Fix Player::dcp_to_content_video with similar but not equal content/DCP frame rates.

3 files changed, 11 insertions, 4 deletions

diff --git a/src/lib/audio_decoder_stream.cc b/src/lib/audio_decoder_stream.cc
index 2f12af198..365be336f 100644
--- a/src/lib/audio_decoder_stream.cc
+++ b/src/lib/audio_decoder_stream.cc
@@ -62,7 +62,7 @@ AudioDecoderStream::get (Frame frame, Frame length, bool accurate)
 {
 	shared_ptr<ContentAudio> dec;
 
-	_content->film()->log()->log (String::compose ("ADS has request for %1 %2", frame, length), Log::TYPE_DEBUG_DECODE);
+	_content->film()->log()->log (String::compose ("-> ADS has request for %1 %2", frame, length), Log::TYPE_DEBUG_DECODE);
 
 	Frame const end = frame + length - 1;
 
diff --git a/src/lib/player.cc b/src/lib/player.cc
index d2ef1a5ff..d6e142c5e 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -524,10 +524,16 @@ Player::dcp_to_content_video (shared_ptr<const Piece> piece, DCPTime t) const
 	shared_ptr<const VideoContent> vc = dynamic_pointer_cast<const VideoContent> (piece->content);
 	DCPTime s = t - piece->content->position ();
 	s = min (piece->content->length_after_trim(), s);
-	/* We're returning a frame index here so we need to floor() the conversion since we want to know the frame
-	   that contains t, I think
+	s = max (DCPTime(), s + DCPTime (piece->content->trim_start(), piece->frc));
+
+	/* It might seem more logical here to convert s to a ContentTime (using the FrameRateChange)
+	   then convert that ContentTime to frames at the content's rate.  However this fails for
+	   situations like content at 29.9978733fps, DCP at 30fps.  The accuracy of the Time type is not
+	   enough to distinguish between the two with low values of time (e.g. 3200 in Time units).
+
+	   Instead we convert the DCPTime using the DCP video rate then account for any skip/repeat.
 	*/
-	return max (ContentTime (), ContentTime (s, piece->frc) + piece->content->trim_start ()).frames_floor (vc->video_frame_rate ());
+	return s.frames_floor (piece->frc.dcp) / piece->frc.factor ();
 }
 
 DCPTime
diff --git a/src/lib/transcoder.cc b/src/lib/transcoder.cc
index ad8e4ab9b..27e35ac52 100644
--- a/src/lib/transcoder.cc
+++ b/src/lib/transcoder.cc
@@ -32,6 +32,7 @@
 #include "player.h"
 #include "job.h"
 #include "writer.h"
+#include "compose.hpp"
 #include "subtitle_content.h"
 #include <boost/signals2.hpp>
 #include <boost/foreach.hpp>