Time-varying image recording device

1. Field of the Invention

The present invention relates to a time-varying image recording device, which is provided in a movie camera that records an image in a digital form, to record time-varying image data in a recording medium.

2. Description of the Related Art

Conventionally, in a time-varying image recording device of a digital type, a series of time-varying image data, i.e., one moving-image file or one motion-image file, is sequentially recorded in blocks, corresponding to a predetermined unit time, in a recording medium. In the recording medium, block information, such as a starting position of a recording area, in which each block is recorded, and a size of the recording area, is recorded at the end portion of the moving-image file. When the moving-image file is reproduced, first, the contents of the block information are read, and then the time-varying image data corresponding to the moving-image file, are read out based on the block information.

Thus, the block information is essential for reproducing moving-image file, and if the block information is lacking, the moving-image file cannot be reproduced. The lack of the block information occurs when an inferior recording area (or a defective area) exists in the recording medium. In such a case, if the recording operation is attempted and data is recorded in the inferior recording area before the recording operation is completed, the recording operation cannot be completed.

Therefore, an object of the present invention is to provide a time-varying image recording device by which, even when a recording operation for a single moving-image file cannot be completed because of the existence of the inferior recording area in the recording medium, as much as possible of the time-varying image data is recorded, so that the moving-image file can be reproduced.

According to the present invention, there is provided a time-varying image recording device that controls a recording operation for recording time-varying image data in a recording medium. In the recording medium, the time-varying image data is sequentially recorded in blocks having a predetermined unit time, and block information containing the total number of blocks, a starting position of a recording area in which each of the blocks is recorded, and a size of each of the recording areas, is recorded after the series of the blocks of the time-varying image data. The time-varying image recording device comprises a data recording processor, a recording process result determination processor, a recording capacity obtaining processor, and a sensing processor.

The data recording processor records time-varying image data for each block, in the recording medium. The recording process result determination processor determines whether the result of the recording process obtained by the data recording processor is normal or not. The recording capacity obtaining processor obtains a block information recording capacity, which is a memory capacity necessary for recording block information, based on the number of blocks already recorded in the recording medium, when the result of the recording process is abnormal. The sensing processor senses an address of the recording medium, at which the data recording processor should record the block information, in accordance with the block information recording capacity.

Further, according to the present invention, there is provided a time-varying image recording device that controls a recording operation for recording time-varying image data in a recording medium. In the recording medium, the time-varying image data is sequentially recorded in blocks having a predetermined unit time, and block information needed for reproducing the time-varying image data, is then recorded after a series of the blocks of the time-varying image data. The time-varying image recording device comprises a data recording processor, a recording process result determination processor, and a block information recording processor.

The data recording processor records time-varying image data for each block in the recording medium. The recording process result determination processor determines whether a result of a recording process executed by the data recording processor is normal or not. When the recording process result determination processor determines the result to be abnormal, the block information recording processor reduces the total quantity of the time-varying image data so that the block information can be recorded, and records the block information next to the last block of the time-varying image data.

The objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings in which:

FIG. 1 is a block diagram showing a general construction of a time-varying image recording device of a first embodiment of the present invention;

FIG. 2 is a view showing a structure of a series of time-varying image data recorded in a recording medium;

FIG. 3 is a flowchart indicating a recording operation of a moving-image, in the first embodiment;

FIG. 4 is view showing a structure of time-varying image data in a case where the block information is recorded when an inferior recording area exists in a recording medium; and

FIG. 5 is a flowchart indicating a recording operation of a moving-image, in a second embodiment.

The present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 is a block diagram showing a general construction of a time-varying image recording device of a first embodiment of the present invention. In the embodiment, although the time-varying image recording device is provided in a movie camera, the device can be mounted in a still camera, which can also record a moving image. In either case, a time-varying image is recorded in a recording medium in a digital format.

An imaging device 11 , provided on the optical axis of the photographing optical system 10 , is a CCD, for example. In the imaging device 11 , an analogue image signal is generated, in accordance with a subject image formed on a light-receiving surface thereof. The analogue image signal is A/D-converted to a digital image data by an A/D-converter (not shown), and is input to an image processing circuit 12 .

The image processing circuit 12 is controlled by a CPU 13 . Namely, the image data is temporarily stored in a working memory 14 , and is then read out so that the image data is subjected to image processing such as a compression process according to the MPEG4, for example. The image data, (i.e., time-varying image data) after being subjected to the image process, is sequentially recorded in blocks in a recording medium (an SD card as a removable recording medium or a hard disk device as an internal recording medium, for example) 15 , together with audio data obtained through an audio sensing circuit (not shown), as described later.

Further, after the image data input to the image processing circuit 12 is temporarily stored in a working memory 14 , the image data is input to an LCD monitor 16 , so that the subject is shown as a moving-image on the monitor 16 .

For indicating a moving-image on the monitor 16 , and recording the image in the recording medium 15 , an operation member 17 provided with various kinds of switches, is connected to the image processing circuit 12 .

FIG. 2 shows a data structure of the time-varying image data recorded in the recording medium 15 . At the beginning of a moving-image file, file structure information F 1 , such as the compression method used for compressing the image data, and the existence of audio data, is recorded. Subsequent to the file structure information F 1 , lots of blocks R 1 , R 2 , R 3 , . . . Rn, each of which is composed of a pair of time-varying image data and audio data, are recorded. The time-varying image data and the audio data in each block have data sizes corresponding to a predetermined unit time, such as 0.5 sec or 1.0 sec.

A single moving-image file has the volume corresponding to the photographing time of the moving-image, and thus, the number of blocks R 1 , R 2 , . . . Rn is changed depending upon the photographing time. Accordingly, for properly reproducing a single moving-image file, block information F 2 containing a starting position of a recording area in which each of the blocks is recorded, a size of each of the blocks, and the total number of the blocks, is recorded at the end portion of the moving-image file, i.e., after the series of the blocks. The block information F 2 is temporarily stored in a working memory 14 , and is always renewed to the newest information. After the moving-image photography is completed, and the last block is recorded in the recording medium 15 , the block information F 2 is read out from the working memory 14 , and recorded in the recording medium 15 .

With reference to FIG. 3 , a recording operation of a moving-image in the recording medium 15 , which is controlled by the CPU 13 , is described.

In Step 101 , a counter indicating the number of recorded blocks (i.e., a recorded block number counter) is initialized. In Step 102 , file structure information F 1 is recorded in a predetermined area of the recording medium 15 .

In Step 103 , time-varying image data and audio data, corresponding to the predetermined unit time, are recorded in one block. In Step 104 , it is determined whether the recording process result of Step 103 was normal or not. When the recording operation is carried out normally, the process goes to Step 105 , in which the recorded block number counter is incremented by one, and it is determined in Step 106 whether the recording operation has been completed. Thus, the recording process result is determined for every block. So long as an end signal, generated due to an operation of the operation member 17 , is not transmitted from the operation member 17 , the recording operation is continued, and thus, the process described above is repeated, so that the time-varying image data is recorded for each block, in the recording medium 15 .

When the photographing operation is completed so that an end signal is transmitted, the process goes from Step 106 to Step 107 , in which block information F 2 is written in the recording medium 15 , and the recording operation for a series of time-varying image data, which forms a single moving-image file, is completed. Thus, Steps 104 , 105 , 106 , and 107 are executed in this order, when no data is recorded in an inferior recording area during a recording operation for a single moving-image file, and the moving-image file shown in FIG. 2 is obtained. Namely, the time-varying image data and the audio data are sequentially recorded in blocks having a unit time in the moving-image file, in sequential order based on elapsed time.

Conversely, when it is determined in Step 104 that the recording process result is abnormal, i.e., when data has been attempted to be recorded in an inferior recording area during the recording operation, the process is performed as follows. In this example, it is supposed that, as shown in FIG. 4 , blocks R 1 , R 2 , . . . Rm, R(m+1), R(m+2), R(m+3) have been recorded in the recording medium 15 . Namely, a recording area, with an address following the recording area corresponding to the block R(m+3), is an inferior recording area Rb, in which a recording operation cannot be carried out.

In this case, the process goes from Step 104 to Step 110 , where a block information recording capacity, which is a memory capacity that is necessary to record the block information F 2 , is obtained based on the number of recorded blocks indicated by the counter obtained in Step 105 . Here, it is supposed that the block information recording capacity is three. Namely, in Step 110 , the three block's worth of block information is formed or maintained, so that the blocks R 1 , R 2 , . . . Rm become recordable. In Step 111 , from the address to which the last block R(m+3), at which the record result has been normal, corresponds, the address goes back by the number of blocks (i.e., 3 blocks) which satisfies the block information recording capacity, so that an address of the recording medium 15 , at which the block information F 2 should be recorded, is sensed. In Step 112 , the block information relating to the three blocks R(M+1), R(m+2), and R(m+3) is then deleted in the working memory 14 , and the block information F 2 is renewed to that corresponding to the block R 1 through the block Rm.

Then, in Step 107 , the block information F 2 is recorded at the address of the recording medium 15 , which was obtained in Step 111 , and thus, the recording operation ends Thus, when the recording result is abnormal, the total quantity of the time-varying image data is reduced so that the block information can be recorded, and the block information is recorded next to the last block of the time-varying image data.

As described above, when an inferior recording area is accessed during a recording operation, recording areas corresponding to some blocks, which are immediately before the inferior recording area, are used for recording not image data and audio data, but the block information F 2 . Due to this, the blocks R 1 , R 2 , . . . Rm, which have been recorded so far, become properly reproduced. Further, even if there is no inferior recording area, when the amount of compressed data of the image file (i.e., the amount of data which is to be recorded in the recording medium) exceeds prediction, and time-varying image data is recorded up to the capacity of the recording medium 15 , the block information F 2 is recorded in the recording medium 15 so that a moving-image can be reproduced.

FIG. 5 is a flowchart indicating a recording operation of a moving-image, in a second embodiment. Operations, which are not indicated in this flowchart, and a construction of hardware, are identical with those of the first embodiment.

The contents of Steps 201 and 202 are the same as those of Steps 101 and 102 of FIG. 3 . In Step 203 , it is determined whether the recording process result of the file structure information F 1 in Step 202 is normal. When the recording process result is abnormal, the recording operation immediately ends.

Conversely, when it is determined in Step 203 that the recording operation is normal, the process goes to Step 204 . The contents of Steps 204 through 210 are respectively identical with those of Steps 103 , 104 , 105 , 106 , 110 , 111 , and 112 .

After it is determined in Step 207 that the recording operation has been completed, or after the block information F 2 is renewed in Step 210 , Step 211 is executed, in which the block information F 2 is recorded. It is then determined in Step 212 whether the recording operation of the block information F 2 , carried out in Step 211 , was normal. In the case of a normal recording, the recording operation of the moving-image file immediately ends. Conversely, in the case of an abnormal recording, Steps 213 through 216 are executed.

In Step 213 , in a similar way as in Step 208 , a block information capacity is again obtained based on the number of blocks which have been already recorded in the recording medium 15 . In Step 214 , in a similar way as Step 209 , the address is moved back by the amount of block information recording capacity, so that an address of the recording medium 15 , at which the block information F 2 should be recorded, is sensed. In Step 215 , in a similar way as in Step 112 , the block information F 2 is renewed to the newest block information F 2 , which corresponds to the blocks R 1 though Rm, in the working memory 14 . In Step 216 , the block information F 2 is then recorded in the recording medium 15 , Thus, the recording operation of the moving-image file is completed.

As described above, according to the second embodiment, it is determined whether the recording operation of the block information F 2 is normal or not, and when the recording operation is abnormal, the block information recording capacity is again obtained. Therefore, in comparison with the first embodiment, a possibility, in which the block information F 2 is recorded, is raised.

Note that, in the first and second embodiments, every time the time-varying image data and audio data are recorded, i.e., at every recording operation for one block, it is determined whether the recording process result is normal or not. However, the determination process can be performed for recording operations of more than one block.

Although the embodiments of the present invention have been described herein with reference to the accompanying drawings, obviously many modifications and changes may be made by those skilled in this art without departing from the scope of the invention.

The present disclosure relates to subject matter contained in Japanese Patent Application No. 2005-146324 (filed on May 19, 2005) which is expressly incorporated herein, by reference, in its entirety.