JP2008160358A - Portable recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To implement a portable recorder capable of recording video for prescribed hours with high picture quality in accordance with a battery residual capacity and an available space of a medium. <P>SOLUTION: The portable recorder includes: a coding means 31 for coding a moving picture signal in one of a standard coding mode, a low-efficiency coding mode, a high-efficiency coding mode, and a high-compression coding mode; a battery residual capacity detection means 41; a medium available space detection means 42; a prediction means 44 for predicting a generated code amount and a power consumption; a coding mode selection means 46 for selecting which of the standard coding mode, the low-efficiency coding mode, the high-efficiency coding mode, and the high-compression coding mode the signal should be coded in, on the basis of relations among the battery residual capacity, the medium available space, the generated code amount, and the power consumption; and a recording part 5 for recording a coded compression code signal into a recording medium. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a portable recording apparatus that is equipped with a battery that drives the apparatus, encodes a video signal, and saves power on a recording medium such as a semiconductor memory.

Recently, portable recording devices using a semiconductor memory as a recording medium have been commercialized. A video signal input from a camera or the like is encoded and recorded on a recording medium such as a flash RAM. It has convenient functions such as playback while randomly accessing any recording location.
On the other hand, the portable recording device operates a video processing circuit, a recording unit, and the like by battery drive. A relatively small battery is used to reduce the weight of the device. It is preferable that the amount of power stored in the battery can be used effectively and the target video signal can be recorded on the recording medium with high image quality as much as possible.

Patent Document 1 discloses an imaging and recording apparatus that can extend the recording time as much as possible even when the remaining battery level is low. The apparatus is an apparatus that encodes and records an image signal using power supplied from a battery. The image signal is encoded by an imaging unit, an encoding unit that encodes a moving image signal obtained from the imaging unit, and an encoding unit. Recording means for recording the recorded moving image signal on a recording medium, and detecting the remaining battery level, changing the encoding algorithm of the encoding means based on the detected remaining battery level, to a memory circuit used at the time of encoding And a control means for reducing the power consumption at the time of encoding.
JP-A-2005-130362

  However, in the imaging and recording apparatus disclosed in Patent Document 1, when the low-efficiency encoding is performed, the quantization width is rough and the encoding is performed with an image quality including encoding distortion, or the MPEG (moving picture experts group) method is used. In this case, the amount of code increases because the B (Bidirectionally predictive-coded) picture is not used, and the recording time is not sufficient to ensure sufficient recording time due to insufficient recording medium capacity. It has not been possible to realize a portable recording apparatus that can perform recording operation by selecting an optimal encoding condition based on the free space.

  Therefore, the present invention has been made to solve the above-described problems, and manages the remaining battery capacity and the free space of the recording medium while matching the state of both the remaining battery capacity and the free space of the medium. An object of the present invention is to provide a portable recording device that enables recording with the highest recording quality.

According to a first aspect of the present invention, when the supplied moving image signal is encoded and recorded on a pre-stored recording medium, the encoding is performed by an encoding method with a large amount of calculation and high power consumption. In the portable recording apparatus that selects whether to perform a method with a small amount of calculation and a small amount of power consumption according to the free capacity of the recording medium and the remaining amount of the battery, and performs the encoding with the selected encoding method, Standard mode for encoding a moving picture signal with a predetermined calculation amount and at a predetermined encoding rate, low encoding with a calculation amount smaller than the predetermined calculation amount and at a higher encoding rate than the predetermined encoding rate Coded in one coding mode selected from the efficiency mode and the high-efficiency mode for coding at a coding amount larger than the predetermined calculation amount and smaller than the predetermined coding rate. Encoding means, free capacity detecting means for detecting the free capacity of the recording medium, battery remaining capacity detecting means for detecting the remaining capacity of the battery, and free capacity detected by the free capacity detecting means The encoding unit is driven in the standard mode according to the first recordable time during which the compressed encoded signal encoded in the standard mode can be recorded and the remaining battery level detected by the remaining battery level detection unit. Predicting means for predicting a second recordable time in which the compressed compression-coded signal can be recorded on the recording medium, and a difference between the first recording time and the second recording time is within a predetermined difference Is selected, the standard mode is selected, the difference between the first recording time and the second recording time exceeds the predetermined difference, and the first recording time is the second recording time. If it is larger than the time, the low efficiency And the difference between the first recording time and the second recording time exceeds the predetermined difference, and the first recording time is smaller than the second recording time. Is a mode selection unit that selects the high-efficiency mode, and a recording that records on the recording medium a compression-encoded signal obtained by encoding the moving image signal by the compression-encoding unit according to the mode selected by the mode selection unit And a portable recording device.
In the second invention, when the supplied video signal is encoded and recorded on a pre-stored recording medium, the encoding is performed by an encoding method with a large amount of calculation and a large amount of power consumption, or the amount of calculation is In a portable recording device that selects whether to use a method with a small amount of power consumption according to the free capacity of the recording medium and the remaining amount of battery, and performs the encoding with the selected encoding method, A standard mode for encoding at a predetermined calculation amount and at a predetermined encoding rate, a low-efficiency mode for encoding at a calculation amount smaller than the predetermined calculation amount and at a higher encoding rate than the predetermined encoding rate, A high-efficiency mode for encoding at an encoding amount larger than the predetermined calculation amount and smaller than the predetermined encoding rate, and the predetermined calculation amount after compressing the information amount of the video signal Encoding means for encoding in one encoding mode selected from among the high compression modes for encoding at an encoding rate that is less than the predetermined encoding rate and a free capacity of the recording medium Free capacity detecting means for detecting the remaining capacity of the battery, remaining battery capacity detecting means for detecting the remaining amount of the battery, and predicting the code amount when the video signal for a predetermined time is encoded in the standard mode, and the predicted A predicting means for predicting a power consumption amount required for recording an encoded signal of a code amount on the recording medium; and a code amount predicted by the predicting means is larger than a free capacity detected by the free capacity detecting means. If the power consumption predicted by the predicting unit is less than the remaining battery level detected by the remaining battery level detecting unit, the standard mode is selected and predicted by the predicting unit. When the code amount is larger than the free space detected by the free space detection unit and the power consumption predicted by the prediction unit is smaller than the remaining battery level detected by the battery remaining amount detection unit, the low amount The efficiency mode is selected, the code amount predicted by the prediction means is less than the free capacity detected by the free capacity detection means, and the power consumption predicted by the prediction means is determined by the battery remaining amount detection means. When the remaining battery level is greater than the detected battery level, the high-efficiency mode is selected, and the code amount predicted by the prediction unit is larger than the free space detected by the free space detection unit and is predicted by the prediction unit. Mode selection in which the high compression mode is selected and encoding is performed by the encoding unit when the amount of consumed power is greater than the remaining battery level detected by the remaining battery level detection unit And a recording unit that records the compressed encoded signal obtained by encoding the moving image signal by the compression encoding unit in the encoding mode selected by the mode selection unit on the recording medium. A portable recording device is provided.

According to the present invention, a standard mode for encoding a moving picture signal with a predetermined calculation amount and a predetermined encoding rate, an arithmetic amount smaller than the predetermined calculation amount and an encoding rate larger than the predetermined encoding rate. Encoding in one encoding mode selected from among a low efficiency mode for encoding and a high efficiency mode for encoding at an encoding amount larger than a predetermined calculation amount and smaller than a predetermined encoding rate Encoding in the standard mode to the free capacity detected by the free capacity detecting means, the free capacity detecting means for detecting the free capacity of the recording medium, the remaining battery capacity detecting means for detecting the remaining capacity of the battery The compressed encoded signal encoded by driving the encoding means in the standard mode based on the first recordable time during which the compressed encoded signal can be recorded and the remaining battery level detected by the remaining battery level detection means Predicting means for predicting the second recordable time that can be recorded on the recording medium, and selecting the standard mode if the difference between the first recording time and the second recording time is within a predetermined difference, When the difference between the first recording time and the second recording time exceeds a predetermined difference and the first recording time is larger than the second recording time, the low efficiency mode is selected and the first recording time is selected. Mode selection means for selecting a high-efficiency mode when the difference between the recording time and the second recording time exceeds a predetermined difference and the first recording time is smaller than the second recording time; and mode selection And a recording unit that records the compressed encoded signal obtained by encoding the moving image signal by the compression encoding unit on the recording medium in accordance with the mode selected by the means, so that the remaining battery capacity and the free space of the recording medium are reduced. While managing both the remaining battery capacity and the range of media free space Fit state can be realized portable recording apparatus capable of the highest keeping recording the recording quality.
Also, a standard mode for encoding a moving image signal with a predetermined calculation amount and a predetermined encoding rate, a low mode for encoding with a calculation amount smaller than the predetermined calculation amount and larger than the predetermined encoding rate. Efficiency mode, high-efficiency mode that encodes at a coding rate that is larger than the predetermined amount of computation and smaller than the predetermined coding rate, and less than the predetermined amount of computation after compressing the information amount of the video signal Encoding means for encoding in one selected encoding mode among high compression modes for encoding at an encoding amount that is smaller than a predetermined encoding rate and a free space for detecting the free capacity of the recording medium The capacity detection means, the battery remaining capacity detection means for detecting the remaining battery capacity, the code amount when the moving image signal for a predetermined time is encoded in the standard mode, and the code of the predicted code amount A predicting means for predicting power consumption required for recording a signal on a recording medium; and a code amount predicted by the predicting means is smaller than the free capacity detected by the free capacity detecting means and is predicted by the predicting means. If the power consumption is less than the remaining battery level detected by the remaining battery level detection means, select the standard mode, and the amount of code predicted by the prediction means will be larger than the free capacity detected by the available capacity detection means. When the power consumption predicted by the prediction unit is smaller than the remaining battery level detected by the battery remaining amount detection unit, the low efficiency mode is selected, and the code amount predicted by the prediction unit is determined by the free capacity detection unit. If the amount of power consumed is less than the detected free capacity and the power consumption predicted by the prediction means is greater than the remaining battery capacity detected by the battery remaining amount detection means, the high efficiency mode is selected and the prediction means High compression when the measured code amount is larger than the free space detected by the free space detection means and the power consumption predicted by the prediction means is larger than the remaining battery amount detected by the battery remaining amount detection means A mode selection unit that selects a mode and performs encoding by the encoding unit, and a compressed encoded signal obtained by encoding the moving image signal by the compression encoding unit according to the encoding mode selected by the mode selection unit is recorded. In the case of providing a recording unit for recording on a medium, the recording quality is kept high within the range of the remaining battery capacity and the medium free capacity while managing the remaining battery capacity and the free capacity of the recording medium, and a predetermined time required. A portable recording apparatus that enables recording can be realized.

Hereinafter, a portable recording apparatus according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a block diagram showing a configuration example of a portable recording apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram showing a configuration example of a main part of the portable recording apparatus according to the embodiment of the present invention. FIG. 3 is a diagram (part 1) illustrating an operation example of the portable recording device according to the embodiment of the present invention. FIG. 4 is a diagram (part 2) illustrating an operation example of the portable recording device according to the embodiment of the present invention. FIG. 5 is a diagram (part 3) illustrating an operation example of the portable recording device according to the embodiment of the present invention. FIG. 6 is a flowchart (part 1) showing the operation of the portable recording apparatus according to the embodiment of the present invention. FIG. 7 is a flowchart (part 2) illustrating the operation of the portable recording apparatus according to the embodiment of the present invention.

  The portable recording device is a portable type capable of recording with the highest recording quality in accordance with the state of both the remaining battery level and the medium free space while managing the remaining battery level and the free space of the recording medium. The purpose of realizing a recording device is to use a standard mode for encoding a moving picture signal with a predetermined calculation amount and a predetermined encoding rate, a code with a calculation amount smaller than the predetermined calculation amount and larger than the predetermined encoding rate. One encoding mode selected from a low-efficiency mode for encoding at an encoding rate and a high-efficiency mode for encoding at an encoding amount larger than a predetermined calculation amount and smaller than a predetermined encoding rate Encoding means for encoding, free capacity detecting means for detecting the free capacity of the recording medium, remaining battery capacity detecting means for detecting the remaining battery capacity, and empty capacity detected by the free capacity detecting means. The encoding unit is driven and encoded in the standard mode according to the first recordable time in which the compressed encoded signal encoded in the standard mode can be recorded on the capacity and the remaining battery level detected by the remaining battery level detection unit Predicting means for predicting a second recordable time in which the compressed encoded signal thus recorded can be recorded on a recording medium, and a difference between the first recording time and the second recording time being within a predetermined difference When the standard mode is selected, and the difference between the first recording time and the second recording time exceeds a predetermined difference, and the first recording time is larger than the second recording time, the low efficiency mode is selected. A mode for selecting the high efficiency mode when the difference between the first recording time and the second recording time exceeds a predetermined difference and the first recording time is smaller than the second recording time. The video signal is compressed by the selection means and the mode selected by the mode selection means. They were realized as and a recording unit for recording the compressed coded signal obtained by coding in the coding means on a recording medium.

The configuration of the portable recording device will be described.
A portable recording device 10 shown in FIG. 1 includes a camera unit 1, a monitor liquid crystal panel unit 2, an image / audio processing unit 3, a system controller unit 4, a recording device unit 5, an operation unit 6, and a power supply unit 7. . The image / audio processing unit 3 includes an image encoding unit 31 and an audio encoding unit 32. The system controller unit 4 includes a remaining power management unit 41, a remaining medium management unit 42, a code amount estimation unit 43, a power amount calculation unit 44, a recording mode switching unit 45, a coding mode selection unit 46, and a control unit 49. Is done. A semiconductor memory 51 is stored in the recording device unit 5. A battery 71 is stored in the power supply unit 7.
The image encoding unit 31 illustrated in FIG. 2 includes a moving image encoder 311 and an encoding parameter setting unit 312. The encoding parameter setting unit 312 performs setting of the number of modes with an inter-frame prediction setting unit 312a for setting the number of patterns for variable block size motion compensation, setting of a prediction system, setting of filter processing, and setting of the number of reference frames. Intraframe prediction setting unit 312b, orthogonal transformation setting unit 312c for setting the size of orthogonal transformation performed with integer precision, and setting of coding parameters for CAVLC (Context Adaptive Variable Length Coding) or CABAC (Context Adaptive Binary Arithmetic Coding) An entropy encoding setting unit 312d to perform and a deblocking filter setting unit 312e to set ON or OFF of the deblocking filter are included.

The operation of the portable recording device will be described.
First, when the operation unit 6 is operated and the portable recording device 10 starts a recording operation, the control unit 49 of the system controller 4 presents a screen for requesting input of a necessary recording time to the monitor liquid crystal panel unit 2. Then, the recording time is input from the operation unit 6 or the like. Next, the medium remaining amount management unit 42 of the system controller 4 detects the remaining amount that can be recorded in the semiconductor memory 51 and inputs an encoded signal generated by operating the audio / video processing unit 3 in the standard encoding mode. It is determined whether or not there is a remaining amount of the semiconductor memory 51 necessary to record the recorded recording time. The remaining power management unit 41 detects the remaining amount of the battery 71, and the remaining battery power is the power required to record the encoded signal generated by encoding the image encoding unit 31 in the standard encoding mode. Determine if there is an amount. When it is determined that the remaining amount of the semiconductor memory 51 is sufficient and the remaining amount of the battery 71 is sufficient, the control unit 49 converts the video signal obtained by imaging with the camera unit 1 into an image in the standard encoding mode. The audio signal is encoded by the audio processing unit 3 and the encoded signal obtained by the encoding is supplied to the semiconductor memory 51 of the recording device unit 5 to be recorded.

  When the remaining amount of the semiconductor memory 51 is sufficient by the remaining medium management unit 42 and the remaining amount of the battery 71 is insufficient by the remaining power management unit 41, the code amount estimation unit 43 A code amount when the processing unit 3 is operated at low efficiency is estimated. The power amount calculation unit 44 estimates the power amount when the image / audio processing unit 3 is operated at a low efficiency. That is, the amount of calculation in the image encoding unit 31 and the audio encoding unit 32 is reduced by operating the audio / video processing unit 3 with low efficiency. The amount of power consumption decreases and the amount of code of the encoded signal increases. If the remaining amount of the semiconductor memory 51 is sufficient with respect to the increased code amount, and the remaining amount of the battery 71 is determined to be sufficient due to the reduced power amount by the power remaining amount management unit 41, encoding is performed. The mode selection unit 46 selects the low efficiency encoding mode. The recording mode switching unit 45 switches the encoding mode of the audio / video processing unit 3 to the low efficiency encoding mode.

  When the remaining amount of the semiconductor memory 51 is insufficient by the medium remaining amount management unit 42 and the remaining amount of the battery 71 is determined to be sufficient by the remaining power management unit 41, the code amount estimation unit 43 A code amount when the processing unit 3 is operated with high efficiency is estimated. High-efficiency encoding processing of an image signal is performed simultaneously with deblocking filter processing for attenuating block noise generated when a DCT (discrete cosine transform) image signal is quantized in a rough quantization step, for example. It is such an encoding. The power amount calculation unit 44 estimates the power amount when the image and sound processing unit 3 is operated with high efficiency. The amount of calculation in the image encoding unit 31 and the audio encoding unit 32 is increased by operating the image / audio processing unit 3 with high efficiency. The power consumption increases and the code amount of the encoded signal decreases. If the remaining amount of the semiconductor memory 51 is sufficient for the decreased code amount and the remaining amount of the battery 71 is determined to be sufficient by the increased amount of power by the remaining power management unit 41, the encoding is performed. The mode selection unit 46 selects the high efficiency encoding mode. The recording mode switching unit 45 switches the encoding mode of the audio / video processing unit 3 to the high efficiency encoding mode.

  When the remaining amount of the semiconductor memory 51 is insufficient by the medium remaining amount management unit 42 and the remaining amount of the battery 71 is determined to be insufficient by the remaining power management unit 41, the code amount estimation unit 43 The amount of code when the processing unit 3 is operated with high compression is estimated. High compression encoding is a standard encoding mode after setting the target code amount to a small value for an image signal whose information amount has been reduced by thinning out the number of pixels of the input image signal or attenuating high frequency components. Is encoded using. The audio signal is also subjected to sub-sampling conversion or the like, and the audio signal with a reduced amount of information is encoded, for example, in the standard encoding mode. The power amount calculation unit 44 estimates the power amount when the video / audio processing unit 3 is operated with high compression. The amount of calculation in the image encoding unit 31 and the audio encoding unit 32 is reduced by operating the image / audio processing unit 3 with high compression. The amount of power consumption is reduced and the code amount of the encoded signal is also reduced. If the remaining amount of the semiconductor memory 51 is sufficient for the reduced code amount and the remaining amount of the battery 71 is determined to be sufficient by the reduced power amount by the remaining power management unit 41, encoding is performed. The mode selection unit 46 selects the high compression encoding mode. The recording mode switching unit 45 switches the encoding mode of the audio / video processing unit 3 to the high compression encoding mode.

If the remaining amount of the semiconductor memory 51 is insufficient or the remaining amount of the battery 71 is determined to be insufficient by the remaining power management unit 41 even in the high compression encoding mode, the information amount of the video / audio signal is further increased. After the decrease, for example, encoding in the standard encoding mode is performed.
The control unit 49 receives the audio / video signal input from the camera unit 1 in any one of the standard encoding mode, the low efficiency encoding mode, the high efficiency encoding mode, and the high compression encoding mode. Encode. Control is performed so that the encoded signal obtained by encoding is recorded at a quality level according to the remaining amount of the semiconductor memory 51 and the remaining amount of the battery 71. As for the power consumed when recording in the semiconductor memory 51, if the amount of code to be recorded decreases, the amount of power required for memory access also decreases. Further, when the high compression encoding mode is selected, an image signal acquired from an imaging device (CCD; Charge Coupled Device) (not shown) of the camera unit 1 is used as a thinned image signal, for example, so that the camera unit 1 The power consumption can be reduced.

Next, this will be described in detail.
The image encoding unit 31 shown in FIG. 2 will be described.
The moving image encoder 311 encodes the image signal input from the camera unit 1 according to the encoding parameter set by the encoding parameter setting unit 312, and the encoded signal obtained by the encoding is the recording device unit 5. Is supplied to the semiconductor memory 51 and recorded. The encoding parameter setting unit 312 sets an encoding parameter in accordance with a command from the recording mode switching unit 45 of the system controller unit 4.
For example, MPEG (moving picture experts group) -4 AVC (Advanced Video Coding) or H.264 standard encoding mode is used. H.264 is an encoding method that performs an operation for obtaining an encoded signal having a predetermined image quality with a relatively small amount of calculation.

The setting of the encoding parameter will be described in order.
The inter-frame prediction setting unit 312a performs a motion vector search in order to perform motion prediction encoding of motion between images of the previous frame and the current frame using a motion vector. The searched image is performed for each part of the image, and the size of the partial image is 16 × 16, 16 × 8, 8 × 16, 8 × 8, 8 × 4, 4 × 8, 4 × 4, etc. Seven pattern sizes are available. The setting of the number of patterns for variable block size motion compensation is performed by using all the number of usable patterns or by selecting a representative pattern. That is, in the high-efficiency encoding mode, a motion vector is obtained for each of these seven patterns, and a pattern that can be encoded with the highest encoding efficiency is selected for encoding. In the standard encoding mode, about two frequently selected patterns out of the seven patterns are designated to obtain a motion vector. The amount of calculation for obtaining the motion vector is proportional to the number of patterns. In the standard encoding mode, a setting is made so as to obtain a motion vector that does not deteriorate so much with a small amount of calculation. In the low-efficiency encoding mode, a motion vector is obtained by designating one pattern having the highest frequency of selection. Coding quality that deteriorates due to an error included in a motion vector prevents an increase in coding distortion by increasing the amount of code to be assigned during intraframe coding.

  The prediction accuracy is set by setting whether a matching error when performing motion prediction is about ½ pixel, or ¼ pixel or １ ／ pixel. Thereafter, the filter processing and the reference frame number are set in the same manner. In any case, when the amount of processing is set large, the amount of power for calculation increases, while the coding efficiency also increases, and an encoded signal capable of reproducing a high-quality image with a small amount of code can be obtained.

The mode number setting in the intra-frame prediction setting unit 312b will be described.
H. H.264 has nine prediction modes for intra-frame prediction. Among them, the standard mode is, for example, vertical direction prediction, horizontal direction prediction, and DC component prediction of a pixel block of 4 × 4 pixels (hereinafter, simply referred to as a 4 × 4 pixel block). For example, three prediction modes among the nine are set. The high-efficiency coding mode is set to use all the prediction modes of the four prediction modes for the 16 × 16 pixel block and the intra-frame prediction coding by the remaining six prediction modes of the 4 × 4 pixel block. . The low-efficiency encoding mode is set so that encoding is performed by selecting one prediction mode that is used most frequently among the nine prediction modes.

The setting of the integer precision in the orthogonal transformation setting unit 312c is to perform both of the orthogonal transformation of the 4 × 4 pixel block with the integer accuracy and the transformation of performing the orthogonal transformation of the 8 × 8 pixel block with the integer accuracy, Alternatively, it is set whether to specify one of the more frequently used ones.
The setting of the encoding method in the entropy encoding setting unit 312d is performed by performing entropy encoding by CAVLC (context adaptive variable length encoding), which is variable length encoding, or by arithmetic encoding (Arithmetic Coding). ) CABAC (context adaptive binary arithmetic coding). CABAC is the H.C. The compression method is more efficient than CAVLC defined as the default encoding in H.264, and the code amount can be reduced by 10 to 15% particularly at a high bit rate. The amount of calculation is larger in CABAC.

  The deblocking filter setting unit 312e sets, for example, a two-dimensional filter for removing distortion components generated at the boundary portion of the pixel block when encoding with a 4 × 4 pixel block. As the filter strength, an adaptive filter coefficient is set according to the magnitude of a DCT coefficient obtained by DCT (discrete cosine transform) conversion of a quantization parameter or a pixel block. This is a process that requires a large amount of calculation for the convolution filter processing on the image signal and consumes a large amount of power. The deblocking filter setting unit 312e reduces the coding distortion that occurs in the high-efficiency encoding mode, and when the operation for performing high-efficiency encoding with less distortion components is realized by a circuit, the deblocking filter setting unit (not shown) Turn on the power to the circuit. When the encoding distortion is reduced by software, an encoding sequence that uses an arithmetic routine for a deblocking filter is set and encoding is performed. When the deblocking filter is turned on, power consumption increases for driving the circuit unit or for executing the encoding sequence, while an encoded signal with a small encoding amount and a small encoding distortion component can be obtained.

With reference to FIG. 3, the code amount of the encoded signal generated in each encoding mode and the power consumption during encoding will be described. The horizontal axis represents the code amount of the generated encoded signal, and the vertical axis represents the power consumption during encoding.
The position of “「 ”in (1) shown in the figure is a position that gives the code amount of the encoded signal and the power consumption during encoding in the standard encoding mode. The position of “◯” in (2) is the position in the low-efficiency encoding mode, and an encoded signal having a larger code amount than that in the standard encoding mode can be obtained, while the power consumption during encoding is the standard encoding mode. Less power is consumed. The position of “◯” in (3) is the position in the high-efficiency encoding mode, and an encoded signal having a smaller code amount than that in the standard encoding mode can be obtained, while the power consumption during encoding is the standard encoding mode. More power is consumed. The position of “Δ mark” in (4) is the position in the high compression encoding mode. In the high compression encoding mode, since the image signal with a reduced amount of information is encoded in advance, the encoding amount of the encoded signal is smaller than in the standard encoding mode, and the power consumption during encoding is also higher than in the standard encoding mode. Are encoded with a small amount of power.

With reference to FIG. 4, recording performed while switching the encoding mode when the remaining battery level is insufficient will be described.
In the figure, the horizontal axis (x) is the remaining amount of the semiconductor memory 51 as a recording medium, and the vertical axis (y) is the remaining amount of the battery 71. Suppose that recording is started in the standard encoding mode from the position (X0, Y0) indicated by “）” in the figure, and the characteristics when a predetermined time has elapsed become (X1, Y1) indicated by “◯”. . Thereafter, when recording is continued in the standard encoding mode, the remaining battery level becomes 0 at the position (X2, 0), and the recording operation is interrupted. The recording medium remaining amount at the time of interruption is X2. The intersection of the extension line of the point (X1, Y1) and the point (X2, 0) and the Y axis is (0, Y4). If the remaining battery level at the start of recording is larger by Y4, recording is possible up to a position where both the remaining battery level and the remaining recording medium level become 0, that is, point (O). Therefore, at the point (X1, Y1), the standard coding mode is changed to the low efficiency coding mode. The code amount of the encoded signal increases, but the power consumption decreases. As a result, the characteristic passes through the point (X3, Y3). The point (X3, Y3) is extended and the position intersecting the Y axis is near the point (O). When the value of Y at the intersection of the straight line connecting the point (X0, Y0) and the point (X1, Y1) and the Y axis is smaller than the predetermined value -d, the coding is changed from the standard coding mode to the low efficiency code. Switch to Enabled mode.

With reference to FIG. 5, recording performed while switching the encoding mode when the recording medium remaining amount is insufficient will be described.
It is assumed that recording is started in the standard encoding mode from the point (X5, Y5) indicated by “「 ”in the figure, and the characteristics after a predetermined time has passed are (X6, Y6). Thereafter, when recording is continued in the standard encoding mode, the remaining amount of the recording medium becomes 0 at the position (0, Y7), and the recording operation is interrupted. Therefore, the coding is switched from the standard coding mode to the high efficiency coding mode at the position of the point (X6, Y6). The power consumption of the encoded signal increases, but the code amount of the generated encoded signal decreases. As a result, the characteristic passes through the point (X8, Y8). The position extending the point (X8, Y8) and intersecting the Y axis is near the point (O). When the value of Y at the intersection of the straight line connecting the point (X5, Y5) and the point (X6, Y6) and the Y axis is larger than the predetermined value d, the encoding is performed from the standard encoding mode to the high efficiency encoding. Switch to mode.

With reference to FIG. 6, the process of the portable recording apparatus 10 when recording is performed with the recording time set.
When recording with the portable recording device 10 is started, the recording time is set by operating the operation unit 6 in S (step) 51, for example. In S52, the remaining capacity of the semiconductor memory 51 is detected by the medium remaining amount management unit 42, and the remaining amount of the battery 71 is detected by the remaining power management unit 41. In S53, it is detected whether the medium capacity for recording the encoded signal for the set time is sufficient. If it is detected that it is sufficient, it is detected whether the battery capacity for recording the encoded signal for the time set in S54 is sufficient. If it is detected that it is not sufficient in S54, the encoding of the audio / video processing unit 3 is set to the low efficiency encoding mode in S55. If it is detected in S54 that it is sufficient, the encoding of the audio / video processing unit 3 is set to the standard encoding mode in S56. If it is detected in S53 that the available medium capacity is not sufficient, and if it is detected in S57 that the remaining battery capacity is sufficient, the encoding of the audio / video processing unit 3 is set to the high-efficiency encoding mode in S58. If it is detected in S57 that the remaining battery level is not sufficient, the encoding of the audio / video processing unit 3 is set to the high compression rate encoding mode in S59. Recording is continued in S61 after setting of these encoding modes. After recording for a predetermined time, it is detected whether or not the recording is ended in S62. When it is detected that the recording is not ended, the operation from S52 is repeated, and when it is detected that the recording is ended, the recording operation is ended.

With reference to FIG. 7, the process of the portable recording device 10 when recording without setting the recording time will be described. The same functional parts as those in FIG.
When recording in the portable recording device 10 is started, the remaining medium amount management unit 42 of the system controller unit 4 detects the free capacity X0 of the semiconductor memory 51 and the remaining power management unit 41 determines that the battery 71 The battery remaining amount Y0 is detected. Thereafter, the encoded signal obtained by encoding in the standard encoding mode for a predetermined time is recorded in the semiconductor memory 51. Next, in S72, the free medium capacity X1 and the remaining battery charge Y1 are detected. In S73, the battery capacity b when the medium free capacity becomes 0 is predicted from the relationship of X0, X1, Y1, and Y2. In S74, it is detected whether the absolute value of b is less than or equal to d which is a predetermined value. If it is detected that the value is not equal to or less than the predetermined value, whether or not the value of b is negative is detected in S75. If it is detected that the value is not negative, the encoding mode is set to the high efficiency mode in S77. If it is detected in S75 that the value of b is negative, the encoding mode is set to a low efficiency mode in S76. If it is detected in S74 that the absolute value of b is less than or equal to the predetermined value d, the encoding mode is set to the standard encoding mode in S78. After the setting in S76, S77, and S78, the recording in S61 is continued. The operation from S72 is repeated until the end of recording is detected in S62.

The prediction of the battery capacity b performed in S73 will be further described.
On the xy coordinates, a straight line passing through the point (Y _m , X _m ) and the point (Y _n , X _n ) and intersecting the y axis at (0, b) is given by Equation 1.

これにより、媒体空き容量が０となるまで記録した場合のバッテリ残量が求められる。
バッテリ残量の予測を直線近似により求める代わりに曲線近似により、さらに正確なバッテリ残量として求めるようにしても良い。 Therefore, the value of b when the straight line passing through the point (Y ₀ , X ₀ ) and the point (Y ₁ , X ₁ ) intersects the y-axis is given by Equation 2.

As a result, the remaining battery level when recording until the medium free space becomes zero is obtained.
The battery remaining amount may be estimated as a more accurate battery remaining amount by curve approximation instead of linear approximation.

As illustrated in FIG. 2 described above, there are a plurality of combinations of encoding parameter settings. The selection of these parameters is grouped by power consumption, generated code amount and encoding quality, and the standard encoding mode, low efficiency encoding mode, high efficiency encoding mode, and high compression encoding mode are operated. Determine the parameters for. Further, a larger number of modes may be set, an optimal encoding mode may be selected for the medium free capacity and the battery remaining capacity, and the recording quality in the portable recording apparatus 10 may be ensured to the maximum.
Set the encoding parameter to H.264. The explanation is based on the H.264 system. For other coding systems, group by power consumption, generated code amount and coding quality, set a plurality of coding modes from their relationship, perform coding in the set coding mode, A recording apparatus capable of ensuring the maximum recording quality can be realized.

As described above, according to the portable recording apparatus 10 shown in the present embodiment, the standard encoding mode for encoding the supplied moving image signal with the predetermined encoding rate at the predetermined efficiency, and the moving image signal with the predetermined code. A low-efficiency encoding mode in which encoding is performed at an efficiency lower than a predetermined efficiency at an encoding rate larger than the encoding rate, and a predetermined efficiency in which distortion generated during encoding is suppressed at an encoding rate smaller than the predetermined encoding rate Encoding means 31 for generating an encoded signal in one selected encoding mode out of the high efficiency encoding modes for encoding at higher efficiency, and an empty capacity for detecting the amount of free data recordable on the recording medium The first recordable time based on the free data amount detected by the detecting means 42, the remaining battery capacity detecting means 41 for detecting the remaining battery capacity, and the free capacity detecting means is estimated. And predicting means for predicting the second recordable time based on the remaining battery level detected by the battery remaining capacity detecting means, the first recordable time predicted by the predicting means and the second recordable time When the ratio to the time is equal to or less than a predetermined multiple, the encoded signal is generated by the encoding means by selecting the standard encoding mode, and the first recordable time predicted by the prediction means is the second. If the recording time is longer than a predetermined multiple, the encoding means generates the encoded signal by selecting the low-efficiency encoding mode, and the first recording possible time predicted by the prediction means A coding mode selection means 46 for selecting a high-efficiency coding mode to generate a coded signal in the coding means when the predetermined multiple is smaller than the second recordable time, and a coding mode selection Depending on the encoding mode selected by In the case of including the recording unit 5 that records the compression encoded signal obtained by encoding by the compression encoding means on the recording medium, the remaining battery capacity and the medium free capacity are managed while managing the remaining battery capacity and the free capacity of the recording medium. A portable recording apparatus capable of recording with the highest recording quality can be realized in accordance with both states of the range.
Also, a standard encoding mode for encoding a moving image signal at a predetermined encoding rate with a predetermined efficiency, a low efficiency code for encoding at a lower encoding efficiency and a higher encoding rate than the predetermined efficiency Encoding mode, high efficiency encoding mode for encoding at a higher encoding efficiency and lower than the predetermined encoding rate, and lower efficiency than the predetermined efficiency after reducing the information amount of the video signal Encoding means 31 for generating an encoded signal in one mode selected from among the high compression encoding modes for encoding at an encoding rate smaller than a predetermined encoding rate, and the amount of free data that can be recorded on the recording medium Free capacity detecting means 42 for detecting the remaining battery capacity detecting means 41 for detecting the remaining capacity of the built-in battery, and a video signal for a predetermined time to be supplied is selected in the standard encoding mode. Predicting means 43 for predicting the generated code amount of the encoded signal generated by encoding by the means, and for predicting the power consumption necessary for recording the encoded signal of the predicted generated code amount on the recording medium, 44, the generated code amount predicted by the predicting means is smaller than the free data amount detected by the free capacity detecting means, and the power consumption predicted by the predicting means is detected by the battery remaining amount detecting means. If the remaining amount is smaller than the remaining amount, the encoding unit generates the encoded signal by selecting the standard encoding mode, and the generated code amount predicted by the predicting unit is larger than the free data amount detected by the free capacity detecting unit. If the power consumption predicted by the prediction unit is smaller than the remaining battery level detected by the battery remaining amount detection unit, the encoding unit generates the encoded signal and the low efficiency encoding mode is selected. The generated code amount predicted by the prediction unit is smaller than the free data amount detected by the free space detection unit, and the power consumption predicted by the prediction unit is detected by the battery remaining amount detection unit. If the remaining capacity is larger than the remaining capacity, the encoding means generates the encoded signal by selecting the high-efficiency encoding mode, and the generated code amount predicted by the predicting means is detected by the free capacity detecting means. If the power consumption amount predicted by the prediction means is larger than the remaining battery capacity detected by the battery remaining amount detection means, the encoding signal is generated by the encoding means in the high compression encoding mode. An encoding mode selection means 46 to be selected and a recording section for recording on the recording medium a compressed encoded signal obtained by encoding with the compression encoding means in the encoding mode selected by the encoding mode selection means 5 so that the recording quality is kept high within the range of the remaining battery capacity and the medium free space while managing the remaining battery capacity and the free space of the recording medium, and recording for a predetermined time required. Therefore, a portable recording device that can perform the above can be realized.

It is a block diagram which shows the structural example of the portable recording device which concerns on implementation of this invention. It is a block diagram which shows the structural example of the principal part of the portable recording device which concerns on implementation of this invention. FIG. 6 is a diagram (part 1) illustrating an operation example of the portable recording device according to the embodiment of the invention. FIG. 10 is a diagram (part 2) illustrating an operation example of the portable recording device according to the embodiment of the invention. FIG. 10 is a diagram (part 3) illustrating an operation example of the portable recording device according to the embodiment of the present invention; FIG. 6 is a diagram (part 1) illustrating an operation of the portable recording apparatus according to the embodiment of the present invention in a flowchart. FIG. 9 is a second diagram illustrating the operation of the portable recording device according to the embodiment of the present invention in a flowchart.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera part 2 Monitor liquid crystal panel part 3 Image audio processing part 4 System controller part 5 Recording apparatus part 6 Operation part 7 Power supply part 10 Portable recording device 31 Image encoding part 32 Audio | voice encoding part 41 Power remaining amount management part 42 Medium remaining amount management unit 43 Code amount estimation unit 44 Power amount calculation unit 45 Recording mode switching unit 46 Coding mode selection unit 49 Control unit 51 Semiconductor memory 71 Battery 311 Video encoder 312 Coding parameter setting unit 312a Interframe prediction setting 312b Intraframe prediction setting unit 312c Orthogonal transformation setting unit 312d Entropy coding setting unit

Claims (2)

When the supplied video signal is encoded and recorded on a pre-stored recording medium, the encoding is performed by an encoding method with a large amount of calculation and a large amount of power consumption, or the amount of calculation is small and the amount of power consumption is small. In a portable recording device that selects according to the free capacity of the recording medium and the remaining amount of battery, and performs the encoding by the selected encoding method,
A standard mode for encoding the moving picture signal with a predetermined calculation amount and a predetermined encoding rate, and encoding with a coding amount smaller than the predetermined calculation amount and larger than the predetermined encoding rate. Encoding is performed in one encoding mode selected from the low-efficiency mode and the high-efficiency mode for encoding at an encoding amount larger than the predetermined calculation amount and smaller than the predetermined encoding rate. Encoding means;
Free space detecting means for detecting the free space of the recording medium;
Battery remaining amount detecting means for detecting the remaining amount of the battery;
Depending on the first recordable time during which the compressed encoded signal encoded in the standard mode can be recorded in the free space detected by the free space detection means, and the remaining battery level detected by the battery remaining amount detection means Predicting means for predicting a second recordable time in which the compressed encoded signal encoded by driving the encoding means in the standard mode can be recorded on the recording medium;
If the difference between the first recording time and the second recording time is within a predetermined difference, select the standard mode,
When the difference between the first recording time and the second recording time exceeds the predetermined difference and the first recording time is larger than the second recording time, the low efficiency mode is set. Selected,
When the difference between the first recording time and the second recording time exceeds the predetermined difference and the first recording time is smaller than the second recording time, the high efficiency mode is set. Mode selection means to select;
A recording unit that records, on the recording medium, a compression-encoded signal obtained by encoding the moving image signal by the compression-encoding unit in the mode selected by the mode selection unit;
A portable recording apparatus comprising: When the supplied video signal is encoded and recorded on a pre-stored recording medium, the encoding is performed by an encoding method with a large amount of calculation and a large amount of power consumption, or the amount of calculation is small and the amount of power consumption is small. In a portable recording device that selects according to the free capacity of the recording medium and the remaining amount of battery, and performs the encoding by the selected encoding method,
A standard mode for encoding the moving picture signal with a predetermined calculation amount and a predetermined encoding rate, and encoding with a coding amount smaller than the predetermined calculation amount and larger than the predetermined encoding rate. A low-efficiency mode, a high-efficiency mode in which the amount of computation is larger than the predetermined amount of computation and is encoded at an encoding rate smaller than the predetermined encoding rate, and the predetermined amount of information after compressing the information amount of the video signal Encoding means for encoding in one encoding mode selected from among the high compression modes for encoding at an encoding amount smaller than the predetermined encoding rate and an encoding rate smaller than the predetermined encoding rate;
Free space detecting means for detecting the free space of the recording medium;
Battery remaining amount detecting means for detecting the remaining amount of the battery;
Prediction for predicting a code amount when a moving image signal for a predetermined time is encoded in the standard mode, and for predicting a power consumption necessary for recording the encoded signal of the predicted code amount on the recording medium Means,
The amount of code predicted by the prediction means is less than the free capacity detected by the free capacity detection means, and the remaining power of the battery detected by the remaining battery capacity detection means is the power consumption predicted by the prediction means. If it is less than the amount, select the standard mode,
The amount of code predicted by the prediction means is greater than the free capacity detected by the free capacity detection means, and the remaining power of the battery detected by the remaining battery capacity detection means is the power consumption predicted by the prediction means. If less than the amount, select the low efficiency mode,
The amount of code predicted by the predicting means is less than the free capacity detected by the free capacity detecting means, and the remaining power of the battery detected by the predictive means is detected by the remaining battery capacity detecting means. If it is more than the amount, select the high efficiency mode,
The amount of code predicted by the prediction means is greater than the free capacity detected by the free capacity detection means, and the remaining power of the battery detected by the remaining battery capacity detection means is the power consumption predicted by the prediction means. Mode selection means for selecting the high compression mode and performing encoding by the encoding means when the amount is larger than the amount;
A recording unit that records a compressed encoded signal obtained by encoding the moving image signal by the compression encoding unit in the encoding mode selected by the mode selection unit, on the recording medium;
A portable recording apparatus comprising:

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