ISO/IEC TR 21000-12:2005 specifies a test bed that is designed to assist in performance assessment of MPEG-21, Scalable Video Codec (SVC) for streaming applications, and for the evaluation of resource delivery technologies over unreliable packet-switched networks. The streaming protocols used in the test bed are based on RTSP and RTP. The Network Adaptation QoS mechanism of MPEG-21 Digital Item Adaptation (DIA) is used for bandwidth-scalable streaming. A subset of MPEG-4 IPMP is also included in the test bed so that encrypted streaming and layered access functionality of a DRM system can be tested for different SVC designs.
The test bed includes a network emulator GUI that interfaces with a Linux-based network emulator, NistNet, for real-time emulation of channel characteristics of various networks. Therefore:
- Various scalable codec (audio, video, scene composition) technologies can be evaluated.
- Various packetization methods and file formats can be evaluated.
- Various multimedia streaming rate control and error control mechanisms can be plugged into the test bed and evaluated.
In summary, the following MPEG technologies are demonstrated by the test bed:
- MPEG scalable audio and video codecs;
- MPEG-4 on IP;
- MPEG-4 IPMP (a small subset); and
- MPEG-21 DIA Network Adaptation QoS.
The architecture and the API are not tied to any particular media codecs. However, currently only the MPEG-4 FGS video and MPEG-4 BSAC audio are officially supported by the software. The support for ISO/IEC 21000-13 (MPEG-21 part 13) SVC will be included when that International Standard is ready.