1 files changed, 125 insertions, 120 deletions

diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc
index 5a1b78762..b2e8cc44a 100644
--- a/src/lib/ffmpeg_decoder.cc
+++ b/src/lib/ffmpeg_decoder.cc
@@ -70,7 +70,6 @@ FFmpegDecoder::FFmpegDecoder (shared_ptr<const Film> f, shared_ptr<const FFmpegC
 	, _decode_audio (audio)
 	, _video_pts_offset (0)
 	, _audio_pts_offset (0)
-	, _just_sought (false)
 {
 	setup_subtitle ();
 
@@ -89,7 +88,7 @@ FFmpegDecoder::FFmpegDecoder (shared_ptr<const Film> f, shared_ptr<const FFmpegC
 	*/
 
 	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 */
 
@@ -143,12 +142,15 @@ FFmpegDecoder::flush ()
 		decode_audio_packet ();
 	}
 
+#if 0	
+	/* XXX */
 	/* Stop us being asked for any more data */
 	_video_position = _ffmpeg_content->video_length ();
 	_audio_position = _ffmpeg_content->audio_length ();
+#endif	
 }
 
-void
+bool
 FFmpegDecoder::pass ()
 {
 	int r = av_read_frame (_format_context, &_packet);
@@ -164,7 +166,7 @@ FFmpegDecoder::pass ()
 		}
 
 		flush ();
-		return;
+		return true;
 	}
 
 	avcodec_get_frame_defaults (_frame);
@@ -183,6 +185,7 @@ FFmpegDecoder::pass ()
 	}
 
 	av_free_packet (&_packet);
+	return false;
 }
 
 /** @param data pointer to array of pointers to buffers.
@@ -297,70 +300,131 @@ 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 (ContentTime, ContentTime, int)> finished)
 {
-	double const time_base = av_q2d (_format_context->streams[_video_stream]->time_base);
+	int frames_read = 0;
+	ContentTime last_video = 0;
+	ContentTime last_audio = 0;
+	bool flushing = false;
 
-	/* 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;
+		}
 
-	if (accurate) {
-		initial -= 5;
-	}
+		++frames_read;
 
-	if (initial < 0) {
-		initial = 0;
+		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 = rint (
+					(av_frame_get_best_effort_timestamp (_frame) * time_base + _video_pts_offset) * TIME_HZ
+					);
+			}
+				
+		} else if (_ffmpeg_content->audio_stream() && _packet.stream_index == _ffmpeg_content->audio_stream()->index (_format_context)) {
+			AVPacket copy_packet = _packet;
+			while (copy_packet.size > 0) {
+
+				int finished;
+				r = avcodec_decode_audio4 (audio_codec_context(), _frame, &finished, &_packet);
+				if (r >= 0 && finished) {
+					last_audio = rint (
+						(av_frame_get_best_effort_timestamp (_frame) * time_base + _audio_pts_offset) *	TIME_HZ
+						);
+				}
+					
+				copy_packet.data += r;
+				copy_packet.size -= r;
+			}
+		}
+		
+		av_free_packet (&_packet);
 	}
 
-	/* Initial seek time in the stream's timebase */
-	int64_t const initial_vt = ((initial / _ffmpeg_content->video_frame_rate()) - _video_pts_offset) / time_base;
+	return frames_read;
+}
+
+bool
+FFmpegDecoder::seek_overrun_finished (ContentTime seek, ContentTime last_video, ContentTime last_audio) const
+{
+	return last_video >= seek || last_audio >= seek;
+}
+
+bool
+FFmpegDecoder::seek_final_finished (int n, int done) const
+{
+	return n == done;
+}
+
+void
+FFmpegDecoder::seek_and_flush (ContentTime t)
+{
+	int64_t const initial_v = ((double (t) / TIME_HZ) - _video_pts_offset) /
+		av_q2d (_format_context->streams[_video_stream]->time_base);
+
+	av_seek_frame (_format_context, _video_stream, initial_v, AVSEEK_FLAG_BACKWARD);
+
+	shared_ptr<FFmpegAudioStream> as = _ffmpeg_content->audio_stream ();
+	if (as) {
+		int64_t initial_a = ((double (t) / TIME_HZ) - _audio_pts_offset) /
+			av_q2d (as->stream(_format_context)->time_base);
 
-	av_seek_frame (_format_context, _video_stream, initial_vt, AVSEEK_FLAG_BACKWARD);
+		av_seek_frame (_format_context, as->index (_format_context), initial_a, AVSEEK_FLAG_BACKWARD);
+	}
 
 	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 (frame == 0 || !accurate) {
-		/* We're already there, or we're as close as we need to be */
-		return;
+	/* 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 ? (0.2 * TIME_HZ) : 0;
+	ContentTime initial_seek = time - pre_roll;
+	if (initial_seek < 0) {
+		initial_seek = 0;
 	}
+	
+	/* Initial seek time in the video stream's timebase */
 
-	while (1) {
-		int r = av_read_frame (_format_context, &_packet);
-		if (r < 0) {
-			return;
-		}
+	seek_and_flush (initial_seek);
 
-		if (_packet.stream_index != _video_stream) {
-			av_free_packet (&_packet);
-			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 (time == 0 || !accurate) {
+		/* We're already there, or we're as close as we need to be */
+		return;
+	}
 
-			if (_video_position >= (frame - 1)) {
-				av_free_packet (&_packet);
-				break;
-			}
-		}
-		
-		av_free_packet (&_packet);
+	int const N = minimal_run (boost::bind (&FFmpegDecoder::seek_overrun_finished, this, time, _1, _2));
+	
+	seek_and_flush (initial_seek);
+	if (N > 0) {
+		minimal_run (boost::bind (&FFmpegDecoder::seek_final_finished, this, N - 1, _3));
 	}
 }
 
@@ -377,6 +441,7 @@ FFmpegDecoder::decode_audio_packet ()
 
 		int frame_finished;
 		int const decode_result = avcodec_decode_audio4 (audio_codec_context(), _frame, &frame_finished, &copy_packet);
+
 		if (decode_result < 0) {
 			shared_ptr<const Film> film = _film.lock ();
 			assert (film);
@@ -385,31 +450,16 @@ FFmpegDecoder::decode_audio_packet ()
 		}
 
 		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);
-				}
-			}
-			
+			ContentTime const t = rint (
+				(av_q2d (_format_context->streams[copy_packet.stream_index]->time_base)
+				 * av_frame_get_best_effort_timestamp(_frame) + _audio_pts_offset) * TIME_HZ
+				);
+
 			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), _audio_position);
+			audio (deinterleave_audio (_frame->data, data_size), t);
 		}
 			
 		copy_packet.data += decode_result;
@@ -458,45 +508,8 @@ FFmpegDecoder::decode_video_packet ()
 		}
 		
 		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.
-				*/
-
-				/* XXX: I think this should be a copy of the last 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);
-			}
-				
+			ContentTime const t = rint ((i->second * av_q2d (_format_context->streams[_video_stream]->time_base) + _video_pts_offset) * TIME_HZ);
+			video (image, false, t);
 		} else {
 			shared_ptr<const Film> film = _film.lock ();
 			assert (film);
@@ -529,14 +542,6 @@ 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 ()
 {
@@ -562,8 +567,8 @@ FFmpegDecoder::decode_subtitle_packet ()
 	double const packet_time = static_cast<double> (sub.pts) / AV_TIME_BASE;
 	
 	/* 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;
+	DCPTime const from = (packet_time + (double (sub.start_display_time) / 1e3)) * TIME_HZ;
+	DCPTime const to = (packet_time + (double (sub.end_display_time) / 1e3)) * TIME_HZ;
 
 	AVSubtitleRect const * rect = sub.rects[0];