Motion video signal processing for recording or reproducing – Local trick play processing – With randomly accessible medium
Reexamination Certificate
1999-08-30
2003-09-23
Tran, Thai (Department: 2615)
Motion video signal processing for recording or reproducing
Local trick play processing
With randomly accessible medium
C386S349000, C369S053150
Reexamination Certificate
active
06625390
ABSTRACT:
TECHNICAL FIELD
The invention relates to an apparatus and a method for recording and reproducing data including video data and audio data, and AV (audio video) server.
BACKGROUND ART
In recent years, following multi-channeling of providing information owing to the familiarization of CATV (cable television) or the like, a demand for reproducing a plurality of visual/audio data simultaneously from a single data recording and reproducing apparatus, unlike VTRs (video tape recorder), has become higher. In order to satisfy this demand, a data recording and reproducing apparatus called a video server which records and reproduces visual/audio data using a random accessible recording and reproducing medium such as a hard disk is coming into wide use.
In general, a video server used in, for example, a broadcasting station is required to have a high transfer rate of data to be sent for obtaining high qualities of visual and audio, and a large capacitance to record data for a long period of time. Therefore, it has been tried to acquire a higher transfer rate of data and a larger capacitance by using a data recording and reproducing apparatus comprising a plurality of hard disk (HD in the followings) drives which can perform accumulation of visual and audio data, and parallel processing. Further, it has been tried to record parity data so as to ensure the reliability even if any of the HD drives accidentally breaks down. As a result, even in a case where different numbers of channels are requested due to contents or broadcasting systems of programs provided by a broadcasting station, it is possible to implement a multi-channel video server applicable to a variety of usage patterns, for example, establishing NVOD (near video on demand) systems by separately recording a plurality of material data and transmitting them through multi-channel simultaneously, or by reproducing the identical material data with a time-lag through multi-channel.
In a data recording and reproducing apparatus used in such a multi-channal video server, RAID (Redundant Arrays of Inexpensive Disks) technique proposed in the article presented by Patterson and some others in 1988, is used. In the article, the RAID is classified into five: RAID-1 to RAID-5. The typical ones among them are the RAID-1, the RAID-3 and the RAID-5. The RAID-1 is a method of writing the same contents on two HDDs.
The RAID-3 is a method of recording input data on a plurality of HDDs by dividing the data at a specific length, while generating parity data and writing them on another HDD.
FIG. 11
is a block diagram showing an example configuration of a data recording and reproducing apparatus using the RAID-3. This data recording and reproducing apparatus
101
comprises: a plurality of hard disk drives (referred as HDDs in the followings)
102
1
to
102
N
(N is an integer of 2 or more); an HDD
109
for recording parity data P as redundancy-code data; a data distributor
106
for generating a plurality of divided data by dividing input data D
I
at a specific length and for distributing each of the divided data to each of the HDDs
102
1
to
102
N
; a parity generator
107
for generating parity data P from the divided data outputted from the data distributor
106
; input memories
104
1
to
104
N
for temporarily keeping each divided data outputted from the data distributor
106
; input memory
108
for temporarily keeping the parity data P outputted from the parity generator
107
; controllers
103
1
to
103
N
and
110
, which are respectively connected to the HDDs
102
1
to
102
N
and
109
, for controlling recording the data kept by the input memories
104
1
to
104
N
and
108
on the HDDs
102
1
to
102
N
and
109
, and for controlling reproducing data from the HDDs
102
1
to
102
N
and
109
; output memories
105
1
to
105
N
and
111
for temporarily keeping data read out from each of the HDDs
102
1 to 102
N
and
109
; an error corrector
112
for restoring the divided data by detecting and correcting errors based on the data kept by the output memories
105
1
to
105
N
and
111
and on error information which is described later; a data multiplier
113
for outputting the output data DO obtained by multiplying the output data from the error corrector
112
; and a CPU
114
for controlling the whole apparatus.
Next, the data-writing operation of the data recording and reproducing apparatus
101
will be described. The input data D
I
is inputted to the data distributor
106
, and a plurality of divided data are generated. Each of the divided data is distributed to be recorded on the input memories
104
1
to
104
N
. It is also inputted to the parity generator
107
. At this time, data may be distributed in order in the following manner: provided that, for example, the data are arranged in data lines D
1
, D
2
, D
3
, D
4
, D
5
, with a unit of bit or byte, the data D
1
is distributed to the first HDD
102
1
, the data D
2
is distributed to the second HDD
102
2
, and so forth, and if the data DN is distributed to the last HDD
102
N
, data is distributed in order to the HDDs beginning at the first HDD
102
1
again.
The parity generator
107
generates the parity data P based on the divided data outputted from the data distributor
106
and outputs it. The input memory
108
temporarily records the parity data P. Then, the controllers
103
1
to
103
N
and
110
of the HDDs
102
1
to
102
N
and respectively
109
read out the divided data and the parity data P from the input memories
104
1
to
104
N
and
108
under the control of the CPU
114
, and writes the data on the HDDs
102
1
to
102
N
and
109
respectively.
Next, the data-reading-out operation of the data recording and reproducing apparatus
101
will be described. Each of the controllers
103
1
to
103
N
and
110
reads out the divided data and the parity data P from the HDDs
102
1
to
102
N
and
109
respectively, and writes them on the output memories
105
1
to
105
N
and
111
respectively. At this time, if an error of data-reading-out operation (referred as reading-out error in the followings) occurs in the HDDs
102
1
to
102
N
and
109
, error information indicating that an error has occurred is sent to the controllers
103
, to
103
N
and
110
as status data from the control section in the HDDs
102
1
to
102
N
and
109
. Then, the error information is sent to the CPU
114
as error information ER
1
to Er
N
and Er
p
from the controllers
103
1
to
103
N
and
110
.
Each of the data recorded on the output memories
105
1
to
105
N
and
111
is synchronized and outputted to the error corrector
112
. At this time, if the reading-out error occurs, error information showing that an error has occurred is sent to the error corrector
112
from the CPU
114
. The error information includes information for identifying the HDD in which the reading-out error has occurred. The error corrector
112
restores the divided data based on the error information and the parity data P and outputs the divided data to the data multiplier
113
. Data can be restored by the error corrector
112
only when reading-out errors have occurred in one HDD. When reading-out errors have occurred in a plurality of HDDs, the error corrector
112
can detect the errors but can not restore the data. The data multiplier
113
rearranges the divided data outputted from the error corrector
112
in the original data line and outputs it outside as the output data D
O
.
In contrast, in the RAID-5, a unit(block) of dividing data is made larger and one divided data is recorded as a data block on one HDD, while exclusive OR (parity data) of the data blocks which correspond to one another and are recorded on the HDDs is calculated and the result is recorded as a parity block on another HDD. The parity block is thus distributed to all the HDDs.
FIG. 12
is a block diagram showing a configuration example of a data recording and reproducing apparatus using the RAID-5. This data recording and reproducing apparatus
201
comprises: a plurality of HDDs
202
1
to
202
N
(N i
Fujita Hiroyuki
Hirose Masaki
Ito Norikazu
Katsuo Satoshi
Sato Koichi
Bell Boyd & Lloyd LLC
Onuaker Christopher
Sony Corporation
Tran Thai
LandOfFree
Apparatus and method for recording and reproducing data, and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for recording and reproducing data, and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for recording and reproducing data, and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3048534