摘要:
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., data limitations resulting from the limited amount of data that can be accurately read from a tape during trick play operation. Method of generating the video processing commands which are output to a receiver during trick play video tape recorder operation are also disclosed.
摘要:
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. The error correction bits are appended to the last data block in the group of trick play data blocks. During trick play operation the trick play data blocks are read back and combined according to trick play data groups. Each group of trick play blocks is then processed using the same error correction circuitry used to process a normal play data block.
摘要:
A digital video tape recorder ("VTR") that selects data useful for generating images during trick playback operation and records the data in trick play tape segments arranged on a tape to form fast scan tracks and multi-speed playback tracks. Each fast scan track comprises trick play tape segments located on a diagonal, relative to the length of the tape, of the same angle as the angle at which the heads of a VTR are expected to pass over the tape during trick play operation at a specific speed and direction of operation. Each multi-speed playback track comprises a plurality of trick play tape segments arranged parallel to the length of the tape. Data which is used for at least one mode of trick play operation is recorded in each trick play tape segment. Each fast scan track and multi-speed track crosses multiple normal play tracks. During playback at a wide variety of speeds and directions, the heads pass over enough trick play segments of the multi-speed playback track to generate recognizable images during trick play operation. Data is recorded in each trick play segment in a manner that optimizes the amount of data that can be routinely recovered during trick playback operation despite tracking errors.
摘要:
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.
摘要:
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. When frame pictures are received one of a plurality of numerous described methods of mapping frame pictures into a single field of a pair of field pictures are used to convert the frame picture into a single field of a pair of field pictures. A plurality of methods for reducing the amount of data required to represent the single field of the pair of field pictures are also described.
摘要:
A mobile communications device initiates a handoff from its current base station (BS) sector network attachment point to a new BS sector. The mobile sends a handoff request over its current wireless link to the current BS sector, which forwards the request to the new BS sector. The new BS sector processes the request assigning dedicated resources. Information identifying the allocated resources is conveyed from the new BS sector via the current BS sector to the mobile. The mobile determines the time of the allocated dedicated segments based upon a received beacon signal from the new BS sector with known timing relationships to dedicated segments. The mobile breaks the original wireless link just prior to the time of the first assigned dedicated segment. The mobile communicates information on the assigned dedicated segments to perform registration operations establishing a new wireless link.
摘要:
A wireless terminal determines a desired mode of base station operation with regard to whether the base station is to function as a network access node or is to function in a peer to peer mode with regard to a frequency band, and communicates a change signal to the base station. Some change signals are request signals requesting a base station to dynamically reallocate spectrum usage, while other change signals are command signals ordering the base station to reallocate spectrum usage. Information indicating a level of authority corresponding to the change signals, in some embodiments, corresponds to one of a device identifier, a user identifier, and a priority level indicator. An exemplary command signal comes from a device used by a government agent with the authority to override spectrum usage.
摘要:
A portable wireless terminal generates and transmits a beacon signal. The beacon signal includes a sequence of beacon signal bursts, each beacon signal burst including one or more beacon symbols. A beacon symbol is transmitted using the air link resources of a beacon symbol transmission unit at a relatively high transmission power level with respect to user data symbols transmitted from the same wireless terminal, thus facilitating easy detection by other wireless terminals. The beacon symbols of the beacon signal occupy a small fraction of the total available air link resources. Beacon signals can, and sometimes do, convey wireless terminal identification information, via the location of the beacon symbols within the portion of the air link resource reserved for beacon symbol transmission units.
摘要:
Wireless terminal beacon signaling is used to achieve timing synchronization between two wireless terminals in a wireless communication system, e.g., in an ad hoc network lacking a centralized timing reference. An exemplary timing structure used by an individual wireless terminal includes a beacon transmission time interval, a beacon monitoring time interval and a silence time interval. A first wireless terminal monitoring for beacon signals from other wireless terminals, detects a beacon signal portion from a second wireless terminal and determines a timing adjustment as a function of the detected beacon signal portion. The first wireless terminal applies the determined timing adjustment, e.g., time shifting its timing structure, such that its beacon signal can be detected by the second wireless terminal. Implementation of the determined timing adjustment sets the timing structures of the two wireless terminals to have a fixed relationship thereby allowing for coordinated communications including a peer-to-peer communications session.
摘要:
A wireless terminal supports both peer to peer communications and access node based communications. The wireless terminal considers and evaluates communications link alternatives and selects between (i) communication using a peer to peer link and (ii) communications using a link with a base station serving as an access node. Received signals corresponding to each of the link alternatives are used in performing link quality determinations. In one example, a received user beacon signal from a peer wireless terminal is the received signal used for the peer to peer link evaluation and a base station beacon signal is the received signal used for the access node link evaluation. A link is selected as a function of quality determination, predicted data throughput, link maintenance energy requirements, and/or least cost routing determination information.