encoder/exportdialog: add compression options for H264 exporting

app/dialog/export/codec/h264section.h

@@ -0,0 +1,89 @@
+#ifndef H264SECTION_H
+#define H264SECTION_H
+
+#include <QSlider>
+#include <QStackedWidget>
+
+#include "codecsection.h"
+#include "widget/slider/floatslider.h"
+
+class H264CRFSection : public QWidget
+{
+public:
+  H264CRFSection(QWidget* parent = nullptr);
+
+  int GetValue() const;
+
+private:
+  static const int kMinimumCRF = 0;
+
+  static const int kDefaultCRF = 23;
+
+  static const int kMaximumCRF = 51;
+
+  QSlider* crf_slider_;
+
+};
+
+class H264BitRateSection : public QWidget
+{
+public:
+  H264BitRateSection(QWidget* parent = nullptr);
+
+  /**
+   * @brief Get user-selected target bit rate (returns in BITS)
+   */
+  int64_t GetTargetBitRate() const;
+
+  /**
+   * @brief Get user-selected maximum bit rate (returns in BITS)
+   */
+  int64_t GetMaximumBitRate() const;
+
+private:
+  FloatSlider* target_rate_;
+
+  FloatSlider* max_rate_;
+
+};
+
+class H264FileSizeSection : public QWidget
+{
+public:
+  H264FileSizeSection(QWidget* parent = nullptr);
+
+  /**
+   * @brief Returns file size in BITS
+   */
+  int64_t GetFileSize() const;
+
+private:
+  FloatSlider* file_size_;
+
+};
+
+class H264Section : public CodecSection
+{
+public:
+  enum CompressionMethod {
+    kConstantRateFactor,
+    kTargetBitRate,
+    kTargetFileSize
+  };
+
+  H264Section(QWidget* parent = nullptr);
+
+  virtual void AddOpts(EncodingParams* params) override;
+
+private:
+  QStackedWidget* compression_method_stack_;
+
+  H264CRFSection* crf_section_;
+
+  H264BitRateSection* bitrate_section_;
+
+  H264FileSizeSection* filesize_section_;
+
+};
+
+#endif // H264SECTION_H