SMPTE ST 299-1
24-Bit Digital Audio Format for SMPTE 292 Bit-Serial Interface
|Publication Date:||21 July 2010|
This standard defines the mapping of 24-bit AES digital audio data and associated control information into the ancillary data space of a serial digital video conforming to SMPTE 292. The audio data are derived from AES3, hereafter referred to as AES audio. The AES audio data may contain linear PCM audio or non- PCM data formatted according to SMPTE 337. Not all implementations compliant with this standard may support all sampling frequencies. Manufacturers are encouraged to indicate which sampling frequencies are supported (see Annex D).
Audio sampled at a clock frequency of either 48 kHz or 96 kHz locked (synchronous) to video, is the preferred implementation for intrastudio applications. As an option, this standard supports AES audio at synchronous or asynchronous sampling rates from 32 kHz to 48 kHz.
Audio channels are transmitted in groups of four, up to a maximum of 16 audio channels in the case of 32 kHz, 44.1 kHz or 48 kHz sampling, and up to a maximum of 8 audio channels in case of 96-kHz sampling. Each group is identified by a unique ancillary data ID.
Audio data packets are multiplexed (embedded) into the horizontal ancillary data space of the Cb/Cr data stream, and audio control packets are multiplexed into the horizontal ancillary data space of the Y data stream.