X-Git-Url: https://git.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fffmpeg_decoder.cc;h=32b00a1d640e321a1d464cd151ddacc7ce6ed636;hb=2e504b33eb9f38cac629ad31b7c107fb0cf5efda;hp=18834c90e1b5249251bf6ba9e14bba1a8a8885f0;hpb=1dffdea0f4cd917a32c2a57109cd53bd916aa7d2;p=dcpomatic.git

diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc
index 18834c90e..32b00a1d6 100644
--- a/src/lib/ffmpeg_decoder.cc
+++ b/src/lib/ffmpeg_decoder.cc
@@ -33,7 +33,6 @@ extern "C" {
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
 }
-#include "film.h"
 #include "filter.h"
 #include "exceptions.h"
 #include "image.h"
@@ -42,6 +41,7 @@ extern "C" {
 #include "ffmpeg_decoder.h"
 #include "filter_graph.h"
 #include "audio_buffers.h"
+#include "ffmpeg_content.h"
 
 #include "i18n.h"
 
@@ -55,21 +55,19 @@ using std::pair;
 using boost::shared_ptr;
 using boost::optional;
 using boost::dynamic_pointer_cast;
-using libdcp::Size;
+using dcp::Size;
 
-FFmpegDecoder::FFmpegDecoder (shared_ptr<const Film> f, shared_ptr<const FFmpegContent> c, bool video, bool audio)
-	: Decoder (f)
-	, VideoDecoder (f)
-	, AudioDecoder (f)
-	, SubtitleDecoder (f)
+FFmpegDecoder::FFmpegDecoder (shared_ptr<const FFmpegContent> c, shared_ptr<Log> log, bool video, bool audio, bool subtitles)
+	: VideoDecoder (c)
+	, AudioDecoder (c)
 	, FFmpeg (c)
+	, _log (log)
 	, _subtitle_codec_context (0)
 	, _subtitle_codec (0)
 	, _decode_video (video)
 	, _decode_audio (audio)
-	, _video_pts_offset (0)
-	, _audio_pts_offset (0)
-	, _just_sought (false)
+	, _decode_subtitles (subtitles)
+	, _pts_offset (0)
 {
 	setup_subtitle ();
 
@@ -82,34 +80,27 @@ FFmpegDecoder::FFmpegDecoder (shared_ptr<const Film> f, shared_ptr<const FFmpegC
 	   Then we remove big initial gaps in PTS and we allow our
 	   insertion of black frames to work.
 
-	   We will do:
-	     audio_pts_to_use = audio_pts_from_ffmpeg + audio_pts_offset;
-	     video_pts_to_use = video_pts_from_ffmpeg + video_pts_offset;
+	   We will do pts_to_use = pts_from_ffmpeg + pts_offset;
 	*/
 
 	bool const have_video = video && c->first_video();
-	bool const have_audio = audio && c->audio_stream() && c->audio_stream()->first_audio;
+	bool const have_audio = _decode_audio && c->audio_stream () && c->audio_stream()->first_audio;
 
 	/* First, make one of them start at 0 */
 
 	if (have_audio && have_video) {
-		_video_pts_offset = _audio_pts_offset = - min (c->first_video().get(), c->audio_stream()->first_audio.get());
+		_pts_offset = - min (c->first_video().get(), c->audio_stream()->first_audio.get());
 	} else if (have_video) {
-		_video_pts_offset = - c->first_video().get();
+		_pts_offset = - c->first_video().get();
+	} else if (have_audio) {
+		_pts_offset = - c->audio_stream()->first_audio.get();
 	}
 
 	/* Now adjust both so that the video pts starts on a frame */
 	if (have_video && have_audio) {
-		double first_video = c->first_video().get() + _video_pts_offset;
-		double const old_first_video = first_video;
-		
-		/* Round the first video up to a frame boundary */
-		if (fabs (rint (first_video * c->video_frame_rate()) - first_video * c->video_frame_rate()) > 1e-6) {
-			first_video = ceil (first_video * c->video_frame_rate()) / c->video_frame_rate ();
-		}
-
-		_video_pts_offset += first_video - old_first_video;
-		_audio_pts_offset += first_video - old_first_video;
+		ContentTime first_video = c->first_video().get() + _pts_offset;
+		ContentTime const old_first_video = first_video;
+		_pts_offset += first_video.round_up (c->video_frame_rate ()) - old_first_video;
 	}
 }
 
@@ -120,9 +111,29 @@ FFmpegDecoder::~FFmpegDecoder ()
 	if (_subtitle_codec_context) {
 		avcodec_close (_subtitle_codec_context);
 	}
-}	
+}
 
 void
+FFmpegDecoder::flush ()
+{
+	/* Get any remaining frames */
+	
+	_packet.data = 0;
+	_packet.size = 0;
+	
+	/* XXX: should we reset _packet.data and size after each *_decode_* call? */
+	
+	if (_decode_video) {
+		while (decode_video_packet ()) {}
+	}
+	
+	if (_ffmpeg_content->audio_stream() && _decode_audio) {
+		decode_audio_packet ();
+		AudioDecoder::flush ();
+	}
+}
+
+bool
 FFmpegDecoder::pass ()
 {
 	int r = av_read_frame (_format_context, &_packet);
@@ -132,43 +143,25 @@ FFmpegDecoder::pass ()
 			/* Maybe we should fail here, but for now we'll just finish off instead */
 			char buf[256];
 			av_strerror (r, buf, sizeof(buf));
-			shared_ptr<const Film> film = _film.lock ();
-			assert (film);
-			film->log()->log (String::compose (N_("error on av_read_frame (%1) (%2)"), buf, r));
-		}
-
-		/* Get any remaining frames */
-		
-		_packet.data = 0;
-		_packet.size = 0;
-		
-		/* XXX: should we reset _packet.data and size after each *_decode_* call? */
-		
-		if (_decode_video) {
-			while (decode_video_packet ()) {}
-		}
-
-		if (_ffmpeg_content->audio_stream() && _decode_audio) {
-			decode_audio_packet ();
+			_log->log (String::compose (N_("error on av_read_frame (%1) (%2)"), buf, r));
 		}
 
-		/* Stop us being asked for any more data */
-		_video_position = _ffmpeg_content->video_length ();
-		_audio_position = _ffmpeg_content->audio_length ();
-		return;
+		flush ();
+		return true;
 	}
 
-	avcodec_get_frame_defaults (_frame);
-
-	if (_packet.stream_index == _video_stream && _decode_video) {
+	int const si = _packet.stream_index;
+	
+	if (si == _video_stream && _decode_video) {
 		decode_video_packet ();
-	} else if (_ffmpeg_content->audio_stream() && _packet.stream_index == _ffmpeg_content->audio_stream()->id && _decode_audio) {
+	} else if (_ffmpeg_content->audio_stream() && _ffmpeg_content->audio_stream()->uses_index (_format_context, si) && _decode_audio) {
 		decode_audio_packet ();
-	} else if (_ffmpeg_content->subtitle_stream() && _packet.stream_index == _ffmpeg_content->subtitle_stream()->id) {
+	} else if (_ffmpeg_content->subtitle_stream() && _ffmpeg_content->subtitle_stream()->uses_index (_format_context, si) && _decode_subtitles) {
 		decode_subtitle_packet ();
 	}
 
 	av_free_packet (&_packet);
+	return false;
 }
 
 /** @param data pointer to array of pointers to buffers.
@@ -189,6 +182,23 @@ FFmpegDecoder::deinterleave_audio (uint8_t** data, int size)
 	shared_ptr<AudioBuffers> audio (new AudioBuffers (_ffmpeg_content->audio_channels(), frames));
 
 	switch (audio_sample_format()) {
+	case AV_SAMPLE_FMT_U8:
+	{
+		uint8_t* p = reinterpret_cast<uint8_t *> (data[0]);
+		int sample = 0;
+		int channel = 0;
+		for (int i = 0; i < total_samples; ++i) {
+			audio->data(channel)[sample] = float(*p++) / (1 << 23);
+
+			++channel;
+			if (channel == _ffmpeg_content->audio_channels()) {
+				channel = 0;
+				++sample;
+			}
+		}
+	}
+	break;
+	
 	case AV_SAMPLE_FMT_S16:
 	{
 		int16_t* p = reinterpret_cast<int16_t *> (data[0]);
@@ -283,69 +293,133 @@ FFmpegDecoder::bytes_per_audio_sample () const
 	return av_get_bytes_per_sample (audio_sample_format ());
 }
 
-void
-FFmpegDecoder::seek (VideoContent::Frame frame, bool accurate)
+int
+FFmpegDecoder::minimal_run (boost::function<bool (optional<ContentTime>, optional<ContentTime>, int)> finished)
 {
-	double const time_base = av_q2d (_format_context->streams[_video_stream]->time_base);
+	int frames_read = 0;
+	optional<ContentTime> last_video;
+	optional<ContentTime> last_audio;
 
-	/* If we are doing an accurate seek, our initial shot will be 5 frames (5 being
-	   a number plucked from the air) earlier than we want to end up.  The loop below
-	   will hopefully then step through to where we want to be.
-	*/
-	int initial = frame;
+	while (!finished (last_video, last_audio, frames_read)) {
+		int r = av_read_frame (_format_context, &_packet);
+		if (r < 0) {
+			/* We should flush our decoders here, possibly yielding a few more frames,
+			   but the consequence of having to do that is too hideous to contemplate.
+			   Instead we give up and say that you can't seek too close to the end
+			   of a file.
+			*/
+			return frames_read;
+		}
+
+		++frames_read;
+
+		double const time_base = av_q2d (_format_context->streams[_packet.stream_index]->time_base);
+
+		if (_packet.stream_index == _video_stream) {
+
+			avcodec_get_frame_defaults (_frame);
+			
+			int finished = 0;
+			r = avcodec_decode_video2 (video_codec_context(), _frame, &finished, &_packet);
+			if (r >= 0 && finished) {
+				last_video = ContentTime::from_seconds (av_frame_get_best_effort_timestamp (_frame) * time_base) + _pts_offset;
+			}
+
+		} else if (_ffmpeg_content->audio_stream() && _ffmpeg_content->audio_stream()->uses_index (_format_context, _packet.stream_index)) {
+			AVPacket copy_packet = _packet;
+			while (copy_packet.size > 0) {
 
-	if (accurate) {
-		initial -= 5;
+				int finished;
+				r = avcodec_decode_audio4 (audio_codec_context(), _frame, &finished, &_packet);
+				if (r >= 0 && finished) {
+					last_audio = ContentTime::from_seconds (av_frame_get_best_effort_timestamp (_frame) * time_base) + _pts_offset;
+				}
+					
+				copy_packet.data += r;
+				copy_packet.size -= r;
+			}
+		}
+		
+		av_free_packet (&_packet);
 	}
 
-	if (initial < 0) {
-		initial = 0;
+	return frames_read;
+}
+
+bool
+FFmpegDecoder::seek_overrun_finished (ContentTime seek, optional<ContentTime> last_video, optional<ContentTime> last_audio) const
+{
+	return (last_video && last_video.get() >= seek) || (last_audio && last_audio.get() >= seek);
+}
+
+bool
+FFmpegDecoder::seek_final_finished (int n, int done) const
+{
+	return n == done;
+}
+
+void
+FFmpegDecoder::seek_and_flush (ContentTime t)
+{
+	ContentTime const u = t - _pts_offset;
+	int64_t s = u.seconds() / av_q2d (_format_context->streams[_video_stream]->time_base);
+
+	if (_ffmpeg_content->audio_stream ()) {
+		s = min (
+			s, int64_t (u.seconds() / av_q2d (_ffmpeg_content->audio_stream()->stream(_format_context)->time_base))
+			);
 	}
 
-	/* Initial seek time in the stream's timebase */
-	int64_t const initial_vt = ((initial / _ffmpeg_content->video_frame_rate()) - _video_pts_offset) / time_base;
+	/* Ridiculous empirical hack */
+	s--;
+	if (s < 0) {
+		s = 0;
+	}
 
-	av_seek_frame (_format_context, _video_stream, initial_vt, AVSEEK_FLAG_BACKWARD);
+	av_seek_frame (_format_context, _video_stream, s, 0);
 
 	avcodec_flush_buffers (video_codec_context());
+	if (audio_codec_context ()) {
+		avcodec_flush_buffers (audio_codec_context ());
+	}
 	if (_subtitle_codec_context) {
 		avcodec_flush_buffers (_subtitle_codec_context);
 	}
+}
 
-	_just_sought = true;
-	_video_position = frame;
+void
+FFmpegDecoder::seek (ContentTime time, bool accurate)
+{
+	Decoder::seek (time, accurate);
+	if (_decode_audio) {
+		AudioDecoder::seek (time, accurate);
+	}
 	
-	if (frame == 0 || !accurate) {
-		/* We're already there, or we're as close as we need to be */
+	/* If we are doing an accurate seek, our initial shot will be 200ms (200 being
+	   a number plucked from the air) earlier than we want to end up.  The loop below
+	   will hopefully then step through to where we want to be.
+	*/
+
+	ContentTime pre_roll = accurate ? ContentTime::from_seconds (0.2) : ContentTime (0);
+	ContentTime initial_seek = time - pre_roll;
+	if (initial_seek < ContentTime (0)) {
+		initial_seek = ContentTime (0);
+	}
+
+	/* Initial seek time in the video stream's timebase */
+
+	seek_and_flush (initial_seek);
+
+	if (!accurate) {
+		/* That'll do */
 		return;
 	}
 
-	while (1) {
-		int r = av_read_frame (_format_context, &_packet);
-		if (r < 0) {
-			return;
-		}
+	int const N = minimal_run (boost::bind (&FFmpegDecoder::seek_overrun_finished, this, time, _1, _2));
 
-		if (_packet.stream_index != _video_stream) {
-			continue;
-		}
-		
-		avcodec_get_frame_defaults (_frame);
-		
-		int finished = 0;
-		r = avcodec_decode_video2 (video_codec_context(), _frame, &finished, &_packet);
-		if (r >= 0 && finished) {
-			_video_position = rint (
-				(av_frame_get_best_effort_timestamp (_frame) * time_base + _video_pts_offset) * _ffmpeg_content->video_frame_rate()
-				);
-			
-			if (_video_position >= (frame - 1)) {
-				av_free_packet (&_packet);
-				break;
-			}
-		}
-		
-		av_free_packet (&_packet);
+	seek_and_flush (initial_seek);
+	if (N > 0) {
+		minimal_run (boost::bind (&FFmpegDecoder::seek_final_finished, this, N - 1, _3));
 	}
 }
 
@@ -357,37 +431,32 @@ FFmpegDecoder::decode_audio_packet ()
 	*/
 	
 	AVPacket copy_packet = _packet;
-
+	
 	while (copy_packet.size > 0) {
 
 		int frame_finished;
 		int const decode_result = avcodec_decode_audio4 (audio_codec_context(), _frame, &frame_finished, &copy_packet);
-		if (decode_result >= 0) {
-			if (frame_finished) {
-
-				if (_audio_position == 0) {
-					/* Where we are in the source, in seconds */
-					double const pts = av_q2d (_format_context->streams[copy_packet.stream_index]->time_base)
-						* av_frame_get_best_effort_timestamp(_frame) + _audio_pts_offset;
-
-					if (pts > 0) {
-						/* Emit some silence */
-						shared_ptr<AudioBuffers> silence (
-							new AudioBuffers (
-								_ffmpeg_content->audio_channels(),
-								pts * _ffmpeg_content->content_audio_frame_rate()
-								)
-							);
-						
-						silence->make_silent ();
-						audio (silence, _audio_position);
-					}
-				}
-					
-				copy_packet.data += decode_result;
-				copy_packet.size -= decode_result;
-			}
+
+		if (decode_result < 0) {
+			_log->log (String::compose ("avcodec_decode_audio4 failed (%1)", decode_result));
+			return;
 		}
+
+		if (frame_finished) {
+			ContentTime const ct = ContentTime::from_seconds (
+				av_frame_get_best_effort_timestamp (_frame) *
+				av_q2d (_ffmpeg_content->audio_stream()->stream (_format_context)->time_base))
+				+ _pts_offset;
+			
+			int const data_size = av_samples_get_buffer_size (
+				0, audio_codec_context()->channels, _frame->nb_samples, audio_sample_format (), 1
+				);
+
+			audio (deinterleave_audio (_frame->data, data_size), ct);
+		}
+			
+		copy_packet.data += decode_result;
+		copy_packet.size -= decode_result;
 	}
 }
 
@@ -404,75 +473,28 @@ FFmpegDecoder::decode_video_packet ()
 	shared_ptr<FilterGraph> graph;
 	
 	list<shared_ptr<FilterGraph> >::iterator i = _filter_graphs.begin();
-	while (i != _filter_graphs.end() && !(*i)->can_process (libdcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format)) {
+	while (i != _filter_graphs.end() && !(*i)->can_process (dcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format)) {
 		++i;
 	}
 
 	if (i == _filter_graphs.end ()) {
-		shared_ptr<const Film> film = _film.lock ();
-		assert (film);
-
-		graph.reset (new FilterGraph (_ffmpeg_content, libdcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format));
+		graph.reset (new FilterGraph (_ffmpeg_content, dcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format));
 		_filter_graphs.push_back (graph);
-
-		film->log()->log (String::compose (N_("New graph for %1x%2, pixel format %3"), _frame->width, _frame->height, _frame->format));
+		_log->log (String::compose (N_("New graph for %1x%2, pixel format %3"), _frame->width, _frame->height, _frame->format));
 	} else {
 		graph = *i;
 	}
 
 	list<pair<shared_ptr<Image>, int64_t> > images = graph->process (_frame);
 
-	string post_process = Filter::ffmpeg_strings (_ffmpeg_content->filters()).second;
-	
 	for (list<pair<shared_ptr<Image>, int64_t> >::iterator i = images.begin(); i != images.end(); ++i) {
 
 		shared_ptr<Image> image = i->first;
-		if (!post_process.empty ()) {
-			image = image->post_process (post_process, true);
-		}
 		
 		if (i->second != AV_NOPTS_VALUE) {
-
-			double const pts = i->second * av_q2d (_format_context->streams[_video_stream]->time_base) + _video_pts_offset;
-
-			if (_just_sought) {
-				/* We just did a seek, so disable any attempts to correct for where we
-				   are / should be.
-				*/
-				_video_position = rint (pts * _ffmpeg_content->video_frame_rate ());
-				_just_sought = false;
-			}
-
-			double const next = _video_position / _ffmpeg_content->video_frame_rate();
-			double const one_frame = 1 / _ffmpeg_content->video_frame_rate ();
-			double delta = pts - next;
-
-			while (delta > one_frame) {
-				/* This PTS is more than one frame forward in time of where we think we should be; emit
-				   a black frame.
-				*/
-				boost::shared_ptr<Image> black (
-					new Image (
-						static_cast<AVPixelFormat> (_frame->format),
-						libdcp::Size (video_codec_context()->width, video_codec_context()->height),
-						true
-						)
-					);
-				
-				black->make_black ();
-				video (image, false, _video_position);
-				delta -= one_frame;
-			}
-
-			if (delta > -one_frame) {
-				/* This PTS is within a frame of being right; emit this (otherwise it will be dropped) */
-				video (image, false, _video_position);
-			}
-				
+			video (image, false, ContentTime::from_seconds (i->second * av_q2d (_format_context->streams[_video_stream]->time_base)) + _pts_offset);
 		} else {
-			shared_ptr<const Film> film = _film.lock ();
-			assert (film);
-			film->log()->log ("Dropping frame without PTS");
+			_log->log ("Dropping frame without PTS");
 		}
 	}
 
@@ -485,15 +507,19 @@ FFmpegDecoder::setup_subtitle ()
 {
 	boost::mutex::scoped_lock lm (_mutex);
 	
-	if (!_ffmpeg_content->subtitle_stream() || _ffmpeg_content->subtitle_stream()->id >= int (_format_context->nb_streams)) {
+	if (!_ffmpeg_content->subtitle_stream()) {
 		return;
 	}
 
-	_subtitle_codec_context = _format_context->streams[_ffmpeg_content->subtitle_stream()->id]->codec;
+	_subtitle_codec_context = _ffmpeg_content->subtitle_stream()->stream(_format_context)->codec;
+	if (_subtitle_codec_context == 0) {
+		throw DecodeError (N_("could not find subtitle stream"));
+	}
+
 	_subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id);
 
 	if (_subtitle_codec == 0) {
-		throw DecodeError (_("could not find subtitle decoder"));
+		throw DecodeError (N_("could not find subtitle decoder"));
 	}
 	
 	if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) {
@@ -501,14 +527,6 @@ FFmpegDecoder::setup_subtitle ()
 	}
 }
 
-bool
-FFmpegDecoder::done () const
-{
-	bool const vd = !_decode_video || (_video_position >= _ffmpeg_content->video_length());
-	bool const ad = !_decode_audio || !_ffmpeg_content->audio_stream() || (_audio_position >= _ffmpeg_content->audio_length());
-	return vd && ad;
-}
-	
 void
 FFmpegDecoder::decode_subtitle_packet ()
 {
@@ -522,49 +540,55 @@ FFmpegDecoder::decode_subtitle_packet ()
 	   indicate that the previous subtitle should stop.
 	*/
 	if (sub.num_rects <= 0) {
-		subtitle (shared_ptr<Image> (), dcpomatic::Rect<double> (), 0, 0);
+		image_subtitle (shared_ptr<Image> (), dcpomatic::Rect<double> (), ContentTime (), ContentTime ());
 		return;
 	} else if (sub.num_rects > 1) {
 		throw DecodeError (_("multi-part subtitles not yet supported"));
 	}
 		
-	/* Subtitle PTS in seconds (within the source, not taking into account any of the
+	/* Subtitle PTS (within the source, not taking into account any of the
 	   source that we may have chopped off for the DCP)
 	*/
-	double const packet_time = static_cast<double> (sub.pts) / AV_TIME_BASE;
+	ContentTime packet_time = ContentTime::from_seconds (static_cast<double> (sub.pts) / AV_TIME_BASE) + _pts_offset;
 	
 	/* hence start time for this sub */
-	Time const from = (packet_time + (double (sub.start_display_time) / 1e3)) * TIME_HZ;
-	Time const to = (packet_time + (double (sub.end_display_time) / 1e3)) * TIME_HZ;
+	ContentTime const from = packet_time + ContentTime::from_seconds (sub.start_display_time / 1e3);
+	ContentTime const to = packet_time + ContentTime::from_seconds (sub.end_display_time / 1e3);
 
 	AVSubtitleRect const * rect = sub.rects[0];
 
 	if (rect->type != SUBTITLE_BITMAP) {
 		throw DecodeError (_("non-bitmap subtitles not yet supported"));
 	}
-	
-	shared_ptr<Image> image (new Image (PIX_FMT_RGBA, libdcp::Size (rect->w, rect->h), true));
+
+	/* Note RGBA is expressed little-endian, so the first byte in the word is R, second
+	   G, third B, fourth A.
+	*/
+	shared_ptr<Image> image (new Image (PIX_FMT_RGBA, dcp::Size (rect->w, rect->h), true));
 
 	/* Start of the first line in the subtitle */
 	uint8_t* sub_p = rect->pict.data[0];
-	/* sub_p looks up into a RGB palette which is here */
+	/* sub_p looks up into a BGRA palette which is here
+	   (i.e. first byte B, second G, third R, fourth A)
+	*/
 	uint32_t const * palette = (uint32_t *) rect->pict.data[1];
 	/* Start of the output data */
 	uint32_t* out_p = (uint32_t *) image->data()[0];
-	
+
 	for (int y = 0; y < rect->h; ++y) {
 		uint8_t* sub_line_p = sub_p;
 		uint32_t* out_line_p = out_p;
 		for (int x = 0; x < rect->w; ++x) {
-			*out_line_p++ = palette[*sub_line_p++];
+			uint32_t const p = palette[*sub_line_p++];
+			*out_line_p++ = ((p & 0xff) << 16) | (p & 0xff00) | ((p & 0xff0000) >> 16) | (p & 0xff000000);
 		}
 		sub_p += rect->pict.linesize[0];
 		out_p += image->stride()[0] / sizeof (uint32_t);
 	}
 
-	libdcp::Size const vs = _ffmpeg_content->video_size ();
+	dcp::Size const vs = _ffmpeg_content->video_size ();
 
-	subtitle (
+	image_subtitle (
 		image,
 		dcpomatic::Rect<double> (
 			static_cast<double> (rect->x) / vs.width,