X-Git-Url: https://git.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Fwx%2Ffilm_viewer.h;h=bf956ef95d3dc29ce2378d9261aaefbf5ac64f8e;hb=6198597b190c3c730057bee54e0421fcd7bcb795;hp=e28703fdd89ea9e3cbd9981ac39ead1edbbb103f;hpb=956da4b106e14c49b179176acf6484c479c21094;p=dcpomatic.git

diff --git a/src/wx/film_viewer.h b/src/wx/film_viewer.h
index e28703fdd..bf956ef95 100644
--- a/src/wx/film_viewer.h
+++ b/src/wx/film_viewer.h
@@ -32,6 +32,25 @@ class Subtitle;
 
 /** @class FilmViewer
  *  @brief A wx widget to view a preview of a Film.
+ *
+ *  The film takes the following path through the viewer:
+ *
+ *  1.  get_frame() asks our _player to decode some data.  If it does, process_video()
+ *      will be called.
+ *
+ *  2.  process_video() takes the image and subtitle from the decoder (_raw_frame and _raw_sub)
+ *      and calls raw_to_display().
+ * 
+ *  3.  raw_to_display() copies _raw_frame to _display_frame, processing it and scaling it.
+ *
+ *  4.  calling _panel->Refresh() and _panel->Update() results in paint_panel() being called;
+ *      this creates frame_bitmap from _display_frame and blits it to the display.  It also
+ *      blits the subtitle, if required.
+ *
+ * update_from_decoder() asks the player to re-emit its current frame on the next pass(), and then
+ * starts from step #1.
+ *
+ * update_from_raw() starts at step #3, then calls _panel->Refresh and _panel->Update.
  */
 class FilmViewer : public wxPanel
 {