摘要:
An interface architecture for interconnecting a plurality of video display devices together over a high speed digital communication link having limited bandwidth provides at each node for transmitting during a "transmit mode"; (1) sequential pixels of digital data (COMVIDOUT) comprising separate luminance and chrominance fields, from a digital TV source associated with each display node which data represents a scaled video window, (2) the local system clock (SCLK), (3) vertical and horizontal communication sync signals (COMVSOUT and COMSHOUT), (4) luminance and chrominance clock enable signals (COMYOCE and COMCOCE) based on a scaling algorithm utilized in the transmitting video device to insure that both the proper pixels and the proper luminance and chrominance fields associated with these pixels are selected by the communications device for transmission. Further, the interface architecture at each display node provides for receiving during a "receive mode", (5) video input data pixels (COMVIDIN), (6) a video input data clock enable signal from the communications adapter (COMVINCE) which controls the storage of the received video data window in the local frame buffer, (7) horizontal and vertical video input sync signals from the communications adapter (COMHSIN and COMVSIN) for properly synchronizing the storing of the received video input data from the communications adapter into the frame buffer beginning ata predetermined address therein. The system utilizes, to a great extent, exisiting hardware in conventional video display device architectures and associated communications adapters such that a versatile generally applicable transmission system is achievable requiring a minimum of additional control hardware and software.
摘要:
A high-speed communications network (10) provides singlecast, multicast, or broadcast image data capability and is implemented utilizing the High-Performance Parallel Interface (HPPI) as a physical channel. A server (12) includes both a HPPI receiver and transmitter. Workstations (18) support a HPPI-compatible receiver (14b), but require only a simplified HPPI output port (20). The workstations are connected such the receiver port of each is driven by data and control signals from an upstream server HPPI transmitter port. Handshaking signals, generated by the receiver ports, ripple upstream to the server or to an upstream workstation output port. A packet of data bursts corresponds to either a complete image frame, or to a rectangular subsection thereof, referred to as a window. A first burst is defined to be a Header burst and contains an Image Header that specifies addresses of addressed workstations. Following the Header burst are image data bursts containing pixel data organized in raster format.
摘要:
Method and apparatus for implementing a raster graphic display video data path that provides arbitrary mixing of a plurality of images. The video data path is highly parallelized, and employs parallel devices operating under the control of a set of look-up tables. The look-up tables are loadable from a controller, such as a host workstation. The raster graphic display video data path functions with unlimited screen resolutions, and also enables a variety of different pixel data formats from a potentially large number of different sources. Outputs from several image sources are mixed under the control of the host workstation, with a resultant pixel value being based on (a) a combined translucency coefficient (alpha) of the images, for each image source, and (b) a window identification number assigned by the host workstation. Pixel value conversion to a common predetermined format provides coherency between pixel values generated by a number of different image sources, such as HDTV and graphics servers. A separate frame buffer is allocated for each of the sources.
摘要:
A locking mechanism is incorporated in a high-resolution video display system including a monitor, a computer for providing controls signals to said display system and two frame buffers, one for storing computer generated graphics images and one for storing video data both of said buffers being operable under control of said computer for reading out data to the monitor. The locking mechanism includes an output lock functionally located between the output of both of the frame buffers and the monitor for preventing video data from overwriting graphics data on said monitor screen. An input lock is also provided for preventing static video data stored in predetermined regions of the video frame buffer from being continually overwritten by motion video data being continually supplied to the video frame buffer. The output lock utilizes an extra bit-plane in the video buffer which stores a predetermined lock pattern and utilizes the normal monitor output port of the buffer operating under control of standard frame buffer addressing circuitry in combination with straight-forward combinational logic to achieve the locking function. The input lock utilizes a small DRAM which stores the input lock pattern data and utilizes this data in conjunction with normal write operations in the video buffer to control circuitry to disable the write function in predetermined regions of the video buffer.
摘要:
A display system is described which includes storage for receiving a compressed pixel image manifesting at least a pair of encoded colors and a bit MASK that defines which pixels of a pixel subset of the pixel image receive one of the colors. The system comprises a plurality of memory modules. The pixels in the subset are interleaved in the memory modules. A generator is provided for applying signals to cause data to be written into each of modules in parallel. Register means are provided for applying data manifesting the encoded colors to the modules. Control apparatus is responsive to the MASK bits for controlling the generator to write the encoded color data, in parallel and in a single memory cycle, into all pixel positions of the subset that are designated for the color(s) by MASK bit position values.
摘要:
An image display system includes an input to a source (10, 12, 14) of image pixel data wherein each pixel is expressed as an M-bit value within a non-linear range of values. A first LUT (16) is coupled to an output of the source for converting each M-bit pixel value to an N-bit value within a linear range of values. An image memory, or frame buffer (18), has an input coupled to an output of the first LUT for storing the N-bit pixel values. The system further includes a second LUT (20) coupled to an output of the frame buffer for converting N-bit pixel values output by the frame buffer to P-bit pixel values within a non-linear range of values. The converted values are subsequently applied to a display (24). In an exemplary embodiment, the first LUT stores gamma corrected pixel values and the second LUT stores inverse gamma corrected pixel values. Preferably the second LUT stores a plurality of sets of inverse gamma corrected pixel values. Also, the frame buffer stores, for each of the N-bit pixel values, a value that specifies a particular one of the plurality of sets of inverse gamma corrected pixel values for use in converting an associated one of the N-bit pixel values.
摘要:
A video pixel presentation rate expansion circuit is provided for use with a high-resolution display system. The overall display system includes a high-resolution monitor, a computer for providing control signals, including a high-resolution frame buffer for storing computer graphics and TV video images and reading out said video data at a rate controlled by said control signals and providing said data with a high-resolution monitor for display. The expansion circuit of the present invention comprises means responsive to an expansion pattern generated by the computer for changing the time base of the video pixel data read out of said frame buffer. Circuit includes means responsive to said expansion pattern for selectively repeating predetermined scan lines of said video display and for selectively repeating certain pixel along a given scan line to match the time base of the video data read out of said frame buffer to the time base of said high-resolution monitor. According to a preferred embodiment of the invention the expansion circuit functions to modify the control signals which controls the read-out of the frame buffer in a predetermined fashion without any additional video buffer storage means.
摘要:
A circuit for interfacing between a digital-television circuit for producing pixel data for television images and a computer graphics display permits rapid scaling and positioning of live television images on the graphics display. In a preferred embodiment, the digital-television/computer-graphics interface circuit of the invention includes memory for storing a horizontal-scaling bit pattern and a vertical-scaling bit pattern. Such a preferred interface circuit is adapted to receive digital-television pixel data from the digital television circuit and, on a pixel-by-pixel basis depending on the state of corresponding bits in the horizontal-scaling bit pattern, to skip the pixel in the case of image contraction and to replicate the pixel in the case of image expansion. The preferred interface circuit is also adapted to receive digital-television pixel data on a television-line by television-line basis and, depending on the state of a corresponding bit of the vertical-scaling bit pattern, to skip the entire line of pixel data in the case of image contraction or to replicate the line in the case of image expansion. The interface circuit may include a hardware vector generator for generating scaling bit patterns in accordance with a procedure analogous to a vector-drawing procedure used in graphics displays, such as the "Bresenham procedure."
摘要:
A method and apparatus for synchronizing two independent rasters, such that a standard TV video and a high resolution computer generated graphics video may each be displayed on a high resolution graphics monitor. This is accomplished utilizing dual frame buffers. A TV frame buffer, comprises a dual port VRAM, with the serial and random ports operating asynchronously. The primary port receives incoming TV video synchronously as it comes in, and the secondary port reads the TV video out synchronously with the high resolution graphics monitor. A high resolution frame buffer in a computer is utilized to store high resolution graphics which is read out synchronously with the high resolution graphics monitor. A switching mechanism selects which of the TV video and the high resolution graphics video is to be displayed at a given time. The TV frame buffer includes an on screen and off screen portion. The computer provides computer data, including high resolution graphics data and audio data to the TV frame buffer, with the graphics data being stored in the on screen portion and the audio data being stored in the off screen portion. The audio data is read out to an audio circuit for replay. The graphics data is combined with the TV video for purposes of windowing.
摘要:
An image buffer semiconductor chip is described that includes circuitry for decompressing, compressed pixel image data such data comprising at least a pair of color codes and a bit mask including bit positions with values that define which pixels in a pixel subset of the pixel image receive the encoded color code data. The chip comprises a matrix of memory modules with the pixels in a pixel subset stored in an interleaved fashion, one pixel per module. A data bus communicates with all of the memory modules and broadcasts the color codes. A mask register stores the bit mask when it appears on the data bus. Circuitry selectively writes a first color code in the modules in accordance with bit values of a first kind in the MASK and writes the second color code into the modules in accordance with bit values of a second kind in the MASK.