diff --git a/media/java/android/media/audiopolicy/AudioMix.java b/media/java/android/media/audiopolicy/AudioMix.java
index d00e5b55fd14e..fbd2d8d031fdf 100644
--- a/media/java/android/media/audiopolicy/AudioMix.java
+++ b/media/java/android/media/audiopolicy/AudioMix.java
@@ -420,6 +420,20 @@ public class AudioMix {
                     rate = 44100;
                 }
                 mFormat = new AudioFormat.Builder().setSampleRate(rate).build();
+            } else {
+                // Ensure that 'mFormat' uses an output channel mask. Using an input channel
+                // mask was not made 'illegal' initially, however the framework code
+                // assumes usage in AudioMixes of output channel masks only (b/194910301).
+                if ((mFormat.getPropertySetMask()
+                                & AudioFormat.AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_MASK) != 0) {
+                    if (mFormat.getChannelCount() == 1
+                            && mFormat.getChannelMask() == AudioFormat.CHANNEL_IN_MONO) {
+                        mFormat = new AudioFormat.Builder(mFormat).setChannelMask(
+                                AudioFormat.CHANNEL_OUT_MONO).build();
+                    }
+                    // CHANNEL_IN_STEREO == CHANNEL_OUT_STEREO so no need to correct.
+                    // CHANNEL_IN_FRONT_BACK is hidden, should not appear.
+                }
             }
             if ((mDeviceSystemType != AudioSystem.DEVICE_NONE)
                     && (mDeviceSystemType != AudioSystem.DEVICE_OUT_REMOTE_SUBMIX)