DW Spectrum User Manual

DW Spectrum provides support for multiple audio devices with audio related controls available at the resource level and both the user and group-level permissions.

Properly configured audio can help users to have a better understanding of what is happening at the scene. In cases where a loudspeaker is present, Using 2-Way Audio enables the option to communicate with resources on site and many analytical solutions include sound detection as a method to trigger an event (seeEvent Rules).

Key Concepts:

•Individual devices can have audio support enabled or disabled (See Configuring Audio on a Device).

•Audio from audio-enabled devices is captured to the archive when recording is enabled for the device.

•Audio will play in live views and from the archive when the user has the Play Audio permission (see Permissions Management).

•There can be multiple volume controls (client, workstation, remote connection services) present in a Site (see Adjusting Volume).

•The Desktop Client can simultaneously play audio from all devices open in a layout when Play audio from all cameras on layout is selected in Local Settings.

NOTE: After enabling audio from all devices in a layout, individually mute devices until only the desired audio streams are active.

Audio-Video Synchronization:

The performance of audio-video synchronization by timestamp  relies on:

•To provide what is considered lip-synced audio, Digital Watchdog synchronizes audio and video streams using the same timestamp for both, as received from the device.

•Accurate synchronization timing in the RTSP stream of the devices.

•Available network bandwidth between devices, servers, and clients.

•Sufficient resources are available in the server-client environment.

Supported Audio Codecs:

•AAC – Advanced Audio Coding is an audio coding standard for lossy digital audio compression.

•G.711 (u-Law/A-law) – an ITU-T PCM speech coding standard providing toll-quality voice compression.

•G.726 – an ITU-T ADPCM speech coding standard with half the bitrate of G.711.

•MPEG Audio (MP1, MP2, and MP3) – an audio coding standard for lossy digital audio compression.