Lexicon S/PDIF
Interface for real-time transmission of digital audio signals. Abbreviation for Sony/Philips Digital InterFace. The abbreviation can also be found in other spellings: SPDIF, S/P-DIF. The interface is now internationally standardized, the correct official designation is therefore IEC 60958-3.
The interface originated in connection with the development of the CD CD in the early 1980s. As the name implies, the companies Sony and Philips collaborated in its development. For professional applications, a variant of this interface exists under the names AES/EBU or AES3. This variant is standardized as IEC 60958-4. The two variants differ in some details, but are similar enough to ensure a certain degree of compatibility in many cases.
The interface was originally designed to transmit a Stereo signal in PCM format with a Sampling Frequency of 32kHz to 48kHz, but has since been extended to support higher sampling frequencies and/or other encoding formats. For example, the transmission of compressed audio data according to the formats DTS, MPEG, AC-3 etc. is possible, whereby surround sound is also supported.
The interface supports real-time transmission, that is, at the speed at which they are played. For this purpose, a clock signal and various control data are transmitted in addition to the audio data. The clock signal can be extracted in the receiver and used to process the audio data in the correct time.
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