streamlined viewable-based lengths

app/node/node.h

@@ -187,6 +187,12 @@ public:
     return input_ids_;
   }
 
+  virtual QVector<QString> inputs_for_output(const QString& output) const
+  {
+    Q_UNUSED(output)
+    return inputs();
+  }
+
   const QVector<QString>& outputs() const
   {
     return outputs_;

app/node/output/track/track.h

@@ -191,6 +191,11 @@ public:
       return ref;
     }
 
+    bool IsValid() const
+    {
+      return type_ > kNone && type_ < kCount && index_ >= 0;
+    }
+
   private:
     Track::Type type_;
 

app/node/output/viewer/viewer.cpp

@@ -92,35 +92,34 @@ QString ViewerOutput::Description() const
 
 QString ViewerOutput::duration() const
 {
-  // Try video first
+  rational using_timebase;
+  Timecode::Display using_display = Core::instance()->GetTimecodeDisplay();
+
+  // Get first enabled streams
   VideoParams video = GetFirstEnabledVideoStream();
-
-  if (video.is_valid() && video.video_type() != VideoParams::kVideoTypeStill) {
-    rational frame_rate_timebase = video.frame_rate_as_time_base();
-
-    return Timecode::timestamp_to_timecode(Timecode::rescale_timestamp_ceil(video.duration(), video.time_base(), frame_rate_timebase),
-                                           frame_rate_timebase,
-                                           Core::instance()->GetTimecodeDisplay());
-  }
-
-  // Try audio second
   AudioParams audio = GetFirstEnabledAudioStream();
 
-  if (audio.is_valid()) {
+  if (video.is_valid() && video.video_type() != VideoParams::kVideoTypeStill) {
+    // Prioritize video
+    using_timebase = video.frame_rate_as_time_base();
+  } else if (audio.is_valid()) {
+    // Use audio as a backup
     // If we're showing in a timecode, we prefer showing audio in seconds instead
-    Timecode::Display display = Core::instance()->GetTimecodeDisplay();
-    if (display == Timecode::kTimecodeDropFrame
-        || display == Timecode::kTimecodeNonDropFrame) {
-      display = Timecode::kTimecodeSeconds;
+    if (using_display == Timecode::kTimecodeDropFrame
+        || using_display == Timecode::kTimecodeNonDropFrame) {
+      using_display = Timecode::kTimecodeSeconds;
     }
 
-    return Timecode::timestamp_to_timecode(audio.duration(),
-                                           audio.time_base(),
-                                           display);
+    using_timebase = audio.sample_rate_as_time_base();
   }
 
-  // Otherwise, return nothing
-  return QString();
+  if (using_timebase.isNull()) {
+    // No timebase, return null
+    return QString();
+  } else {
+    // Return time transformed to timecode
+    return Timecode::time_to_timecode(GetLength(), using_timebase, using_display);
+  }
 }
 
 QString ViewerOutput::rate() const
@@ -248,6 +247,20 @@ void ViewerOutput::InvalidateCache(const TimeRange& range, const QString& from,
   super::InvalidateCache(range, from, element, job_time);
 }
 
+QVector<QString> ViewerOutput::inputs_for_output(const QString &output) const
+{
+  QVector<QString> inputs;
+  Track::Type type = Track::Reference::TypeFromString(output);
+
+  if (type == Track::kVideo) {
+    inputs.append(kTextureInput);
+  } else if (type == Track::kAudio) {
+    inputs.append(kSamplesInput);
+  }
+
+  return inputs;
+}
+
 const rational& ViewerOutput::GetLength() const
 {
   return last_length_;

app/node/output/viewer/viewer.h

@@ -67,6 +67,8 @@ public:
 
   virtual void InvalidateCache(const TimeRange& range, const QString& from, int element, qint64 job_time) override;
 
+  virtual QVector<QString> inputs_for_output(const QString& output) const override;
+
   VideoParams GetVideoParams(int index = 0) const
   {
     return GetStandardValue(kVideoParamsInput, index).value<VideoParams>();

app/node/traverser.cpp

@@ -25,12 +25,13 @@
 
 namespace olive {
 
-NodeValueDatabase NodeTraverser::GenerateDatabase(const Node* node, const TimeRange &range)
+NodeValueDatabase NodeTraverser::GenerateDatabase(const Node* node, const QString& output, const TimeRange &range)
 {
   NodeValueDatabase database;
 
   // We need to insert tables into the database for each input
-  foreach (const QString& input, node->inputs()) {
+  auto inputs = node->inputs_for_output(output);
+  foreach (const QString& input, inputs) {
     if (IsCancelled()) {
       return NodeValueDatabase();
     }
@@ -104,7 +105,7 @@ NodeValueTable NodeTraverser::GenerateTable(const Node *n, const QString& output
   // FIXME: Cache certain values here if we've already processed them before
 
   // Generate database of input values of node
-  NodeValueDatabase database = GenerateDatabase(n, range);
+  NodeValueDatabase database = GenerateDatabase(n, output, range);
 
   // By this point, the node should have all the inputs it needs to render correctly
   NodeValueTable table = n->Value(output, database);

app/node/traverser.h

@@ -42,7 +42,7 @@ public:
     return GenerateTable(output.node(), output.output(), range);
   }
 
-  NodeValueDatabase GenerateDatabase(const Node *node, const TimeRange &range);
+  NodeValueDatabase GenerateDatabase(const Node *node, const QString &output, const TimeRange &range);
 
 protected:
   NodeValueTable ProcessInput(const Node *node, const QString &input, const TimeRange &range);