When we talk about embedded audio in a SDI video signal, we refer to the digital audio that is included in the frame of the SDI digital video signal. That is, through a single cable or fiber, a video signal plus the audio signal associated with that video is transmitted.
The SMPTE 299M-2004 standard describes how a digital audio signal of 24 bits and its control information are included in the ancillary data space of a video frame according to the SMPTE 292M standard.
AES audio data may contain PCM audio data or non- PCM data formatted according to SMPTE 337.
They are organized into groups of 4 channels of digital audio and up to 4 groups can be transmitted, giving a maximum of 16 channels (8 AES pairs) at sampling rates of 32 kHz, 44.1 kHz or 48 kHz. At 96 kHz, up to 8 channels can be transmitted. The characteristics of the digital audio of all channels must be equal (sampling frequency, sampling phase and timing).
Each audio group has a unique identifier. Audio data packets are embedded in the horizontal ancillary space of Cb / Cr (chrominance) data stream.
Control packets for audio (providing information such as frame number, sampling frequency, audio processing delay, and channel status) are embedded in the horizontal ancillary space of the Y (luminance) data stream.
In certain applications, it may be necessary to extract audio from the SDI signal and transmit it separately from the video. This is possible using audio de-embedder devices.
PINANSON PRODUCTS WITH DE-EMBEDDER
3G-SDI digital video splitter + analogue audio distribution: from the de-embedded audio of the SDI signal and converted to analogue at line level
