From: Carl Hetherington <cth@carlh.net>
Date: Mon, 3 Dec 2018 20:53:34 +0000 (+0000)
Subject: Work around width/height being 0 in subtitle_codec_context(), seen
X-Git-Tag: v2.13.81~4
X-Git-Url: https://main.carlh.net/gitweb/?p=dcpomatic.git;a=commitdiff_plain;h=1a719b15445a6244ce47c69157b64f1fd3377635

Work around width/height being 0 in subtitle_codec_context(), seen
in the wild in a MP4, apparently from a DVD rip.
---

diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc
index 3d9e965a9..ce20997c8 100644
--- a/src/lib/ffmpeg_decoder.cc
+++ b/src/lib/ffmpeg_decoder.cc
@@ -659,8 +659,19 @@ FFmpegDecoder::decode_bitmap_subtitle (AVSubtitleRect const * rect, ContentTime
 		out_p += image->stride()[0] / sizeof (uint32_t);
 	}
 
-	int const target_width = subtitle_codec_context()->width;
-	int const target_height = subtitle_codec_context()->height;
+	int target_width = subtitle_codec_context()->width;
+	if (target_width == 0 && video_codec_context()) {
+		/* subtitle_codec_context()->width == 0 has been seen in the wild but I don't
+		   know if it's supposed to mean something from FFmpeg's point of view.
+		*/
+		target_width = video_codec_context()->width;
+	}
+	int target_height = subtitle_codec_context()->height;
+	if (target_height == 0 && video_codec_context()) {
+		target_height = video_codec_context()->height;
+	}
+	DCPOMATIC_ASSERT (target_width);
+	DCPOMATIC_ASSERT (target_height);
 	dcpomatic::Rect<double> const scaled_rect (
 		static_cast<double> (rect->x) / target_width,
 		static_cast<double> (rect->y) / target_height,