export: allow exporting subtitles to sidecar files

app/dialog/export/export.cpp

@@ -32,7 +32,6 @@
 
 #include "common/digit.h"
 #include "common/qtutils.h"
-#include "core.h"
 #include "dialog/task/task.h"
 #include "node/project/project.h"
 #include "node/project/sequence/sequence.h"
@@ -250,6 +249,12 @@ ExportDialog::ExportDialog(ViewerOutput *viewer_node, QWidget *parent) :
   preview_viewer_->ConnectViewerNode(viewer_node_);
   preview_viewer_->SetColorMenuEnabled(false);
   preview_viewer_->SetColorTransform(video_tab_->CurrentOCIOColorSpace());
+
+  // We don't check if the codec supports subtitles because we can always export to a sidecar file
+  bool has_subtitle_codecs = SequenceHasSubtitles();
+  connect(subtitles_enabled_, &QCheckBox::toggled, subtitle_tab_, &QWidget::setEnabled);
+  subtitles_enabled_->setChecked(has_subtitle_codecs);
+  subtitles_enabled_->setEnabled(has_subtitle_codecs);
 }
 
 rational ExportDialog::GetSelectedTimebase() const
@@ -445,9 +450,9 @@ void ExportDialog::FormatChanged(ExportFormat::Format current_format)
   audio_enabled_->setChecked(has_audio_codecs);
   audio_enabled_->setEnabled(has_audio_codecs);
 
-  bool has_subtitle_codecs = subtitle_tab_->SetFormat(current_format);
-  subtitles_enabled_->setChecked(has_subtitle_codecs);
-  subtitles_enabled_->setEnabled(has_subtitle_codecs);
+  if (subtitles_enabled_->isEnabled()) {
+    subtitle_tab_->SetFormat(current_format);
+  }
 }
 
 void ExportDialog::ResolutionChanged()
@@ -503,6 +508,20 @@ void ExportDialog::SetDefaultFilename()
   filename_edit_->setText(file_location);
 }
 
+bool ExportDialog::SequenceHasSubtitles() const
+{
+  if (Sequence *s = dynamic_cast<Sequence*>(viewer_node_)) {
+    TrackList *tl = s->track_list(Track::kSubtitle);
+    for (Track *t : tl->GetTracks()) {
+      if (!t->IsMuted() && !t->Blocks().empty()) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
 ExportParams ExportDialog::GenerateParams() const
 {
   VideoParams video_render_params(static_cast<int>(video_tab_->width_slider()->GetValue()),
@@ -519,7 +538,7 @@ ExportParams ExportDialog::GenerateParams() const
                                   audio_tab_->sample_format_combobox()->GetSampleFormat());
 
   ExportParams params;
-  params.set_encoder(Encoder::GetTypeFromFormat(format_combobox_->GetFormat()));
+  params.set_format(format_combobox_->GetFormat());
   params.SetFilename(filename_edit_->text().trimmed());
   params.SetExportLength(viewer_node_->GetLength());
 
@@ -561,8 +580,15 @@ ExportParams ExportDialog::GenerateParams() const
     params.set_audio_bit_rate(audio_tab_->bit_rate_slider()->GetValue() * 1000);
   }
 
-  if (subtitles_enabled_->isChecked()) {
-    params.EnableSubtitles(subtitle_tab_->GetSubtitleCodec());
+  if (subtitles_enabled_->isEnabled()
+      && subtitles_enabled_->isChecked()) {
+    if (!subtitle_tab_->GetSidecarEnabled()) {
+      // Export subtitles embedded in container
+      params.EnableSubtitles(subtitle_tab_->GetSubtitleCodec());
+    } else {
+      // Export subtitles to a sidecar file
+      params.EnableSidecarSubtitles(subtitle_tab_->GetSidecarFormat(), subtitle_tab_->GetSubtitleCodec());
+    }
   }
 
   return params;

app/dialog/export/export.h

@@ -63,6 +63,8 @@ private:
   void LoadPresets();
   void SetDefaultFilename();
 
+  bool SequenceHasSubtitles() const;
+
   ExportParams GenerateParams() const;
 
   ViewerOutput* viewer_node_;

app/dialog/export/exportformatcombobox.cpp

@@ -46,6 +46,13 @@ ExportFormatComboBox::ExportFormatComboBox(Mode mode, QWidget *parent) :
         continue;
       }
       break;
+    case kShowSubtitlesOnly:
+      if (!ExportFormat::GetVideoCodecs(f).isEmpty()
+          || ExportFormat::GetSubtitleCodecs(f).isEmpty()
+          || !ExportFormat::GetAudioCodecs(f).isEmpty()) {
+        continue;
+      }
+      break;
     }
 
     QString format_name = ExportFormat::GetName(f);

app/dialog/export/exportformatcombobox.h

@@ -34,7 +34,8 @@ public:
   enum Mode {
     kShowAllFormats,
     kShowAudioOnly,
-    kShowVideoOnly
+    kShowVideoOnly,
+    kShowSubtitlesOnly
   };
 
   ExportFormatComboBox(Mode mode, QWidget *parent = nullptr);

app/dialog/export/exportsubtitlestab.cpp

@@ -1,7 +1,6 @@
 #include "exportsubtitlestab.h"
 
 #include <QGridLayout>
-#include <QLabel>
 
 namespace olive {
 
@@ -15,22 +14,46 @@ ExportSubtitlesTab::ExportSubtitlesTab(QWidget *parent) :
 
   int row = 0;
 
+  sidecar_checkbox_ = new QCheckBox(tr("Export to sidecar file"));
+  layout->addWidget(sidecar_checkbox_, row, 0, 1, 2);
+
+  row++;
+
+  sidecar_format_label_ = new QLabel(tr("Sidecar Format:"));
+  sidecar_format_label_->setVisible(false);
+  layout->addWidget(sidecar_format_label_, row, 0);
+
+  sidecar_format_combobox_ = new ExportFormatComboBox(ExportFormatComboBox::kShowSubtitlesOnly);
+  sidecar_format_combobox_->setVisible(false);
+  layout->addWidget(sidecar_format_combobox_, row, 1);
+
+  row++;
+
   layout->addWidget(new QLabel(tr("Codec:")), row, 0);
 
   codec_combobox_ = new QComboBox();
   layout->addWidget(codec_combobox_, row, 1);
 
   outer_layout->addStretch();
+
+  connect(sidecar_checkbox_, &QCheckBox::toggled, sidecar_format_label_, &QWidget::setVisible);
+  connect(sidecar_checkbox_, &QCheckBox::toggled, sidecar_format_combobox_, &QWidget::setVisible);
 }
 
 int ExportSubtitlesTab::SetFormat(ExportFormat::Format format)
 {
   auto scodecs = ExportFormat::GetSubtitleCodecs(format);
-  setEnabled(!scodecs.isEmpty());
+
+  sidecar_checkbox_->setChecked(scodecs.empty());
+  sidecar_checkbox_->setEnabled(!scodecs.empty());
+
+  scodecs = ExportFormat::GetSubtitleCodecs(sidecar_format_combobox_->GetFormat());
+
   codec_combobox_->clear();
   foreach (ExportCodec::Codec scodec, scodecs) {
     codec_combobox_->addItem(ExportCodec::GetCodecName(scodec), scodec);
   }
+
   return scodecs.size();
 }
 

app/dialog/export/exportsubtitlestab.h

@@ -21,10 +21,12 @@
 #ifndef EXPORTSUBTITLESTAB_H
 #define EXPORTSUBTITLESTAB_H
 
+#include <QCheckBox>
 #include <QComboBox>
+#include <QLabel>
 
 #include "codec/exportformat.h"
-#include "render/subtitleparams.h"
+#include "dialog/export/exportformatcombobox.h"
 
 namespace olive {
 
@@ -34,6 +36,12 @@ class ExportSubtitlesTab : public QWidget
 public:
   ExportSubtitlesTab(QWidget *parent = nullptr);
 
+  bool GetSidecarEnabled() const { return sidecar_checkbox_->isChecked(); }
+  void SetSidecarEnabled(bool e) { sidecar_checkbox_->setEnabled(e); }
+
+  ExportFormat::Format GetSidecarFormat() const { return sidecar_format_combobox_->GetFormat(); }
+  void SetSidecarFormat(ExportFormat::Format f) { sidecar_format_combobox_->SetFormat(f); }
+
   int SetFormat(ExportFormat::Format format);
 
   ExportCodec::Codec GetSubtitleCodec()
@@ -42,6 +50,11 @@ public:
   }
 
 private:
+  QCheckBox *sidecar_checkbox_;
+
+  QLabel *sidecar_format_label_;
+  ExportFormatComboBox *sidecar_format_combobox_;
+
   QComboBox *codec_combobox_;
 
 };