@java.lang.Override
    public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
      if (inputTrack_ != 0) {
        output.writeInt32(2, inputTrack_);
      }
      if (inputChannel_ != 0) {
        output.writeInt32(3, inputChannel_);
      }
      if (outputChannel_ != 0) {
        output.writeInt32(4, outputChannel_);
      }
      if (java.lang.Double.doubleToRawLongBits(gainDb_) != 0) {
        output.writeDouble(5, gainDb_);
      }
      if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(inputKey_)) {
        com.google.protobuf.GeneratedMessageV3.writeString(output, 6, inputKey_);
      }
      getUnknownFields().writeTo(output);
    }
<pre>
Audio volume control in dB. Negative values decrease volume,
positive values increase. The default is 0.
</pre>

<code>double gain_db = 5;</code>

@return The gainDb.
java-video-live-stream/proto-google-cloud-live-stream-v1/src/main/java/com/google/cloud/video/livestream/v1/AudioStream.java