Various hacks.

19 files changed, 235 insertions, 277 deletions

diff --git a/src/lib/audio_decoder.cc b/src/lib/audio_decoder.cc
index e1c93ac77..fbc66c335 100644
--- a/src/lib/audio_decoder.cc
+++ b/src/lib/audio_decoder.cc
@@ -30,6 +30,7 @@ using boost::shared_ptr;
 
 AudioDecoder::AudioDecoder (shared_ptr<const Film> f, shared_ptr<const AudioContent> c)
 	: Decoder (f)
+	, _next_audio (0)
 	, _audio_content (c)
 	, _output_audio_frame_rate (_audio_content->output_audio_frame_rate (f))
 {
@@ -104,7 +105,7 @@ AudioDecoder::emit_audio (shared_ptr<const AudioBuffers> data, Time time)
 {
 	/* XXX: map audio to 5.1 */
 	
-	/* Maybe sample-rate convert */
+	/* Maybe resample */
 	if (_swr_context) {
 
 		/* Compute the resampled frames count and add 32 for luck */
@@ -128,6 +129,8 @@ AudioDecoder::emit_audio (shared_ptr<const AudioBuffers> data, Time time)
 	}
 
 	Audio (data, time);
+
+	_next_audio = time + _film->audio_frames_to_time (data->frames());
 }
 
 		
diff --git a/src/lib/audio_decoder.h b/src/lib/audio_decoder.h
index 94845ec23..8af519576 100644
--- a/src/lib/audio_decoder.h
+++ b/src/lib/audio_decoder.h
@@ -43,6 +43,9 @@ public:
 
 	void emit_audio (boost::shared_ptr<const AudioBuffers>, Time);
 
+protected:
+	Time _next_audio;
+
 private:
 	boost::shared_ptr<const AudioContent> _audio_content;
 	SwrContext* _swr_context;
diff --git a/src/lib/content.cc b/src/lib/content.cc
index 618dafee2..43d0ef958 100644
--- a/src/lib/content.cc
+++ b/src/lib/content.cc
@@ -29,9 +29,15 @@ using std::string;
 using boost::shared_ptr;
 using boost::lexical_cast;
 
+Content::Content (Time s)
+	: _start (s)
+{
+
+}
+
 Content::Content (boost::filesystem::path f)
 	: _file (f)
-	, _time (0)
+	, _start (0)
 {
 
 }
@@ -40,14 +46,14 @@ Content::Content (shared_ptr<const cxml::Node> node)
 {
 	_file = node->string_child ("File");
 	_digest = node->string_child ("Digest");
-	_time = node->number_child<Time> ("Time");
+	_start = node->number_child<Time> ("Start");
 }
 
 Content::Content (Content const & o)
 	: boost::enable_shared_from_this<Content> (o)
 	, _file (o._file)
 	, _digest (o._digest)
-	, _time (o._time)
+	, _start (o._start)
 {
 
 }
@@ -58,7 +64,7 @@ Content::as_xml (xmlpp::Node* node) const
 	boost::mutex::scoped_lock lm (_mutex);
 	node->add_child("File")->add_child_text (_file.string());
 	node->add_child("Digest")->add_child_text (_digest);
-	node->add_child("Time")->add_child_text (lexical_cast<string> (_time));
+	node->add_child("Start")->add_child_text (lexical_cast<string> (_start));
 }
 
 void
diff --git a/src/lib/content.h b/src/lib/content.h
index b8062b280..db1e56bc4 100644
--- a/src/lib/content.h
+++ b/src/lib/content.h
@@ -39,6 +39,7 @@ class Film;
 class Content : public boost::enable_shared_from_this<Content>
 {
 public:
+	Content (Time);
 	Content (boost::filesystem::path);
 	Content (boost::shared_ptr<const cxml::Node>);
 	Content (Content const &);
@@ -49,7 +50,7 @@ public:
 	virtual void as_xml (xmlpp::Node *) const;
 	virtual boost::shared_ptr<Content> clone () const = 0;
 	virtual Time length (boost::shared_ptr<const Film>) const = 0;
-	
+
 	boost::filesystem::path file () const {
 		boost::mutex::scoped_lock lm (_mutex);
 		return _file;
@@ -60,9 +61,13 @@ public:
 		return _digest;
 	}
 
-	Time time () const {
+	Time start () const {
 		boost::mutex::scoped_lock lm (_mutex);
-		return _time;
+		return _start;
+	}
+
+	Time end (boost::shared_ptr<const Film> f) const {
+		return start() + length(f);
 	}
 
 	boost::signals2::signal<void (boost::weak_ptr<Content>, int)> Changed;
@@ -75,7 +80,7 @@ protected:
 private:
 	boost::filesystem::path _file;
 	std::string _digest;
-	Time _time;
+	Time _start;
 };
 
 #endif
diff --git a/src/lib/decoder.cc b/src/lib/decoder.cc
index 2308bbd98..637e0ddb2 100644
--- a/src/lib/decoder.cc
+++ b/src/lib/decoder.cc
@@ -21,15 +21,11 @@
  *  @brief Parent class for decoders of content.
  */
 
-#include <iostream>
 #include "film.h"
-#include "exceptions.h"
-#include "util.h"
 #include "decoder.h"
 
 #include "i18n.h"
 
-using std::string;
 using boost::shared_ptr;
 
 /** @param f Film.
@@ -40,10 +36,3 @@ Decoder::Decoder (shared_ptr<const Film> f)
 {
 	_film_connection = f->Changed.connect (bind (&Decoder::film_changed, this, _1));
 }
-
-/** @return true on error */
-bool
-Decoder::seek (Time)
-{
-	throw DecodeError (N_("decoder does not support seek"));
-}
diff --git a/src/lib/decoder.h b/src/lib/decoder.h
index 3876e6c1a..668e44d38 100644
--- a/src/lib/decoder.h
+++ b/src/lib/decoder.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2013 Carl Hetherington <cth@carlh.net>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -42,10 +42,6 @@ class FilterGraph;
 
 /** @class Decoder.
  *  @brief Parent class for decoders of content.
- *
- *  These classes can be instructed run through their content (by
- *  calling ::go), and they emit signals when video or audio data is
- *  ready for something else to process.
  */
 class Decoder
 {
@@ -53,23 +49,38 @@ public:
 	Decoder (boost::shared_ptr<const Film>);
 	virtual ~Decoder () {}
 
-	virtual bool pass () = 0;
-	virtual bool seek (Time);
-	virtual bool seek_back () {
-		return true;
-	}
-	virtual bool seek_forward () {
-		return true;
-	}
+	/** Perform one decode pass of the content, which may or may not
+	 *  cause the object to emit some data.
+	 */
+	virtual void pass () = 0;
 
-	boost::signals2::signal<void()> OutputChanged;
+	/** Seek this decoder to as close as possible to some time,
+	 *  expressed relative to our source's start.
+	 *  @param t Time.
+	 */
+	virtual void seek (Time t) {}
+
+	/** Seek back one video frame */
+	virtual void seek_back () {}
+
+	/** Seek forward one video frame */
+	virtual void seek_forward () {}
+
+	/** @return Approximate time of the next content that we will emit,
+	 *  expressed relative to the start of our source.
+	 */
+	virtual Time next () const = 0;
 
 protected:
-	boost::shared_ptr<const Film> _film;
+
+	/** The Film that we are decoding in */
+	boost::weak_ptr<const Film> _film;
 
 private:
+	/** This will be called when our Film emits Changed */
 	virtual void film_changed (Film::Property) {}
 
+	/** Connection to our Film */
 	boost::signals2::scoped_connection _film_connection;
 };
 
diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc
index 0ca9fc535..c0867095f 100644
--- a/src/lib/ffmpeg_decoder.cc
+++ b/src/lib/ffmpeg_decoder.cc
@@ -59,6 +59,7 @@ using std::string;
 using std::vector;
 using std::stringstream;
 using std::list;
+using std::min;
 using boost::shared_ptr;
 using boost::optional;
 using boost::dynamic_pointer_cast;
@@ -224,9 +225,7 @@ FFmpegDecoder::setup_subtitle ()
 bool
 FFmpegDecoder::pass ()
 {
-	cout << "ffd pass.\n";
 	int r = av_read_frame (_format_context, &_packet);
-	cout << "A " << r << "\n";
 
 	if (r < 0) {
 		if (r != AVERROR_EOF) {
@@ -257,9 +256,7 @@ FFmpegDecoder::pass ()
 	avcodec_get_frame_defaults (_frame);
 
 	if (_packet.stream_index == _video_stream && _decode_video) {
-		cout << "dvp\n";
 		decode_video_packet ();
-		cout << "ok.\n";
 	} else if (_ffmpeg_content->audio_stream() && _packet.stream_index == _ffmpeg_content->audio_stream()->id && _decode_audio) {
 		decode_audio_packet ();
 	} else if (_ffmpeg_content->subtitle_stream() && _packet.stream_index == _ffmpeg_content->subtitle_stream()->id && _decode_subtitles) {
@@ -284,7 +281,6 @@ FFmpegDecoder::pass ()
 		}
 	}
 
-	cout << "out.\n";
 	av_free_packet (&_packet);
 	return false;
 }
@@ -419,30 +415,6 @@ FFmpegDecoder::pixel_format () const
 	return _video_codec_context->pix_fmt;
 }
 
-int
-FFmpegDecoder::time_base_numerator () const
-{
-	return _video_codec_context->time_base.num;
-}
-
-int
-FFmpegDecoder::time_base_denominator () const
-{
-	return _video_codec_context->time_base.den;
-}
-
-int
-FFmpegDecoder::sample_aspect_ratio_numerator () const
-{
-	return _video_codec_context->sample_aspect_ratio.num;
-}
-
-int
-FFmpegDecoder::sample_aspect_ratio_denominator () const
-{
-	return _video_codec_context->sample_aspect_ratio.den;
-}
-
 string
 FFmpegDecoder::stream_name (AVStream* s) const
 {
@@ -485,21 +457,21 @@ FFmpegDecoder::seek (Time t)
 bool
 FFmpegDecoder::seek_back ()
 {
-	if (last_content_time() < 2.5) {
+	if (next() < 2.5) {
 		return true;
 	}
 	
-	return do_seek (last_content_time() - 2.5 * TIME_HZ / video_frame_rate(), true, true);
+	return do_seek (next() - 2.5 * TIME_HZ / video_frame_rate(), true, true);
 }
 
 bool
 FFmpegDecoder::seek_forward ()
 {
-	if (last_content_time() >= (video_length() - video_frame_rate())) {
+	if (next() >= (video_length() - video_frame_rate())) {
 		return true;
 	}
 	
-	return do_seek (last_content_time() - 0.5 * TIME_HZ / video_frame_rate(), true, true);
+	return do_seek (next() - 0.5 * TIME_HZ / video_frame_rate(), true, true);
 }
 
 bool
@@ -507,8 +479,6 @@ FFmpegDecoder::do_seek (Time t, bool backwards, bool accurate)
 {
 	int64_t const vt = t / (av_q2d (_format_context->streams[_video_stream]->time_base) * TIME_HZ);
 
-	cout << "seek to " << vt << " (acc=" << accurate << ") (sec " << (vt * av_q2d (_format_context->streams[_video_stream]->time_base)) << "\n";
-
 	int const r = av_seek_frame (_format_context, _video_stream, vt, backwards ? AVSEEK_FLAG_BACKWARD : 0);
 
 	avcodec_flush_buffers (_video_codec_context);
@@ -540,7 +510,6 @@ FFmpegDecoder::do_seek (Time t, bool backwards, bool accurate)
 		}
 	}
 
-	cout << "seek ok.\n";
 	return r < 0;
 }
 
@@ -605,16 +574,12 @@ bool
 FFmpegDecoder::decode_video_packet ()
 {
 	int frame_finished;
-	cout << "avc decode v2\n";
 	if (avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet) < 0 || !frame_finished) {
 		return false;
 	}
-	cout << "done that.\n";
 		
 	boost::mutex::scoped_lock lm (_filter_graphs_mutex);
 
-	cout << "got lock.\n";
-	
 	shared_ptr<FilterGraph> graph;
 	
 	list<shared_ptr<FilterGraph> >::iterator i = _filter_graphs.begin();
@@ -622,8 +587,6 @@ FFmpegDecoder::decode_video_packet ()
 		++i;
 	}
 
-	cout << "found graph.\n";
-	
 	if (i == _filter_graphs.end ()) {
 		graph.reset (new FilterGraph (_film, this, libdcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format));
 		_filter_graphs.push_back (graph);
@@ -633,9 +596,7 @@ FFmpegDecoder::decode_video_packet ()
 	}
 
 
-	cout << "pushed in.\n";
 	list<shared_ptr<Image> > images = graph->process (_frame);
-	cout << "got " << images.size() << "\n";
 	
 	for (list<shared_ptr<Image> >::iterator i = images.begin(); i != images.end(); ++i) {
 		int64_t const bet = av_frame_get_best_effort_timestamp (_frame);
@@ -643,9 +604,8 @@ FFmpegDecoder::decode_video_packet ()
 			/* XXX: may need to insert extra frames / remove frames here ...
 			   (as per old Matcher)
 			*/
-			cout << "emitting.\n";
-			emit_video (*i, false, bet * av_q2d (_format_context->streams[_video_stream]->time_base) * TIME_HZ);
-			cout << "emitted.\n";
+			Time const t = bet * av_q2d (_format_context->streams[_video_stream]->time_base) * TIME_HZ;
+			emit_video (*i, false, t);
 		} else {
 			_film->log()->log ("Dropping frame without PTS");
 		}
@@ -653,3 +613,9 @@ FFmpegDecoder::decode_video_packet ()
 
 	return true;
 }
+
+Time
+FFmpegDecoder::next () const
+{
+	return min (_next_video, _next_audio);
+}
diff --git a/src/lib/ffmpeg_decoder.h b/src/lib/ffmpeg_decoder.h
index 1c3f252fd..3b629e3ae 100644
--- a/src/lib/ffmpeg_decoder.h
+++ b/src/lib/ffmpeg_decoder.h
@@ -62,13 +62,15 @@ public:
 	FFmpegDecoder (boost::shared_ptr<const Film>, boost::shared_ptr<const FFmpegContent>, bool video, bool audio, bool subtitles);
 	~FFmpegDecoder ();
 
+	bool pass ();
+	bool seek (Time);
+	bool seek_back ();
+	bool seek_forward ();
+	Time next () const;
+
 	float video_frame_rate () const;
 	libdcp::Size native_size () const;
 	ContentVideoFrame video_length () const;
-	int time_base_numerator () const;
-	int time_base_denominator () const;
-	int sample_aspect_ratio_numerator () const;
-	int sample_aspect_ratio_denominator () const;
 
 	std::vector<boost::shared_ptr<FFmpegSubtitleStream> > subtitle_streams () const {
 		return _subtitle_streams;
@@ -78,11 +80,6 @@ public:
 		return _audio_streams;
 	}
 
-	bool seek (Time);
-	bool seek_forward ();
-	bool seek_back ();
-	bool pass ();
-
 	boost::shared_ptr<const FFmpegContent> ffmpeg_content () const {
 		return _ffmpeg_content;
 	}
diff --git a/src/lib/filter_graph.cc b/src/lib/filter_graph.cc
index 09bbf5dcd..4a91349cb 100644
--- a/src/lib/filter_graph.cc
+++ b/src/lib/filter_graph.cc
@@ -90,10 +90,7 @@ FilterGraph::FilterGraph (shared_ptr<const Film> film, FFmpegDecoder* decoder, l
 	a << _size.width << N_(":")
 	  << _size.height << N_(":")
 	  << _pixel_format << N_(":")
-	  << decoder->time_base_numerator() << N_(":")
-	  << decoder->time_base_denominator() << N_(":")
-	  << decoder->sample_aspect_ratio_numerator() << N_(":")
-	  << decoder->sample_aspect_ratio_denominator();
+	  << "0:1:0:1";
 
 	int r;
 
diff --git a/src/lib/imagemagick_decoder.cc b/src/lib/imagemagick_decoder.cc
index c6b19b742..ed2db80d8 100644
--- a/src/lib/imagemagick_decoder.cc
+++ b/src/lib/imagemagick_decoder.cc
@@ -119,3 +119,9 @@ ImageMagickDecoder::seek (double t)
 	_position = f;
 	return false;
 }
+
+Time
+ImageMagickDecoder::next () const
+{
+	return _next_video;
+}
diff --git a/src/lib/imagemagick_decoder.h b/src/lib/imagemagick_decoder.h
index cb68655ce..ba54c0efa 100644
--- a/src/lib/imagemagick_decoder.h
+++ b/src/lib/imagemagick_decoder.h
@@ -30,6 +30,10 @@ class ImageMagickDecoder : public VideoDecoder
 public:
 	ImageMagickDecoder (boost::shared_ptr<const Film>, boost::shared_ptr<const ImageMagickContent>);
 
+	bool pass ();
+	bool seek (double);
+	Time next () const;
+
 	float video_frame_rate () const {
 		return 24;
 	}
@@ -37,9 +41,6 @@ public:
 	libdcp::Size native_size () const;
 	ContentVideoFrame video_length () const;
 
-	bool seek (double);
-	bool pass ();
-
 	boost::shared_ptr<const ImageMagickContent> content () const {
 		return _imagemagick_content;
 	}
@@ -47,24 +48,6 @@ public:
 protected:
 	PixelFormat pixel_format () const;
 
-	int time_base_numerator () const {
-		return 0;
-	}
-
-	int time_base_denominator () const {
-		return 0;
-	}
-
-	int sample_aspect_ratio_numerator () const {
-		/* XXX */
-		return 1;
-	}
-
-	int sample_aspect_ratio_denominator () const {
-		/* XXX */
-		return 1;
-	}
-
 private:
 	boost::shared_ptr<const ImageMagickContent> _imagemagick_content;
 	boost::shared_ptr<Image> _image;
diff --git a/src/lib/player.cc b/src/lib/player.cc
index dd250d2e1..eb704f733 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -39,6 +39,17 @@ using boost::shared_ptr;
 using boost::weak_ptr;
 using boost::dynamic_pointer_cast;
 
+struct Piece
+{
+	Piece (shared_ptr<Content> c, shared_ptr<Decoder> d)
+		: content (c)
+		, decoder (d)
+	{}
+	
+	shared_ptr<Content> content;
+	shared_ptr<Decoder> decoder;
+};
+
 Player::Player (shared_ptr<const Film> f, shared_ptr<const Playlist> p)
 	: _film (f)
 	, _playlist (p)
@@ -50,7 +61,7 @@ Player::Player (shared_ptr<const Film> f, shared_ptr<const Playlist> p)
 	, _audio_buffers (MAX_AUDIO_CHANNELS, 0)
 	, _last_video (0)
 	, _last_was_black (false)
-	, _last_audio (0)
+	, _next_audio (0)
 {
 	_playlist->Changed.connect (bind (&Player::playlist_changed, this));
 	_playlist->ContentChanged.connect (bind (&Player::content_changed, this, _1, _2));
@@ -77,72 +88,63 @@ Player::disable_subtitles ()
 bool
 Player::pass ()
 {
-	if (!_have_valid_decoders) {
-		setup_decoders ();
-		_have_valid_decoders = true;
+	if (!_have_valid_pieces) {
+		setup_pieces ();
+		_have_valid_pieces = true;
 	}
 
         /* Here we are just finding the active decoder with the earliest last emission time, then
-           calling pass on it.  If there is no decoder, we skip our position on until there is.
-           Hence this method will cause video and audio to be emitted, and it is up to the
-           process_{video,audio} methods to tidy it up.
+           calling pass on it.
         */
 
-        Time earliest_pos = TIME_MAX;
-        shared_ptr<DecoderRecord> earliest;
-        Time next_wait = TIME_MAX;
-
-        for (list<shared_ptr<DecoderRecord> >::iterator i = _decoders.begin(); i != _decoders.end(); ++i) {
-                Time const ts = (*i)->content->time();
-                Time const te = (*i)->content->time() + (*i)->content->length (_film);
-                if (ts <= _position && te > _position) {
-                        Time const pos = ts + (*i)->last;
-                        if (pos < earliest_pos) {
-                                earliest_pos = pos;
-                                earliest = *i;
-                        }
-                }
+        Time earliest_t = TIME_MAX;
+        shared_ptr<Piece> earliest;
 
-                if (ts > _position) {
-                        next_wait = min (next_wait, ts - _position);
-                }
-        }
+	for (list<shared_ptr<Piece> >::iterator i = _pieces.begin(); i != _pieces.end(); ++i) {
+		if ((*i)->content->end(_film) < _position) {
+			continue;
+		}
+		
+		Time const t = (*i)->content->start() + (*i)->decoder->next();
+		if (t < earliest_t) {
+			earliest_t = t;
+			earliest = *i;
+		}
+	}
 
-        if (earliest) {
-		cout << "pass on decoder...\n";
-                earliest->decoder->pass ();
-                _position = earliest->last;
-        } else if (next_wait < TIME_MAX) {
-		cout << "nw " << next_wait << " for " << _position << "\n";
-                _position += next_wait;
-        } else {
-                return true;
-        }
+	if (!earliest) {
+		return true;
+	}
+	
+	earliest->decoder->pass ();
+
+	/* Move position to earliest active next emission */
+
+	for (list<shared_ptr<Piece> >::iterator i = _pieces.begin(); i != _pieces.end(); ++i) {
+		if ((*i)->content->end(_film) < _position) {
+			continue;
+		}
+
+		Time const t = (*i)->content->start() + (*i)->decoder->next();
+
+		if (t < _position) {
+			_position = t;
+		}
+	}
 
         return false;
 }
 
 void
-Player::process_video (shared_ptr<DecoderRecord> dr, shared_ptr<const Image> image, bool same, shared_ptr<Subtitle> sub, Time time)
+Player::process_video (shared_ptr<Piece> piece, shared_ptr<const Image> image, bool same, shared_ptr<Subtitle> sub, Time time)
 {
-        shared_ptr<VideoDecoder> vd = dynamic_pointer_cast<VideoDecoder> (dr->decoder);
-        
-        Time const global_time = dr->content->time() + time;
-	cout << "need to fill in " << global_time << " vs " << _last_video << "\n";
-        while ((global_time - _last_video) > 1) {
-                /* Fill in with black */
-		cout << "(b)\n";
-                emit_black_frame ();
-        }
-
-        Video (image, same, sub, global_time);
-        dr->last = time;
-	_last_video = global_time;
-	_last_was_black = false;
+	time += piece->start ();
+	
+        Video (image, same, sub, time);
 }
 
 void
-Player::process_audio (shared_ptr<DecoderRecord> dr, shared_ptr<const AudioBuffers> audio, Time time)
+Player::process_audio (shared_ptr<Piece> piece, shared_ptr<const AudioBuffers> audio, Time time)
 {
         /* XXX: mapping */
 
@@ -150,13 +152,15 @@ Player::process_audio (shared_ptr<DecoderRecord> dr, shared_ptr<const AudioBuffe
            be added to any more, so it can be emitted.
         */
 
-        if (time > _last_audio) {
+	time += piece->start ();
+
+        if (time > _next_audio) {
                 /* We can emit some audio from our buffers */
-                OutputAudioFrame const N = min (_film->time_to_audio_frames (time - _last_audio), static_cast<OutputAudioFrame> (_audio_buffers.frames()));
+                OutputAudioFrame const N = min (_film->time_to_audio_frames (time - _next_audio), static_cast<OutputAudioFrame> (_audio_buffers.frames()));
                 shared_ptr<AudioBuffers> emit (new AudioBuffers (_audio_buffers.channels(), N));
                 emit->copy_from (&_audio_buffers, N, 0, 0);
-                Audio (emit, _last_audio);
-                _last_audio += _film->audio_frames_to_time (N);
+                Audio (emit, _next_audio);
+                _next_audio += _film->audio_frames_to_time (N);
 
                 /* And remove it from our buffers */
                 if (_audio_buffers.frames() > N) {
@@ -166,55 +170,23 @@ Player::process_audio (shared_ptr<DecoderRecord> dr, shared_ptr<const AudioBuffe
         }
 
         /* Now accumulate the new audio into our buffers */
-
-        if (_audio_buffers.frames() == 0) {
-                /* We have no remaining data.  Emit silence up to the start of this new data */
-                if ((time - _last_audio) > 0) {
-                        emit_silence (time - _last_audio);
-                }
-        }
-
-        _audio_buffers.ensure_size (time - _last_audio + audio->frames());
-        _audio_buffers.accumulate (audio.get(), 0, _film->time_to_audio_frames (time - _last_audio));
-        dr->last = time + _film->audio_frames_to_time (audio->frames ());
+        _audio_buffers.ensure_size (time - _next_audio + audio->frames());
+        _audio_buffers.accumulate (audio.get(), 0, _film->time_to_audio_frames (time - _next_audio));
 }
 
 /** @return true on error */
 bool
 Player::seek (Time t)
 {
-	if (!_have_valid_decoders) {
-		setup_decoders ();
-		_have_valid_decoders = true;
+	if (!_have_valid_pieces) {
+		setup_pieces ();
+		_have_valid_pieces = true;
 	}
 
-	if (_decoders.empty ()) {
+	if (_pieces.empty ()) {
 		return true;
 	}
 
-	cout << "seek to " << t << "\n";
-
-	Time current_time = 0;
-	shared_ptr<VideoDecoder> current;
-        for (list<shared_ptr<DecoderRecord> >::iterator i = _decoders.begin(); i != _decoders.end(); ++i) {
-		shared_ptr<VideoDecoder> v = dynamic_pointer_cast<VideoDecoder> ((*i)->decoder);
-		if (!v) {
-			continue;
-		}
-
-		if ((*i)->content->time() < t && (*i)->content->time() >= current_time) {
-			current_time = (*i)->content->time();
-			current = v;
-		}
-	}
-
-	if (current) {
-		cout << "got a decoder to seek to " << (t - current_time) << ".\n";
-		current->seek (t - current_time);
-		_position = t;
-		_last_video = t;
-	}
-
 	/* XXX: don't seek audio because we don't need to... */
 
 	return false;
@@ -233,19 +205,27 @@ Player::seek_forward ()
 	/* XXX */
 }
 
+struct ContentSorter
+{
+	bool operator() (shared_ptr<Content> a, shared_ptr<Content> b)
+	{
+		return a->time() < b->time();
+	}
+};
 
 void
 Player::setup_decoders ()
 {
-	list<shared_ptr<DecoderRecord> > old_decoders = _decoders;
+	list<shared_ptr<Piece> > old_pieces = _pieces;
 
-	_decoders.clear ();
+	_pieces.clear ();
 
 	Playlist::ContentList content = _playlist->content ();
+	content.sort (ContentSorter ());
+	
 	for (Playlist::ContentList::iterator i = content.begin(); i != content.end(); ++i) {
 
-		shared_ptr<DecoderRecord> dr (new DecoderRecord);
-		dr->content = *i;
+		shared_ptr<Decoder> decoder;
 		
                 /* XXX: into content? */
 
@@ -256,7 +236,7 @@ Player::setup_decoders ()
 			fd->Video.connect (bind (&Player::process_video, this, dr, _1, _2, _3, _4));
 			fd->Audio.connect (bind (&Player::process_audio, this, dr, _1, _2));
 
-			dr->decoder = fd;
+			decoder = fd;
 		}
 		
 		shared_ptr<const ImageMagickContent> ic = dynamic_pointer_cast<const ImageMagickContent> (*i);
@@ -264,10 +244,13 @@ Player::setup_decoders ()
 			shared_ptr<ImageMagickDecoder> id;
 			
 			/* See if we can re-use an old ImageMagickDecoder */
-			for (list<shared_ptr<DecoderRecord> >::const_iterator i = old_decoders.begin(); i != old_decoders.end(); ++i) {
-				shared_ptr<ImageMagickDecoder> imd = dynamic_pointer_cast<ImageMagickDecoder> ((*i)->decoder);
-				if (imd && imd->content() == ic) {
-					id = imd;
+			for (list<shared_ptr<Piece> >::const_iterator i = old_pieces.begin(); i != old_pieces.end(); ++i) {
+				shared_ptr<ContentPiece> cp = dynamic_pointer_cast<ContentPiece> (*i);
+				if (cp) {
+					shared_ptr<ImageMagickDecoder> imd = dynamic_pointer_cast<ImageMagickDecoder> (cp->decoder ());
+					if (imd && imd->content() == ic) {
+						id = imd;
+					}
 				}
 			}
 
@@ -276,7 +259,7 @@ Player::setup_decoders ()
 				id->Video.connect (bind (&Player::process_video, this, dr, _1, _2, _3, _4));
 			}
 
-			dr->decoder = id;
+			decoder = id;
 		}
 
 		shared_ptr<const SndfileContent> sc = dynamic_pointer_cast<const SndfileContent> (*i);
@@ -284,10 +267,42 @@ Player::setup_decoders ()
 			shared_ptr<AudioDecoder> sd (new SndfileDecoder (_film, sc));
 			sd->Audio.connect (bind (&Player::process_audio, this, dr, _1, _2));
 
-			dr->decoder = sd;
+			decoder = sd;
 		}
 
-		_decoders.push_back (dr);
+		_pieces.push_back (shared_ptr<new ContentPiece> (*i, decoder));
+	}
+
+	/* Fill in visual gaps with black and audio gaps with silence */
+
+	Time video_pos = 0;
+	Time audio_pos = 0;
+	list<shared_ptr<Piece> > pieces_copy = _pieces;
+	for (list<shared_ptr<Piece> >::iterator i = pieces_copy.begin(); i != pieces_copy.end(); ++i) {
+		if (dynamic_pointer_cast<VideoContent> ((*i)->content)) {
+			Time const diff = video_pos - (*i)->content->time();
+			if (diff > 0) {
+				_pieces.push_back (
+					shared_ptr<Piece> (
+						shared_ptr<Content> (new NullContent (video_pos, diff)),
+						shared_ptr<Decoder> (new BlackDecoder (video_pos, diff))
+						)
+					);
+			}
+						
+			video_pos = (*i)->content->time() + (*i)->content->length();
+		} else {
+			Time const diff = audio_pos - (*i)->content->time();
+			if (diff > 0) {
+				_pieces.push_back (
+					shared_ptr<Piece> (
+						shared_ptr<Content> (new NullContent (audio_pos, diff)),
+						shared_ptr<Decoder> (new SilenceDecoder (audio_pos, diff))
+						)
+					);
+			}
+			audio_pos = (*i)->content->time() + (*i)->content->length();
+		}
 	}
 
 	_position = 0;
@@ -302,14 +317,14 @@ Player::content_changed (weak_ptr<Content> w, int p)
 	}
 
 	if (p == VideoContentProperty::VIDEO_LENGTH) {
-		_have_valid_decoders = false;
+		_have_valid_pieces = false;
 	}
 }
 
 void
 Player::playlist_changed ()
 {
-	_have_valid_decoders = false;
+	_have_valid_pieces = false;
 }
 
 void
diff --git a/src/lib/player.h b/src/lib/player.h
index 4b9635157..13bdcead4 100644
--- a/src/lib/player.h
+++ b/src/lib/player.h
@@ -36,7 +36,7 @@ class Job;
 class Film;
 class Playlist;
 class AudioContent;
-class Decoder;
+class Piece;
 
 /** @class Player
  *  @brief A class which can `play' a Playlist; emitting its audio and video.
@@ -62,20 +62,9 @@ public:
 
 private:
 
-	struct DecoderRecord
-	{
-		DecoderRecord ()
-			: last (0)
-		{}
-		
-		boost::shared_ptr<Content> content;
-		boost::shared_ptr<Decoder> decoder;
-		Time last;
-	};
-	
-	void process_video (boost::shared_ptr<DecoderRecord>, boost::shared_ptr<const Image>, bool, boost::shared_ptr<Subtitle>, Time);
-	void process_audio (boost::shared_ptr<DecoderRecord>, boost::shared_ptr<const AudioBuffers>, Time);
-	void setup_decoders ();
+	void process_video (boost::shared_ptr<Piece>, boost::shared_ptr<const Image>, bool, boost::shared_ptr<Subtitle>, Time);
+	void process_audio (boost::shared_ptr<Piece>, boost::shared_ptr<const AudioBuffers>, Time);
+	void setup_pieces ();
 	void playlist_changed ();
 	void content_changed (boost::weak_ptr<Content>, int);
 	void emit_black_frame ();
@@ -88,16 +77,20 @@ private:
 	bool _audio;
 	bool _subtitles;
 
-	/** Our decoders are ready to go; if this is false the decoders must be (re-)created before they are used */
-	bool _have_valid_decoders;
-	std::list<boost::shared_ptr<DecoderRecord> > _decoders;
+	/** Our pieces are ready to go; if this is false the pieces must be (re-)created before they are used */
+	bool _have_valid_pieces;
+	std::list<boost::shared_ptr<Piece> > _pieces;
 
-	/* XXX: position and last_video? Need both? */
+	/** Time of the earliest thing not yet to have been emitted */
 	Time _position;
+	Time _last_black;
+	Time _last_silence;
+
+	/* XXX: position and last_video? Need both? */
 	AudioBuffers _audio_buffers;
 	Time _last_video;
 	bool _last_was_black;
-	Time _last_audio;
+	Time _next_audio;
 };
 
 #endif
diff --git a/src/lib/sndfile_decoder.cc b/src/lib/sndfile_decoder.cc
index f114979de..0f2d54d15 100644
--- a/src/lib/sndfile_decoder.cc
+++ b/src/lib/sndfile_decoder.cc
@@ -113,3 +113,9 @@ SndfileDecoder::audio_frame_rate () const
 {
 	return _info.samplerate;
 }
+
+Time
+SndfileDecoder::next () const
+{
+	return _next_audio;
+}
diff --git a/src/lib/sndfile_decoder.h b/src/lib/sndfile_decoder.h
index 64bd2f7f5..35e50c629 100644
--- a/src/lib/sndfile_decoder.h
+++ b/src/lib/sndfile_decoder.h
@@ -30,6 +30,7 @@ public:
 	~SndfileDecoder ();
 
 	bool pass ();
+	Time next ();
 
 	int audio_channels () const;
 	ContentAudioFrame audio_length () const;
diff --git a/src/lib/video_content.h b/src/lib/video_content.h
index 67217e10c..8b0461e3f 100644
--- a/src/lib/video_content.h
+++ b/src/lib/video_content.h
@@ -37,6 +37,7 @@ public:
 class VideoContent : public virtual Content
 {
 public:
+	VideoContent (Time);
 	VideoContent (boost::filesystem::path);
 	VideoContent (boost::shared_ptr<const cxml::Node>);
 	VideoContent (VideoContent const &);
diff --git a/src/lib/video_decoder.cc b/src/lib/video_decoder.cc
index 0c8cda294..cb74a7987 100644
--- a/src/lib/video_decoder.cc
+++ b/src/lib/video_decoder.cc
@@ -34,9 +34,8 @@ using boost::optional;
 
 VideoDecoder::VideoDecoder (shared_ptr<const Film> f, shared_ptr<const VideoContent> c)
 	: Decoder (f)
+	, _next_video (0)
 	, _video_content (c)
-	, _video_frame (0)
-	, _last_content_time (0)
 {
 
 }
@@ -58,7 +57,8 @@ VideoDecoder::emit_video (shared_ptr<Image> image, bool same, Time t)
 	Video (image, same, sub, t);
 	++_video_frame;
 
-	_last_content_time = t;
+	/* XXX: who's doing skip / repeat? */
+	_next_video = t + _film->video_frames_to_time (1);
 }
 
 /** Set up the current subtitle.  This will be put onto frames that
@@ -76,13 +76,3 @@ VideoDecoder::emit_subtitle (shared_ptr<TimedSubtitle> s)
 		_timed_subtitle->subtitle()->set_position (Position (p.x - _video_content->crop().left, p.y - _video_content->crop().top));
 	}
 }
-
-void
-VideoDecoder::set_progress (Job* j) const
-{
-	assert (j);
-
-	if (_film->length()) {
-		j->set_progress (float (_video_frame) / _film->time_to_video_frames (_film->length()));
-	}
-}
diff --git a/src/lib/video_decoder.h b/src/lib/video_decoder.h
index 147dc60be..3a3bc252a 100644
--- a/src/lib/video_decoder.h
+++ b/src/lib/video_decoder.h
@@ -30,39 +30,24 @@ class VideoDecoder : public VideoSource, public virtual Decoder
 public:
 	VideoDecoder (boost::shared_ptr<const Film>, boost::shared_ptr<const VideoContent>);
 
+	/* Calls for VideoContent to find out about itself */
+
 	/** @return video frame rate second, or 0 if unknown */
 	virtual float video_frame_rate () const = 0;
-	/** @return native size in pixels */
-	virtual libdcp::Size native_size () const = 0;
+	/** @return video size in pixels */
+	virtual libdcp::Size video_size () const = 0;
 	/** @return length according to our content's header */
 	virtual ContentVideoFrame video_length () const = 0;
 
-	virtual int time_base_numerator () const = 0;
-	virtual int time_base_denominator () const = 0;
-	virtual int sample_aspect_ratio_numerator () const = 0;
-	virtual int sample_aspect_ratio_denominator () const = 0;
-
-	void set_progress (Job *) const;
-	
-	int video_frame () const {
-		return _video_frame;
-	}
-
-	Time last_content_time () const {
-		return _last_content_time;
-	}
-
 protected:
 	
-	virtual PixelFormat pixel_format () const = 0;
-
 	void emit_video (boost::shared_ptr<Image>, bool, Time);
 	void emit_subtitle (boost::shared_ptr<TimedSubtitle>);
 
+	Time _next_video;
+
 private:
 	boost::shared_ptr<const VideoContent> _video_content;
-	int _video_frame;
-	Time _last_content_time;
 	boost::shared_ptr<TimedSubtitle> _timed_subtitle;
 };
 
diff --git a/src/lib/video_source.h b/src/lib/video_source.h
index 7ad554480..0b0985c87 100644
--- a/src/lib/video_source.h
+++ b/src/lib/video_source.h
@@ -43,6 +43,7 @@ public:
 	 *  First parameter is the video image.
 	 *  Second parameter is true if the image is the same as the last one that was emitted.
 	 *  Third parameter is either 0 or a subtitle that should be on this frame.
+	 *  Fourth parameter is the time relative to the start of this source's content.
 	 */
 	boost::signals2::signal<void (boost::shared_ptr<const Image>, bool, boost::shared_ptr<Subtitle>, Time)> Video;