int64_t H264BitRateSection::GetMaximumBitRate() const
{
  return qRound64(max_rate_->GetValue() * 1000000.0);
}

H264FileSizeSection::H264FileSizeSection(QWidget *parent) :
  QWidget(parent)
{
  QGridLayout* layout = new QGridLayout(this);
  layout->setMargin(0);

  int row = 0;

  layout->addWidget(new QLabel(tr("Target File Size (MB):")), row, 0);

  file_size_ = new FloatSlider();
  file_size_->SetMinimum(0);
  layout->addWidget(file_size_, row, 1);

  row++;

  layout->addWidget(new QLabel(tr("Two-Pass")), row, 0);

  QCheckBox* two_pass_box = new QCheckBox();
  layout->addWidget(two_pass_box, row, 1);

  // File size defaults
  file_size_->SetValue(700.0);
}

int64_t H264FileSizeSection::GetFileSize() const
{
  // Convert megabytes to BITS
  return qRound64(file_size_->GetValue() * 1024.0 * 1024.0 * 8.0);
}