Make sure 2-channel MXFs don't get extra channel descriptors (#2631).

With all the EasyDCP tests done in bug #2487 we didn't look at stereo
MXFs as it appeared fairly early on that EasyDCP would reject them all.

In #2631 it's pointed out that it seems to make no sense to have descriptors
for channels which aren't there.  I've still got no docs for any of this,
but let's try fixing that.

2 files changed, 15 insertions, 1 deletions

diff --git a/cscript b/cscript
index 5edc3b8c4..be61c5330 100644
--- a/cscript
+++ b/cscript
@@ -508,7 +508,7 @@ def dependencies(target, options):
         # Use distro-provided FFmpeg on Arch
         deps = []
 
-    deps.append(('libdcp', 'v1.8.85'))
+    deps.append(('libdcp', 'v1.8.86'))
     deps.append(('libsub', 'v1.6.44'))
     deps.append(('leqm-nrt', '30dcaea1373ac62fba050e02ce5b0c1085797a23'))
     deps.append(('rtaudio', 'f619b76'))
diff --git a/test/mca_subdescriptors_test.cc b/test/mca_subdescriptors_test.cc
index d3702b9cc..e34a909f4 100644
--- a/test/mca_subdescriptors_test.cc
+++ b/test/mca_subdescriptors_test.cc
@@ -72,12 +72,26 @@ test_descriptors(int mxf_channels, vector<dcp::Channel> active_channels, vector<
 }
 
 
+/* This seems like an impossible case but let's check it anyway */
+BOOST_AUTO_TEST_CASE(mca_subdescriptors_written_correctly_mono_in_2_channel)
+{
+	test_descriptors(2, { dcp::Channel::CENTRE }, { "chL", "chR" }, "sg51");
+}
+
+
 BOOST_AUTO_TEST_CASE(mca_subdescriptors_written_correctly_mono_in_6_channel)
 {
 	test_descriptors(6, { dcp::Channel::CENTRE }, { "chL", "chR", "chC", "chLFE", "chLs", "chRs" }, "sg51");
 }
 
 
+/* If we only have two channels in the MXF we shouldn't see any extra descriptors */
+BOOST_AUTO_TEST_CASE(mca_subdescriptors_written_correctly_stereo_in_2_channel)
+{
+	test_descriptors(2, { dcp::Channel::LEFT, dcp::Channel::RIGHT }, { "chL", "chR" }, "sg51");
+}
+
+
 BOOST_AUTO_TEST_CASE(mca_subdescriptors_written_correctly_stereo_in_6_channel)
 {
 	test_descriptors(6, { dcp::Channel::LEFT, dcp::Channel::RIGHT }, { "chL", "chR", "chC", "chLFE", "chLs", "chRs" }, "sg51");