Multimedia data recording apparatus, monitor system, and multimedia data recording method

• US 20060152636A1
• Filed: 10/20/2004
• Published: 07/13/2006
• Est. Priority Date: 10/20/2003
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Co. (Panasonic Holdings Corporation)
• Inventors: Yoshio, Hiroaki, Kawai, Fumi, Matsukawa, Takayuki
• Granted Patent: US 7,609,941 B2
• Time in Patent Office: Days
• US Class Current: 348/715
• CPC Class Codes: G08B 13/19667 Details realated to data compression, encryption or encoding, e.g. resolution modes for reducing data volume to lower transmission bandwidth or memory requirements
• CPC Class Codes: G08B 13/19669 Event triggers storage or change of storage policy
• CPC Class Codes: H04N 5/76 Television signal recording
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

A multimedia data recording apparatus is disclosed that enables large-volume recorded data to be recorded for a long period in accordance with the importance of the data, by means of a simple configuration and simple processing, and without imposing a heavy load on the system. In this apparatus, a layer classification section classifies video data captured by a surveillance camera and input via a video processing section into a plurality of layers on a frame-by-frame basis according to importance. A data recording section assigns a file to each layer and records classified data in a data recording medium. If an information amount reduction section detects that the vacant capacity of the data recording medium has reached or fallen below a threshold value, it deletes a frame belonging to the lowest layer among the plurality of layers.

Claims

1. A multimedia data recording apparatus comprising:

a layer classification section that classifies multimedia data into a plurality of hierarchical layers according to data contents or data precision;

a recording section that continuously records data classified into said layers in memory; and

a data amount reduction section that, when vacant capacity of said memory is at or below a threshold value, performs deletion in order starting with data classified into a lower layer of said hierarchical layers among data recorded in said memory.

3. The multimedia data recording apparatus according to claim 1, wherein said layer classification section classifies said multimedia data into a plurality of hierarchical layers according to frame rate, required image quality or resolution, image variation amount between frames, required storage time, MPEG (Moving Picture Experts Group) data picture type, importance of a recorded event, or an enhancement layer of data coded by an MPEG scalable coding method.

5. The multimedia data recording apparatus according to claim 1, wherein said data amount reduction section performs deletion in order starting with older data or less important data among data recorded in a lower layer.

6. The multimedia data recording apparatus according to claim 5, wherein said data amount reduction section does not delete data that has not passed a minimum storage time among data recorded in a lower layer.

7. The multimedia data recording apparatus according to claim 1, wherein:

said layer classification section sets said multimedia data in a plurality of segments according to a time of acquisition of this data and then classifies said multimedia data into said layers for each said segment; and

said data amount reduction section selects a segment whose said time of acquisition is older, and performs deletion in order starting with data recorded in a lower layer within this segment.

8. A monitoring system equipped with the multimedia data recording apparatus according to claim 1, said monitoring system further comprising a detection section that detects event occurrence in a monitored area;

wherein said data amount reduction section excludes at least one or a plurality of layers in which data related to said event is recorded from data amount reduction as a protected layer.

9. A monitoring system comprising:

the multimedia data recording apparatus according to claim 1;

a measuring section that measures frequency of access to data recorded in said memory; and

a change section that changes at least one or a plurality of layers in which data whose frequency of access is greater than or equal to a predetermined value among data recorded in said memory to a protected layer that is not subject to data amount reduction by said data amount reduction section.

10. A monitoring system comprising:

the multimedia data recording apparatus according to claim 1;

and

a determination section that determines mutual similarity of data recorded in said memory;

wherein said data amount reduction section performs deletion in order starting with data recorded in a lower layer for a layer in which older data is recorded among data determined to have a high degree of similarity by said determination section.

2. (canceled)

4. (canceled)

11. A multimedia data recording method comprising:

a layer classifying step of classifying multimedia data into a plurality of hierarchical layers according to data contents or data precision;

a recording step of continuously recording data classified into said layers in memory; and

a data amount reducing step of, when vacant capacity of said memory is at or below a threshold value, taking older data or less important data among data recorded in said memory as its object, and reducing a data amount of these data.