摘要:
An apparatus and method for recording on and reproducing from a magnetic tape a digital signal by rotating heads. A synchronizing signal, a control signal, and an error correction code are added to the digital signal, and the digital signal with those signals added is converted into a block form. At the recording time, a recording signal produced from a recording circuit is recorded on the recording medium by a first head of the rotating heads, and at the same time the recorded signal is reproduced by a second head of the rotating heads. In addition, there are provided a first recording mode in which two error correction codes are added, and a second recording mode in which three error correction codes are added. Thus, the recorded signal can be confirmed by the simultaneous playback made at the recording time so that the reliability in data can be assured.
摘要:
The present invention relates to an information providing system. More particularly, this invention relates to an information management apparatus capable of reliable management of distributed information and an information providing system employing the same information management apparatus. The information management apparatus comprises a main information reproducing means for reproducing main information recorded in a given recording medium; and a reproduction management means for managing the main information reproducing means for reproducing the main information. The present invention provides a receiving means provided with a means for recording distributed information and control information limiting the number of main information reproducing cycles on a recording medium, and a main information reproducing means provided with a reproduction disabling means for limiting the reproduction of main information.
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 digital information signal transmitting/receiving method and system having a transmitter for transmitting an encrypted digital information signal and a plurality of receivers for receiving the encrypted digital information signal from the transmitter. The transmitter simultaneously distributes a plurality of identification codes associated with the receivers at a time ahead of the digital information signal. The receivers detect whether a particular identification code assigned to the receiver was included within a received plurality of identification codes. When the particular identification code has been detected as having been received the received encrypted digital information signal is decrypted into the original digital information. In order to request that a particular identification code be included so as to allow access to a program, either one of the receivers or the recorders each generate an information request signal. The transmitter is responsive to the information request signals to add to the digital information signal at a time ahead of the digital information signal, identification signals for identifying the receivers or the recorders which generated the information request signals, thereby producing a transmission signal formed of those signals, and to distribute this transmission signal to the receivers. The recorders control the received information signal to be recorded in response to the identification signals received by the receivers.
摘要:
Methods of operating a digital video recording and playback device to identify trick play data, e.g., data that is intended for use during trick play modes of video playback device operation such as fast forward and reverse, by recording headers containing specific trick play information along with the trick play data are described. In one embodiment, the recording of headers which identify data as data intended for use during trick play as opposed to normal play operation is described. In addition to identifying data recorded data as normal play or trick play data headers associated with recorded data may identify the speed and direction of video tape recorder operation during which the specific data associated with the header is intended to be displayed at. When a data block includes data packets, a header may be used to identify various ones of the data packets as being for use during one mode of trick play operation, e.g., a first fast forward speed of operation, and other packets in the same data block as being for use during a second mode of trick play operation.
摘要:
In a reproducing apparatus, a generator circuit for adding copy information during the vertical blanking period of a reproduced video signal output is provided, and copy information in compliance with copy information contained in the reproduced signal is added and delivered. In a recording apparatus, a detection circuit for detecting copy information in an inputted video signal is provided, and permission/inhibition of copy is controlled on the basis of the detected copy information and when copy is permitted, necessary copy information is generated and added to a recording signal.
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 recording method is provided for a video tape recording apparatus having modes for recording PCM audio signals in a plurality of transmission rates. Index codes for a video signal, which enable a search reproduction and so on, are recorded on a video tape in a constant transmission rate irrespective of the transmission rate of a PCM audio signal to be recorded. Further, an amble pattern at the same frequency as the transmission rate of the PCM audio signal is recorded immediately behind the PCM signal recording area. A reproducing apparatus may be provided only with an index detecting circuit corresponding to the constant transmission rate.
摘要:
A digital-to-analog converter device for PCM signals at different sampling frequencies comprises a signal converter which expands the frequency distance between a PCM signal band and a side band by converting the sampling frequencies associated with the PCM signals to be reproduced into higher frequencies. With this signal converter, a single low-pass filter can be simplified, having a gradual ramp cut-off characteristic for removal of the side band wherein a pass band cut-off frequency and a stop band cut-off frequency can be adapted for low pass filtering of the PCM signals at different sampling frequencies.
摘要:
The recording area of the magnetic tape is divided into a first area for recording a PCM converted audio signal and a second area for recording a PCM converted video information. In recording the audio signal and the video information which have been separately PCM converted, the magnetic tape is wrapped around the rotary heads so that a wrap angle of each of said first and second areas is less than 90.degree. with respect to the rotary heads of a predetermined diameter.