IRIS Digital Media Libraries

IRIS Digital Media Libraries

The IRIS Digital Media Libraries provide programming support for digital media development on Silicon Graphics platforms. These libraries are included with the IDO. The term digital media describes digitally sampled audio and video (including still image) data, MIDI event streams, and other associated information such as time codes. Sampled audio/video data can be digitally encoded in a variety of uncompressed and compressed formats

The IRIS Digital Media Development Environment provides programming support for digital audio, digital video, and MIDI applications. The libraries provide programming interfaces to:

audio, video, and MIDI I/O subsystems
data format conversion (including compression)
digital media file importation/exportation
high-level playback functions

The five libraries that comprise the IRIS Digital Media Development Environment are briefly described in the following paragraphs.

Digital Audio Libraries

The digital audio libraries provide a device-independent programming interface to the digital audio I/O subsystems built into Silicon Graphics workstations. You can use the digital audio libraries individually or in combination. Table 6-2 describes the libraries contained in the digital audio library set.

Digital Audio Libraries
Library Library Function
Audio Provides an interface for configuring the audio system, managing audio I/O between the application program and audio hardware, specifying attributes of digital audio data, and facilitating real-time programming.
Audio File Provides an interface for reading and writing the standard digital audio file formats AIFF and AIFF-C standards.
CD Audio Provides an interface for optional Silicon Graphics SCSI CD-ROM drives. This interface features a special mode that allows it to read audio CD format as well as CD-ROM format.
DAT Audio Provides an interface for optional Silicon Graphics SCSI DAT drives.

Digital Audio Libraries
Library	Library Function
Audio	Provides an interface for configuring the audio system, managing audio I/O between the application program and audio hardware, specifying attributes of digital audio data, and facilitating real-time programming.
Audio File	Provides an interface for reading and writing the standard digital audio file formats AIFF and AIFF-C standards.
CD Audio	Provides an interface for optional Silicon Graphics SCSI CD-ROM drives. This interface features a special mode that allows it to read audio CD format as well as CD-ROM format.
DAT Audio	Provides an interface for optional Silicon Graphics SCSI DAT drives.

Figure 6-11 diagrams the interaction between an audio application and the audio libraries, the device drivers, the IRIX filesystem, the audio hardware, and the optional SCSI devices.

Figure 6-11 : Interaction of Digital Audio System Components

MIDI library

The Musical Instrument Digital Interface (MIDI) Library provides a programming interface for timestamped MIDI input/output via serial ports.

Video Library

The Video Library provides both device-independent and device-dependent interfaces to the on-board Indy VINO, and to video options such as Indy Video(TM), Galileo Video(TM), Indigo2 Video(TM), and Sirius Video(TM).

Compression Library

The Compression Library (CL) provides an algorithm-independent, extensible interface for compressing and decompressing animation, video, audio, and image data. The CL interface supports the Cosmo Compress JPEG codec (available for Indigo R4000, Indy, Indigo 2) in addition to several software codecs, including software JPEG. Cosmo Compress connects to a Galileo-family video device to allow realtime JPEG video capture and playback. In this configuration, Cosmo operates as a component of the video I/O system.

Movie Library

The Movie Library is a collection of routines that provides a C language API for creating, reading, writing, editing, and playing movie files. Supported file formats include Silicon Graphics Movie File (SGIMF) format and the Apple" QuickTime(TM) movie file format.