Abstract: A processing facility is provided for simultaneously receiving multiple streams of digital audio data and based thereon concurrently outputting both an unmixed digital audio signal and a mixed digital audio signal. The processing facility can be implemented, for example, within an audio decoder of a set top box. The facility includes receiving a first stream of digital audio data and a second stream of digital audio data, and outputting the first stream of digital audio data as an unmixed digital audio signal. Simultaneous therewith, the first stream of digital audio data and the second stream of digital audio data are digitally mixed and outputted as a mixed digital audio signal. If necessary, the second stream of digital audio data is redigitized based on a sample frequency of the first stream of digital audio data, and either or both the first stream and second stream of digital audio data are decoded prior to mixing.

Abstract: An integrated digital video system is configured to implement picture-in-picture merging of video signals from two or more video sources, as well as selective overlaying of on-screen display graphics onto the resultant merged signal. The picture-in-picture signal is produced for display by a television system otherwise lacking picture-in-picture capability. The digital video system can be implemented, for example, as an integrated decode system within a digital video set-top box or a digital video disc player. In one implementation, a decompressed digital video signal is downscaled and merged with an uncompressed video signal to produce the multi-screen display. The uncompressed video signal can comprise either analog or digital video. OSD graphics can be combined within the integrated system with the resultant multi-screen display or only with a received uncompressed analog video signal.

Abstract: A programmable bi-directional external graphics/video (EGV) port for a video decode system chip having a video decoder and an internal digital display generator circuit is provided. The programmable EGV port employs a fixed number of signal input/output (I/O) pins on the video decode system chip while providing a plurality of connection configurations for an external graphics controller, an external digital display generator circuit and an external digital multi-standard decoder to the video decoder or the internal digital display generator circuit of the chip. The EGV port includes receiver/driver circuitry for accommodating in parallel a plurality of input/output signals, including pixel data signals and corresponding synchronization signals, as well as a programmable port controller adapted to be coupled between the receiver/driver circuitry and an internal bus of the video decode system allowing access to at least one of the video decoder and the internal digital display generator circuit.

Abstract: A digital video encoder system having a motion estimation processor, and an interface to the motion estimation processor. The motion estimation processor includes a reference memory interface, and inverse quantization processor, an inverse discrete cosine transform processor, and a motion estimation processor unit including a hierarchal search unit. The motion estimation processor is utilized generating temporally compressed datastreams, that is, I-P and I-P-B datastreams.

Abstract: A power-on reset circuit is used to initialize a system component upon power-on. The circuit comprises a digital circuit such as a shift register which exhibits a multiplicity of uncertain or random outputs upon power-on. These output are coupled to digital logic such as an AND gate which itself outputs a power-on reset signal when any of the outputs of the shift register is not a predetermined output level. Because the outputs of the shift register are uncertain or arbitrary upon power-on and there are a multiplicity of such outputs, it is not likely that all of the outputs of the shift register will coincidentally exhibit the predetermined levels upon power-on. Consequently, it is very likely that the AND gate will provide the power-on reset signal upon power-on to initialize the system component.