Abstract: Methods and apparatus for processing digital video data to reduce the amount of video data required to represent a video frame by representing a frame or pair of field pictures into a single field of a pair of field picture are described. To prevent the second field of the field picture from being displayed a DSM byte associated with the field picture is set so that only the field representing the video frame is displayed. In accordance with the present invention, a field, e.g., a transparent predictively coded field is used as the field picture which is not displayed. In this manner, very little data is required to represent the field picture that is not displayed. When the received frames are represented as pairs of field pictures a single field of the pair of field pictures is selected to represent the video frame with the other field picture being replaced with a field which requires very little data.

Abstract: Methods of operating a digital video recording and playback device, such as a video tape recorder, to arrange trick play data into one or more groups, to generate error correction bits for each group of trick play data, e.g., a group of trick play data blocks, and to correct the data after being read back using the error correction bits is disclosed. The trick play data blocks are made to be smaller than normal play data blocks with multiple trick play data blocks being equal in size to a single normal play data block. By making a group of trick play data blocks equal in size to a single normal play data block, the group of trick play data blocks may be processed as a unit by the same error correction circuitry and in the same manner used to process individual normal play data blocks. In accordance with one embodiment, the error correction bits for a group of trick play data blocks are calculated treating the data in the group of trick play data blocks as a single unit.

Abstract: Digital video tape recorder apparatus that generates commands to instruct a television receiver to perform special processing, e.g., processing designed to enhance image quality, on video data received from the digital video tape recorder during trick play operation is disclosed. The commands from the video tape recorder inform the television receiver that the video tape recorder is operating in trick play mode and that video processing not performed on normal play video data output by the video tape recorder during normal play operation should be performed on the trick play video data which is output during trick play operation. The video data output during trick play operation is a subset of the normal play video data. The video processing commands output during trick play operation instruct a receiver to perform video processing intended to compensate for normal play data intentionally omitted by the video tape recorder from the trick play video data because of, e.g.

Abstract: A method and apparatus for controlling the display of progressively refreshed decoded compressed image representative data is disclosed. Subframes of intracoded video signals, and subframes of intercoded video signals based on the intracoded video signals of successive video frames are used to construct a reference video frame. Refresh descriptor data is provided indicating the number of video frames necessary for acquiring intracoded video signals to form the reference video frame. The display of video frames is inhibited based on the refresh descriptor data until a suitable video frame of intracoded video signals and intercoded video signals based thereon is constructed. In another embodiment of the invention, at least one array of memory elements is provided for storing data corresponding to the subframes of a video frame. Each subframe of a video frame corresponds to one element of the memory array.

Abstract: A technique for determining the constellation size of a QAM signal received by a QAM receiver. In general, the implementation of my technique has, as an input signal, a QAM signal having one of a plurality of constellation sizes and determines of constellation size, e.g., 4, 16, 32-ary, by analyzing the probability density function (pdf) of the QAM signal over a pre-established time period. To properly analyze the QAM signal, the signal is-first squared and then normalized to a preset value, e.g., 2.0. As such, the signal power in any of the various constellations is normalized to a fixed level. By generating a histogram of the squared and normalized QAM signal, the technique determines the number of levels of modulation contained in the QAM signal. Each constellation size has a unique number of modulation levels and thus forms unique histogram. From the histogram, a particular constellation size can be determined.

Abstract: A video recorder compatible receiver for receiving video data from a video recorder such as a video tape recorder ("VTR"). The receiver includes an error concealment circuit, a digital VTR port adapted for coupling to a VTR and/or a tuner module. The receiver receives digital video data from the VTR by either the digital VTR port or the tuner module. VTR commands may also be received from a VTR. Upon receiving a VTR command indicating that the VTR is operating in trick play mode or upon detecting video data that is indicative of VTR trick play operation, the error concealment circuit of the receiver disables normal play error concealment and enables trick play error concealment. The error concealment circuit may perform temporal and spatial filtering on the video data received from the VTR when trick play error concealment is enabled.