implemented core subtitle support

app/task/export/export.cpp

@@ -56,7 +56,7 @@ bool ExportTask::Run()
   }
 
   if (!encoder_->Open()) {
-    SetError(tr("Failed to open file"));
+    SetError(tr("Failed to open file: %1").arg(encoder_->GetError()));
     encoder_->deleteLater();
     return false;
   }
@@ -102,6 +102,7 @@ bool ExportTask::Run()
 
   // Start render process
   TimeRangeList video_range, audio_range;
+  TimeRange subtitle_range;
 
   if (params_.video_enabled()) {
     video_range = {range};
@@ -111,7 +112,11 @@ bool ExportTask::Run()
     audio_range = {range};
   }
 
-  Render(color_manager_, video_range, audio_range, RenderMode::kOnline, nullptr,
+  if (params_.subtitles_enabled()) {
+    subtitle_range = range;
+  }
+
+  Render(color_manager_, video_range, audio_range, subtitle_range, RenderMode::kOnline, nullptr,
          video_force_size, video_force_matrix, encoder_->GetDesiredPixelFormat(),
          color_processor_);
 
@@ -191,6 +196,11 @@ void ExportTask::AudioDownloaded(const TimeRange &range, SampleBufferPtr samples
   }
 }
 
+void ExportTask::EncodeSubtitle(const SubtitleBlock *sub)
+{
+  encoder_->WriteSubtitle(sub);
+}
+
 void ExportTask::WriteAudioLoop(const TimeRange& time, SampleBufferPtr samples)
 {
   encoder_->WriteAudio(samples);

app/task/export/export.h

@@ -42,6 +42,8 @@ protected:
 
   virtual void AudioDownloaded(const TimeRange& range, SampleBufferPtr samples, qint64 job_time) override;
 
+  virtual void EncodeSubtitle(const SubtitleBlock *sub) override;
+
   virtual bool TwoStepFrameRendering() const override
   {
     return false;

app/task/precache/precachetask.cpp

@@ -67,6 +67,7 @@ bool PreCacheTask::Run()
   Render(project_->color_manager(),
          video_range,
          TimeRangeList(),
+         TimeRange(),
          RenderMode::kOnline,
          viewer()->video_frame_cache());
 

app/task/render/render.cpp

@@ -21,6 +21,7 @@
 #include "render.h"
 
 #include "common/timecodefunctions.h"
+#include "node/project/sequence/sequence.h"
 #include "render/rendermanager.h"
 
 namespace olive {
@@ -40,7 +41,7 @@ RenderTask::~RenderTask()
 
 bool RenderTask::Render(ColorManager* manager,
                         const TimeRangeList& video_range,
-                        const TimeRangeList &audio_range,
+                        const TimeRangeList &audio_range, const TimeRange &subtitle_range,
                         RenderMode::Mode mode,
                         FrameHashCache* cache, const QSize &force_size,
                         const QMatrix4x4 &force_matrix, VideoParams::Format force_format,
@@ -129,6 +130,50 @@ bool RenderTask::Render(ColorManager* manager,
                 mode, cache, force_size, force_matrix, force_format, force_color_output);
   }
 
+  // Subtitle loop, loops over all blocks in sequence on all tracks
+  if (!subtitle_range.length().isNull()) {
+    Sequence *sequence = dynamic_cast<Sequence*>(viewer_);
+    if (sequence) {
+      TrackList *list = sequence->track_list(Track::kSubtitle);
+      QVector<int> block_indexes(list->GetTrackCount(), 0);
+
+      QVector<int> tracks_to_push;
+      do {
+        tracks_to_push.clear();
+
+        for (int i=0; i<block_indexes.size(); i++) {
+          Track *this_track = list->GetTrackAt(i);
+          int &this_block_index = block_indexes[i];
+          if (this_block_index >= this_track->Blocks().size()) {
+            continue;
+          }
+          Block *this_block = this_track->Blocks().at(this_block_index);
+
+          Track *compare_track = tracks_to_push.isEmpty() ? nullptr : list->GetTrackAt(tracks_to_push.first());
+          const int &compare_block_index = tracks_to_push.isEmpty() ? -1 : block_indexes.at(tracks_to_push.first());
+          Block *compare_block = compare_track ? compare_track->Blocks().at(compare_block_index) : nullptr;
+          if (!compare_track || compare_block->in() >= this_block->in()) {
+            if (compare_track && compare_block->in() != this_block->in()) {
+              tracks_to_push.clear();
+            }
+            tracks_to_push.append(i);
+          }
+        }
+
+        for (int i=0; i<tracks_to_push.size(); i++) {
+          Track *this_track = list->GetTrackAt(tracks_to_push.at(i));
+          Block *this_block = this_track->Blocks().at(block_indexes.at(tracks_to_push.at(i)));
+
+          if (const SubtitleBlock *sub = dynamic_cast<const SubtitleBlock*>(this_block)) {
+            EncodeSubtitle(sub);
+          }
+
+          block_indexes[tracks_to_push.at(i)]++;
+        }
+      } while (!tracks_to_push.isEmpty());
+    }
+  }
+
   finished_watcher_mutex_.lock();
 
   while (!IsCancelled()) {
@@ -238,6 +283,11 @@ void RenderTask::DownloadFrame(QThread *thread, FramePtr frame, const QByteArray
                                                                  hash));
 }
 
+void RenderTask::EncodeSubtitle(const SubtitleBlock *subtitle)
+{
+  Q_UNUSED(subtitle)
+}
+
 void RenderTask::PrepareWatcher(RenderTicketWatcher *watcher, QThread *thread)
 {
   watcher->moveToThread(thread);

app/task/render/render.h

@@ -23,6 +23,7 @@
 
 #include <QtConcurrent/QtConcurrent>
 
+#include "node/block/subtitle/subtitle.h"
 #include "node/color/colormanager/colormanager.h"
 #include "node/output/viewer/viewer.h"
 #include "task/task.h"
@@ -41,7 +42,8 @@ public:
 
 protected:
   bool Render(ColorManager *manager, const TimeRangeList &video_range,
-              const TimeRangeList &audio_range, RenderMode::Mode mode,
+              const TimeRangeList &audio_range, const TimeRange &subtitle_range,
+              RenderMode::Mode mode,
               FrameHashCache *cache, const QSize& force_size = QSize(0, 0),
               const QMatrix4x4& force_matrix = QMatrix4x4(),
               VideoParams::Format force_format = VideoParams::kFormatInvalid,
@@ -53,6 +55,8 @@ protected:
 
   virtual void AudioDownloaded(const TimeRange& range, SampleBufferPtr samples, qint64 job_time) = 0;
 
+  virtual void EncodeSubtitle(const SubtitleBlock *subtitle);
+
   ViewerOutput* viewer() const
   {
     return viewer_;