An Implementation of Real-Time Audio Monitoring in Network Camera - Multimedia and Signal Processing - page 413

Fig. 1. Network Camera Topology

2 Solution and Principles

2.1 A Solution to Network Camera

In this paper, a network camera solution is adopted which is based on Ambarella A5s
platform and embedded real-time operating system Linux. A5s is supported with a
hardware reference design, SDK (software developer's kit) and full camera software
application. This solution [2] realizes multimedia processing containing audio and
video capture, compression and network transmission in single board by using a high-
integrated chip which integrates an image sensor pipeline, a HD (High Definition)
H.264 video Codec (DSP) and a 528MHz ARM11 processor. The hardware frame-
work [2] of the whole system is illustrated in Fig. 2.

Fig. 2. Hardware Overview

As a consequence of high complexity of H.264 encoding, video encoding is im-
plemented by DSP hardware, which enhances encoding efficiency greatly and guaran-
tees that ARM11 processor can run application programs efficiently such as audio
encoding and network transmission, both focused on in this paper. Audio subsystem