[Chromecast] Add channel count check in AudioDecoderAndroid.

Bug: internal b/140189221

Test: Cast from Youtube to Android TV.
      TTS on Android Things.

Change-Id: I285f06ce5f44d6d0875e43d5d7ed62328e7ece70
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1917342Reviewed-by: Kenneth MacKay <kmackay@chromium.org>
Reviewed-by: Yuchen Liu <yucliu@chromium.org>
Commit-Queue: Ziyang Cheng <ziyangch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#715358}

chromecast/media/cma/backend/android/audio_decoder_android.cc

@@ -53,6 +53,13 @@ const int64_t kInvalidTimestamp = std::numeric_limits<int64_t>::min();
 
 const int64_t kNoPendingOutput = -1;
 
+bool IsValidChannelNumber(int channel_number) {
+  // Currently, we only support following channel numbers.
+  return (channel_number == 1) || (channel_number == 2) ||
+         (channel_number == 4) || (channel_number == 6) ||
+         (channel_number == 8);
+}
+
 }  // namespace
 
 AudioDecoderAndroid::RateShifterInfo::RateShifterInfo(float playback_rate)
@@ -119,6 +126,7 @@ bool AudioDecoderAndroid::Start(int64_t start_pts) {
   TRACE_FUNCTION_ENTRY0();
   current_pts_ = start_pts;
   DCHECK(IsValidConfig(config_));
+  DCHECK(IsValidChannelNumber(config_.channel_number));
   sink_.Reset(this, config_.channel_number, config_.samples_per_second,
               backend_->Primary(), backend_->DeviceId(),
               backend_->ContentType());
@@ -253,7 +261,7 @@ bool AudioDecoderAndroid::SetConfig(const AudioConfig& config) {
 
   TRACE_FUNCTION_ENTRY0();
   DCHECK(task_runner_->BelongsToCurrentThread());
-  if (!IsValidConfig(config)) {
+  if (!IsValidConfig(config) || !IsValidChannelNumber(config.channel_number)) {
     LOG(ERROR) << "Invalid audio config passed to SetConfig";
     return false;
   }
@@ -296,6 +304,7 @@ void AudioDecoderAndroid::CreateDecoder() {
 
   DCHECK(!decoder_);
   DCHECK(IsValidConfig(config_));
+  DCHECK(IsValidChannelNumber(config_.channel_number));
 
   // No need to create a decoder if the samples are already decoded.
   if (BypassDecoder()) {
@@ -401,6 +410,11 @@ void AudioDecoderAndroid::OnBufferDecoded(
     delegate_->OnPushBufferComplete(MediaPipelineBackendAndroid::kBufferFailed);
     return;
   }
+  if (!IsValidChannelNumber(config.channel_number)) {
+    LOG(ERROR) << "Channel number changes to be invalid.";
+    delegate_->OnPushBufferComplete(MediaPipelineBackendAndroid::kBufferFailed);
+    return;
+  }
 
   Statistics delta;
   delta.decoded_bytes = input_bytes;

chromecast/media/cma/backend/android/java/src/org/chromium/chromecast/cma/backend/android/AudioSinkAudioTrackImpl.java

@@ -246,6 +246,7 @@ class AudioSinkAudioTrackImpl {
                     return AudioFormat.CHANNEL_OUT_7POINT1;
                 }
             default:
+                Log.e(TAG, "Unsupported channel count: " + channelCount);
                 return AudioFormat.CHANNEL_OUT_DEFAULT;
         }
     }