Abstract: According to one embodiment, a graphics/video processor includes a memory controller. The memory controller includes a first arbiter that receives memory client requests to access a memory device, and a first memory buffer coupled to the first arbiter. The first arbiter stores client requests that are selected by the first arbiter. The memory controller also includes a second arbiter coupled to the first memory buffer and a second memory buffer coupled to the second arbiter. The second arbiter receives requests from the memory client requests stored in the first memory buffer. The second memory buffer stores the client requests selected by the second arbiter. Further, the memory controller includes a third arbiter coupled to the second memory buffer. The third arbiter provides access of the memory device to the client requests stored in the second memory buffer.

Abstract: A receiver includes a sample rate converter configured to receive an input data stream having a variable data rate and to output a data stream having a fixed data rate. In some embodiments, the input data stream corresponds to digital video, digital audio and/or metadata, while in other embodiments the input data stream corresponds to any digital data stream that needs to be data rate converted for use by a receiving device. The sample rate converter is configured to track an externally sourced reference time signal corresponding to the input data stream.

Abstract: A sample rate converter includes a digital filter and control logic coupled to the digital filter. The digital filter is configured to receive an input data stream and to up convert the input data stream to produce an output data stream having a fixed data rate. The control logic configured to dynamically select a set of coefficients for taps in the digital filter during each clock cycle corresponding to the fixed data rate. The set of coefficients selected for each clock cycle is in accordance with a phase of the input data stream.

Abstract: According to one embodiment, a graphics/video processor includes a memory controller. The memory controller includes a first arbiter that receives memory client requests to access a memory device, and a first memory buffer coupled to the first arbiter. The first arbiter stores client requests that are selected by the first arbiter. The memory controller also includes a second arbiter coupled to the first memory buffer and a second memory buffer coupled to the second arbiter. The second arbiter receives requests from the memory client requests stored in the first memory buffer. The second memory buffer stores the client requests selected by the second arbiter. Further, the memory controller includes a third arbiter coupled to the second memory buffer. The third arbiter provides access of the memory device to the client requests stored in the second memory buffer.

Abstract: According to one embodiment, a graphics/video processor includes a memory controller. The memory controller includes a first arbiter that receives memory client requests to access a memory device, and a first memory buffer coupled to the first arbiter. The first arbiter stores client requests that are selected by the first arbiter. The memory controller also includes a second arbiter coupled to the first memory buffer and a second memory buffer coupled to the second arbiter. The second arbiter receives requests from the memory client requests stored in the first memory buffer. The second memory buffer stores the client requests selected by the second arbiter. Further, the memory controller includes a third arbiter coupled to the second memory buffer. The third arbiter provides access of the memory device to the client requests stored in the second memory buffer.

Abstract: A method and a system for reconstructing a partial transport stream are described. One embodiment of the method includes time-stamping each packet when the packet arrives, storing of the selected subset of packets and the associated timestamps in a storage medium, reading the stored packets and their timestamps from the storage medium, and reconstructing the partial transport stream with the packets and their timestamps.

Abstract: According to one embodiment, a graphics/video processor includes a memory controller. The memory controller includes a first arbiter that receives memory client requests to access a memory device, and a first memory buffer coupled to the first arbiter. The first arbiter stores client requests that are selected by the first arbiter. The memory controller also includes a second arbiter coupled to the first memory buffer and a second memory buffer coupled to the second arbiter. The second arbiter receives requests from the memory client requests stored in the first memory buffer. The second memory buffer stores the client requests selected by the second arbiter. Further, the memory controller includes a third arbiter coupled to the second memory buffer. The third arbiter provides access of the memory device to the client requests stored in the second memory buffer.

Abstract: A memory system for B frames of pixel data, where each B frame includes a plurality of sections, and where each of the plurality of sections includes pixel data corresponding to the top and bottom fields of a frame. The memory system includes a memory organized into a plurality of segments for storing the pixel data, where the number of segments equals the number of frame sections plus two additional segments. However, each of the segments is half the size of a frame section. The memory system also includes a segmentation device for receiving and separating pixel data according to the top and bottom fields of each frame. The segmentation device tracks the segments to determine two available segments of said memory, and for each section of each frame, stores pixel data from the top field into one of the available segments and stores pixel data from the bottom field into the other available segment of the memory.

Abstract: A Motion Picture Experts Group (MPEG) multiplexed data bitstream includes encoded video and audio data units, which are prefixed with headers including Presentation Time Stamps (PTS) indicating desired presentation times for the respective data units. The data units are decoded, and presented at a fixed time after decoding, such that the fixed time can be subtracted from the PTS to provide a desired decoding time. The bitstream is parsed, the video and audio headers are stored in video and audio header memories, and the associated video and audio data units are stored in video and audio channel memories respectively. A first interrupt is generated each time a header is stored, and a host microcontroller responds by storing the PTS from the header and the starting address of the corresponding data unit in the channel memory as an entry in a list.

Abstract: A video decoder system for reconstructing, storing and retrieving bidirectionally predictive-coded (B) frames for display including pull-down conversion includes a reconstruction unit for reconstructing the frames, where the reconstruction unit reconstructs the top-upper field of every other frame twice. The frame is conceptually divided into four sections, including top-upper, top-lower, bottom-upper and bottom-lower sections. A memory having only three segments for storing pixel data is provided, where each segment is sized to store any one of the frame sections. A segmentor receives and separates the pixel data according to the top and bottom fields for each section of each frame, and stores pixel data from the top field into one segment pixel data from the bottom field into another segment. The segrnentor initially selects any two segments for the upper half of the first frame, and then selects a segment being retrieved for display and the third segment for the bottom half of the first frame.

Abstract: An MPEG decoder system and method for decoding frames of a video sequence. The MPEG decoder includes frame reconstruction or decoder logic which operates to reconstruct a bi-directionally encoded (B) frame with minimal memory requirements. The MPEG decoder operates to decode or reconstruct the frame twice, once during each field display period. The picture reconstruction unit operates to decode or reconstruct the B frame twice, once each during a first field time and a second field time. The first field time substantially corresponds to the time when the first or top field of the picture is displayed, and the second field time substantially corresponds to the time when the second or bottom field of the picture is displayed. This obviates the necessity of storing the reconstructed B frame data, thus reducing memory requirements.

Abstract: A low cost and easily implemented apparatus and method for synchronizing serially connected clock circuits is ideally suited to audio applications. The circuit takes data from a bitstream clock source and from the local source and counts the number of pulses received from each. A desired clock count is calculated based as a multiple of the ratio of the bitstream clock source frequency to the local clock signal frequency. Based on the samples received from the bitstream clock relative to the local clock at a later point in time, samples are either repeated or dropped to correct any error in the bitstream signal.

Abstract: A novel synchronization scheme for use in connection with digital signal video decoder comprises a pre-parser, a channel buffer, and a post-parser. The pre-parser synchronizes to a multiplexed system bitstream received from a fixed rate channel. The video bitstream component of a multiplexed system bitstream is then extracted and synchronized prior to being transferred bit-serially from the pre-parser to a channel buffer. The post-parser is coupled to the channel buffer and to a video decoder in a series configuration. The post-parser separates the various layers of video data from the video bitstream component. The post-parser performs a translation operation on the video bitstream component and converts the bitstream data into symbol data. The symbol data is subsequently processed by the video decoder so as to reconstruct an originally encoded picture or frame.

Abstract: A Motion Picture Experts Group (MPEG) multiplexed data bitstream includes encoded video and audio data units, which are prefixed with headers including Presentation Time Stamps (PTS) indicating desired presentation times for the respective data units. The data units are decoded, and presented at a fixed time after decoding, such that the fixed time can be subtracted from the PTS to provide a desired decoding time. The bitstream is parsed, the video and audio headers are stored in video and audio header memories, and the associated video and audio data units are stored in video and audio channel memories respectively. A first interrupt is generated each time a header is stored, and a host microcontroller responds by storing the PTS from the header and the starting address of the corresponding data unit in the channel memory as an entry in a list.

Abstract: A low cost and easily implemented apparatus and method for synchronizing serially connected clock circuits is ideally suited to audio applications. The circuit takes data from a bitstream clock source and from the local source and counts the number of pulses received from each. A desired clock count is calculated based as a multiple of the ratio of the bitstream clock source frequency to the local clock signal frequency. Based on the samples received from the bitstream clock relative to the local clock at a late point in time, samples are either repeated or dropped to correct any error in the bitstream signal.

Abstract: A novel channel buffer management scheme for a video decoder minimizes the amount of memory allocated to buffer a video bitstream received from a transmission channel. A channel buffer accumulates picture data encoded in a video bitstream received from a fixed rate channel. Picture data is read out of the channel buffer by a video decoder immediately after a predetermined or expected amount of bitstream data is received by the channel buffer. Picture decoding, reconstructing, and displaying operations are synchronized to permit the transfer of picture data from the channel buffer to the decoder whenever all of the data bits comprising a picture are received in the channel buffer. A microcontroller monitors and regulates the operation of the novel channel buffer management scheme to avoid overflow or underflow of bitstream data in the channel buffer.

Abstract: A novel synchronization scheme for use in connection with digital signal video decoder comprises a pre-parser, a channel buffer, and a post-parser. The pre-parser synchronizes to a multiplexed system bitstream received from a fixed rate channel. The video bitstream component of a multiplexed system bitstream is then extracted and synchronized prior to being transferred bit-serially from the pre-parser to a channel buffer. The post-parser is coupled to the channel buffer and to a video decoder in a series configuration. The post-parser separates the various layers of video data from the video bitstream component. The post-parser performs a translation operation on the video bitstream component and converts the bitstream data into symbol data. The symbol data is subsequently processed by the video decoder so as to reconstruct an originally encoded picture or frame.

Abstract: A novel channel buffer management scheme for a video decoder minimizes the amount of memory allocated to buffer a video bitstream received from a transmission channel. A channel buffer accumulates picture data encoded in a video bitstream received from a fixed rate channel. Picture data is read out of the channel buffer by a video decoder immediately after a predetermined or expected amount of bitstream data is received by the channel buffer. Picture decoding, reconstructing, and displaying operations are synchronized to permit the transfer of picture data from the channel buffer to the decoder whenever all of the data bits comprising a picture are received in the channel buffer. A microcontroller monitors and regulates the operation of the novel channel buffer management scheme to avoid overflow or underflow of bitstream data in the channel buffer.