The capability of providing real-time multimedia player over the Internet is an important future application for embedded system. However, the main challenge of such an application is the limitation on computation performance and memory size in architecture of embedded system, especially while encoding and decoding. In this paper, a Streaming Packet Tracer (SPT) algorithm is proposed for real-time tracing the streaming packet header. Based on the SPT algorithm, we present a novel software-based technique which enables a non-DSP embedded system to play and record real-time streaming audio simultaneously. To verify the feasibility of the proposed technique, a real-time Internet radio recorder has been implemented on SBC-2410x embedded system successfully. The experimental results show that our achievement has reduced the CPU usage rate from over 100% to about 30%-40% in comparison with other recording method.