From Digital Interface Handbook, Third Edition


There is an increasing trend towards employing standard computer interfaces and networks to transfer audio information, as opposed to dedicated audio interfaces. Such computer interfaces are typically used for a variety of purposes in general data communications and they may need to be adapted for audio applications that require sample-accurate real-time transfer. The increasing ubiquity of computer systems in audio environments makes it inevitable that generic data communication technology will gradually take the place of dedicated interfaces. It also makes sense economically to take advantage of the 'mass market' features of the computer industry.

The applications and protocols described in this chapter are primarily concerned with real-time audio communications or 'streaming', rather than file transfer, and the coverage is limited to studio contexts. The reason for this is that these applications are similar to those for which the dedicated audio interfaces described elsewhere in this book would be used. Some examples are given of proprietary technology that addresses the problems of streaming audio over computer networks but not every proprietary solution is covered in detail. The wider issue of Internet audio streaming for the consumer distribution of music or broadcasts is not covered in any detail. Those interested in more detailed aspects of network applications in digital audio are referred to Andy Bailey's book Network Technology for Digital Audio1.

5.1 Introduction to Carrying Audio Over Computer Interfaces

Dedicated audio interfaces mostly carry audio data in a sample-clock-synchronized fashion, often with an embedded sample clock signal, carrying little or...

Products & Services
Voice Loggers and Audio Recorders
Audio recorders / voice loggers are used to locate, retrieve, duplicate and/or distribute audio voice or data information from single system environments to large multi-channel networked systems.
Video and Audio Software
Video and audio software is used to process audio and video signals. Applications can include motion analysis, security, ID systems, etc.
Teleconferencing and Webcast Services
Teleconferencing and webcast service providers host video conferencing or webinars for business presentations.
Sound Cards
Sound cards are computer expansion cards that enable audio inputs and outputs. They connect to the computer via the internal bus or an external connection.
Video Servers
Video servers enable distribution of video signals over networks including local area networks (LANs) and the Internet.

Topics of Interest

6.1 The Importance of Synchronization Unlike analog audio, digital audio has a discrete-time structure, because it is a sampled signal in which the samples may be further grouped into frames and...

4.1 Background to Dedicated Audio Interfaces When digital audio interfaces were first introduced it was assumed that digital audio signals would need to be carried between devices on connections...

Eur Ing Andrew W. Jones Bsc CEng MIEE Engineering Learning Executive BBC Training & Development 2.8.1 Layered Approach to Broadcast Media Interfaces It is common to talk of a 'stack' when referring...

Overview For the purposes of this book, digital audio interfaces will be divided into two types. This chapter is concerned with those that are dedicated point-to-point audio interfaces (e.g.

Chapter List Chapter 7: Introduction to Streaming Media Chapter 8: Video Encoding Chapter 9: Audio Encoding Chapter 10: Preprocessing Chapter 11: Stream Serving Chapter 12: Live Webcasting...