Add a note to the design docs.

diff --git a/doc/design/decoder_structures.tex b/doc/design/decoder_structures.tex
index 594c6645023b2b1a46afbed84345f35073bd3b4f..9b9be33cdd4ea0e6e552b8241a8770c623b15db4 100644 (file)
--- a/doc/design/decoder_structures.tex
+++ b/doc/design/decoder_structures.tex
@@ -194,6 +194,10 @@ The diff between \texttt{back-to-pass} and \texttt{master} as at 21/2/2017 can b
     \texttt{Player} from different streams at different times.  The
     \texttt{AudioMerger} just accepts data, mixes and spits it out
     again.
+\item \texttt{AudioMerger} made aware of periods with no content to
+  allow referenced reels; adds a fair amount of complexity.  Without
+  this the referenced reel gaps are silence-padded which confuses
+  things later on as our VF DCP gets audio data that it does not need.
 \item Obvious consumer changes: what was a loop over the playlist
   length and calls to \texttt{get()} is now calls to \texttt{pass()}.
   \item Maybe-seek stuff gone.