Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, graphics input and audio input simultaneously. The system includes a video decoder having a chroma-locked sample rate converter. The chroma-locked sample rate converter converts the samples to those taken at a sample rate that is a multiple of the chroma subcarrier frequency and that is locked to chroma bursts of the analog video signal in a control loop. The video decoder also includes a line-locked sample rate converter that receives samples at a multiple of the chroma subcarrier frequency and converts the samples to samples with a sample frequency that is a multiple of the horizontal line rate of the video input. The line-locked sample rate converter measures the horizontal line rate to an accuracy of a fraction of a pixel and adjusts the sample rate and phase of the line-locked sample rate converter to produce accurate line-locked samples.

Abstract: A graphics display system integrated circuit is used in a set-top box for controlling a television display. The graphics display system processes analog video input, digital video input, and graphics input. The system incorporates a unified memory architecture that is shared by the graphics system, a CPU, and other peripherals. The unified memory architecture uses real time scheduling to service tasks. Critical instant analysis is used to find a schedule for memory usage that does not affect memory requirements of real time tasks while at the same time servicing non-real-time tasks as needed.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, a graphics input and an audio input simultaneously. The system may use anti-aliased text and graphics to provide high quality display of graphical elements, or glyphs, which represent an image of a character of text or graphics, on television and other displays. The graphical elements may be superimposed over live video or arbitrary graphics imagery.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, and graphics input. The chip includes a single polyphase filter that preferably provides both anti-flutter filtering and scaling of graphics. Anti-flutter filtering may help reduce display flicker due to the interlaced nature of television displays. The scaling of graphics may be used to convert the normally square pixel aspect ratio of graphics to the normally rectangular pixel aspect ratio of video.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, a graphics input and an audio input simultaneously. The chip includes a display engine that processes graphics images organized as windows. The system includes plurality of line buffers for receiving the graphics contents. The graphics contents are composited into each of the plurality of line buffers by blending the graphics contents with the existing contents of the line buffer until all of the graphics surfaces for the line have been composited.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, a graphics input and an audio input simultaneously. The chip includes a display engine that processes graphics images organized as windows. The display engine processes graphics images formatted in any one of a plurality of formats including a color look up table (CLUT) format. A color look-up (CLUT) table loading mechanism preferably facilitates the transfer of real-time CLUT table data during graphics composition. The loading mechanism may be triggered by a window descriptor that contains a color look-up table load command.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, and graphics input. The chip blends graphics and video information by various graphics windows using alpha values for the windows, alpha values per pixel, or both. The chip calculates a composite alpha value based on the window's alpha values and the alpha values per pixel. Blended graphics and video may then be composited using the composite alpha value.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, a graphics input and an audio input simultaneously. The system may use anti-aliased text and graphics to provide high quality display of graphical elements, or glyphs, which represent an image of a character of text or graphics, on television and other displays. The graphical elements may be superimposed over live video or arbitrary graphics imagery.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, and graphics input. The chip includes a single polyphase filter that preferably provides both anti-flutter filtering and scaling of graphics. Anti-flutter filtering may help reduce display flicker due to the interlaced nature of television displays. The scaling of graphics may be used to convert the normally square pixel aspect ratio of graphics to the normally rectangular pixel aspect ratio of video.

Abstract: A graphics display system integrated circuit processes analog video input, digital video input, and graphics input. The system incorporates a graphics accelerator that includes memory for graphics data. The accelerator preferably includes a coprocessor for performing vector type operations on a plurality of components of one pixel of the graphics data. The accelerator also includes an expanded instruction set for storing and loading data.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, a graphics input and an audio input simultaneously. The chip includes a display engine that processes graphics images organized as windows. The display engine processes graphics images formatted in any one of a plurality of formats including a color look up table (CLUT) format. A color look-up (CLUT) table loading mechanism preferably facilitates the transfer of real-time CLUT table data during graphics composition. The loading mechanism may be triggered by a window descriptor that contains a color look-up table load command.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, graphics input and audio input simultaneously. The system includes a video decoder having a chroma-locked sample rate converter. The chroma-locked sample rate converter converts the samples to those taken at a sample rate that is a multiple of the chroma subcarrier frequency and that is locked to chroma bursts of the analog video signal in a control loop. The video decoder also includes a line-locked sample rate converter that receives samples at a multiple of the chroma subcarrier frequency and converts the samples to samples with a sample frequency that is a multiple of the horizontal line rate of the video input. The line-locked sample rate converter measures the horizontal line rate to an accuracy of a fraction of a pixel and adjusts the sample rate and phase of the line-locked sample rate converter to produce accurate line-locked samples.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, and graphics input. The chip includes a single polyphase filter that preferably provides both anti-flutter filtering and scaling of graphics. Anti-flutter filtering may help reduce display flicker due to the interlaced nature of television displays. The scaling of graphics may be used to convert the normally square pixel aspect ratio of graphics to the normally rectangular pixel aspect ratio of video.

Abstract: A graphics display system integrated circuit is used in a set-top box for controlling a television display. The graphics display system processes analog video input, digital video input, and graphics input. The system incorporates a unified memory architecture that is shared by the graphics system, a CPU, and other peripherals. The unified memory architecture uses real time scheduling to service tasks. Critical instant analysis is used to find a schedule for memory usage that does not affect memory requirements of real time tasks while at the same time servicing non-real-time tasks as needed.

Abstract: A graphics display system integrated circuit is used in a set-top box for controlling a television display. The graphics display system processes analog video input, digital video input, and graphics input. The system incorporates a unified memory architecture that is shared by the graphics system, a CPU, and other peripherals. The unified memory architecture uses real time scheduling to service tasks. Critical instant analysis is used to find a schedule for memory usage that does not affect memory requirements of real time tasks while at the same time servicing non-real-time tasks as needed.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, a graphics input and an audio input simultaneously. The chip includes a display engine that processes graphics images organized as windows. The display engine processes graphics images formatted in any one of a plurality of formats including a color look up table (CLUT) format. A color look-up (CLUT) table loading mechanism preferably facilitates the transfer of real-time CLUT table data during graphics composition. The loading mechanism may be triggered by a window descriptor that contains a color look-up table load command.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, a graphics input and an audio input simultaneously. The chip uses window descriptors to describe logical surfaces, or windows, of graphics information to be displayed on the screen. The chip incorporates a unified memory architecture that provides a high level of system performance while conserving memory bandwidth and chip size. Video and graphics scaling capabilities as well as anti-flutter filtering capability are provided.

Abstract: A graphics display system integrated circuit processes analog video input, digital video input, and graphics input. The system incorporates a graphics accelerator that includes memory for graphics data. The accelerator preferably includes a coprocessor for performing vector type operations on a plurality of components of one pixel of the graphics data. The accelerator also includes an expanded instruction set for storing and loading data.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, and graphics input. The chip blends graphics and video information by various graphics windows using alpha values for the windows, alpha values per pixel, or both. The chip calculates a composite alpha value based on the window's alpha values and the alpha values per pixel. Blended graphics and video may then be composited using the composite alpha value.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, graphics input and audio input simultaneously. The system includes a video decoder having a chroma-locked sample rate converter. The chroma-locked sample rate converter converts the samples to those taken at a sample rate that is a multiple of the chroma subcarrier frequency and that is locked to chroma bursts of the analog video signal in a control loop. The video decoder also includes a line-locked sample rate converter that receives samples at a multiple of the chroma subcarrier frequency and converts the samples to samples with a sample frequency that is a multiple of the horizontal line rate of the video input. The line-locked sample rate converter measures the horizontal line rate to an accuracy of a fraction of a pixel and adjusts the sample rate and phase of the line-locked sample rate converter to produce accurate line-locked samples.