Video data saving device and video data saving method

Abstract

A video data transmitting device 30 manages storage areas 31a, 31b of a memory card 31 by equally segmenting these storage areas into partitions whose capacities are equal to each other. Image data forming video data is stored piece by piece in each partition in the sequence from a head partition toward a tail partition. Then, the image data is overwritten sequentially from the oldest, whereby the storage areas 31a, 31b are always temporarily stored with N-pieces of image data starting from a point of the time when recording the image data and ending to a point of time tracing back for a predetermined period of time.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a diagram showing architecture of a remote monitor system in the present embodiment;

FIG. 2 is a diagram showing a configuration of a video data transmitting device;

FIG. 3 is an explanatory diagram showing a method of recording (writing) video data in first and second storage areas; and

FIG. 4 is a diagram showing storage statuses of the image data in the second storage area (a) before detecting abnormality and (b) after detecting the abnormality.

Claims

1. A video data saving device comprising: a partition defining unit segmenting a whole storage area of a storage medium constructed of a flash memory and defining a plurality of partitions of which capacities are equal to each other on said segmented areas;a writing unit attaching, each time image data forming video data is inputted, time information to the image data and writing the image data attached with the time information to said partition stored with the oldest image data in said storage area; anda storing unit storing, each time said writing unit writes the image data to any one of said partitions, the time information written to said partition and a piece of information specifying a location of said partition in said storage area in a way that associates these items of information with each other.

2. A video data saving device according to claim 1, further comprising a status switchover unit setting, when instructed to store the image data, a predetermined number of partitions to which the image data are written just before a point of time when instructed in a write disabled status of the image data, wherein said writing unit, when writing the image data to any one of said partitions, writes the image data to said partition stored with the oldest image data in said partitions excluding said partitions set in the write disabled status of the image data.

3. A video data saving device according to claim 2, wherein said writing unit, when writing the image data to any one of said partitions, attaches to the image data, together with the time information, a piece of flag information showing a status purporting that the image data is permitted to be overwritten, and writes the image data attached with these items of information to said partition stored with the oldest image data in said partitions excluding said partitions to which the flag information showing a status purporting that the image data is inhibited from being overwritten, and said status switchover unit switches over, when instructed to store the image data, the flag information of a predetermined number of partitions to which the image data are written just before a point of the time when instructed, from the overwrite permission status to the overwrite inhibition status.

4. A video data saving device according to claim 1, further comprising a transmitting unit transmitting, when any one of terminal devices issues a request via a network, the image data stored in said partition set in the write disabled status of the image data to this terminal device.

5. A video data saving method comprising: segmenting equally a whole storage area of a storage medium constructed of a flash memory and defining a plurality of partitions of which capacities are equal to each other on said segmented areas;attaching, each time image data forming video data is inputted, time information to the image data and writing the image data attached with the time information to said partition stored with the oldest image data in said storage area; andstoring, each time the image data is written to any one of said partitions, the time information written to said partition and a piece of information specifying a location of said partition in said storage area in a way that associates these items of information with each other.