decoder: signal indexing progress

Better UI interactions, actually shows the progress of the index function in
the task manager now.

app/codec/decoder.cpp

@@ -180,3 +180,10 @@ void Decoder::Conform(const AudioRenderingParams &params, const QAtomicInt* canc
 void Decoder::Index(const QAtomicInt *cancelled)
 {
 }
+
+void Decoder::SignalIndexProgress(const int64_t &ts)
+{
+  if (stream()->duration() != AV_NOPTS_VALUE && stream()->duration() != 0) {
+    emit IndexProgress(qRound(100.0 * static_cast<double>(ts) / static_cast<double>(stream()->duration())));
+  }
+}

app/codec/decoder.h

@@ -234,7 +234,15 @@ public:
    */
   virtual void Index(const QAtomicInt* cancelled);
 
+signals:
+  /**
+   * @brief While indexing, this signal will provide progress as a percentage (0-100 inclusive) if available
+   */
+  void IndexProgress(int);
+
 protected:
+  void SignalIndexProgress(const int64_t& ts);
+
   bool open_;
 
 private:

app/codec/ffmpeg/ffmpegdecoder.cpp

@@ -868,6 +868,8 @@ void FFmpegDecoder::UnconditionalAudioIndex(AVPacket *pkt, AVFrame *frame, const
         if (data_frame != frame) {
           av_frame_free(&data_frame);
         }
+
+        SignalIndexProgress(frame->pts);
       }
     }
 
@@ -917,6 +919,8 @@ void FFmpegDecoder::UnconditionalVideoIndex(AVPacket* pkt, AVFrame* frame, const
       //CacheFrameToDisk(frame);
 
       video_stream->append_frame_index(frame->pts);
+
+      SignalIndexProgress(frame->pts);
     } else {
       // Assume we've reached the end of the file
       break;

app/task/index/index.cpp

@@ -17,6 +17,8 @@ void IndexTask::Action()
 
     decoder->set_stream(stream_);
 
+    connect(decoder.get(), &Decoder::IndexProgress, this, &IndexTask::ProgressChanged);
+
     decoder->Open();
     decoder->Index(&IsCancelled());
     decoder->Close();