Rotary head apparatus for recording and/or reproducing an information track to/from a magnetic tape having predetermined orientation characteristics to prevent unbalance of performance between the channel
A rotary head apparatus for recording and/or reproducing an information track to/from a magnetic tape having predetermined orientation characteristics is constructed by: a first magnetic head having a first azimuth angle; a second magnetic head which has a second azimuth angle whose performance is relatively inferior to that of the first magnetic head and forms or reproduces the information track of a width larger than that of the first magnetic head; and a rotating member for rotating the first and second magnetic heads. The angle of the second azimuth angle for the orientation direction of the tape is larger than that of the first azimuth angle.
In a magnetic recording and reproducing device having a 1ch head and a 2ch head, an azimuth recording operation is carried out on an obliquely evaporated magnetic tape. Angles .theta.1 and .theta.2 formed by a direction of a head azimuth of the 1ch head and the 2ch head and a longitudinal direction of the magnetic tape are respectively set to angles at which an output difference between a reproducing signal of a track recorded by the 1ch head and a reproducing signal of a track recorded by the 2ch head is located within three decibels. Thus, an output difference between the two magnetic heads is reduced while the loss of electromagnetic conversion is reduced.
A rotary head assembly including a plurality of magnetic heads with predetermined azimuth angles. These magnetic heads are formed by mounting MR elements of MR heads and magnetic gaps in inductive heads so that they are exposed from an outer periphery of a rotary drum. End portions of the MR elements of the MR heads are positioned at the same height H.sub.0 ', and end portions defining the magnetic gaps in the inductive heads are positioned at the same height H.sub.0. The rotary head assembly is used in a helical-scanning-type magnetic recording and reproducing apparatus, which includes MR heads and inductive heads and which can provide a large reproducing operation output when forming azimuth angles at the magnetic gaps using thin-film magnetic heads.
The present invention provides, in one embodiment, a system and method for concealing video errors. The system encodes, reorders, and packetizes video information into video data packets for transmission over a communication network such that the system conceals errors caused by lost video data packets when the system receives, depacketizes, orders, and decodes the data packets. In one embodiment, the system and method encodes and packetizes video information, such that adjacent macroblocks are not placed in the same video data packets. Additionally, the system and method may provide information accompanying the video data packets to facilitate the decoding process. An advantage to such a scheme is that errors due to video data packet loss are spatially distributed over a video frame. Thus, if regions of data surrounding a lost macroblock are successfully decoded, the decoder may predict motion vectors and spatial content with a higher degree of accuracy, which leads to higher video quality.
