public Builder clearActiveInput() {
      activeInput_ = getDefaultInstance().getActiveInput();
      bitField0_ = (bitField0_ & ~0x00000020);
      onChanged();
      return this;
    }
<pre>
Output only. The
[InputAttachment.key][google.cloud.video.livestream.v1.InputAttachment.key]
that serves as the current input source. The first input in the
[input_attachments][google.cloud.video.livestream.v1.Channel.input_attachments]
is the initial input source.
</pre>

<code>string active_input = 6 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>

@return This builder for chaining.
java-video-live-stream/proto-google-cloud-live-stream-v1/src/main/java/com/google/cloud/video/livestream/v1/Channel.java