JP2008004973A - Apparatus and method for recording video - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video recording apparatus capable of accessing a recorded frame at a high speed and having improved recording efficiency. <P>SOLUTION: The video recording apparatus 10 is provided with a video encoder 12 for encoding inputted video images, and generating video streams; a stream adjusting section 14 for adjusting the data length of the hierarchically encoded frame, and generating a plurality of kinds of recording data; and a plurality of cyclic recorders 16a-16f for recording the recording data. Each of the plurality of cycling recorders 16a-16f corresponds to respective plurality of recording data. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a video recording apparatus and a video recording method, and more particularly to video recording capable of acquiring an arbitrary frame at high speed in a method of recording an old video by overwriting it with a new video.

  Video is no longer inseparable from our daily lives, and it can be viewed on various display terminals such as personal computers, mobile terminals, TVs, and high-definition TVs through transmission methods such as the Internet, mobile phone networks, broadcast waves, and recording media. It became an important existence to let you enjoy the information. Since video usually has an enormous amount of information, the amount of information is compressed using video encoding technology, converted into a video stream, transmitted over a network, or recorded on a recording device.

  Further, in the field of video recording, not only the amount of information is compressed but also the following techniques are required with the diversification of video utilization modes. In other words, a technology that searches for a specific video in a short time from the recorded video, or a technology that efficiently records a necessary video by overwriting a new video over an unimportant video in the past in a technology for recording a video in real time. Is required.

  Patent Document 1 describes a video recording apparatus that can search video at high speed. In the apparatus of Patent Document 1, recording is performed so that the start position of the I frame of the video stream is the start position of the sector in the recording area. According to the method of Patent Document 1, when searching for an I frame, it is only necessary to search for the head of a sector, and an arbitrary video can be searched in a short time. Here, the “I frame” is a frame that is encoded without using the information of the preceding and succeeding frames in video encoding, that is, without motion prediction compensation encoding. Therefore, the I frame can be decoded alone. In motion prediction compensation encoding, encoding is performed using P frames and B frames in addition to I frames. Here, the “P frame” refers to a frame that is encoded with reference to the video of the previous I frame or P frame in time, and the P frame cannot be decoded without the I frame. The “B frame” refers to a frame that is encoded with reference to the preceding and subsequent I frames and P frames, and the B frame cannot be decoded without the I frame and the P frame. Therefore, the importance of frames is higher in the order of I frame, P frame, and B frame. In addition, since motion prediction compensation coding encodes the difference between the previous and next frames, the coding efficiency is improved when the difference is small, and generally the coding efficiency is higher than the coding without motion prediction compensation. It is said to be good. The B frame is encoded using a difference from more frames than the P frame. Therefore, the encoding efficiency is good in the order of B frame, P frame, and I frame.

In the video recording apparatus described in Patent Document 2, when the recording area is exhausted, only the B frame is deleted from the recorded video stream, and a new video stream is recorded in the free recording area. According to the apparatus of Patent Document 2, by deleting a B frame of a past video that is not important compared to an I frame or a P frame and recording a new video with priority, the video can be efficiently recorded in a limited recording area. It becomes possible to record.
JP 2001-197443 A JP 2004-7819 A

  However, in the video recording apparatus of Patent Document 1, it takes time to search for a frame because it is not known in which sector in the recording area the frame is recorded. That is, a desired frame must be searched in order from the beginning of the recording area. If the number of sectors in the recording area is N, the search time order is N. Even if the binary tree search method is used, the order of the search time is logN.

  Further, in the video recording apparatus of Patent Document 2, since the deleted B frame does not know what number frame, it is not known in which recording area the newly recorded frame is recorded. Also, even if a new frame is to be recorded in the deleted B frame recording area, the sizes of both frames do not always match, and there is a possibility that a wasteful space will be generated in the recording area.

  In view of the above background, an object of the present invention is to provide a video recording apparatus and a video recording method that enable high-speed access to recorded frames and improve recording efficiency.

  The video recording apparatus of the present invention includes a video stream input means for inputting a video stream composed of a plurality of hierarchically encoded frames, and recording data for adjusting the data length of the frames and generating a plurality of types of recording data And a plurality of circulating recording means for recording the recording data corresponding to the type of the recording data.

  In this way, a plurality of types of recording data whose data length is adjusted by the recording data generation unit are generated, and the generated recording data is recorded in the cyclic recording unit according to each type. It is possible to manage the recording location of the recording data depending on whether it is recorded the second time, and it is possible to access any recording data at high speed. Also, by recording in a plurality of circulating recording means, the order of overwriting the data is not uniformly changed to the oldest order, but the old data can be left, and video can be efficiently recorded in a limited recording area. it can. For example, when two circulating recording means having the same capacity are provided, one frame is recorded on one circulating recording means, and the remaining frames are recorded on the other circulating recording means. If the recording speed is changed, old data overwritten by the latter circulating recording means remains in the former circulating recording means, so that new data can be recorded with high image quality and old data can be recorded with low image quality. It can be left, and a finite recording area can be used effectively.

  In the video recording apparatus, the recording data generation means may generate different types of recording data according to the encoding type of the frame.

  Since the importance of the frame differs depending on the encoding type, it is preferable to generate the recording data according to the encoding type. Thereby, for example, a high-importance I frame can be recorded for a long time, a low-importance P frame can be recorded for a shorter time, and a B-frame having the lowest importance can be recorded for the shortest time. A new image can be recorded with a lower frame rate and a higher frame rate.

  In the video recording apparatus, the recording data generation means may generate a plurality of recording data from one frame.

  With this configuration, it is possible to record a portion that has a strong influence on image quality in one frame and a portion that does not have that effect on separate circulating recording means, and select and acquire the image quality and resolution of the video stream arbitrarily. Is possible.

  In the video recording apparatus, recording data having a length including at least the basic layer of the basic layer and the enhancement layer included in the frame may be generated.

  With this configuration, the base layer can be generated by a method with high encoding efficiency, and the video encoding efficiency is improved.

  In the video recording apparatus, the circulating recording unit may record information indicating the length of the base layer together with the frame.

  With this configuration, information indicating the length of the base layer can be acquired, so that the base layer can be acquired at high speed.

  The video recording method according to the present invention includes a video stream input step for inputting a video stream consisting of a plurality of hierarchically encoded frames, and recording data for adjusting the data length of the frames to generate a plurality of types of recording data A generating step; and a circulating recording step for recording the recording data in the circulating recording means corresponding to the type of the recording data.

  With this configuration, as with the video recording apparatus of the present invention, arbitrary recording data can be accessed at high speed, and video can be efficiently recorded in a limited recording area. Various configurations of the video recording apparatus of the present invention can also be applied to the video recording method of the present invention.

  In order to record a video stream composed of a plurality of hierarchically encoded frames, the program of the present invention adjusts the video stream input step of inputting the video stream to a computer, the data length of the frame, and a plurality of types A recording data generating step for generating the recording data, and a circulating recording step for recording the recording data in the circulating recording means corresponding to the type of the recording data.

  With this configuration, as with the video recording apparatus of the present invention, arbitrary recording data can be accessed at high speed, and video can be efficiently recorded in a limited recording area. Various configurations of the video recording apparatus of the present invention can also be applied to the program of the present invention.

  According to the present invention, a plurality of types of recording data whose data lengths have been adjusted by the recording data generation unit are generated, and the generated recording data is recorded on the circular recording unit according to each type, thereby circulating The recording location of the recording data is managed according to the number of the recording means, and it is possible to access any recording data at a high speed and to efficiently record the video in the recording area. Has an effect.

  Embodiments of a video recording apparatus according to the present invention will be described below in detail with reference to the drawings. In the embodiment described below, an example will be described in which video is hierarchically encoded into a base layer and an enhancement layer and recorded.

  FIG. 1 is a block diagram showing a configuration of a video recording apparatus according to an embodiment of the present invention. In FIG. 1, the video recording apparatus 10 includes a video encoding unit 12, a stream adjustment unit 14, circulation recording units 16 a to 16 f, and a stream acquisition unit 18.

  The video encoding unit 12 inputs video from the outside of the video recording device 10 as an original image screen by screen, generates a video stream by hierarchical encoding, and outputs the video stream to the stream adjustment unit 14. Here, an example in which the video recording device 10 includes the video encoding unit 12 has been described, but the video encoding unit 12 may be provided outside the video recording device 10.

  The stream adjustment unit 14 receives the video stream from the video encoding unit 12, adjusts the video stream, and outputs the video stream to the circulation recording units 16a to 16f. The circular recording units 16a to 16f overwrite and record the frames of the video stream input from the stream adjustment unit 14 on the sectors in which the oldest frames in the recording areas of the respective circular recording units 16a to 16f are recorded. Here, the stream adjustment unit 14 corresponds to the video stream input unit and the recording data generation unit of the present invention, and the circulation recording units 16a to 16f correspond to the circulation recording unit.

  The stream acquisition unit 18 acquires video streams from the circulation recording units 16 a to 16 f based on video acquisition signals input from the outside of the video recording device 10.

  Next, the operation of the video recording apparatus 10 configured as described above will be described. The video recording apparatus 10 performs a video recording operation for encoding an input video and recording it as a video stream, and a video acquisition operation for outputting the recorded video stream. First, the video recording operation will be described.

  FIG. 2 is a flowchart showing an example of the video recording operation of the video recording apparatus 10 according to the embodiment shown in FIG. The flowchart shown in FIG. 2 is executed by software by executing a control program stored in a storage device (not shown) (for example, ROM or flash memory) by a CPU (not shown). It is also possible to do so.

  First, the video encoding unit 12 of the video recording apparatus 10 performs a video encoding process (S10). Specifically, the video encoding unit 12 inputs video as an original image screen by screen from the outside of the video recording apparatus 10, generates a video stream by hierarchical encoding, and outputs the video stream to the stream adjustment unit 14.

  Here, as the video hierarchical encoding method of the video encoding unit 12, several encoding methods such as JPEG2000 can be mentioned. In this embodiment, MPEG-4 described in ISO / IEC 14496-2 Amendment 2 is used. Use FGS (Fine Granularity Scalable coding). Of course, other encoding methods may be used as long as the effects of the present invention can be obtained. MPEG-4 FGS is standardized as an encoding method that enables fine selection of the image quality of a decoded image, and the encoded video stream is composed of a base layer stream and an enhancement layer stream. . The base layer is a high-compression, low-quality video stream that can be decoded alone. The enhancement layer is a video stream for improving the image quality of the base layer, and the image quality of the decoded image is improved by increasing the code amount to be decoded by the enhancement layer. The video encoding unit 12 uses a motion prediction / compensation encoding method using I frames, P frames, and B frames as the encoding method of the base layer. In the present embodiment, the frame rate of the video input to the video recording device 10 is 30 fps. Further, the frame rate of the I frame of the base layer encoded by the video encoding unit 12 is 1 fps, the P frame is 9 fps, and the B frame is 20 fps.

  FIG. 3A is a diagram showing the encoding types of frames arranged in the input order of original images, and FIG. 3B is a diagram showing the encoding types of frames arranged in the order of generation as a video stream. As shown in FIG. 3 (a), the input order continues to I frame F01, B frame F02, B frame F03, P frame F04. However, as shown in FIG. 3B, the stream is generated in the order of the I frame F01 followed by the P frame F04, followed by the B frames F02 and F03. This is because the B frames F02 and F03 are encoded with reference to the decoded image after encoding the P frame F04.

  In addition, the video encoding unit 12 performs bit-plane encoding for each frame using MPEG-4 FGS as the encoding method of the enhancement layer. The enhancement layer performs intra-frame coding for all frames. For convenience of explanation, the enhancement layer when the base layer is an I frame is referred to as an “I frame enhancement layer”. The same shall apply.

  Next, the stream adjustment unit 14 of the video recording apparatus 10 performs stream adjustment processing to generate recording data (S12). Specifically, the stream adjustment unit 14 inputs a video stream from the video encoding unit 12, and outputs recording data generated by adjusting the video stream to the circulation recording units 16a to 16f. This stream adjustment process corresponds to the recording data generation step of the present invention.

  Here, generation of recording data will be described. FIG. 4A is a diagram illustrating a structure of a frame including a base layer and an enhancement layer. “I”, “P”, and “B” described in rectangles representing the video stream of the base layer represent frame types. As shown in FIG. 4A, the code amount of the video stream is usually different between the base layer and the enhancement layer.

  FIG. 4B shows the structure of recording data generated by stream adjustment. The stream adjustment unit 14 connects the head portion of the enhancement layer after the base layer so that the total code amount becomes a predetermined code amount A, B, C bytes for each of the I frame, P frame, and B frame. Cut and align. Further, the stream adjustment unit 14 trims all remaining enhancement layers to the same code amount D bytes for each frame. Further, the remaining enhancement layer is discarded here. In the present embodiment, a trimmed video stream including a base layer is referred to as a base layer side stream, and a stream including only an enhancement layer is referred to as an enhancement layer side stream. These streams correspond to the recording data of the present invention. The stream length of the base layer side stream is set in advance so that it does not fall below the code amount of the base layer video stream. Note that the recording data may be generated by dividing the video stream connecting the base layer and the enhancement layer into three or more, but in this embodiment, it is divided into two.

  Further, in order to stabilize the image quality when the base layer side stream is decoded in each frame, the code amounts A and B are set so that the code amount of the enhancement layer video stream included in the base layer side stream is substantially constant in each frame. It is desirable to set C bytes. For the same reason, the code amount of the enhancement layer side stream is preferably the same amount of D bytes for all I, P, and B frames.

  The stream adjustment unit 14 outputs the recording data generated as described above to the circulation recording units 16a to 16f according to the type. Specifically, the base layer side stream E01 of the I frame is sent to the circulating recording unit 16a, the base layer side streams E04 and E07 of the P frame are sent to the circulating recording unit 16b, and the base layer side streams E02, E03, E05, E06 is transmitted to the circular recording unit 16c, the I-frame enhancement layer side stream E08 to the cyclic recording unit 16d, the P-frame enhancement layer side streams E11 and E14 to the cyclic recording unit 16e, and the B-frame enhancement layer side streams E09 and E10. , E12, E13 are output to the circulating recording unit 16f.

  Next, the circulating recording units 16a to 16f of the video recording apparatus 10 perform the circulating recording process (S14). Specifically, the circular recording units 16a to 16f store the video stream frames (recording data) input from the stream adjustment unit 14 in the sectors in which the oldest frames in the recording areas of the respective circular recording units are recorded. Overwrite and record. This circulating recording process corresponds to the circulating recording step of the present invention.

  Here, circulating recording will be described. FIG. 5 is a diagram showing the concept of the circular recording according to the present embodiment. In the following description, the circulating recording unit 16a will be described as an example. The recording area 20 is divided into a predetermined number of sectors. The size of each sector is A bytes which is the same as the length of the recording data. Sector 22 records the video stream of the newest frame, and sector 24 records the video stream of the oldest frame. The circular recording unit 16a overwrites the sector 24 on the base layer side stream of the input I frame. The circulating recording unit 16a can replace old video with new video one after another by overwriting the input video stream on the sector of the oldest video stream. When the circular recording unit 16a records video streams one after another and the sector 22 in which the latest video stream is recorded reaches the end of the recording area 20, the next sector to be recorded is the head sector of the recording area 20. Here, since the size of the sector (A byte) is equal to the code amount of the base layer side stream of the I frame adjusted by the stream adjustment unit 14, the recording area 20 has no gap of 1 byte. It is possible to record a code.

  Similarly, the circular recording unit 16b is divided into predetermined B-byte sectors, the circular recording unit 16c is divided into predetermined C-byte sectors, and the circular recording units 16d to 16f are divided into predetermined D-byte sectors. It has a recording area. Therefore, the data input according to the type is recorded without any gaps in the circulation recording units 16b to 16f.

  Here, for example, if the number of sectors in the storage area of each of the circular recording units 16a to 16f is 30000, the I frame is 1 fps, so 8 hours and 20 minutes, the P frame is 55 minutes and 33 seconds, 3 frames, and the B frame Can record 25 minutes of video. Therefore, I frames, P frames, and B frames exist up to 25 minutes before the current time, so 30 fps, I frames and P frames exist up to about 55 minutes before, 10 fps, and only I frames up to about 8 hours before Therefore, it is possible to decode and reproduce the video at 1 fps. The recording time can be changed according to the frame rate and the number of sectors in each of the circular recording units 16a to 16f. Furthermore, for example, if the number of sectors in the circular recording unit 16d is halved to 15,000, the importance of the video is set finely over time, such that the I frame records 4 hours out of 8 hours with high image quality. It is possible to record.

  Next, the video recording apparatus 10 performs an end determination process (S16). Specifically, the video encoding unit 12 determines the presence / absence of a video input from the outside of the video recording device 10, and if there is no video input, the processing is terminated, and if not, the processing returns to step S10. The example of the video recording operation of the video recording apparatus 10 has been described above.

  Next, a video acquisition operation of the video recording apparatus 10 will be described. FIG. 6 is a flowchart showing an example of the video acquisition operation of the video recording apparatus 10 according to the embodiment shown in FIG. Note that the flowchart shown in FIG. 6 is executed by software by executing a control program stored in a storage device (not shown) such as a ROM or a flash memory by a CPU (not shown). It is also possible to do so.

  First, the video recording apparatus 10 performs an input determination process (S20). Specifically, the stream acquisition unit 18 waits for input of a video acquisition signal instructing acquisition of a video stream from the outside of the video recording apparatus 10, and if there is a video acquisition signal, the process proceeds to step S22. If not, continue waiting. If the video acquisition signal indicates an invalid request, the stream acquisition unit 18 outputs an error signal to the outside of the video recording device 10 and continues standby.

  Here, the video acquisition signal includes information such as the time, frame rate, and image quality of the video that the user wants to acquire, and information on whether or not to end the video acquisition operation. The video recording apparatus 10 can uniquely calculate information such as an acquirable time, frame rate, and image quality from a predetermined frame rate and the number and size of sectors of each of the circular recording units 16a to 16f. is there. That is, from which time the video recording apparatus 10 records each of the I frame, the P frame, and the B frame based on the encoding frame rate of the video encoding unit 12 and the number of sectors in the recording areas of the circular recording units 16a to 16f. Uniquely calculate what you are doing. Thereby, the stream acquisition unit 18 determines whether or not the video acquisition signal is an acquisition requestable video stream, and returns an error signal if acquisition is not possible.

  Next, the video recording apparatus 10 performs an end determination process (S22). Specifically, if the stream acquisition unit 18 indicates a video acquisition signal input from the outside of the video recording device 10 and indicates an instruction to end the video acquisition process, the process ends, otherwise The process proceeds to step S24.

  If the video signal is not an end instruction, the video recording apparatus 10 performs a stream selection process (S24). Specifically, the stream acquisition unit 18 generates a frame selection signal indicating a frame to be acquired from the circulation recording units 16a to 16f based on the video acquisition signal input from the outside of the video recording device 10.

  Here, the frame selection signal is generated by the stream acquisition unit 18 from the time and image quality indicated by the video acquisition signal, and indicates how many frames from the I frame, P frame, and B frame currently being recorded should be acquired. Show. For example, consider a case in which an image of 1 second is acquired from V seconds ago. Since the I frame is recorded at 1 fps, one frame before V is selected. Since the P frame is recorded at 9 fps, nine frames are selected from the previous 9 × V frames. Since the B frame is recorded at 20 fps, 20 frames are selected from the previous 20 × V frames.

  However, if the video acquisition signal indicates that the video stream is to be acquired at 10 fps, only the I frame and P frame are selected. If the video acquisition signal indicates that the video stream is to be acquired at 1 fps, only the I frame is selected. To do. When the video acquisition signal instructs acquisition of the enhancement layer side stream, the frame of the enhancement layer side stream corresponding to the frame of the base layer side stream is selected. In addition, the video acquisition signal may include an instruction to acquire a frame rate as high as possible, an instruction to acquire an enhancement layer side stream only for I frames, an instruction to acquire half of the enhancement layer side stream, and the like. .

  Next, the video recording apparatus 10 performs a stream extraction process (S26). Specifically, the stream acquisition unit 18 extracts video streams from the circulation recording units 16a to 16f based on the frame selection signal generated in the stream selection process (S24).

上式に示すように、ＸがＰより小さい場合、ＰとＸの差がＹとなる。ＸがＰより大きい場合、ＮからＸとＰの差を引いたものがＹとなる。そして、上式によって求めたセクタの番号Ｙの記録領域２０内での先頭アドレスは、セクタの番号Ｙから１を引いた数とセクタのサイズＡの積によって表される。つまり、ストリーム取得部１８が、Ｘ枚前のＩフレームを取得する場合、記録領域２０の先頭から（Ｙ−１）×Ａバイト目からＡバイト分の情報を抽出すればよい。以上に説明した抽出を、フレーム選択信号が示すフレーム全てに対して行う。 A method in which the stream acquisition unit 18 searches and extracts the frame indicated by the frame selection signal by the circulating recording units 16a to 16f will be described. For example, consider a case where the stream acquisition unit 18 acquires an I frame from the circulating recording unit 16a. In this case, the stream acquisition unit 18 obtains a frame for acquiring the sector number Y of the previous I frame by using the following equation as the number N of sectors of the circulating recording unit 16a and the position P of the sector currently being recorded.

As shown in the above equation, when X is smaller than P, the difference between P and X is Y. When X is larger than P, Y is obtained by subtracting the difference between X and P from N. The head address in the recording area 20 of the sector number Y obtained by the above equation is represented by the product of the number obtained by subtracting 1 from the sector number Y and the sector size A. That is, when the stream acquisition unit 18 acquires an I frame before X, it is only necessary to extract information corresponding to A bytes from the beginning of the recording area 20 (Y−1) × A bytes. The extraction described above is performed for all the frames indicated by the frame selection signal.

  Next, the video recording apparatus 10 performs a stream composition process (S28). Specifically, the stream acquisition unit 18 rearranges the video streams extracted in the stream extraction process (S26) and outputs them to the outside of the video recording apparatus 10. After the stream synthesis process (S28), the process returns to step S20.

  The video stream rearrangement method in the stream synthesizing process is uniquely determined from the frame rates of the I frame, the P frame, and the B frame. First, consider the base layer side stream. Assume that the extracted I frames are S, P frames are T, and B frames are U. Since the I frame is recorded at 1 fps, S is a video stream for S seconds. Since the P frame is 9 fps, the T stream is the backward T / 9 seconds out of the S seconds, and the B frame is 20 fps, so the U frame is the backward U / 20 seconds of the S seconds. Therefore, first, for the past (ST / 9) seconds, only I frames are arranged in order of oldest time. Next, for (S−U / 20) seconds, 9 P frames per I frame are arranged in order of oldest time. In the last U / 20 seconds, the combination of two B frames continued after the I frame and each P frame, followed by nine times, and finally the two B frames continued. Line up like so. The enhancement layer side stream is connected and arranged immediately after the base layer side stream of the corresponding frame. It should be noted that S ≧ T / 9 ≧ U / 20, and the above description holds true whether the times represented by the I frame, the P frame, and the B frame are the same or different.

  In this way, the stream acquisition unit 18 can search and acquire any frame recorded by the circulation recording units 16a to 16f at high speed. In this way, the stream acquisition unit 18 rearranges the frames acquired from the circulation recording units 16a to A09 along the original time series, and outputs them to the outside of the video recording apparatus 10. The example of the video acquisition operation of the video recording apparatus 10 has been described above.

  Since the video recording apparatus 10 according to the present embodiment performs cyclic recording with the total code amount of the hierarchically encoded base layer and enhancement layer fixed to a predetermined size, the video recording apparatus 10 in the recording areas of the cyclic recording units 16a to 16f. A video stream can be recorded without a gap, and a video stream can be acquired at high speed.

  Further, since the video recording apparatus 10 records each of the I frame, the P frame, and the B frame in different circulation recording units 16a to 16f, the older video can be recorded at a lower frame rate.

  Further, since the video recording apparatus 10 records each of the base layer side stream and the enhancement layer side stream in different circulation recording units 16a to 16f, it is possible to select the image quality and acquire the video stream.

  Moreover, since the video recording apparatus 10 records the code amount of the base layer at the head of the sector in the recording area of the circulating recording units 16a to 16f, it is possible to acquire only the base layer at high speed.

  The video recording apparatus of the present invention has been described in detail with reference to the embodiment, but the present invention is not limited to the above embodiment. For example, when recording the base layer side stream, the circular recording units 16a to 16f may record the code amount of the base layer as a header at the head of the sector. As a result, when the video acquisition signal indicates that only the base layer is to be acquired, the stream acquisition unit 18 refers to the header and searches for the end of the base layer without searching the sectors in order from the top. It is possible to know at high speed.

  The present invention has an excellent effect that frames can be acquired at high speed by arbitrarily selecting image quality and resolution. The present invention is composed of a plurality of surveillance cameras, and records and searches a large amount of video efficiently. It is useful as a video recording device or the like in a real-time video monitoring system that needs to be performed.

The figure which shows the structure of the video recording apparatus by embodiment of this invention The flowchart which shows the video recording operation | movement of the video recording device by embodiment of this invention. (A) Conceptual diagram showing types of encoding of frames arranged in the input order of the original image (b) Conceptual diagram showing types of encoding of frames arranged in the order of generation as a video stream (A) Conceptual diagram of video stream before stream adjustment processing (b) Conceptual diagram of video stream after stream adjustment processing Conceptual diagram of circular recording according to an embodiment of the present invention The flowchart which shows the image | video acquisition operation | movement of the video recording device by embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Video recording device 12 Video encoding part 14 Stream adjustment part 16a-16f Circulation recording part 18 Stream acquisition part 20 Recording area 22 The sector where the video stream of the newest frame was recorded 24 The sector where the video stream of the oldest frame was recorded

Claims (7)

Video stream input means for inputting a video stream composed of a plurality of hierarchically encoded frames;
Recording data generation means for adjusting the data length of the frame and generating a plurality of types of recording data;
A plurality of circulating recording means for recording the recording data corresponding to the type of the recording data;
A video recording device comprising:   The video recording apparatus according to claim 1, wherein the recording data generation unit generates different types of recording data according to an encoding type of the frame.   The video recording apparatus according to claim 1, wherein the recording data generating unit generates a plurality of recording data from one frame.   The video recording apparatus according to claim 1, wherein the recording data generation unit generates recording data having a length including at least a basic layer among a basic layer and an enhancement layer included in the frame.   The video recording apparatus according to claim 4, wherein the circulating recording unit records information indicating a length of the base layer together with the frame. A video stream input step of inputting a video stream consisting of a plurality of frames that are hierarchically encoded;
A recording data generation step of adjusting the data length of the frame and generating a plurality of types of recording data;
A circular recording step of recording the recording data on a circular recording means corresponding to the type of the recording data;
A video recording method comprising: In order to record a video stream consisting of a plurality of hierarchically encoded frames,
A video stream input step for inputting the video stream;
A recording data generation step of adjusting the data length of the frame and generating a plurality of types of recording data;
A circular recording step of recording the recording data on a circular recording means corresponding to the type of the recording data;
A program that executes

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