public com.google.protobuf.ByteString getRateControlModeBytes() {
        java.lang.Object ref = rateControlMode_;
        if (ref instanceof String) {
          com.google.protobuf.ByteString b =
              com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
          rateControlMode_ = b;
          return b;
        } else {
          return (com.google.protobuf.ByteString) ref;
        }
      }
<pre>
Specify the `rate_control_mode`. The default is `vbr`.

Supported rate control modes:

- `vbr` - variable bitrate
- `crf` - constant rate factor
</pre>

<code>string rate_control_mode = 6;</code>

@return The bytes for rateControlMode.
java-video-transcoder/proto-google-cloud-video-transcoder-v1/src/main/java/com/google/cloud/video/transcoder/v1/VideoStream.java