
A better solution than forcing OPUS_APPLICATION_VOIP when enabling DTX has been found, which is to set OPUS_SIGNAL_VOICE. This reduces the uncertainty of entering DTX over silence period of audio. This CL contains the setup of OPUS_SIGNAL_VOICE and decoupling opus application mode with DTX. BUG=4559 R=henrik.lundin@webrtc.org, henrika@webrtc.org Review URL: https://webrtc-codereview.appspot.com/46959004 Cr-Commit-Position: refs/heads/master@{#9168}