From 12f9b1acfc614e9ddeb27ced0c2c05c245b780e9 Mon Sep 17 00:00:00 2001
From: itsmattkc <34096995+itsmattkc@users.noreply.github.com>
Date: Sat, 23 Jul 2022 15:22:57 -0700
Subject: [PATCH] export: allow exporting subtitles to sidecar files

---
 app/codec/encoder.cpp                      | 31 ++++++++++++-
 app/codec/encoder.h                        | 15 ++++++
 app/dialog/export/export.cpp               | 40 +++++++++++++---
 app/dialog/export/export.h                 |  2 +
 app/dialog/export/exportformatcombobox.cpp |  7 +++
 app/dialog/export/exportformatcombobox.h   |  3 +-
 app/dialog/export/exportsubtitlestab.cpp   | 27 ++++++++++-
 app/dialog/export/exportsubtitlestab.h     | 15 +++++-
 app/task/export/export.cpp                 | 54 +++++++++++++++++++---
 app/task/export/export.h                   |  4 +-
 app/task/export/exportparams.cpp           | 12 -----
 app/task/export/exportparams.h             |  5 --
 app/task/render/render.cpp                 |  7 ++-
 13 files changed, 183 insertions(+), 39 deletions(-)

diff --git a/app/codec/encoder.cpp b/app/codec/encoder.cpp
index 7abf5d39f..31b187a5a 100644
--- a/app/codec/encoder.cpp
+++ b/app/codec/encoder.cpp
@@ -93,7 +93,8 @@ EncodingParams::EncodingParams() :
   video_color_range_(kYUVDefault),
   audio_enabled_(false),
   audio_bit_rate_(0),
-  subtitles_enabled_(false)
+  subtitles_enabled_(false),
+  subtitles_are_sidecar_(false)
 {
 }
 
@@ -117,6 +118,29 @@ void EncodingParams::EnableSubtitles(const ExportCodec::Codec &scodec)
   subtitles_codec_ = scodec;
 }
 
+void EncodingParams::EnableSidecarSubtitles(const ExportFormat::Format &sfmt, const ExportCodec::Codec &scodec)
+{
+  subtitles_enabled_ = true;
+  subtitles_are_sidecar_ = true;
+  subtitle_sidecar_fmt_ = sfmt;
+  subtitles_codec_ = scodec;
+}
+
+void EncodingParams::DisableVideo()
+{
+  video_enabled_ = false;
+}
+
+void EncodingParams::DisableAudio()
+{
+  audio_enabled_ = false;
+}
+
+void EncodingParams::DisableSubtitles()
+{
+  subtitles_enabled_ = false;
+}
+
 void EncodingParams::Save(QXmlStreamWriter *writer) const
 {
   writer->writeTextElement(QStringLiteral("filename"), filename_);
@@ -217,6 +241,11 @@ Encoder *Encoder::CreateFromFormat(ExportFormat::Format f, const EncodingParams
   return CreateFromID(GetTypeFromFormat(f), params);
 }
 
+Encoder *Encoder::CreateFromParams(const EncodingParams &params)
+{
+  return CreateFromFormat(params.format(), params);
+}
+
 QStringList Encoder::GetPixelFormatsForCodec(ExportCodec::Codec c) const
 {
   return QStringList();
diff --git a/app/codec/encoder.h b/app/codec/encoder.h
index 7b95fa7fb..e4c6db587 100644
--- a/app/codec/encoder.h
+++ b/app/codec/encoder.h
@@ -58,6 +58,14 @@ public:
   void EnableVideo(const VideoParams& video_params, const ExportCodec::Codec& vcodec);
   void EnableAudio(const AudioParams& audio_params, const ExportCodec::Codec &acodec);
   void EnableSubtitles(const ExportCodec::Codec &scodec);
+  void EnableSidecarSubtitles(const ExportFormat::Format &sfmt, const ExportCodec::Codec &scodec);
+
+  void DisableVideo();
+  void DisableAudio();
+  void DisableSubtitles();
+
+  const ExportFormat::Format &format() const { return format_; }
+  void set_format(const ExportFormat::Format &format) { format_ = format; }
 
   void set_video_option(const QString& key, const QString& value) { video_opts_.insert(key, value); }
   void set_video_bit_rate(const int64_t& rate) { video_bit_rate_ = rate; }
@@ -92,6 +100,8 @@ public:
   void set_audio_bit_rate(const int64_t& b) { audio_bit_rate_ = b; }
 
   bool subtitles_enabled() const { return subtitles_enabled_; }
+  bool subtitles_are_sidecar() const { return subtitles_are_sidecar_; }
+  ExportFormat::Format subtitle_sidecar_fmt() const { return subtitle_sidecar_fmt_; }
   ExportCodec::Codec subtitles_codec() const { return subtitles_codec_; }
 
   const rational& GetExportLength() const { return export_length_; }
@@ -101,6 +111,7 @@ public:
 
 private:
   QString filename_;
+  ExportFormat::Format format_;
 
   bool video_enabled_;
   ExportCodec::Codec video_codec_;
@@ -121,6 +132,8 @@ private:
   int64_t audio_bit_rate_;
 
   bool subtitles_enabled_;
+  bool subtitles_are_sidecar_;
+  ExportFormat::Format subtitle_sidecar_fmt_;
   ExportCodec::Codec subtitles_codec_;
 
   rational export_length_;
@@ -152,6 +165,8 @@ public:
 
   static Encoder *CreateFromFormat(ExportFormat::Format f, const EncodingParams &params);
 
+  static Encoder *CreateFromParams(const EncodingParams &params);
+
   virtual QStringList GetPixelFormatsForCodec(ExportCodec::Codec c) const;
   virtual std::vector<AudioParams::Format> GetSampleFormatsForCodec(ExportCodec::Codec c) const;
 
diff --git a/app/dialog/export/export.cpp b/app/dialog/export/export.cpp
index b512c3910..986d3a169 100644
--- a/app/dialog/export/export.cpp
+++ b/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;
diff --git a/app/dialog/export/export.h b/app/dialog/export/export.h
index df16c4850..9cd7d274a 100644
--- a/app/dialog/export/export.h
+++ b/app/dialog/export/export.h
@@ -63,6 +63,8 @@ private:
   void LoadPresets();
   void SetDefaultFilename();
 
+  bool SequenceHasSubtitles() const;
+
   ExportParams GenerateParams() const;
 
   ViewerOutput* viewer_node_;
diff --git a/app/dialog/export/exportformatcombobox.cpp b/app/dialog/export/exportformatcombobox.cpp
index c185b27a8..dcbcdd01d 100644
--- a/app/dialog/export/exportformatcombobox.cpp
+++ b/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);
diff --git a/app/dialog/export/exportformatcombobox.h b/app/dialog/export/exportformatcombobox.h
index 2f60867af..c90479e72 100644
--- a/app/dialog/export/exportformatcombobox.h
+++ b/app/dialog/export/exportformatcombobox.h
@@ -34,7 +34,8 @@ public:
   enum Mode {
     kShowAllFormats,
     kShowAudioOnly,
-    kShowVideoOnly
+    kShowVideoOnly,
+    kShowSubtitlesOnly
   };
 
   ExportFormatComboBox(Mode mode, QWidget *parent = nullptr);
diff --git a/app/dialog/export/exportsubtitlestab.cpp b/app/dialog/export/exportsubtitlestab.cpp
index 27c40fc16..330942810 100644
--- a/app/dialog/export/exportsubtitlestab.cpp
+++ b/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();
 }
 
diff --git a/app/dialog/export/exportsubtitlestab.h b/app/dialog/export/exportsubtitlestab.h
index a88f4d904..faa5d4bdf 100644
--- a/app/dialog/export/exportsubtitlestab.h
+++ b/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_;
 
 };
diff --git a/app/task/export/export.cpp b/app/task/export/export.cpp
index e471d6862..3df5f1240 100644
--- a/app/task/export/export.cpp
+++ b/app/task/export/export.cpp
@@ -58,7 +58,14 @@ bool ExportTask::Run()
     params_.SetFilename(FileFunctions::GetSafeTemporaryFilename(real_filename));
   }
 
-  encoder_ = Encoder::CreateFromID(params_.encoder(), params_);
+  // If we're exporting to a sidecar subtitle file, disable the subtitles in the main encoder
+  bool subtitles_enabled = params_.subtitles_enabled();
+  ExportParams sidecar_params = params_;
+  if (subtitles_enabled && params_.subtitles_are_sidecar()) {
+    params_.DisableSubtitles();
+  }
+
+  encoder_ = std::shared_ptr<Encoder>(Encoder::CreateFromParams(params_));
 
   if (!encoder_) {
     SetError(tr("Failed to create encoder"));
@@ -67,10 +74,38 @@ bool ExportTask::Run()
 
   if (!encoder_->Open()) {
     SetError(tr("Failed to open file: %1").arg(encoder_->GetError()));
-    encoder_->deleteLater();
     return false;
   }
 
+  if (subtitles_enabled && params_.subtitles_are_sidecar()) {
+    // Construct sidecar params
+    sidecar_params.DisableVideo();
+    sidecar_params.DisableAudio();
+
+    QString sidecar_filename;
+    {
+      QFileInfo fi(real_filename);
+      sidecar_filename = fi.completeBaseName();
+      sidecar_filename.append('.');
+      sidecar_filename.append(ExportFormat::GetExtension(sidecar_params.subtitle_sidecar_fmt()));
+      sidecar_filename = fi.dir().filePath(sidecar_filename);
+    }
+    sidecar_params.SetFilename(sidecar_filename);
+
+    subtitle_encoder_ = std::shared_ptr<Encoder>(Encoder::CreateFromFormat(sidecar_params.subtitle_sidecar_fmt(), sidecar_params));
+    if (!subtitle_encoder_) {
+      SetError(tr("Failed to create subtitle encoder"));
+      return false;
+    }
+
+    if (!subtitle_encoder_->Open()) {
+      SetError(tr("Failed to open subtitle sidecar file: %1").arg(sidecar_filename));
+      return false;
+    }
+  } else {
+    subtitle_encoder_ = encoder_;
+  }
+
   if (params_.has_custom_range()) {
     // Render custom range only
     range = params_.custom_range();
@@ -121,7 +156,7 @@ bool ExportTask::Run()
     audio_range = {range};
   }
 
-  if (params_.subtitles_enabled()) {
+  if (subtitles_enabled) {
     subtitle_range = range;
   }
 
@@ -132,13 +167,18 @@ bool ExportTask::Run()
   bool success = true;
 
   encoder_->Close();
-
   if (!encoder_->GetError().isEmpty()) {
     SetError(encoder_->GetError());
     success = false;
   }
 
-  delete encoder_;
+  if (subtitle_encoder_ != encoder_) {
+    subtitle_encoder_->Close();
+    if (!subtitle_encoder_->GetError().isEmpty()) {
+      SetError(subtitle_encoder_->GetError());
+      success = false;
+    }
+  }
 
   // If cancelled, delete the file we made, which is always a file we created since we write to a
   // temp file during the actual encoding process
@@ -209,8 +249,8 @@ bool ExportTask::AudioDownloaded(const TimeRange &range, const SampleBuffer &sam
 
 bool ExportTask::EncodeSubtitle(const SubtitleBlock *sub)
 {
-  if (!encoder_->WriteSubtitle(sub)) {
-    SetError(encoder_->GetError());
+  if (!subtitle_encoder_->WriteSubtitle(sub)) {
+    SetError(subtitle_encoder_->GetError());
     return false;
   } else {
     return true;
diff --git a/app/task/export/export.h b/app/task/export/export.h
index bf696978e..4bed7cd8b 100644
--- a/app/task/export/export.h
+++ b/app/task/export/export.h
@@ -60,7 +60,9 @@ private:
 
   ExportParams params_;
 
-  Encoder* encoder_;
+  std::shared_ptr<Encoder> encoder_;
+
+  std::shared_ptr<Encoder> subtitle_encoder_;
 
   ColorProcessorPtr color_processor_;
 
diff --git a/app/task/export/exportparams.cpp b/app/task/export/exportparams.cpp
index dd7154044..dfe79686d 100644
--- a/app/task/export/exportparams.cpp
+++ b/app/task/export/exportparams.cpp
@@ -28,16 +28,6 @@ ExportParams::ExportParams() :
 {
 }
 
-const Encoder::Type &ExportParams::encoder() const
-{
-  return encoder_id_;
-}
-
-void ExportParams::set_encoder(const Encoder::Type &id)
-{
-  encoder_id_ = id;
-}
-
 bool ExportParams::has_custom_range() const
 {
   return has_custom_range_;
@@ -104,8 +94,6 @@ void ExportParams::Save(QXmlStreamWriter *writer) const
 {
   writer->writeStartElement(QStringLiteral("export"));
 
-  writer->writeTextElement(QStringLiteral("encoder"), QString::number(encoder_id_));
-
   writer->writeTextElement(QStringLiteral("vscale"), QString::number(video_scaling_method_));
 
   writer->writeTextElement(QStringLiteral("range"), QString::number(has_custom_range_));
diff --git a/app/task/export/exportparams.h b/app/task/export/exportparams.h
index b72597a6c..46f213f9c 100644
--- a/app/task/export/exportparams.h
+++ b/app/task/export/exportparams.h
@@ -39,9 +39,6 @@ public:
 
   ExportParams();
 
-  const Encoder::Type& encoder() const;
-  void set_encoder(const Encoder::Type& id);
-
   bool has_custom_range() const;
   const TimeRange& custom_range() const;
   void set_custom_range(const TimeRange& custom_range);
@@ -59,8 +56,6 @@ public:
   virtual void Save(QXmlStreamWriter* writer) const override;
 
 private:
-  Encoder::Type encoder_id_;
-
   VideoScalingMethod video_scaling_method_;
 
   bool has_custom_range_;
diff --git a/app/task/render/render.cpp b/app/task/render/render.cpp
index 23fa2e387..d427b9608 100644
--- a/app/task/render/render.cpp
+++ b/app/task/render/render.cpp
@@ -95,8 +95,7 @@ bool RenderTask::Render(ColorManager* manager,
 
   // Subtitle loop, loops over all blocks in sequence on all tracks
   if (!subtitle_range.length().isNull()) {
-    Sequence *sequence = dynamic_cast<Sequence*>(viewer_);
-    if (sequence) {
+    if (Sequence *sequence = dynamic_cast<Sequence*>(viewer_)) {
       TrackList *list = sequence->track_list(Track::kSubtitle);
       QVector<int> block_indexes(list->GetTrackCount(), 0);
 
@@ -106,6 +105,10 @@ bool RenderTask::Render(ColorManager* manager,
 
         for (int i=0; i<block_indexes.size(); i++) {
           Track *this_track = list->GetTrackAt(i);
+          if (this_track->IsMuted()) {
+            continue;
+          }
+
           int &this_block_index = block_indexes[i];
           if (this_block_index >= this_track->Blocks().size()) {
             continue;