Description of the issue

configLen is 0 but it is recommended to have a preroll config


General compliance
Best practice


ISO IEC 23003-3 (USAC):
configLen: configLen is preroll frames related Config element length, and out of band UsacConfig may be not the same as the one for preroll frames, it is recommended to have the preroll configuration beside the preroll frames.

Possible solution/action

ISO IEC 23003-3:
Configure or update the USAC encoder in order to put a Config element in the AudioPreRoll element, then reencode the content.