Use optional<> for _video_stream.

4 files changed, 29 insertions, 16 deletions

diff --git a/src/lib/ffmpeg.cc b/src/lib/ffmpeg.cc
index 656142cd4..7b1eae2b1 100644
--- a/src/lib/ffmpeg.cc
+++ b/src/lib/ffmpeg.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2013-2015 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2013-2016 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
@@ -56,7 +56,6 @@ FFmpeg::FFmpeg (boost::shared_ptr<const FFmpegContent> c)
 	, _avio_context (0)
 	, _format_context (0)
 	, _frame (0)
-	, _video_stream (-1)
 {
 	setup_general ();
 	setup_decoders ();
@@ -140,7 +139,7 @@ FFmpeg::setup_general ()
 
 	/* Find video stream */
 
-	int video_stream_undefined_frame_rate = -1;
+	optional<int> video_stream_undefined_frame_rate;
 
 	for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
 		AVStream* s = _format_context->streams[i];
@@ -158,11 +157,11 @@ FFmpeg::setup_general ()
 	/* Files from iTunes sometimes have two video streams, one with the avg_frame_rate.num and .den set
 	   to zero.  Only use such a stream if there is no alternative.
 	*/
-	if (_video_stream == -1 && video_stream_undefined_frame_rate != -1) {
-		_video_stream = video_stream_undefined_frame_rate;
+	if (!_video_stream && video_stream_undefined_frame_rate) {
+		_video_stream = video_stream_undefined_frame_rate.get();
 	}
 
-	if (_video_stream < 0) {
+	if (!_video_stream) {
 		throw DecodeError (N_("could not find video stream"));
 	}
 
@@ -224,7 +223,8 @@ FFmpeg::setup_decoders ()
 AVCodecContext *
 FFmpeg::video_codec_context () const
 {
-	return _format_context->streams[_video_stream]->codec;
+	DCPOMATIC_ASSERT (_video_stream);
+	return _format_context->streams[_video_stream.get()]->codec;
 }
 
 AVCodecContext *
diff --git a/src/lib/ffmpeg.h b/src/lib/ffmpeg.h
index 43efcf74f..d38fd6362 100644
--- a/src/lib/ffmpeg.h
+++ b/src/lib/ffmpeg.h
@@ -72,7 +72,7 @@ protected:
 	AVFrame* _frame;
 
 	/** Index of video stream within AVFormatContext */
-	int _video_stream;
+	boost::optional<int> _video_stream;
 
 	/* It would appear (though not completely verified) that one must have
 	   a mutex around calls to avcodec_open* and avcodec_close... and here
diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc
index 68dcd5186..72df69126 100644
--- a/src/lib/ffmpeg_decoder.cc
+++ b/src/lib/ffmpeg_decoder.cc
@@ -121,7 +121,7 @@ FFmpegDecoder::pass (PassReason reason, bool accurate)
 	int const si = _packet.stream_index;
 	shared_ptr<const FFmpegContent> fc = _ffmpeg_content;
 
-	if (si == _video_stream && !_ignore_video && (accurate || reason != PASS_REASON_SUBTITLE)) {
+	if (_video_stream && si == _video_stream.get() && !_ignore_video && (accurate || reason != PASS_REASON_SUBTITLE)) {
 		decode_video_packet ();
 	} else if (fc->subtitle_stream() && fc->subtitle_stream()->uses_index (_format_context, si)) {
 		decode_subtitle_packet ();
@@ -295,11 +295,18 @@ FFmpegDecoder::seek (ContentTime time, bool accurate)
 	   http://www.mjbshaw.com/2012/04/seeking-in-ffmpeg-know-your-timestamp.html
 	*/
 
+	DCPOMATIC_ASSERT (_video_stream);
+
 	ContentTime u = time - _pts_offset;
 	if (u < ContentTime ()) {
 		u = ContentTime ();
 	}
-	av_seek_frame (_format_context, _video_stream, u.seconds() / av_q2d (_format_context->streams[_video_stream]->time_base), AVSEEK_FLAG_BACKWARD);
+	av_seek_frame (
+		_format_context,
+		_video_stream.get(),
+		u.seconds() / av_q2d (_format_context->streams[_video_stream.get()]->time_base),
+		AVSEEK_FLAG_BACKWARD
+		);
 
 	avcodec_flush_buffers (video_codec_context());
 
@@ -380,6 +387,8 @@ FFmpegDecoder::decode_audio_packet ()
 bool
 FFmpegDecoder::decode_video_packet ()
 {
+	DCPOMATIC_ASSERT (_video_stream);
+
 	int frame_finished;
 	if (avcodec_decode_video2 (video_codec_context(), _frame, &frame_finished, &_packet) < 0 || !frame_finished) {
 		return false;
@@ -410,7 +419,7 @@ FFmpegDecoder::decode_video_packet ()
 		shared_ptr<Image> image = i->first;
 
 		if (i->second != AV_NOPTS_VALUE) {
-			double const pts = i->second * av_q2d (_format_context->streams[_video_stream]->time_base) + _pts_offset.seconds ();
+			double const pts = i->second * av_q2d (_format_context->streams[_video_stream.get()]->time_base) + _pts_offset.seconds ();
 			video (
 				shared_ptr<ImageProxy> (new RawImageProxy (image)),
 				llrint (pts * _ffmpeg_content->active_video_frame_rate ())
diff --git a/src/lib/ffmpeg_examiner.cc b/src/lib/ffmpeg_examiner.cc
index 2b8b2b743..eeb0cfc38 100644
--- a/src/lib/ffmpeg_examiner.cc
+++ b/src/lib/ffmpeg_examiner.cc
@@ -113,7 +113,7 @@ FFmpegExaminer::FFmpegExaminer (shared_ptr<const FFmpegContent> c, shared_ptr<Jo
 
 		AVCodecContext* context = _format_context->streams[_packet.stream_index]->codec;
 
-		if (_packet.stream_index == _video_stream) {
+		if (_video_stream && _packet.stream_index == _video_stream.get()) {
 			video_packet (context);
 		}
 
@@ -179,6 +179,8 @@ FFmpegExaminer::FFmpegExaminer (shared_ptr<const FFmpegContent> c, shared_ptr<Jo
 void
 FFmpegExaminer::video_packet (AVCodecContext* context)
 {
+	DCPOMATIC_ASSERT (_video_stream);
+
 	if (_first_video && !_need_video_length) {
 		return;
 	}
@@ -186,11 +188,11 @@ FFmpegExaminer::video_packet (AVCodecContext* context)
 	int frame_finished;
 	if (avcodec_decode_video2 (context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
 		if (!_first_video) {
-			_first_video = frame_time (_format_context->streams[_video_stream]);
+			_first_video = frame_time (_format_context->streams[_video_stream.get()]);
 		}
 		if (_need_video_length) {
 			_video_length = frame_time (
-				_format_context->streams[_video_stream]
+				_format_context->streams[_video_stream.get()]
 				).get_value_or (ContentTime ()).frames_round (video_frame_rate().get ());
 		}
 	}
@@ -297,11 +299,12 @@ FFmpegExaminer::frame_time (AVStream* s) const
 optional<double>
 FFmpegExaminer::video_frame_rate () const
 {
+	DCPOMATIC_ASSERT (_video_stream);
 	/* This use of r_frame_rate is debateable; there's a few different
 	 * frame rates in the format context, but this one seems to be the most
 	 * reliable.
 	 */
-	return av_q2d (av_stream_get_r_frame_rate (_format_context->streams[_video_stream]));
+	return av_q2d (av_stream_get_r_frame_rate (_format_context->streams[_video_stream.get()]));
 }
 
 dcp::Size
@@ -320,7 +323,8 @@ FFmpegExaminer::video_length () const
 optional<double>
 FFmpegExaminer::sample_aspect_ratio () const
 {
-	AVRational sar = av_guess_sample_aspect_ratio (_format_context, _format_context->streams[_video_stream], 0);
+	DCPOMATIC_ASSERT (_video_stream);
+	AVRational sar = av_guess_sample_aspect_ratio (_format_context, _format_context->streams[_video_stream.get()], 0);
 	if (sar.num == 0) {
 		/* I assume this means that we don't know */
 		return optional<double> ();