Aspects disclosed in the detailed description include packetizing encoded audio frames into compressed-over-pulse code modulation (PCM) (COP) packets for transmission over PCM interfaces. In one aspect, a COP packetizing circuit is configured to receive an encoded audio frame generated from a PCM frame, and generate a COP packet that includes the encoded audio frame irrespective of the audio format. The COP packet is generated with a packet length proportional to a PCM length of the PCM frame, allowing the COP packetizing circuit to transmit the COP packet over an isochronous PCM interface with a lower bit rate than the PCM frame to reduce power. The COP packetizing circuit provides a mobile computing device with a single packetizing scheme that supports multiple audio formats, and allows for reducing power through bit rate scaling.