Various work on range setting.

22 files changed, 81 insertions, 64 deletions

diff --git a/src/lib/ab_transcoder.cc b/src/lib/ab_transcoder.cc
index beedd478f..0579aa4ff 100644
--- a/src/lib/ab_transcoder.cc
+++ b/src/lib/ab_transcoder.cc
@@ -66,7 +66,7 @@ ABTranscoder::~ABTranscoder ()
 }
 
 void
-ABTranscoder::process_video (shared_ptr<Image> yuv, int frame, shared_ptr<Subtitle> sub, int index)
+ABTranscoder::process_video (shared_ptr<Image> yuv, SourceFrame frame, shared_ptr<Subtitle> sub, int index)
 {
 	if (index == 0) {
 		/* Keep this image around until we get the other half */
diff --git a/src/lib/ab_transcoder.h b/src/lib/ab_transcoder.h
index 7bf5dd4a1..a136fd270 100644
--- a/src/lib/ab_transcoder.h
+++ b/src/lib/ab_transcoder.h
@@ -24,6 +24,7 @@
 
 #include <boost/shared_ptr.hpp>
 #include <stdint.h>
+#include "util.h"
 
 class Job;
 class Encoder;
@@ -54,7 +55,7 @@ public:
 	void go ();
 
 private:
-	void process_video (boost::shared_ptr<Image>, int, boost::shared_ptr<Subtitle>, int);
+	void process_video (boost::shared_ptr<Image>, SourceFrame, boost::shared_ptr<Subtitle>, int);
 	
 	boost::shared_ptr<Film> _film_a;
 	boost::shared_ptr<Film> _film_b;
@@ -63,6 +64,6 @@ private:
 	boost::shared_ptr<Encoder> _encoder;
 	boost::shared_ptr<Decoder> _da;
 	boost::shared_ptr<Decoder> _db;
-	int _last_frame;
+	SourceFrame _last_frame;
 	boost::shared_ptr<Image> _image;
 };
diff --git a/src/lib/check_hashes_job.cc b/src/lib/check_hashes_job.cc
index d1483933d..3967d0d70 100644
--- a/src/lib/check_hashes_job.cc
+++ b/src/lib/check_hashes_job.cc
@@ -57,10 +57,10 @@ CheckHashesJob::run ()
 		throw EncodeError ("cannot check hashes of a DCP with unknown length");
 	}
 	
-	int const N = _film->dcp_length().get();
+	SourceFrame const N = _film->dcp_trim_start() + _film->dcp_length().get();
 	DCPFrameRate const dfr = dcp_frame_rate (_film->frames_per_second ());
 	
-	for (int i = 0; i < N; i += dfr.skip) {
+	for (SourceFrame i = _film->dcp_trim_start(); i < N; i += dfr.skip) {
 		string const j2k_file = _opt->frame_out_path (i, false);
 		string const hash_file = j2k_file + ".md5";
 
diff --git a/src/lib/dcp_video_frame.cc b/src/lib/dcp_video_frame.cc
index 1dcc81f0d..c185de0f4 100644
--- a/src/lib/dcp_video_frame.cc
+++ b/src/lib/dcp_video_frame.cc
@@ -76,7 +76,7 @@ using boost::shared_ptr;
 DCPVideoFrame::DCPVideoFrame (
 	shared_ptr<const Image> yuv, shared_ptr<Subtitle> sub,
 	Size out, int p, int subtitle_offset, float subtitle_scale,
-	Scaler const * s, int f, float fps, string pp, int clut, int bw, Log* l
+	Scaler const * s, SourceFrame f, float fps, string pp, int clut, int bw, Log* l
 	)
 	: _input (yuv)
 	, _subtitle (sub)
@@ -376,7 +376,7 @@ DCPVideoFrame::encode_remotely (ServerDescription const * serv)
  *  @param frame Frame index.
  */
 void
-EncodedData::write (shared_ptr<const Options> opt, int frame)
+EncodedData::write (shared_ptr<const Options> opt, SourceFrame frame)
 {
 	string const tmp_j2k = opt->frame_out_path (frame, true);
 
diff --git a/src/lib/dcp_video_frame.h b/src/lib/dcp_video_frame.h
index 0ff29f7bf..5ae53f1e8 100644
--- a/src/lib/dcp_video_frame.h
+++ b/src/lib/dcp_video_frame.h
@@ -50,7 +50,7 @@ public:
 	virtual ~EncodedData () {}
 
 	void send (boost::shared_ptr<Socket> socket);
-	void write (boost::shared_ptr<const Options>, int);
+	void write (boost::shared_ptr<const Options>, SourceFrame);
 
 	/** @return data */
 	uint8_t* data () const {
@@ -106,13 +106,17 @@ public:
 class DCPVideoFrame
 {
 public:
-	DCPVideoFrame (boost::shared_ptr<const Image>, boost::shared_ptr<Subtitle>, Size, int, int, float, Scaler const *, int, float, std::string, int, int, Log *);
+	DCPVideoFrame (
+		boost::shared_ptr<const Image>, boost::shared_ptr<Subtitle>, Size,
+		int, int, float, Scaler const *, SourceFrame, float, std::string, int, int, Log *
+		);
+	
 	virtual ~DCPVideoFrame ();
 
 	boost::shared_ptr<EncodedData> encode_locally ();
 	boost::shared_ptr<EncodedData> encode_remotely (ServerDescription const *);
 
-	int frame () const {
+	SourceFrame frame () const {
 		return _frame;
 	}
 	
@@ -127,7 +131,7 @@ private:
 	int _subtitle_offset;
 	float _subtitle_scale;
 	Scaler const * _scaler;          ///< scaler to use
-	int _frame;                      ///< frame index within the Film
+	SourceFrame _frame;              ///< frame index within the Film's source
 	int _frames_per_second;          ///< Frames per second that we will use for the DCP (rounded)
 	std::string _post_process;       ///< FFmpeg post-processing string to use
 	int _colour_lut_index;           ///< Colour look-up table to use (see Config::colour_lut_index ())
diff --git a/src/lib/decoder.cc b/src/lib/decoder.cc
index a8da1ae67..3e210c9cc 100644
--- a/src/lib/decoder.cc
+++ b/src/lib/decoder.cc
@@ -140,7 +140,8 @@ Decoder::go ()
 
 	while (pass () == false) {
 		if (_job && _film->dcp_length()) {
-			_job->set_progress (float ((_video_frame_index - _film->dcp_trim_start())) / _film->dcp_length().get());
+			SourceFrame const p = _video_frame_index - _film->dcp_trim_start();
+			_job->set_progress (float (p) / _film->dcp_length().get());
 		}
 	}
 
diff --git a/src/lib/decoder.h b/src/lib/decoder.h
index e8e73cc9f..0741c4f54 100644
--- a/src/lib/decoder.h
+++ b/src/lib/decoder.h
@@ -81,7 +81,7 @@ public:
 	void go ();
 
 	/** @return the index of the last video frame to be processed */
-	int video_frame_index () const {
+	SourceFrame video_frame_index () const {
 		return _video_frame_index;
 	}
 
@@ -94,11 +94,11 @@ public:
 	}
 
 	/** Emitted when a video frame is ready.
-	 *  First parameter is the frame.
+	 *  First parameter is the frame within the source.
 	 *  Second parameter is its index within the content.
 	 *  Third parameter is either 0 or a subtitle that should be on this frame.
 	 */
-	boost::signals2::signal<void (boost::shared_ptr<Image>, int, boost::shared_ptr<Subtitle>)> Video;
+	boost::signals2::signal<void (boost::shared_ptr<Image>, SourceFrame, boost::shared_ptr<Subtitle>)> Video;
 
 	/** Emitted when some audio data is ready */
 	boost::signals2::signal<void (boost::shared_ptr<AudioBuffers>)> Audio;
@@ -133,7 +133,7 @@ private:
 	void emit_audio (uint8_t* data, int size);
 	
 	/** last video frame to be processed */
-	int _video_frame_index;
+	SourceFrame _video_frame_index;
 
 	std::list<boost::shared_ptr<FilterGraph> > _filter_graphs;
 
diff --git a/src/lib/encoder.cc b/src/lib/encoder.cc
index 7352dcfb1..bb23c9e59 100644
--- a/src/lib/encoder.cc
+++ b/src/lib/encoder.cc
@@ -67,7 +67,7 @@ Encoder::skipping () const
 }
 
 /** @return Index of last frame to be successfully encoded */
-int
+SourceFrame
 Encoder::last_frame () const
 {
 	boost::mutex::scoped_lock (_history_mutex);
@@ -75,10 +75,10 @@ Encoder::last_frame () const
 }
 
 /** Should be called when a frame has been encoded successfully.
- *  @param n Frame index.
+ *  @param n Source frame index.
  */
 void
-Encoder::frame_done (int n)
+Encoder::frame_done (SourceFrame n)
 {
 	boost::mutex::scoped_lock lock (_history_mutex);
 	_just_skipped = false;
diff --git a/src/lib/encoder.h b/src/lib/encoder.h
index 590b8aaa9..704b55e46 100644
--- a/src/lib/encoder.h
+++ b/src/lib/encoder.h
@@ -31,6 +31,7 @@
 extern "C" {
 #include <libavutil/samplefmt.h>
 }
+#include "util.h"
 
 class Options;
 class Image;
@@ -58,10 +59,10 @@ public:
 
 	/** Called with a frame of video.
 	 *  @param i Video frame image.
-	 *  @param f Frame number within the film.
+	 *  @param f Frame number within the film's source.
 	 *  @param s A subtitle that should be on this frame, or 0.
 	 */
-	virtual void process_video (boost::shared_ptr<const Image> i, int f, boost::shared_ptr<Subtitle> s) = 0;
+	virtual void process_video (boost::shared_ptr<const Image> i, SourceFrame f, boost::shared_ptr<Subtitle> s) = 0;
 
 	/** Called with some audio data.
 	 *  @param d Array of pointers to floating point sample data for each channel.
@@ -74,10 +75,10 @@ public:
 
 	float current_frames_per_second () const;
 	bool skipping () const;
-	int last_frame () const;
+	SourceFrame last_frame () const;
 
 protected:
-	void frame_done (int n);
+	void frame_done (SourceFrame n);
 	void frame_skipped ();
 	
 	/** Film that we are encoding */
@@ -95,8 +96,8 @@ protected:
 	static int const _history_size;
 	/** true if the last frame we processed was skipped (because it was already done) */
 	bool _just_skipped;
-	/** Index of the last frame to be processed */
-	int _last_frame;
+	/** Source index of the last frame to be processed */
+	SourceFrame _last_frame;
 };
 
 #endif
diff --git a/src/lib/examine_content_job.cc b/src/lib/examine_content_job.cc
index 6d1233a8c..58b9282b8 100644
--- a/src/lib/examine_content_job.cc
+++ b/src/lib/examine_content_job.cc
@@ -105,7 +105,7 @@ ExamineContentJob::run ()
 	}
 
 	string const tdir = _film->dir ("thumbs");
-	vector<int> thumbs;
+	vector<SourceFrame> thumbs;
 
 	for (boost::filesystem::directory_iterator i = boost::filesystem::directory_iterator (tdir); i != boost::filesystem::directory_iterator(); ++i) {
 
diff --git a/src/lib/film.cc b/src/lib/film.cc
index da664a5a5..cacd30764 100644
--- a/src/lib/film.cc
+++ b/src/lib/film.cc
@@ -282,7 +282,7 @@ Film::examine_content ()
 		return;
 	}
 
-	set_thumbs (vector<int> ());
+	set_thumbs (vector<SourceFrame> ());
 	boost::filesystem::remove_all (dir ("thumbs"));
 
 	/* This call will recreate the directory */
@@ -428,7 +428,7 @@ Film::write_metadata () const
 	/* Cached stuff; this is information about our content; we could
 	   look it up each time, but that's slow.
 	*/
-	for (vector<int>::const_iterator i = _thumbs.begin(); i != _thumbs.end(); ++i) {
+	for (vector<SourceFrame>::const_iterator i = _thumbs.begin(); i != _thumbs.end(); ++i) {
 		f << "thumb " << *i << "\n";
 	}
 	f << "width " << _size.width << "\n";
@@ -567,17 +567,19 @@ Film::thumb_file (int n) const
 	return thumb_file_for_frame (thumb_frame (n));
 }
 
-/** @param n A frame index within the Film.
+/** @param n A frame index within the Film's source.
  *  @return The path to the thumb's image file for this frame;
  *  we assume that it exists.
  */
 string
-Film::thumb_file_for_frame (int n) const
+Film::thumb_file_for_frame (SourceFrame n) const
 {
 	return thumb_base_for_frame(n) + ".png";
 }
 
-/** Must not be called with the _state_mutex locked */
+/** @param n Thumb index.
+ *  Must not be called with the _state_mutex locked.
+ */
 string
 Film::thumb_base (int n) const
 {
@@ -585,7 +587,7 @@ Film::thumb_base (int n) const
 }
 
 string
-Film::thumb_base_for_frame (int n) const
+Film::thumb_base_for_frame (SourceFrame n) const
 {
 	stringstream s;
 	s.width (8);
@@ -599,11 +601,11 @@ Film::thumb_base_for_frame (int n) const
 }
 
 /** @param n A thumb index.
- *  @return The frame within the Film that it is for.
+ *  @return The frame within the Film's source that it is for.
  *
  *  Must not be called with the _state_mutex locked.
  */
-int
+SourceFrame
 Film::thumb_frame (int n) const
 {
 	boost::mutex::scoped_lock lm (_state_mutex);
@@ -698,11 +700,11 @@ Film::target_audio_sample_rate () const
 	return rint (t);
 }
 
-boost::optional<int>
+boost::optional<SourceFrame>
 Film::dcp_length () const
 {
 	if (!length()) {
-		return boost::optional<int> ();
+		return boost::optional<SourceFrame> ();
 	}
 
 	return length().get() - dcp_trim_start() - dcp_trim_end();
@@ -1194,7 +1196,7 @@ Film::set_package_type (string p)
 }
 
 void
-Film::set_thumbs (vector<int> t)
+Film::set_thumbs (vector<SourceFrame> t)
 {
 	{
 		boost::mutex::scoped_lock lm (_state_mutex);
@@ -1214,7 +1216,7 @@ Film::set_size (Size s)
 }
 
 void
-Film::set_length (int l)
+Film::set_length (SourceFrame l)
 {
 	{
 		boost::mutex::scoped_lock lm (_state_mutex);
diff --git a/src/lib/film.h b/src/lib/film.h
index eeaae2acd..06ebba3ce 100644
--- a/src/lib/film.h
+++ b/src/lib/film.h
@@ -87,7 +87,7 @@ public:
 
 	std::string thumb_file (int) const;
 	std::string thumb_base (int) const;
-	int thumb_frame (int) const;
+	SourceFrame thumb_frame (int) const;
 
 	int target_audio_sample_rate () const;
 	
@@ -95,7 +95,7 @@ public:
 	void read_metadata ();
 
 	Size cropped_size (Size) const;
-	boost::optional<int> dcp_length () const;
+	boost::optional<SourceFrame> dcp_length () const;
 	std::string dci_name () const;
 	std::string dcp_name () const;
 
@@ -187,12 +187,12 @@ public:
 		return _scaler;
 	}
 
-	int dcp_trim_start () const {
+	SourceFrame dcp_trim_start () const {
 		boost::mutex::scoped_lock lm (_state_mutex);
 		return _dcp_trim_start;
 	}
 
-	int dcp_trim_end () const {
+	SourceFrame dcp_trim_end () const {
 		boost::mutex::scoped_lock lm (_state_mutex);
 		return _dcp_trim_end;
 	}
@@ -289,7 +289,7 @@ public:
 		return _package_type;
 	}
 
-	std::vector<int> thumbs () const {
+	std::vector<SourceFrame> thumbs () const {
 		boost::mutex::scoped_lock lm (_state_mutex);
 		return _thumbs;
 	}
@@ -299,7 +299,7 @@ public:
 		return _size;
 	}
 
-	boost::optional<int> length () const {
+	boost::optional<SourceFrame> length () const {
 		boost::mutex::scoped_lock lm (_state_mutex);
 		return _length;
 	}
@@ -368,9 +368,9 @@ public:
 	void set_studio (std::string);
 	void set_facility (std::string);
 	void set_package_type (std::string);
-	void set_thumbs (std::vector<int>);
+	void set_thumbs (std::vector<SourceFrame>);
 	void set_size (Size);
-	void set_length (int);
+	void set_length (SourceFrame);
 	void unset_length ();
 	void set_audio_sample_rate (int);
 	void set_content_digest (std::string);
@@ -392,8 +392,8 @@ private:
 
 	boost::gregorian::date _dci_date;
 
-	std::string thumb_file_for_frame (int) const;
-	std::string thumb_base_for_frame (int) const;
+	std::string thumb_file_for_frame (SourceFrame) const;
+	std::string thumb_base_for_frame (SourceFrame) const;
 	void signal_changed (Property);
 	void examine_content_finished ();
 	
@@ -422,8 +422,8 @@ private:
 	std::vector<Filter const *> _filters;
 	/** Scaler algorithm to use */
 	Scaler const * _scaler;
-	int _dcp_trim_start;
-	int _dcp_trim_end;
+	SourceFrame _dcp_trim_start;
+	SourceFrame _dcp_trim_end;
 	/** true to create an A/B comparison DCP, where the left half of the image
 	    is the video without any filters or post-processing, and the right half
 	    has the specified filters and post-processing.
@@ -460,11 +460,11 @@ private:
 	/* Data which are cached to speed things up */
 
 	/** Vector of frame indices for each of our `thumbnails' */
-	std::vector<int> _thumbs;
+	std::vector<SourceFrame> _thumbs;
 	/** Size, in pixels, of the source (ignoring cropping) */
 	Size _size;
 	/** Actual length of the source (in video frames) from examining it */
-	boost::optional<int> _length;
+	boost::optional<SourceFrame> _length;
 	/** Sample rate of the source audio, in Hz */
 	int _audio_sample_rate;
 	/** MD5 digest of our content file */
diff --git a/src/lib/imagemagick_encoder.cc b/src/lib/imagemagick_encoder.cc
index e8b060997..e0e2d1cdc 100644
--- a/src/lib/imagemagick_encoder.cc
+++ b/src/lib/imagemagick_encoder.cc
@@ -50,7 +50,7 @@ ImageMagickEncoder::ImageMagickEncoder (shared_ptr<const Film> f, shared_ptr<con
 }
 
 void
-ImageMagickEncoder::process_video (shared_ptr<const Image> image, int frame, shared_ptr<Subtitle> sub)
+ImageMagickEncoder::process_video (shared_ptr<const Image> image, SourceFrame frame, shared_ptr<Subtitle> sub)
 {
 	shared_ptr<Image> scaled = image->scale_and_convert_to_rgb (_opt->out_size, _opt->padding, _film->scaler());
 	shared_ptr<Image> compact (new CompactImage (scaled));
diff --git a/src/lib/imagemagick_encoder.h b/src/lib/imagemagick_encoder.h
index c112300e3..3d8edd25e 100644
--- a/src/lib/imagemagick_encoder.h
+++ b/src/lib/imagemagick_encoder.h
@@ -37,7 +37,7 @@ public:
 	ImageMagickEncoder (boost::shared_ptr<const Film> f, boost::shared_ptr<const Options> o);
 
 	void process_begin (int64_t audio_channel_layout) {}
-	void process_video (boost::shared_ptr<const Image>, int, boost::shared_ptr<Subtitle>);
+	void process_video (boost::shared_ptr<const Image>, SourceFrame, boost::shared_ptr<Subtitle>);
 	void process_audio (boost::shared_ptr<const AudioBuffers>) {}
 	void process_end () {}
 };
diff --git a/src/lib/j2k_still_encoder.cc b/src/lib/j2k_still_encoder.cc
index edcf0de89..aab686417 100644
--- a/src/lib/j2k_still_encoder.cc
+++ b/src/lib/j2k_still_encoder.cc
@@ -49,7 +49,7 @@ J2KStillEncoder::J2KStillEncoder (shared_ptr<const Film> f, shared_ptr<const Opt
 }
 
 void
-J2KStillEncoder::process_video (shared_ptr<const Image> yuv, int frame, shared_ptr<Subtitle> sub)
+J2KStillEncoder::process_video (shared_ptr<const Image> yuv, SourceFrame frame, shared_ptr<Subtitle> sub)
 {
 	pair<string, string> const s = Filter::ffmpeg_strings (_film->filters());
 	DCPVideoFrame* f = new DCPVideoFrame (
diff --git a/src/lib/j2k_still_encoder.h b/src/lib/j2k_still_encoder.h
index 86bebc0d2..89222ce18 100644
--- a/src/lib/j2k_still_encoder.h
+++ b/src/lib/j2k_still_encoder.h
@@ -37,7 +37,7 @@ public:
 	J2KStillEncoder (boost::shared_ptr<const Film>, boost::shared_ptr<const Options>);
 
 	void process_begin (int64_t audio_channel_layout) {}
-	void process_video (boost::shared_ptr<const Image>, int, boost::shared_ptr<Subtitle>);
+	void process_video (boost::shared_ptr<const Image>, SourceFrame, boost::shared_ptr<Subtitle>);
 	void process_audio (boost::shared_ptr<const AudioBuffers>) {}
 	void process_end () {}
 };
diff --git a/src/lib/j2k_wav_encoder.cc b/src/lib/j2k_wav_encoder.cc
index bac7d5f35..f93fd9460 100644
--- a/src/lib/j2k_wav_encoder.cc
+++ b/src/lib/j2k_wav_encoder.cc
@@ -106,7 +106,7 @@ J2KWAVEncoder::close_sound_files ()
 }	
 
 void
-J2KWAVEncoder::process_video (shared_ptr<const Image> yuv, int frame, shared_ptr<Subtitle> sub)
+J2KWAVEncoder::process_video (shared_ptr<const Image> yuv, SourceFrame frame, shared_ptr<Subtitle> sub)
 {
 	boost::mutex::scoped_lock lock (_worker_mutex);
 
diff --git a/src/lib/j2k_wav_encoder.h b/src/lib/j2k_wav_encoder.h
index 99924829d..2272d7f49 100644
--- a/src/lib/j2k_wav_encoder.h
+++ b/src/lib/j2k_wav_encoder.h
@@ -51,7 +51,7 @@ public:
 	~J2KWAVEncoder ();
 
 	void process_begin (int64_t audio_channel_layout);
-	void process_video (boost::shared_ptr<const Image>, int, boost::shared_ptr<Subtitle>);
+	void process_video (boost::shared_ptr<const Image>, SourceFrame, boost::shared_ptr<Subtitle>);
 	void process_audio (boost::shared_ptr<const AudioBuffers>);
 	void process_end ();
 
diff --git a/src/lib/make_dcp_job.cc b/src/lib/make_dcp_job.cc
index 4102f8384..a1ffd9672 100644
--- a/src/lib/make_dcp_job.cc
+++ b/src/lib/make_dcp_job.cc
@@ -55,10 +55,12 @@ MakeDCPJob::name () const
 	return String::compose ("Make DCP for %1", _film->name());
 }
 
+/** @param f DCP frame index */
 string
 MakeDCPJob::j2c_path (int f) const
 {
-	return _opt->frame_out_path (f * dcp_frame_rate(_film->frames_per_second()).skip, false);
+	SourceFrame const s = (f * dcp_frame_rate(_film->frames_per_second()).skip) + _film->dcp_trim_start();
+	return _opt->frame_out_path (s, false);
 }
 
 string
@@ -84,6 +86,7 @@ MakeDCPJob::run ()
 	int frames = 0;
 	switch (_film->content_type ()) {
 	case VIDEO:
+		/* Source frames -> DCP frames */
 		frames = _film->dcp_length().get() / dfr.skip;
 		break;
 	case STILL:
diff --git a/src/lib/options.h b/src/lib/options.h
index aef9ca112..043e3692f 100644
--- a/src/lib/options.h
+++ b/src/lib/options.h
@@ -52,11 +52,11 @@ public:
 		return _frame_out_path;
 	}
 
-	/** @param f Frame index.
+	/** @param f Source frame index.
 	 *  @param t true to return a temporary file path, otherwise a permanent one.
 	 *  @return The path to write this video frame to.
 	 */
-	std::string frame_out_path (int f, bool t, std::string e = "") const {
+	std::string frame_out_path (SourceFrame f, bool t, std::string e = "") const {
 		if (e.empty ()) {
 			e = _frame_out_extension;
 		}
@@ -96,8 +96,10 @@ public:
 	float ratio;                ///< ratio of the wanted output image (not considering padding)
 	int padding;                ///< number of pixels of padding (in terms of the output size) each side of the image
 	bool apply_crop;            ///< true to apply cropping
-	int decode_video_skip;      ///< skip frames such that we don't decode any frame where (index % decode_video_skip) != 0; e.g.
-	                            ///< 1 for every frame, 2 for every other frame, etc.
+	/** Skip frames such that we don't decode any frame where (index % decode_video_skip) != 0; e.g.
+	 *  1 for every frame, 2 for every other frame, etc.
+	 */
+	SourceFrame decode_video_skip; 
 	bool decode_audio;          ///< true to decode audio, otherwise false
 	bool decode_subtitles;
 
diff --git a/src/lib/transcode_job.cc b/src/lib/transcode_job.cc
index 877214316..31808c103 100644
--- a/src/lib/transcode_job.cc
+++ b/src/lib/transcode_job.cc
@@ -110,5 +110,6 @@ TranscodeJob::remaining_time () const
 	}
 
 	/* We assume that dcp_length() is valid */
-	return ((_film->dcp_length().get() - _encoder->last_frame()) / fps);
+	SourceFrame const left = _film->dcp_length().get() - _encoder->last_frame() - _film->dcp_trim_start();
+	return left / fps;
 }
diff --git a/src/lib/util.h b/src/lib/util.h
index 26c6ed9fa..f87328dba 100644
--- a/src/lib/util.h
+++ b/src/lib/util.h
@@ -54,6 +54,8 @@ extern std::string md5_digest (std::string);
 extern std::string md5_digest (void const *, int);
 extern void ensure_ui_thread ();
 
+typedef int SourceFrame;
+
 struct DCPFrameRate
 {
 	int frames_per_second;