exportdialog: allow restoring parameters

app/dialog/export/codec/h264section.h

@@ -37,6 +37,7 @@ public:
   H264CRFSection(int default_crf, QWidget* parent = nullptr);
 
   int GetValue() const;
+  void SetValue(int c);
 
   static const int kDefaultH264CRF = 18;
   static const int kDefaultH265CRF = 23;
@@ -59,11 +60,13 @@ public:
    * @brief Get user-selected target bit rate (returns in BITS)
    */
   int64_t GetTargetBitRate() const;
+  void SetTargetBitRate(int64_t b);
 
   /**
    * @brief Get user-selected maximum bit rate (returns in BITS)
    */
   int64_t GetMaximumBitRate() const;
+  void SetMaximumBitRate(int64_t b);
 
 private:
   FloatSlider* target_rate_;
@@ -82,6 +85,7 @@ public:
    * @brief Returns file size in BITS
    */
   int64_t GetFileSize() const;
+  void SetFileSize(int64_t f);
 
 private:
   FloatSlider* file_size_;
@@ -103,6 +107,8 @@ public:
 
   virtual void AddOpts(EncodingParams* params) override;
 
+  virtual void SetOpts(const EncodingParams *p) override;
+
 private:
   QStackedWidget* compression_method_stack_;