Lexington, MA STMicroelectronics announced a portfolio of technologies that it is developing for audio/video streaming in wireless home IP-based networks. These technologies are targeted at enabling consumers to share multimedia content within different devices (set-top boxes, PCs, DVD players/recorders, mobile terminals) that are connected through wireless links. The technologies that under development include video transcoding, advanced video encoders, and robust decoders (H.264), Adaptive Playout, 802.11n WLAN, and Security/DRM (Digital Rights Management).
ST is very focused on video transcoding, which is a technique that allows compressed digital video streams to be adapted to different network transmission and receiver conditions without requiring that the bitstreams be fully decoded and then re-encoded. ST’s Advanced Systems Technology (AST) group is developing a transcoding technology called Dynamic Bitstream Shaper (DBS). This is a global MPEG-2/ H.264 input/output framework that will support changes in bitrate, frame rate, frame size and coding standard without needing to decode and re-encode the bitstream.
Video transcoding is needed whenever it is necessary to modify the form in which the digital content is delivered. Common examples include changing the bitrate to fit a particular channel rate or storage time in PVR-like applications or changing the resolution to allow for different capabilities in the receiving equipment such as sending a High Definition (HD) video stream to a Standard Definition (SD) TV set or displaying SD video on a CIF mobile terminal. Video transcoding also allows the frame rate to be easily changed, for example to achieve fast forward/rewind or to best exploit the available channel or storage capacity. This can also be used, in conjunction with frame size change, to fit terminal/client capabilities, for example to display a 30Hz sequence on 15Hz mobile display.
ST has developed and tested high performance algorithms for MPEG-2 to MPEG-2 bitstream and MPEG-2 to H.264 bitstream transcoding, both with bit-rate, frame rate and resolution change supported. Currently being developed are advanced algorithms for H.264 to MPEG-2 and H.264 to H.264 bitstream transcoding, also with bit-rate, frame rate and resolution changes. ST is also extending transcoding to support VC-1. ST’s DBS technology will deliver reduced computational workload and power consumption, reduced delays and increased quality compared to today’s state-of-the-art decoding/re-encoding methods.
In the area of multimedia encoding and decoding, ST has developed new high-quality and low-complexity algorithms for consumer H.264 encoding and decoding, including motion estimation and rate control algorithms. Error detection and concealment algorithms have also been developed for H.264 decoding, allowing the decoder to sustain and conceal data packet losses, a common condition on wireless packed-based best effort IP networks. Adaptive Playout techniques have also been developed that enable buffering delays during interactive multimedia services such as videoconferencing or channel changing to be minimized, ensuring that the user does not experience annoying artifacts.
To achieve the best possible Quality of Service (QoS), ST’s proprietary Cross-Layer Controller algorithm allows all of the transmission parameters such as WLAN configuration and video stream bit rate, frame rate and resolution to be optimized jointly and dynamically.
ST will be demonstrating these technologies at the Consumer Electronics Show to be held in Las Vegas in January 2006, including a wireless home IP-based network in which media servers and renderers share audiovisual content through an IEEE 802.11g Wireless LAN according to DLNA (Digital Living Network Alliance) guidelines, including UPnP (Universal Plug and Play).
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