From: Carl Hetherington <cth@carlh.net>
Date: Sat, 25 May 2019 23:30:28 +0000 (+0000)
Subject: Fix slightly unbelievable out-of-bounds array access when setting up the audio map... 
X-Git-Tag: v2.14.5
X-Git-Url: https://main.carlh.net/gitweb/?p=dcpomatic.git;a=commitdiff_plain;h=677eaab5c03e9c614ae2bc417a43bd5c1295bb8d

Fix slightly unbelievable out-of-bounds array access when setting up the audio map for mixdown-to-stereo.
---

diff --git a/src/lib/audio_mapping.cc b/src/lib/audio_mapping.cc
index 86add09f4..f07d5dece 100644
--- a/src/lib/audio_mapping.cc
+++ b/src/lib/audio_mapping.cc
@@ -163,6 +163,8 @@ AudioMapping::AudioMapping (cxml::ConstNodePtr node, int state_version)
 void
 AudioMapping::set (int input_channel, int output_channel, float g)
 {
+	DCPOMATIC_ASSERT (input_channel < int(_gain.size()));
+	DCPOMATIC_ASSERT (output_channel < int(_gain[0].size()));
 	_gain[input_channel][output_channel] = g;
 }
 
diff --git a/src/wx/film_viewer.cc b/src/wx/film_viewer.cc
index 0fc338247..098fc2598 100644
--- a/src/wx/film_viewer.cc
+++ b/src/wx/film_viewer.cc
@@ -186,14 +186,26 @@ FilmViewer::recreate_butler ()
 		   Map so that Lt = L(-3dB) + Ls(-3dB) + C(-6dB) + Lfe(-10dB)
 		               Rt = R(-3dB) + Rs(-3dB) + C(-6dB) + Lfe(-10dB)
 		*/
-		map.set (dcp::LEFT,   0, 1 / sqrt(2)); // L -> Lt
-		map.set (dcp::RIGHT,  1, 1 / sqrt(2)); // R -> Rt
-		map.set (dcp::CENTRE, 0, 1 / 2.0); // C -> Lt
-		map.set (dcp::CENTRE, 1, 1 / 2.0); // C -> Rt
-		map.set (dcp::LFE,    0, 1 / sqrt(10)); // Lfe -> Lt
-		map.set (dcp::LFE,    1, 1 / sqrt(10)); // Lfe -> Rt
-		map.set (dcp::LS,     0, 1 / sqrt(2)); // Ls -> Lt
-		map.set (dcp::RS,     1, 1 / sqrt(2)); // Rs -> Rt
+		if (_film->audio_channels() > 0) {
+			map.set (dcp::LEFT,   0, 1 / sqrt(2)); // L -> Lt
+		}
+		if (_film->audio_channels() > 1) {
+			map.set (dcp::RIGHT,  1, 1 / sqrt(2)); // R -> Rt
+		}
+		if (_film->audio_channels() > 2) {
+			map.set (dcp::CENTRE, 0, 1 / 2.0); // C -> Lt
+			map.set (dcp::CENTRE, 1, 1 / 2.0); // C -> Rt
+		}
+		if (_film->audio_channels() > 3) {
+			map.set (dcp::LFE,    0, 1 / sqrt(10)); // Lfe -> Lt
+			map.set (dcp::LFE,    1, 1 / sqrt(10)); // Lfe -> Rt
+		}
+		if (_film->audio_channels() > 4) {
+			map.set (dcp::LS,     0, 1 / sqrt(2)); // Ls -> Lt
+		}
+		if (_film->audio_channels() > 5) {
+			map.set (dcp::RS,     1, 1 / sqrt(2)); // Rs -> Rt
+		}
 	}
 
 	_butler.reset (new Butler(_player, map, _audio_channels, bind(&PlayerVideo::force, _1, AV_PIX_FMT_RGB24), false, true));