X-Git-Url: https://git.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fplayer.cc;h=dd064d3cdc221b44df74d32b958cf4ade2245e72;hb=65f95aa3614fc1b633c38e173349b123a191447f;hp=dffe7dbee52d3a7bde7372dde98464d9c8f99b2f;hpb=ee7d51a99b4bf09ae167f8d66683d80a1cb045f7;p=dcpomatic.git

diff --git a/src/lib/player.cc b/src/lib/player.cc
index dffe7dbee..dd064d3cd 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -87,7 +87,7 @@ Player::Player (shared_ptr<const Film> film, shared_ptr<const Playlist> playlist
 	, _always_burn_subtitles (false)
 	, _fast (false)
 	, _play_referenced (false)
-	, _audio_merger (_film->audio_channels(), _film->audio_frame_rate())
+	, _audio_merger (_film->audio_frame_rate())
 {
 	_film_changed_connection = _film->Changed.connect (bind (&Player::film_changed, this, _1));
 	_playlist_changed_connection = _playlist->Changed.connect (bind (&Player::playlist_changed, this));
@@ -143,8 +143,9 @@ Player::setup_pieces ()
 		}
 
 		if (decoder->subtitle) {
-			decoder->subtitle->ImageData.connect (bind (&Player::image_subtitle, this, weak_ptr<Piece> (piece), _1));
-			decoder->subtitle->TextData.connect (bind (&Player::text_subtitle, this, weak_ptr<Piece> (piece), _1));
+			decoder->subtitle->ImageStart.connect (bind (&Player::image_subtitle_start, this, weak_ptr<Piece> (piece), _1));
+			decoder->subtitle->TextStart.connect (bind (&Player::text_subtitle_start, this, weak_ptr<Piece> (piece), _1));
+			decoder->subtitle->Stop.connect (bind (&Player::subtitle_stop, this, weak_ptr<Piece> (piece), _1));
 		}
 	}
 
@@ -156,6 +157,22 @@ Player::setup_pieces ()
 		}
 	}
 
+	if (!_play_referenced) {
+		BOOST_FOREACH (shared_ptr<Piece> i, _pieces) {
+			shared_ptr<DCPContent> dc = dynamic_pointer_cast<DCPContent> (i->content);
+			if (dc) {
+				if (dc->reference_video()) {
+					_no_video.push_back (DCPTimePeriod (dc->position(), dc->end()));
+				}
+				if (dc->reference_audio()) {
+					_no_audio.push_back (DCPTimePeriod (dc->position(), dc->end()));
+				}
+			}
+		}
+	}
+
+	_last_video_time = optional<DCPTime> ();
+	_last_audio_time = optional<DCPTime> ();
 	_have_valid_pieces = true;
 }
 
@@ -212,10 +229,16 @@ Player::playlist_content_changed (weak_ptr<Content> w, int property, bool freque
 void
 Player::set_video_container_size (dcp::Size s)
 {
+	if (s == _video_container_size) {
+		return;
+	}
+
 	_video_container_size = s;
 
 	_black_image.reset (new Image (AV_PIX_FMT_RGB24, _video_container_size, true));
 	_black_image->make_black ();
+
+	Changed (false);
 }
 
 void
@@ -348,7 +371,7 @@ DCPTime
 Player::resampled_audio_to_dcp (shared_ptr<const Piece> piece, Frame f) const
 {
 	/* See comment in dcp_to_content_video */
-	DCPTime const d = DCPTime::from_frames (f, _film->audio_frame_rate()) - DCPTime (piece->content->trim_start (), piece->frc);
+	DCPTime const d = DCPTime::from_frames (f, _film->audio_frame_rate()) - DCPTime (piece->content->trim_start(), piece->frc);
 	return max (DCPTime (), d + piece->content->position ());
 }
 
@@ -394,13 +417,6 @@ Player::set_ignore_video ()
 	_ignore_video = true;
 }
 
-/** Set this player never to produce any audio data */
-void
-Player::set_ignore_audio ()
-{
-	_ignore_audio = true;
-}
-
 /** Set whether or not this player should always burn text subtitles into the image,
  *  regardless of the content settings.
  *  @param burn true to always burn subtitles, false to obey content settings.
@@ -491,23 +507,6 @@ Player::get_reel_assets ()
 	return a;
 }
 
-list<shared_ptr<Piece> >
-Player::overlaps (DCPTime from, DCPTime to, boost::function<bool (Content *)> valid)
-{
-	if (!_have_valid_pieces) {
-		setup_pieces ();
-	}
-
-	list<shared_ptr<Piece> > overlaps;
-	BOOST_FOREACH (shared_ptr<Piece> i, _pieces) {
-		if (valid (i->content.get ()) && i->content->position() < to && i->content->end() > from) {
-			overlaps.push_back (i);
-		}
-	}
-
-	return overlaps;
-}
-
 bool
 Player::pass ()
 {
@@ -528,34 +527,28 @@ Player::pass ()
 		}
 	}
 
-	if (!earliest) {
-		/* No more content; fill up to the length of our playlist with silent black */
-
-		DCPTime const length = _playlist->length ();
-
-		DCPTime const frame = DCPTime::from_frames (1, _film->video_frame_rate());
-		DCPTime from;
-		if (_last_time) {
-			from = _last_time.get() + frame;
-		}
-		for (DCPTime i = from; i < length; i += frame) {
-			Video (black_player_video_frame (), i);
+	if (earliest) {
+		earliest->done = earliest->decoder->pass ();
+		if (earliest->done && earliest->content->audio) {
+			/* Flush the Player audio system for this piece */
+			BOOST_FOREACH (AudioStreamPtr i, earliest->content->audio->streams()) {
+				audio_flush (earliest, i);
+			}
 		}
+	}
 
-		DCPTime t = _last_audio_time;
-		while (t < length) {
-			DCPTime block = min (DCPTime::from_seconds (0.5), length - t);
-			shared_ptr<AudioBuffers> silence (new AudioBuffers (_film->audio_channels(), block.frames_round(_film->audio_frame_rate())));
-			silence->make_silent ();
-			Audio (silence, t);
-			t += block;
-		}
+	if (_last_video_time) {
+		fill_video (DCPTimePeriod (_last_video_time.get(), earliest ? earliest_content : _playlist->length()));
+	} else if (_last_seek_time) {
+		fill_video (DCPTimePeriod (_last_seek_time.get(), _last_seek_time.get() + one_video_frame ()));
+	}
 
+	/* XXX: fill audio */
+
+	if (!earliest) {
 		return true;
 	}
 
-	earliest->done = earliest->decoder->pass ();
-
 	/* Emit any audio that is ready */
 
 	DCPTime pull_from = _playlist->length ();
@@ -565,27 +558,56 @@ Player::pass ()
 		}
 	}
 
-//	cout << "PULL " << to_string(pull_from) << "\n";
-	pair<shared_ptr<AudioBuffers>, DCPTime> audio = _audio_merger.pull (pull_from);
-	if (audio.first->frames() > 0) {
-		DCPOMATIC_ASSERT (audio.second >= _last_audio_time);
-		DCPTime t = _last_audio_time;
-		while (t < audio.second) {
-			/* Silence up to the time of this new audio */
-			DCPTime block = min (DCPTime::from_seconds (0.5), audio.second - t);
-			shared_ptr<AudioBuffers> silence (new AudioBuffers (_film->audio_channels(), block.frames_round(_film->audio_frame_rate())));
-			silence->make_silent ();
-			Audio (silence, t);
-			t += block;
+	list<pair<shared_ptr<AudioBuffers>, DCPTime> > audio = _audio_merger.pull (pull_from);
+	for (list<pair<shared_ptr<AudioBuffers>, DCPTime> >::iterator i = audio.begin(); i != audio.end(); ++i) {
+		if (_last_audio_time && i->second < _last_audio_time.get()) {
+			/* There has been an accurate seek and we have received some audio before the seek time;
+			   discard it.
+			*/
+			pair<shared_ptr<AudioBuffers>, DCPTime> cut = discard_audio (i->first, i->second, *_last_audio_time);
+			if (!cut.first) {
+				continue;
+			}
+			*i = cut;
 		}
 
-		Audio (audio.first, audio.second);
-		_last_audio_time = audio.second + DCPTime::from_frames(audio.first->frames(), _film->audio_frame_rate());
+		if (_last_audio_time) {
+			/* XXX: does this remain necessary? */
+			fill_audio (DCPTimePeriod (_last_audio_time.get(), i->second));
+		}
+
+		Audio (i->first, i->second);
+		_last_audio_time = i->second + DCPTime::from_frames(i->first->frames(), _film->audio_frame_rate());
 	}
 
 	return false;
 }
 
+optional<PositionImage>
+Player::subtitles_for_frame (DCPTime time) const
+{
+	list<PositionImage> subtitles;
+
+	BOOST_FOREACH (PlayerSubtitles i, _active_subtitles.get_burnt (time, _always_burn_subtitles)) {
+
+		/* Image subtitles */
+		list<PositionImage> c = transform_image_subtitles (i.image);
+		copy (c.begin(), c.end(), back_inserter (subtitles));
+
+		/* Text subtitles (rendered to an image) */
+		if (!i.text.empty ()) {
+			list<PositionImage> s = render_subtitles (i.text, i.fonts, _video_container_size, time);
+			copy (s.begin(), s.end(), back_inserter (subtitles));
+		}
+	}
+
+	if (subtitles.empty ()) {
+		return optional<PositionImage> ();
+	}
+
+	return merge (subtitles);
+}
+
 void
 Player::video (weak_ptr<Piece> wp, ContentVideo video)
 {
@@ -594,54 +616,25 @@ Player::video (weak_ptr<Piece> wp, ContentVideo video)
 		return;
 	}
 
-	/* Time and period of the frame we will emit */
-	DCPTime const time = content_video_to_dcp (piece, video.frame);
-	DCPTimePeriod const period (time, time + DCPTime::from_frames (1, _film->video_frame_rate()));
-
-	/* Discard if it's outside the content's period */
-	if (time < piece->content->position() || time >= piece->content->end()) {
+	FrameRateChange frc(piece->content->active_video_frame_rate(), _film->video_frame_rate());
+	if (frc.skip && (video.frame % 2) == 1) {
 		return;
 	}
 
-	/* Get any subtitles */
-
-	optional<PositionImage> subtitles;
-
-	for (list<pair<PlayerSubtitles, DCPTimePeriod> >::const_iterator i = _subtitles.begin(); i != _subtitles.end(); ++i) {
-
-		if (!i->second.overlap (period)) {
-			continue;
-		}
-
-		list<PositionImage> sub_images;
-
-		/* Image subtitles */
-		list<PositionImage> c = transform_image_subtitles (i->first.image);
-		copy (c.begin(), c.end(), back_inserter (sub_images));
-
-		/* Text subtitles (rendered to an image) */
-		if (!i->first.text.empty ()) {
-			list<PositionImage> s = render_subtitles (i->first.text, i->first.fonts, _video_container_size, time);
-			copy (s.begin (), s.end (), back_inserter (sub_images));
-		}
+	/* Time and period of the frame we will emit */
+	DCPTime const time = content_video_to_dcp (piece, video.frame);
+	DCPTimePeriod const period (time, time + one_video_frame());
 
-		if (!sub_images.empty ()) {
-			subtitles = merge (sub_images);
-		}
+	/* Discard if it's outside the content's period or if it's before the last accurate seek */
+	if (time < piece->content->position() || time >= piece->content->end() || (_last_video_time && time < _last_video_time)) {
+		return;
 	}
 
-	/* Fill gaps */
+	/* Fill gaps caused by (the hopefully rare event of) a decoder not emitting contiguous video */
 
-	if (_last_time) {
-		/* XXX: this may not work for 3D */
-		DCPTime const frame = DCPTime::from_frames (1, _film->video_frame_rate());
-		for (DCPTime i = _last_time.get() + frame; i < time; i += frame) {
-			if (_playlist->video_content_at(i) && _last_video) {
-				Video (shared_ptr<PlayerVideo> (new PlayerVideo (*_last_video)), i);
-			} else {
-				Video (black_player_video_frame (), i);
-			}
-		}
+	/* XXX: is this necessary? can it be done by the fill in pass? */
+	if (_last_video_time) {
+		fill_video (DCPTimePeriod (_last_video_time.get(), time));
 	}
 
 	_last_video.reset (
@@ -659,75 +652,60 @@ Player::video (weak_ptr<Piece> wp, ContentVideo video)
 			)
 		);
 
+	optional<PositionImage> subtitles = subtitles_for_frame (time);
 	if (subtitles) {
 		_last_video->set_subtitle (subtitles.get ());
 	}
 
-	_last_time = time;
-
-	Video (_last_video, *_last_time);
-
-	/* Discard any subtitles we no longer need */
+	Video (_last_video, time);
 
-	for (list<pair<PlayerSubtitles, DCPTimePeriod> >::iterator i = _subtitles.begin (); i != _subtitles.end(); ) {
-		list<pair<PlayerSubtitles, DCPTimePeriod> >::iterator tmp = i;
-		++tmp;
+	_last_video_time = time + one_video_frame ();
 
-		if (i->second.to < time) {
-			_subtitles.erase (i);
-		}
-
-		i = tmp;
-	}
+	_active_subtitles.clear_before (time);
 }
 
 void
-Player::audio (weak_ptr<Piece> wp, AudioStreamPtr stream, ContentAudio content_audio)
+Player::audio_flush (shared_ptr<Piece> piece, AudioStreamPtr stream)
 {
-	shared_ptr<Piece> piece = wp.lock ();
-	if (!piece) {
-		return;
-	}
-
 	shared_ptr<AudioContent> content = piece->content->audio;
 	DCPOMATIC_ASSERT (content);
 
-	/* Gain */
-	if (content->gain() != 0) {
-		shared_ptr<AudioBuffers> gain (new AudioBuffers (content_audio.audio));
-		gain->apply_gain (content->gain ());
-		content_audio.audio = gain;
+	shared_ptr<Resampler> r = resampler (content, stream, false);
+	if (!r) {
+		return;
 	}
 
-	/* Resample */
-	if (stream->frame_rate() != content->resampled_frame_rate()) {
-		shared_ptr<Resampler> r = resampler (content, stream, true);
-		pair<shared_ptr<const AudioBuffers>, Frame> ro = r->run (content_audio.audio, content_audio.frame);
-		content_audio.audio = ro.first;
-		content_audio.frame = ro.second;
+	pair<shared_ptr<const AudioBuffers>, Frame> ro = r->flush ();
+	if (ro.first->frames() == 0) {
+		return;
 	}
 
-	/* XXX: end-trimming used to be checked here */
+	ContentAudio content_audio;
+	content_audio.audio = ro.first;
+	content_audio.frame = ro.second;
 
 	/* Compute time in the DCP */
 	DCPTime time = resampled_audio_to_dcp (piece, content_audio.frame) + DCPTime::from_seconds (content->delay() / 1000.0);
 
-	/* Remove anything that comes before the start of the content */
-	if (time < piece->content->position()) {
-		DCPTime const discard_time = piece->content->position() - time;
-		Frame discard_frames = discard_time.frames_round(_film->audio_frame_rate());
-		Frame remaining_frames = content_audio.audio->frames() - discard_frames;
-		if (remaining_frames <= 0) {
-			/* This audio is entirely discarded */
-			return;
-		}
-		shared_ptr<AudioBuffers> cut (new AudioBuffers (content_audio.audio->channels(), remaining_frames));
-		cut->copy_from (content_audio.audio.get(), remaining_frames, discard_frames, 0);
-		content_audio.audio = cut;
-		time += discard_time;
+	audio_transform (content, stream, content_audio, time);
+}
+
+/** Do our common processing on some audio */
+void
+Player::audio_transform (shared_ptr<AudioContent> content, AudioStreamPtr stream, ContentAudio content_audio, DCPTime time)
+{
+	DCPOMATIC_ASSERT (content_audio.audio->frames() > 0);
+
+	/* Gain */
+
+	if (content->gain() != 0) {
+		shared_ptr<AudioBuffers> gain (new AudioBuffers (content_audio.audio));
+		gain->apply_gain (content->gain ());
+		content_audio.audio = gain;
 	}
 
-	/* Remap channels */
+	/* Remap */
+
 	shared_ptr<AudioBuffers> dcp_mapped (new AudioBuffers (_film->audio_channels(), content_audio.audio->frames()));
 	dcp_mapped->make_silent ();
 
@@ -747,19 +725,73 @@ Player::audio (weak_ptr<Piece> wp, AudioStreamPtr stream, ContentAudio content_a
 
 	content_audio.audio = dcp_mapped;
 
+	/* Process */
+
 	if (_audio_processor) {
 		content_audio.audio = _audio_processor->run (content_audio.audio, _film->audio_channels ());
 	}
 
-//	cout << "PUSH " << content_audio.audio->frames() << " @ " << to_string(time) << "\n";
-	_audio_merger.push (content_audio.audio, time);
+	/* Push */
 
+	_audio_merger.push (content_audio.audio, time);
 	DCPOMATIC_ASSERT (_stream_states.find (stream) != _stream_states.end ());
 	_stream_states[stream].last_push_end = time + DCPTime::from_frames (content_audio.audio->frames(), _film->audio_frame_rate());
 }
 
 void
-Player::image_subtitle (weak_ptr<Piece> wp, ContentImageSubtitle subtitle)
+Player::audio (weak_ptr<Piece> wp, AudioStreamPtr stream, ContentAudio content_audio)
+{
+	DCPOMATIC_ASSERT (content_audio.audio->frames() > 0);
+
+	shared_ptr<Piece> piece = wp.lock ();
+	if (!piece) {
+		return;
+	}
+
+	shared_ptr<AudioContent> content = piece->content->audio;
+	DCPOMATIC_ASSERT (content);
+
+	/* Resample */
+	if (stream->frame_rate() != content->resampled_frame_rate()) {
+		shared_ptr<Resampler> r = resampler (content, stream, true);
+		pair<shared_ptr<const AudioBuffers>, Frame> ro = r->run (content_audio.audio, content_audio.frame);
+		if (ro.first->frames() == 0) {
+			return;
+		}
+		content_audio.audio = ro.first;
+		content_audio.frame = ro.second;
+	}
+
+	/* Compute time in the DCP */
+	DCPTime time = resampled_audio_to_dcp (piece, content_audio.frame) + DCPTime::from_seconds (content->delay() / 1000.0);
+	/* And the end of this block in the DCP */
+	DCPTime end = time + DCPTime::from_frames(content_audio.audio->frames(), content->resampled_frame_rate());
+
+	/* Remove anything that comes before the start or after the end of the content */
+	if (time < piece->content->position()) {
+		pair<shared_ptr<AudioBuffers>, DCPTime> cut = discard_audio (content_audio.audio, time, piece->content->position());
+		if (!cut.first) {
+			/* This audio is entirely discarded */
+			return;
+		}
+		content_audio.audio = cut.first;
+		time = cut.second;
+	} else if (time > piece->content->end()) {
+		/* Discard it all */
+		return;
+	} else if (end > piece->content->end()) {
+		Frame const remaining_frames = DCPTime(piece->content->end() - time).frames_round(_film->audio_frame_rate());
+		DCPOMATIC_ASSERT (remaining_frames > 0);
+		shared_ptr<AudioBuffers> cut (new AudioBuffers (content_audio.audio->channels(), remaining_frames));
+		cut->copy_from (content_audio.audio.get(), remaining_frames, 0, 0);
+		content_audio.audio = cut;
+	}
+
+	audio_transform (content, stream, content_audio, time);
+}
+
+void
+Player::image_subtitle_start (weak_ptr<Piece> wp, ContentImageSubtitle subtitle)
 {
 	shared_ptr<Piece> piece = wp.lock ();
 	if (!piece) {
@@ -780,17 +812,13 @@ Player::image_subtitle (weak_ptr<Piece> wp, ContentImageSubtitle subtitle)
 
 	PlayerSubtitles ps;
 	ps.image.push_back (subtitle.sub);
-	DCPTimePeriod period (content_time_to_dcp (piece, subtitle.period().from), content_time_to_dcp (piece, subtitle.period().to));
+	DCPTime from (content_time_to_dcp (piece, subtitle.from()));
 
-	if (piece->content->subtitle->use() && (piece->content->subtitle->burn() || _always_burn_subtitles)) {
-		_subtitles.push_back (make_pair (ps, period));
-	} else {
-		Subtitle (ps, period);
-	}
+	_active_subtitles.add_from (wp, ps, from);
 }
 
 void
-Player::text_subtitle (weak_ptr<Piece> wp, ContentTextSubtitle subtitle)
+Player::text_subtitle_start (weak_ptr<Piece> wp, ContentTextSubtitle subtitle)
 {
 	shared_ptr<Piece> piece = wp.lock ();
 	if (!piece) {
@@ -798,7 +826,7 @@ Player::text_subtitle (weak_ptr<Piece> wp, ContentTextSubtitle subtitle)
 	}
 
 	PlayerSubtitles ps;
-	DCPTimePeriod const period (content_time_to_dcp (piece, subtitle.period().from), content_time_to_dcp (piece, subtitle.period().to));
+	DCPTime const from (content_time_to_dcp (piece, subtitle.from()));
 
 	BOOST_FOREACH (dcp::SubtitleString s, subtitle.subs) {
 		s.set_h_position (s.h_position() + piece->content->subtitle->x_offset ());
@@ -820,34 +848,74 @@ Player::text_subtitle (weak_ptr<Piece> wp, ContentTextSubtitle subtitle)
 			s.set_aspect_adjust (xs / ys);
 		}
 
-		s.set_in (dcp::Time(period.from.seconds(), 1000));
-		s.set_out (dcp::Time(period.to.seconds(), 1000));
+		s.set_in (dcp::Time(from.seconds(), 1000));
 		ps.text.push_back (SubtitleString (s, piece->content->subtitle->outline_width()));
 		ps.add_fonts (piece->content->subtitle->fonts ());
 	}
 
-	if (piece->content->subtitle->use() && (piece->content->subtitle->burn() || _always_burn_subtitles)) {
-		_subtitles.push_back (make_pair (ps, period));
-	} else {
-		Subtitle (ps, period);
+	_active_subtitles.add_from (wp, ps, from);
+}
+
+void
+Player::subtitle_stop (weak_ptr<Piece> wp, ContentTime to)
+{
+	if (!_active_subtitles.have (wp)) {
+		return;
+	}
+
+	shared_ptr<Piece> piece = wp.lock ();
+	if (!piece) {
+		return;
+	}
+
+	DCPTime const dcp_to = content_time_to_dcp (piece, to);
+
+	pair<PlayerSubtitles, DCPTime> from = _active_subtitles.add_to (wp, dcp_to);
+
+	if (piece->content->subtitle->use() && !_always_burn_subtitles && !piece->content->subtitle->burn()) {
+		Subtitle (from.first, DCPTimePeriod (from.second, dcp_to));
 	}
 }
 
 void
 Player::seek (DCPTime time, bool accurate)
 {
+	if (_audio_processor) {
+		_audio_processor->flush ();
+	}
+
+	for (ResamplerMap::iterator i = _resamplers.begin(); i != _resamplers.end(); ++i) {
+		i->second->flush ();
+		i->second->reset ();
+	}
+
+	_audio_merger.clear ();
+	_active_subtitles.clear ();
+
 	BOOST_FOREACH (shared_ptr<Piece> i, _pieces) {
-		if (i->content->position() <= time && time < i->content->end()) {
+		if (time < i->content->position()) {
+			/* Before; seek to 0 */
+			i->decoder->seek (ContentTime(), accurate);
+			i->done = false;
+		} else if (i->content->position() <= time && time < i->content->end()) {
+			/* During; seek to position */
 			i->decoder->seek (dcp_to_content_time (i, time), accurate);
 			i->done = false;
+		} else {
+			/* After; this piece is done */
+			i->done = true;
 		}
 	}
 
 	if (accurate) {
-		_last_time = time - DCPTime::from_frames (1, _film->video_frame_rate ());
+		_last_video_time = time;
+		_last_audio_time = time;
 	} else {
-		_last_time = optional<DCPTime> ();
+		_last_video_time = optional<DCPTime> ();
+		_last_audio_time = optional<DCPTime> ();
 	}
+
+	_last_seek_time = time;
 }
 
 shared_ptr<Resampler>
@@ -876,3 +944,62 @@ Player::resampler (shared_ptr<const AudioContent> content, AudioStreamPtr stream
 	_resamplers[make_pair(content, stream)] = r;
 	return r;
 }
+
+void
+Player::fill_video (DCPTimePeriod period)
+{
+	/* XXX: this may not work for 3D */
+	BOOST_FOREACH (DCPTimePeriod i, subtract(period, _no_video)) {
+		for (DCPTime j = i.from; j < i.to; j += one_video_frame()) {
+			if (_playlist->video_content_at(j) && _last_video) {
+				Video (shared_ptr<PlayerVideo> (new PlayerVideo (*_last_video)), j);
+			} else {
+				shared_ptr<PlayerVideo> black = black_player_video_frame ();
+				optional<PositionImage> subtitles = subtitles_for_frame (j);
+				if (subtitles) {
+					black->set_subtitle (subtitles.get ());
+				}
+				Video (black, j);
+			}
+			_last_video_time = j;
+		}
+	}
+}
+
+void
+Player::fill_audio (DCPTimePeriod period)
+{
+	BOOST_FOREACH (DCPTimePeriod i, subtract(period, _no_audio)) {
+		DCPTime t = i.from;
+		while (t < i.to) {
+			DCPTime block = min (DCPTime::from_seconds (0.5), i.to - t);
+			Frame const samples = block.frames_round(_film->audio_frame_rate());
+			if (samples) {
+				shared_ptr<AudioBuffers> silence (new AudioBuffers (_film->audio_channels(), samples));
+				silence->make_silent ();
+				Audio (silence, t);
+			}
+			t += block;
+		}
+	}
+}
+
+DCPTime
+Player::one_video_frame () const
+{
+	return DCPTime::from_frames (1, _film->video_frame_rate ());
+}
+
+pair<shared_ptr<AudioBuffers>, DCPTime>
+Player::discard_audio (shared_ptr<const AudioBuffers> audio, DCPTime time, DCPTime discard_to) const
+{
+	DCPTime const discard_time = discard_to - time;
+	Frame const discard_frames = discard_time.frames_round(_film->audio_frame_rate());
+	Frame remaining_frames = audio->frames() - discard_frames;
+	if (remaining_frames <= 0) {
+		return make_pair(shared_ptr<AudioBuffers>(), DCPTime());
+	}
+	shared_ptr<AudioBuffers> cut (new AudioBuffers (audio->channels(), remaining_frames));
+	cut->copy_from (audio.get(), remaining_frames, discard_frames, 0);
+	return make_pair(cut, time + discard_time);
+}