renderer: improved code flow

app/codec/decoder.cpp

@@ -85,7 +85,7 @@ bool Decoder::Open(const CodecStream &stream)
   }
 }
 
-FramePtr Decoder::RetrieveVideo(const rational &timecode, const RetrieveVideoParams &divider)
+FramePtr Decoder::RetrieveVideo(const rational &timecode, const RetrieveVideoParams &divider, const QAtomicInt *cancelled)
 {
   QMutexLocker locker(&mutex_);
 
@@ -101,7 +101,11 @@ FramePtr Decoder::RetrieveVideo(const rational &timecode, const RetrieveVideoPar
     return nullptr;
   }
 
-  return RetrieveVideoInternal(timecode, divider);
+  if (cancelled && *cancelled) {
+    return nullptr;
+  }
+
+  return RetrieveVideoInternal(timecode, divider, cancelled);
 }
 
 Decoder::RetrieveAudioData Decoder::RetrieveAudio(const TimeRange &range, const AudioParams &params, const QString& cache_path, Footage::LoopMode loop_mode, RenderMode::Mode mode)
@@ -248,10 +252,11 @@ int64_t Decoder::GetImageSequenceIndex(const QString &filename)
   return number_only.toLongLong();
 }
 
-FramePtr Decoder::RetrieveVideoInternal(const rational &timecode, const RetrieveVideoParams &divider)
+FramePtr Decoder::RetrieveVideoInternal(const rational &timecode, const RetrieveVideoParams &divider, const QAtomicInt *cancelled)
 {
   Q_UNUSED(timecode)
   Q_UNUSED(divider)
+  Q_UNUSED(cancelled)
   return nullptr;
 }
 

app/codec/decoder.h

@@ -184,7 +184,7 @@ public:
    *
    * This function is thread safe and can only run while the decoder is open. \see Open()
    */
-  FramePtr RetrieveVideo(const rational& timecode, const RetrieveVideoParams& divider);
+  FramePtr RetrieveVideo(const rational& timecode, const RetrieveVideoParams& divider, const QAtomicInt *cancelled = nullptr);
 
   enum RetrieveAudioStatus {
     kInvalid = -1,
@@ -284,7 +284,7 @@ protected:
    * Sub-classes must override this function IF they support video. Function is already mutexed
    * so sub-classes don't need to worry about thread safety.
    */
-  virtual FramePtr RetrieveVideoInternal(const rational& timecode, const RetrieveVideoParams& divider);
+  virtual FramePtr RetrieveVideoInternal(const rational& timecode, const RetrieveVideoParams& divider, const QAtomicInt *cancelled);
 
   virtual bool ConformAudioInternal(const QString& filename, const AudioParams &params, const QAtomicInt* cancelled);
 

app/codec/ffmpeg/ffmpegdecoder.cpp

@@ -145,7 +145,7 @@ bool FFmpegDecoder::OpenInternal()
   return output_frame;
 }*/
 
-FramePtr FFmpegDecoder::RetrieveVideoInternal(const rational &timecode, const RetrieveVideoParams &params)
+FramePtr FFmpegDecoder::RetrieveVideoInternal(const rational &timecode, const RetrieveVideoParams &params, const QAtomicInt *cancelled)
 {
   if (!InitScaler(params)) {
     return nullptr;
@@ -154,7 +154,7 @@ FramePtr FFmpegDecoder::RetrieveVideoInternal(const rational &timecode, const Re
   AVStream* s = instance_.avstream();
 
   // Retrieve frame
-  FFmpegFramePool::ElementPtr return_frame = RetrieveFrame(timecode);
+  FFmpegFramePool::ElementPtr return_frame = RetrieveFrame(timecode, cancelled);
 
   // We found the frame, we'll return a copy
   if (return_frame) {
@@ -661,7 +661,7 @@ void FFmpegDecoder::ClearFrameCache()
   }
 }
 
-FFmpegFramePool::ElementPtr FFmpegDecoder::RetrieveFrame(const rational& time)
+FFmpegFramePool::ElementPtr FFmpegDecoder::RetrieveFrame(const rational& time, const QAtomicInt *cancelled)
 {
   int64_t target_ts = GetTimeInTimebaseUnits(time, instance_.avstream()->time_base, instance_.avstream()->start_time);
 
@@ -704,6 +704,10 @@ FFmpegFramePool::ElementPtr FFmpegDecoder::RetrieveFrame(const rational& time)
   AVFrame* working_frame = av_frame_alloc();
 
   while (true) {
+    // Break out of loop if we've cancelled
+    if (cancelled && *cancelled) {
+      break;
+    }
 
     // Pull from the decoder
     av_frame_unref(working_frame);

app/codec/ffmpeg/ffmpegdecoder.h

@@ -63,7 +63,7 @@ public:
 
 protected:
   virtual bool OpenInternal() override;
-  virtual FramePtr RetrieveVideoInternal(const rational &timecode, const RetrieveVideoParams& params) override;
+  virtual FramePtr RetrieveVideoInternal(const rational &timecode, const RetrieveVideoParams& params, const QAtomicInt *cancelled) override;
   virtual bool ConformAudioInternal(const QString& filename, const AudioParams &params, const QAtomicInt* cancelled) override;
   virtual void CloseInternal() override;
 
@@ -137,7 +137,7 @@ private:
 
   void ClearFrameCache();
 
-  FFmpegFramePool::ElementPtr RetrieveFrame(const rational &time);
+  FFmpegFramePool::ElementPtr RetrieveFrame(const rational &time, const QAtomicInt *cancelled);
 
   void RemoveFirstFrame();
 

app/codec/oiio/oiiodecoder.cpp

@@ -101,9 +101,10 @@ bool OIIODecoder::OpenInternal()
   return OpenImageHandler(stream().filename());
 }
 
-FramePtr OIIODecoder::RetrieveVideoInternal(const rational &timecode, const RetrieveVideoParams &divider)
+FramePtr OIIODecoder::RetrieveVideoInternal(const rational &timecode, const RetrieveVideoParams &divider, const QAtomicInt *cancelled)
 {
   Q_UNUSED(timecode)
+  Q_UNUSED(cancelled)
 
   FramePtr frame = Frame::Create();
 

app/codec/oiio/oiiodecoder.h

@@ -44,7 +44,7 @@ public:
 
 protected:
   virtual bool OpenInternal() override;
-  virtual FramePtr RetrieveVideoInternal(const rational &timecode, const RetrieveVideoParams& divider) override;
+  virtual FramePtr RetrieveVideoInternal(const rational &timecode, const RetrieveVideoParams& divider, const QAtomicInt *cancelled) override;
   virtual void CloseInternal() override;
 
 private: