2 files changed, 21 insertions, 0 deletions
diff --git a/src/lib/audio_buffers.cc b/src/lib/audio_buffers.cc
index 119a499b4..4f01146f9 100644
--- a/src/lib/audio_buffers.cc
+++ b/src/lib/audio_buffers.cc
@@ -335,3 +335,22 @@ AudioBuffers::update_data_pointers ()
         }
 }
 
+
+/** Set a new channel count, either discarding data (if new_channels is less than the current
+ *  channels()), or filling with silence (if new_channels is more than the current channels()
+ */
+void
+AudioBuffers::set_channels(int new_channels)
+{
+	DCPOMATIC_ASSERT(new_channels > 0);
+
+	ScopeGuard sg = [this]() { update_data_pointers(); };
+
+	int const old_channels = channels();
+	_data.resize(new_channels);
+
+	for (int channel = old_channels; channel < new_channels; ++channel) {
+		_data[channel].resize(frames());
+	}
+}
+
diff --git a/src/lib/audio_buffers.h b/src/lib/audio_buffers.h
index 4db0fa255..645348aa0 100644
--- a/src/lib/audio_buffers.h
+++ b/src/lib/audio_buffers.h
@@ -65,6 +65,8 @@ public:
 
 	void set_frames (int f);
 
+	void set_channels(int new_channels);
+
 	void make_silent ();
 	void make_silent (int channel);
 	void make_silent (int from, int frames);