X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fplayer.cc;h=70d6fa8773a445977da35edd2d2b286a042221dd;hb=56139fd8f98ad306c32567c4b8070fe7ff18ab1e;hp=6b7dc27223938e3faa0460eaf83a8af3d5ca160c;hpb=764dfcd5aea143d1246873667e646f86d99e33a4;p=dcpomatic.git

diff --git a/src/lib/player.cc b/src/lib/player.cc
index 6b7dc2722..70d6fa877 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -22,15 +22,20 @@
 #include "film.h"
 #include "ffmpeg_decoder.h"
 #include "ffmpeg_content.h"
-#include "imagemagick_decoder.h"
-#include "imagemagick_content.h"
+#include "still_image_decoder.h"
+#include "still_image_content.h"
+#include "moving_image_decoder.h"
+#include "moving_image_content.h"
 #include "sndfile_decoder.h"
 #include "sndfile_content.h"
+#include "subtitle_content.h"
 #include "playlist.h"
 #include "job.h"
 #include "image.h"
 #include "ratio.h"
 #include "resampler.h"
+#include "log.h"
+#include "scaler.h"
 
 using std::list;
 using std::cout;
@@ -43,22 +48,22 @@ using boost::shared_ptr;
 using boost::weak_ptr;
 using boost::dynamic_pointer_cast;
 
-#define DEBUG_PLAYER 1
+//#define DEBUG_PLAYER 1
 
 class Piece
 {
 public:
 	Piece (shared_ptr<Content> c)
 		: content (c)
-		, video_position (c->start ())
-		, audio_position (c->start ())
+		, video_position (c->position ())
+		, audio_position (c->position ())
 	{}
 	
 	Piece (shared_ptr<Content> c, shared_ptr<Decoder> d)
 		: content (c)
 		, decoder (d)
-		, video_position (c->start ())
-		, audio_position (c->start ())
+		, video_position (c->position ())
+		, audio_position (c->position ())
 	{}
 	
 	shared_ptr<Content> content;
@@ -71,14 +76,14 @@ public:
 std::ostream& operator<<(std::ostream& s, Piece const & p)
 {
 	if (dynamic_pointer_cast<FFmpegContent> (p.content)) {
-		s << "\tffmpeg     ";
-	} else if (dynamic_pointer_cast<ImageMagickContent> (p.content)) {
-		s << "\timagemagick";
+		s << "\tffmpeg	   ";
+	} else if (dynamic_pointer_cast<StillImageContent> (p.content)) {
+		s << "\tstill image";
 	} else if (dynamic_pointer_cast<SndfileContent> (p.content)) {
-		s << "\tsndfile    ";
+		s << "\tsndfile	   ";
 	}
 	
-	s << " at " << p.content->start() << " until " << p.content->end();
+	s << " at " << p.content->position() << " until " << p.content->end();
 	
 	return s;
 }
@@ -92,11 +97,12 @@ Player::Player (shared_ptr<const Film> f, shared_ptr<const Playlist> p)
 	, _have_valid_pieces (false)
 	, _video_position (0)
 	, _audio_position (0)
-	, _audio_buffers (f->dcp_audio_channels(), 0)
+	, _audio_merger (f->audio_channels(), bind (&Film::time_to_audio_frames, f.get(), _1), bind (&Film::audio_frames_to_time, f.get(), _1))
+	, _last_emit_was_black (false)
 {
-	_playlist->Changed.connect (bind (&Player::playlist_changed, this));
-	_playlist->ContentChanged.connect (bind (&Player::content_changed, this, _1, _2));
-	_film->Changed.connect (bind (&Player::film_changed, this, _1));
+	_playlist_changed_connection = _playlist->Changed.connect (bind (&Player::playlist_changed, this));
+	_playlist_content_changed_connection = _playlist->ContentChanged.connect (bind (&Player::content_changed, this, _1, _2, _3));
+	_film_changed_connection = _film->Changed.connect (bind (&Player::film_changed, this, _1));
 	set_video_container_size (_film->container()->size (_film->full_frame ()));
 }
 
@@ -124,8 +130,8 @@ Player::pass ()
 	cout << "= PASS\n";
 #endif	
 
-        Time earliest_t = TIME_MAX;
-        shared_ptr<Piece> earliest;
+	Time earliest_t = TIME_MAX;
+	shared_ptr<Piece> earliest;
 	enum {
 		VIDEO,
 		AUDIO
@@ -136,7 +142,7 @@ Player::pass ()
 			continue;
 		}
 
-		if (dynamic_pointer_cast<VideoDecoder> ((*i)->decoder)) {
+		if (_video && dynamic_pointer_cast<VideoDecoder> ((*i)->decoder)) {
 			if ((*i)->video_position < earliest_t) {
 				earliest_t = (*i)->video_position;
 				earliest = *i;
@@ -144,7 +150,7 @@ Player::pass ()
 			}
 		}
 
-		if (dynamic_pointer_cast<AudioDecoder> ((*i)->decoder)) {
+		if (_audio && dynamic_pointer_cast<AudioDecoder> ((*i)->decoder)) {
 			if ((*i)->audio_position < earliest_t) {
 				earliest_t = (*i)->audio_position;
 				earliest = *i;
@@ -166,12 +172,12 @@ Player::pass ()
 	case VIDEO:
 		if (earliest_t > _video_position) {
 #ifdef DEBUG_PLAYER
-			cout << "no video here; emitting black frame.\n";
+			cout << "no video here; emitting black frame (earliest=" << earliest_t << ", video_position=" << _video_position << ").\n";
 #endif
 			emit_black ();
 		} else {
 #ifdef DEBUG_PLAYER
-			cout << "Pass " << *earliest << "\n";
+			cout << "Pass video " << *earliest << "\n";
 #endif			
 			earliest->decoder->pass ();
 		}
@@ -180,27 +186,52 @@ Player::pass ()
 	case AUDIO:
 		if (earliest_t > _audio_position) {
 #ifdef DEBUG_PLAYER
-			cout << "no audio here; emitting silence.\n";
+			cout << "no audio here (none until " << earliest_t << "); emitting silence.\n";
 #endif
 			emit_silence (_film->time_to_audio_frames (earliest_t - _audio_position));
 		} else {
 #ifdef DEBUG_PLAYER
-			cout << "Pass " << *earliest << "\n";
-#endif			
+			cout << "Pass audio " << *earliest << "\n";
+#endif
 			earliest->decoder->pass ();
+
+			if (earliest->decoder->done()) {
+				shared_ptr<AudioContent> ac = dynamic_pointer_cast<AudioContent> (earliest->content);
+				assert (ac);
+				shared_ptr<Resampler> re = resampler (ac, false);
+				if (re) {
+					shared_ptr<const AudioBuffers> b = re->flush ();
+					if (b->frames ()) {
+						process_audio (earliest, b, ac->audio_length ());
+					}
+				}
+			}
 		}
 		break;
 	}
 
+	if (_audio) {
+		Time audio_done_up_to = TIME_MAX;
+		for (list<shared_ptr<Piece> >::iterator i = _pieces.begin(); i != _pieces.end(); ++i) {
+			if (dynamic_pointer_cast<AudioDecoder> ((*i)->decoder)) {
+				audio_done_up_to = min (audio_done_up_to, (*i)->audio_position);
+			}
+		}
+
+		TimedAudioBuffers<Time> tb = _audio_merger.pull (audio_done_up_to);
+		Audio (tb.audio, tb.time);
+		_audio_position += _film->audio_frames_to_time (tb.audio->frames ());
+	}
+		
 #ifdef DEBUG_PLAYER
-	cout << "\tpost pass " << _video_position << " " << _audio_position << "\n";
+	cout << "\tpost pass _video_position=" << _video_position << " _audio_position=" << _audio_position << "\n";
 #endif	
 
-        return false;
+	return false;
 }
 
 void
-Player::process_video (weak_ptr<Piece> weak_piece, shared_ptr<const Image> image, bool same, VideoContent::Frame frame)
+Player::process_video (weak_ptr<Piece> weak_piece, shared_ptr<const Image> image, Eyes eyes, bool same, VideoContent::Frame frame)
 {
 	shared_ptr<Piece> piece = weak_piece.lock ();
 	if (!piece) {
@@ -210,56 +241,54 @@ Player::process_video (weak_ptr<Piece> weak_piece, shared_ptr<const Image> image
 	shared_ptr<VideoContent> content = dynamic_pointer_cast<VideoContent> (piece->content);
 	assert (content);
 
-	FrameRateConversion frc (content->video_frame_rate(), _film->dcp_video_frame_rate());
+	FrameRateConversion frc (content->video_frame_rate(), _film->video_frame_rate());
 	if (frc.skip && (frame % 2) == 1) {
 		return;
 	}
 
-	image = image->crop (content->crop(), true);
+	Time const relative_time = (frame * frc.factor() * TIME_HZ / _film->video_frame_rate());
+	if (content->trimmed (relative_time)) {
+		return;
+	}
+
+	/* Convert to RGB first, as FFmpeg doesn't seem to like handling YUV images with odd widths */
+	shared_ptr<Image> work_image = image->scale (image->size (), _film->scaler(), PIX_FMT_RGB24, true);
+
+	work_image = work_image->crop (content->crop(), true);
 
 	libdcp::Size const image_size = content->ratio()->size (_video_container_size);
 	
-	image = image->scale_and_convert_to_rgb (image_size, _film->scaler(), true);
+	work_image = work_image->scale (image_size, _film->scaler(), PIX_FMT_RGB24, true);
 
-#if 0	
-	if (film->with_subtitles ()) {
-		shared_ptr<Subtitle> sub;
-		if (_timed_subtitle && _timed_subtitle->displayed_at (t)) {
-			sub = _timed_subtitle->subtitle ();
-		}
-		
-		if (sub) {
-			dcpomatic::Rect const tx = subtitle_transformed_area (
-				float (image_size.width) / content->video_size().width,
-				float (image_size.height) / content->video_size().height,
-				sub->area(), film->subtitle_offset(), film->subtitle_scale()
-				);
-			
-			shared_ptr<Image> im = sub->image()->scale (tx.size(), film->scaler(), true);
-			image->alpha_blend (im, tx.position());
-		}
+	Time time = content->position() + relative_time - content->trim_start ();
+	    
+	if (_film->with_subtitles () && _out_subtitle.image && time >= _out_subtitle.from && time <= _out_subtitle.to) {
+		work_image->alpha_blend (_out_subtitle.image, _out_subtitle.position);
 	}
-#endif	
 
 	if (image_size != _video_container_size) {
 		assert (image_size.width <= _video_container_size.width);
 		assert (image_size.height <= _video_container_size.height);
-		shared_ptr<Image> im (new SimpleImage (PIX_FMT_RGB24, _video_container_size, true));
+		shared_ptr<Image> im (new Image (PIX_FMT_RGB24, _video_container_size, true));
 		im->make_black ();
-		im->copy (image, Position ((_video_container_size.width - image_size.width) / 2, (_video_container_size.height - image_size.height) / 2));
-		image = im;
+		im->copy (work_image, Position<int> ((_video_container_size.width - image_size.width) / 2, (_video_container_size.height - image_size.height) / 2));
+		work_image = im;
 	}
 
-	Time time = content->start() + (frame * frc.factor() * TIME_HZ / _film->dcp_video_frame_rate());
-	
-        Video (image, same, time);
-	time += TIME_HZ / _film->dcp_video_frame_rate();
+#ifdef DCPOMATIC_DEBUG
+	_last_video = piece->content;
+#endif
+
+	Video (work_image, eyes, content->colour_conversion(), same, time);
+	time += TIME_HZ / _film->video_frame_rate();
 
 	if (frc.repeat) {
-		Video (image, true, time);
-		time += TIME_HZ / _film->dcp_video_frame_rate();
+		Video (work_image, eyes, content->colour_conversion(), true, time);
+		time += TIME_HZ / _film->video_frame_rate();
 	}
 
+	_last_emit_was_black = false;
+
 	_video_position = piece->video_position = time;
 }
 
@@ -274,57 +303,66 @@ Player::process_audio (weak_ptr<Piece> weak_piece, shared_ptr<const AudioBuffers
 	shared_ptr<AudioContent> content = dynamic_pointer_cast<AudioContent> (piece->content);
 	assert (content);
 
+	/* Gain */
+	if (content->audio_gain() != 0) {
+		shared_ptr<AudioBuffers> gain (new AudioBuffers (audio));
+		gain->apply_gain (content->audio_gain ());
+		audio = gain;
+	}
+
+	/* Resample */
 	if (content->content_audio_frame_rate() != content->output_audio_frame_rate()) {
-		audio = resampler(content)->run (audio);
+		shared_ptr<Resampler> r = resampler (content, true);
+		pair<shared_ptr<const AudioBuffers>, AudioContent::Frame> ro = r->run (audio, frame);
+		audio = ro.first;
+		frame = ro.second;
+	}
+	
+	Time const relative_time = _film->audio_frames_to_time (frame);
+
+	if (content->trimmed (relative_time)) {
+		return;
 	}
 
+	Time time = content->position() + (content->audio_delay() * TIME_HZ / 1000) + relative_time;
+	
 	/* Remap channels */
-	shared_ptr<AudioBuffers> dcp_mapped (new AudioBuffers (_film->dcp_audio_channels(), audio->frames()));
+	shared_ptr<AudioBuffers> dcp_mapped (new AudioBuffers (_film->audio_channels(), audio->frames()));
 	dcp_mapped->make_silent ();
 	list<pair<int, libdcp::Channel> > map = content->audio_mapping().content_to_dcp ();
 	for (list<pair<int, libdcp::Channel> >::iterator i = map.begin(); i != map.end(); ++i) {
-		dcp_mapped->accumulate_channel (audio.get(), i->first, i->second);
+		if (i->first < audio->channels() && i->second < dcp_mapped->channels()) {
+			dcp_mapped->accumulate_channel (audio.get(), i->first, i->second);
+		}
 	}
 
 	audio = dcp_mapped;
 
-        /* The time of this audio may indicate that some of our buffered audio is not going to
-           be added to any more, so it can be emitted.
-        */
-
-	Time const time = content->start() + (frame * TIME_HZ / _film->dcp_audio_frame_rate());
-
-        if (time > _audio_position) {
-                /* We can emit some audio from our buffers */
-                OutputAudioFrame const N = _film->time_to_audio_frames (time - _audio_position);
-		assert (N <= _audio_buffers.frames());
-                shared_ptr<AudioBuffers> emit (new AudioBuffers (_audio_buffers.channels(), N));
-                emit->copy_from (&_audio_buffers, N, 0, 0);
-                Audio (emit, _audio_position);
-                _audio_position = piece->audio_position = time + _film->audio_frames_to_time (N);
-
-                /* And remove it from our buffers */
-                if (_audio_buffers.frames() > N) {
-                        _audio_buffers.move (N, 0, _audio_buffers.frames() - N);
-                }
-                _audio_buffers.set_frames (_audio_buffers.frames() - N);
-        }
-
-        /* Now accumulate the new audio into our buffers */
-        _audio_buffers.ensure_size (_audio_buffers.frames() + audio->frames());
-        _audio_buffers.accumulate_frames (audio.get(), 0, 0, audio->frames ());
-	_audio_buffers.set_frames (_audio_buffers.frames() + audio->frames());
+	/* We must cut off anything that comes before the start of all time */
+	if (time < 0) {
+		int const frames = - time * _film->audio_frame_rate() / TIME_HZ;
+		if (frames >= audio->frames ()) {
+			return;
+		}
+
+		shared_ptr<AudioBuffers> trimmed (new AudioBuffers (audio->channels(), audio->frames() - frames));
+		trimmed->copy_from (audio.get(), audio->frames() - frames, frames, 0);
+
+		audio = trimmed;
+		time = 0;
+	}
+
+	_audio_merger.push (audio, time);
+	piece->audio_position += _film->audio_frames_to_time (audio->frames ());
 }
 
 void
 Player::flush ()
 {
-	if (_audio_buffers.frames() > 0) {
-		shared_ptr<AudioBuffers> emit (new AudioBuffers (_audio_buffers.channels(), _audio_buffers.frames()));
-		emit->copy_from (&_audio_buffers, _audio_buffers.frames(), 0, 0);
-		Audio (emit, _audio_position);
-		_audio_position += _film->audio_frames_to_time (_audio_buffers.frames ());
-		_audio_buffers.set_frames (0);
+	TimedAudioBuffers<Time> tb = _audio_merger.flush ();
+	if (tb.audio) {
+		Audio (tb.audio, tb.time);
+		_audio_position += _film->audio_frames_to_time (tb.audio->frames ());
 	}
 
 	while (_video_position < _audio_position) {
@@ -337,7 +375,10 @@ Player::flush ()
 	
 }
 
-/** @return true on error */
+/** Seek so that the next pass() will yield (approximately) the requested frame.
+ *  Pass accurate = true to try harder to get close to the request.
+ *  @return true on error
+ */
 void
 Player::seek (Time t, bool accurate)
 {
@@ -356,15 +397,23 @@ Player::seek (Time t, bool accurate)
 			continue;
 		}
 		
-		Time s = t - vc->start ();
+		Time s = t - vc->position ();
 		s = max (static_cast<Time> (0), s);
-		s = min (vc->length(), s);
+		s = min (vc->length_after_trim(), s);
 
-		FrameRateConversion frc (vc->video_frame_rate(), _film->dcp_video_frame_rate());
-		VideoContent::Frame f = s * vc->video_frame_rate() / (frc.factor() * TIME_HZ);
+		(*i)->video_position = (*i)->audio_position = vc->position() + s;
+
+		FrameRateConversion frc (vc->video_frame_rate(), _film->video_frame_rate());
+		/* Here we are converting from time (in the DCP) to a frame number in the content.
+		   Hence we need to use the DCP's frame rate and the double/skip correction, not
+		   the source's rate.
+		*/
+		VideoContent::Frame f = (s + vc->trim_start ()) * _film->video_frame_rate() / (frc.factor() * TIME_HZ);
 		dynamic_pointer_cast<VideoDecoder>((*i)->decoder)->seek (f, accurate);
 	}
 
+	_video_position = _audio_position = t;
+	
 	/* XXX: don't seek audio because we don't need to... */
 }
 
@@ -375,45 +424,58 @@ Player::setup_pieces ()
 
 	_pieces.clear ();
 
-	Playlist::ContentList content = _playlist->content ();
+	ContentList content = _playlist->content ();
 	sort (content.begin(), content.end(), ContentSorter ());
 
-	for (Playlist::ContentList::iterator i = content.begin(); i != content.end(); ++i) {
+	for (ContentList::iterator i = content.begin(); i != content.end(); ++i) {
 
 		shared_ptr<Piece> piece (new Piece (*i));
 
-                /* XXX: into content? */
+		/* XXX: into content? */
 
 		shared_ptr<const FFmpegContent> fc = dynamic_pointer_cast<const FFmpegContent> (*i);
 		if (fc) {
 			shared_ptr<FFmpegDecoder> fd (new FFmpegDecoder (_film, fc, _video, _audio));
 			
-			fd->Video.connect (bind (&Player::process_video, this, piece, _1, _2, _3));
+			fd->Video.connect (bind (&Player::process_video, this, piece, _1, _2, _3, _4));
 			fd->Audio.connect (bind (&Player::process_audio, this, piece, _1, _2));
+			fd->Subtitle.connect (bind (&Player::process_subtitle, this, piece, _1, _2, _3, _4));
 
 			piece->decoder = fd;
 		}
 		
-		shared_ptr<const ImageMagickContent> ic = dynamic_pointer_cast<const ImageMagickContent> (*i);
+		shared_ptr<const StillImageContent> ic = dynamic_pointer_cast<const StillImageContent> (*i);
 		if (ic) {
-			shared_ptr<ImageMagickDecoder> id;
+			shared_ptr<StillImageDecoder> id;
 			
-			/* See if we can re-use an old ImageMagickDecoder */
+			/* See if we can re-use an old StillImageDecoder */
 			for (list<shared_ptr<Piece> >::const_iterator j = old_pieces.begin(); j != old_pieces.end(); ++j) {
-				shared_ptr<ImageMagickDecoder> imd = dynamic_pointer_cast<ImageMagickDecoder> ((*j)->decoder);
+				shared_ptr<StillImageDecoder> imd = dynamic_pointer_cast<StillImageDecoder> ((*j)->decoder);
 				if (imd && imd->content() == ic) {
 					id = imd;
 				}
 			}
 
 			if (!id) {
-				id.reset (new ImageMagickDecoder (_film, ic));
-				id->Video.connect (bind (&Player::process_video, this, piece, _1, _2, _3));
+				id.reset (new StillImageDecoder (_film, ic));
+				id->Video.connect (bind (&Player::process_video, this, piece, _1, _2, _3, _4));
 			}
 
 			piece->decoder = id;
 		}
 
+		shared_ptr<const MovingImageContent> mc = dynamic_pointer_cast<const MovingImageContent> (*i);
+		if (mc) {
+			shared_ptr<MovingImageDecoder> md;
+
+			if (!md) {
+				md.reset (new MovingImageDecoder (_film, mc));
+				md->Video.connect (bind (&Player::process_video, this, piece, _1, _2, _3, _4));
+			}
+
+			piece->decoder = md;
+		}
+
 		shared_ptr<const SndfileContent> sc = dynamic_pointer_cast<const SndfileContent> (*i);
 		if (sc) {
 			shared_ptr<AudioDecoder> sd (new SndfileDecoder (_film, sc));
@@ -434,7 +496,7 @@ Player::setup_pieces ()
 }
 
 void
-Player::content_changed (weak_ptr<Content> w, int p)
+Player::content_changed (weak_ptr<Content> w, int property, bool frequent)
 {
 	shared_ptr<Content> c = w.lock ();
 	if (!c) {
@@ -442,12 +504,19 @@ Player::content_changed (weak_ptr<Content> w, int p)
 	}
 
 	if (
-		p == ContentProperty::START || p == ContentProperty::LENGTH ||
-		p == VideoContentProperty::VIDEO_CROP || p == VideoContentProperty::VIDEO_RATIO
+		property == ContentProperty::POSITION || property == ContentProperty::LENGTH ||
+		property == ContentProperty::TRIM_START || property == ContentProperty::TRIM_END ||
+		property == VideoContentProperty::VIDEO_CROP || property == VideoContentProperty::VIDEO_RATIO
 		) {
 		
 		_have_valid_pieces = false;
-		Changed ();
+		Changed (frequent);
+
+	} else if (property == SubtitleContentProperty::SUBTITLE_OFFSET || property == SubtitleContentProperty::SUBTITLE_SCALE) {
+		update_subtitle ();
+		Changed (frequent);
+	} else if (property == VideoContentProperty::VIDEO_FRAME_TYPE) {
+		Changed (frequent);
 	}
 }
 
@@ -455,24 +524,28 @@ void
 Player::playlist_changed ()
 {
 	_have_valid_pieces = false;
-	Changed ();
+	Changed (false);
 }
 
 void
 Player::set_video_container_size (libdcp::Size s)
 {
 	_video_container_size = s;
-	_black_frame.reset (new SimpleImage (PIX_FMT_RGB24, _video_container_size, true));
+	_black_frame.reset (new Image (PIX_FMT_RGB24, _video_container_size, true));
 	_black_frame->make_black ();
 }
 
 shared_ptr<Resampler>
-Player::resampler (shared_ptr<AudioContent> c)
+Player::resampler (shared_ptr<AudioContent> c, bool create)
 {
 	map<shared_ptr<AudioContent>, shared_ptr<Resampler> >::iterator i = _resamplers.find (c);
 	if (i != _resamplers.end ()) {
 		return i->second;
 	}
+
+	if (!create) {
+		return shared_ptr<Resampler> ();
+	}
 	
 	shared_ptr<Resampler> r (new Resampler (c->content_audio_frame_rate(), c->output_audio_frame_rate(), c->audio_channels()));
 	_resamplers[c] = r;
@@ -482,16 +555,24 @@ Player::resampler (shared_ptr<AudioContent> c)
 void
 Player::emit_black ()
 {
-	/* XXX: use same here */
-	Video (_black_frame, false, _video_position);
+#ifdef DCPOMATIC_DEBUG
+	_last_video.reset ();
+#endif
+	
+	Video (_black_frame, EYES_BOTH, ColourConversion(), _last_emit_was_black, _video_position);
 	_video_position += _film->video_frames_to_time (1);
+	_last_emit_was_black = true;
 }
 
 void
 Player::emit_silence (OutputAudioFrame most)
 {
-	OutputAudioFrame N = min (most, _film->dcp_audio_frame_rate() / 2);
-	shared_ptr<AudioBuffers> silence (new AudioBuffers (_film->dcp_audio_channels(), N));
+	if (most == 0) {
+		return;
+	}
+	
+	OutputAudioFrame N = min (most, _film->audio_frame_rate() / 2);
+	shared_ptr<AudioBuffers> silence (new AudioBuffers (_film->audio_channels(), N));
 	silence->make_silent ();
 	Audio (silence, _audio_position);
 	_audio_position += _film->audio_frames_to_time (N);
@@ -505,12 +586,69 @@ Player::film_changed (Film::Property p)
 	   last time we were run.
 	*/
 
-	if (
-		p == Film::SCALER || p == Film::WITH_SUBTITLES ||
-		p == Film::SUBTITLE_SCALE || p == Film::SUBTITLE_OFFSET ||
-		p == Film::CONTAINER
-		) {
-		
-		Changed ();
+	if (p == Film::SCALER || p == Film::WITH_SUBTITLES || p == Film::CONTAINER) {
+		Changed (false);
 	}
 }
+
+void
+Player::process_subtitle (weak_ptr<Piece> weak_piece, shared_ptr<Image> image, dcpomatic::Rect<double> rect, Time from, Time to)
+{
+	_in_subtitle.piece = weak_piece;
+	_in_subtitle.image = image;
+	_in_subtitle.rect = rect;
+	_in_subtitle.from = from;
+	_in_subtitle.to = to;
+
+	update_subtitle ();
+}
+
+void
+Player::update_subtitle ()
+{
+	shared_ptr<Piece> piece = _in_subtitle.piece.lock ();
+	if (!piece) {
+		return;
+	}
+
+	if (!_in_subtitle.image) {
+		_out_subtitle.image.reset ();
+		return;
+	}
+
+	shared_ptr<SubtitleContent> sc = dynamic_pointer_cast<SubtitleContent> (piece->content);
+	assert (sc);
+
+	dcpomatic::Rect<double> in_rect = _in_subtitle.rect;
+	libdcp::Size scaled_size;
+
+	in_rect.y += sc->subtitle_offset ();
+
+	/* We will scale the subtitle up to fit _video_container_size, and also by the additional subtitle_scale */
+	scaled_size.width = in_rect.width * _video_container_size.width * sc->subtitle_scale ();
+	scaled_size.height = in_rect.height * _video_container_size.height * sc->subtitle_scale ();
+
+	/* Then we need a corrective translation, consisting of two parts:
+	 *
+	 * 1.  that which is the result of the scaling of the subtitle by _video_container_size; this will be
+	 *     rect.x * _video_container_size.width and rect.y * _video_container_size.height.
+	 *
+	 * 2.  that to shift the origin of the scale by subtitle_scale to the centre of the subtitle; this will be
+	 *     (width_before_subtitle_scale * (1 - subtitle_scale) / 2) and
+	 *     (height_before_subtitle_scale * (1 - subtitle_scale) / 2).
+	 *
+	 * Combining these two translations gives these expressions.
+	 */
+	
+	_out_subtitle.position.x = rint (_video_container_size.width * (in_rect.x + (in_rect.width * (1 - sc->subtitle_scale ()) / 2)));
+	_out_subtitle.position.y = rint (_video_container_size.height * (in_rect.y + (in_rect.height * (1 - sc->subtitle_scale ()) / 2)));
+	
+	_out_subtitle.image = _in_subtitle.image->scale (
+		scaled_size,
+		Scaler::from_id ("bicubic"),
+		_in_subtitle.image->pixel_format (),
+		true
+		);
+	_out_subtitle.from = _in_subtitle.from + piece->content->position ();
+	_out_subtitle.to = _in_subtitle.to + piece->content->position ();
+}