JP2007306246A - Recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a recording apparatus which can select an encoding system used to encode recording data out of a plurality of systems to easily change the encoding system during recording. <P>SOLUTION: For example, when a setting screen for encoding systems is called during recording of image data, the setting screen for selecting one of the plurality of encoding systems is displayed. When an encoding system different from an encoding system currently in use is selected, the encoding system is switched from a next recording frame. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a recording apparatus and a control method therefor, and more particularly to a recording apparatus that can select an encoding method used for encoding recording data from a plurality of methods.

  Conventionally, a video camera that captures a moving image, encodes the captured moving image, and records the encoded moving image on a disk medium such as a DVD is known. In this type of video camera, the user can usually set the recording image quality, and as the better image quality is set, the amount of encoded data per unit time increases.

  In addition, in such a video camera, a configuration has been proposed in which the user can change the image quality such as the bit rate while checking the recorded image during recording (see, for example, Patent Document 1).

  Further, for example, in the DVD video format, moving image data is encoded and recorded by the MPEG method, but in recent years, various moving image encoding methods have been proposed. Therefore, it is also considered that moving image data is encoded and recorded using a moving image encoding method other than MPEG.

JP 2001-326908 A

  As described above, in the conventional apparatus, although it is considered to change the bit rate of the recording data during recording, the parameter of the same encoding method is only changed.

  That is, changing the encoding method after the start of recording is not considered. For this reason, when it is desired to change the encoding method, it is necessary to once stop recording, then change the encoding method by operating the menu screen or the like, and then start recording again.

  The present invention has been made in view of such problems of the prior art, and in a recording apparatus capable of selecting a plurality of encoding methods to be used for encoding recording data, the encoding method can be easily performed during recording. Is intended to be changeable.

  The above-described object is to encode input data by applying any one of a plurality of encoding methods and output as encoded data, a predetermined amount of encoded data, A generating unit for generating a recording frame including information representing an encoding method used for encoding the encoded data, a recording unit for recording the recording frame on a recording medium, and an encoding method during recording by the recording unit. It has an accepting unit that accepts a change instruction and notifies the encoding unit after the change to the encoding unit, and the encoding unit uses the notified changed encoding method from the input data included in the new recording frame. This is achieved by the recording apparatus of the present invention characterized in that encoding is performed.

  With such a configuration, according to the present invention, it is possible to easily change the encoding method during recording in a recording apparatus that can select a plurality of encoding methods to be used for encoding the recording data. it can.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram illustrating a configuration example of a video camera as an example of a recording apparatus according to the present embodiment. The video camera of this embodiment can change the image encoding method and the audio encoding method while capturing a moving image.

  In FIG. 1, a video camera 100 includes, for example, a moving image input unit 5 connected to an imaging unit (not shown), and an audio input unit 6 connected to a microphone or the like. The imaging unit includes a lens, an imaging device, a focus and diaphragm control mechanism, and the like, and outputs an analog image signal representing the captured subject image. Note that moving images and audio may be input from an external device.

  The A / D converters 7 and 8 convert the moving image and sound into digital data and output them at a predetermined sampling rate and sampling bit number, respectively. A signal processor (DSP) 9 includes an image encoder 11 and an audio encoder 12. The image encoder 11 and the audio encoder 12 correspond to a plurality of encoding methods.

  The CPU 1 controls the operation of the entire video camera 100 by executing a control program stored in a ROM (not shown) or the like. In FIG. 1, among functions realized by the CPU 1 executing software, functions related to the present embodiment are shown as functional blocks built in the CPU 1. The encoding method selection unit 2, the recordable time calculation unit 3, and the file division instruction unit 4 correspond to this.

  The operation unit 13 generally includes a plurality of buttons and dials, and is used by the user to give various instructions to the video camera 100. The display unit 28 is, for example, a liquid crystal display (LCD), and is used not only as a viewfinder or a reproduction monitor but also as a GUI display such as a menu screen.

  The power source / battery 15 is a general power source such as a secondary battery or an AC adapter, and is a driving power source for the video camera 100. The remaining battery level detector 14 detects the type of power source and the remaining battery level and notifies the CPU 1 of the detected type. The recordable capacity detector 16 detects the remaining capacity of the recording medium 25 and notifies the CPU 1 of it.

  The memory 10 is a RAM used as a work memory for the CPU 1 and the DSP 9 and may have a nonvolatile area. The signal processing ECC circuit 18 adds a code for error correction to the encoded data or performs error correction processing. The modem 19 and the AD / DA converter 20 perform modulation / demodulation and data type conversion necessary for recording and reproduction. The AD / DA converter 17 converts the data format necessary for the processing of the recordable capacity detector 16.

  The head 21, the servo / head control circuit 22, the motor control unit 23, and the spindle motor 24 constitute a recording / reproducing mechanism, and read / write an optical recording medium such as a DVD that can be recorded / reproduced according to the control of the CPU 1.

Next, shooting and recording processing operations in the video camera of the present embodiment will be described using the flowchart shown in FIG.
Although details will not be described here, in the shooting standby state, usually, the captured image data input from the imaging unit is displayed on the display unit 28 in order to cause the display unit 28 to function as a viewfinder. Is being processed.

  When the user gives an instruction to start recording by pressing a recording start button included in the operation unit 13 or the like, the CPU 1 detects it (step S101) and starts photographing and recording operations (step S103). An analog signal type moving image or sound is input through a moving image input unit 5 and a sound input unit 6 from an imaging unit or a microphone (not shown).

  The input moving image is converted into digital data by the A / D converter 7 and then input to the DSP 9. The image encoder 11 of the DSP 9 corresponds to an encoder (any one of Encoder 1, 2,..., N) corresponding to the moving image encoding method set at that time, and according to the image quality setting. The moving image data is encoded using the encoded parameters. Then, the encoder 11 sequentially writes the encoded moving image data, which is the encoding result, in the memory 10.

  Similarly, the input voice is converted into digital data by the A / D converter 8 and then input to the DSP 9. The speech encoder 12 of the DSP 9 corresponds to the encoder (any one of Encoder 1, 2,..., N) corresponding to the speech encoding method set at that time, and the sound quality setting etc. The audio data is encoded using the encoding parameters. Then, the encoder 12 sequentially writes the encoded audio data as the encoding result in the memory 10.

  During shooting, it is checked whether or not an instruction for calling the encoding method setting screen has been issued through the operation unit 13 (step S105). If there is no instruction, the encoding operation of moving images and sounds is continued according to the setting at the start of recording. (Step S103).

  The encoded moving image data and encoded audio data stored in the memory 10 are read out to the signal processing ECC circuit 18. The signal processing ECC circuit 18 adds a header such as management information to the read data, and converts the read data into a code added with error correction parity (Reed-Solomon code, BCH code, etc.) according to the format of the recording medium. .

  The image and audio data converted by the signal processing ECC circuit 18 are modulated by a modulator / demodulator 19 according to a modulation method in accordance with the format of the recording medium. The modulated data is D / A converted by the AD / DA converter 20 and becomes a type that can be recorded on the recording medium 25.

  Recording of data onto the recording medium 25 is performed by a recording / reproducing mechanism that receives a command from the CPU 1. Specifically, the command is transmitted from the CPU 1 through the servo head control circuit 22 and from the servo head control circuit 22 through the motor control circuit 23 and the head 21. The spindle motor 24 and the head 21 perform a predetermined recording operation, and the recording data output from the D / A converter 20 is recorded on the recording medium 25.

  On the other hand, the battery remaining amount detector 14 monitors the output voltage from the power source / battery 15 at regular intervals, calculates the power capacity of the power source / battery, and notifies the CPU 1 of the power capacity value as digital data.

  The recordable capacity detector 16 reads the address information of the recording medium 25 from the recording medium 25 by the head 21, and detects the address from the data after A / D conversion by the AD / DA converter 17. Then, the recordable capacity of the recording medium 25 is calculated, and the recordable capacity value is notified to the CPU 1 as digital data. The address detection is originally a process that is always performed when data is recorded on the recording medium 25. In this embodiment, the recordable capacity value is obtained using this process.

  When the user wants to change the encoding method of the moving image during shooting, the menu screen is displayed on the display unit 28 using the operation unit 13, for example, and the encoding method setting screen is displayed by a known method. When the CPU 1 detects that the encoding method setting screen has been called (step S105), the CPU 1 calculates a recordable time for each encoding method.

  If the calling of the encoding system setting screen is not detected, the presence / absence of the recording end instruction is confirmed (step S106), and if the end instruction is received, the recording process is ended. If there is no end instruction, the recording process is continued.

  In step S <b> 107, the CPU 1 stores the power capacity value received from the remaining battery level detector 14, the recordable capacity value received from the recordable capacity detector 16, and a code stored in advance in a nonvolatile area of the memory 10. The recordable time for each encoding method is calculated from the amount of generated data (bit rate) for each encoding method and information related to power consumption.

  Any calculation method may be used. For example, the time obtained from the default bit rate and the recordable capacity for each encoding method, the time obtained from the power capacity value and the power consumption density for each encoding method, The shorter one can be set as the recordable time.

  In the case of being driven by a commercial power supply, the recordable time can be calculated from the recordable capacity and the bit rate. Also, in the present embodiment, step S107 is executed only when the moving picture encoding scheme setting screen is called, and when the voice encoding scheme setting screen is called, step S107 is skipped.

  Typical encoding methods are MPEG2 and H.264 for moving images. For audio such as H.264, MP3 and AAC are known. The encoding schemes are different in the complexity of calculation, and the power consumed by each of the image encoder 11 and the audio encoder 12 used in the DSP 9 varies depending on the encoding scheme. For this reason, in a device that supports a plurality of types of encoding methods, such as the video camera of this embodiment, it is preferable to calculate the recordable time for each encoding method and notify the user.

  The recordable time can be calculated at regular time intervals, and can be calculated even when the encoding method setting screen is called as in the present embodiment. And whenever it calculates, it can display on the display part 28 and can alert | report to a user.

  During recording, when the battery capacity or recordable time becomes less than the predetermined value, a warning message such as “Recordable time is remaining ○ minutes” is displayed on the display unit 28, or a sound is notified through a speaker (not shown). It is also possible to do. At this time, it is also preferable to display information indicating whether the recordable capacity of the recording medium is low or whether the battery capacity is low.

  Next, the CPU 1 displays an encoding scheme setting screen (step S109). FIG. 3 shows an example of a setting screen for the moving image encoding method. In the present embodiment, as shown in FIG. 3, an encoding method selection menu is displayed in the lower right corner of the screen while displaying the moving image being recorded on the display unit 28.

The encoding method selection menu associates the names of selectable individual encoding methods with the recordable time calculated in step S107 and displays them as menu items that can be selected from the operation unit 13.
In the example of FIG. 3, the moving image / audio encoding method currently used, the recordable time, the remaining battery level, and the like are separately displayed in the lower left corner of the screen.

Further, when the voice encoding method setting screen is called in step S105, the process immediately proceeds to step S109, and while the moving image being recorded is displayed on the display unit 28 as shown in FIG. The encoding method selection menu is displayed in the lower corner.
The encoding method selection menu displays the names of individual selectable encoding methods as menu items that can be selected from the operation unit 13.
Further, as in FIG. 3, the moving image / audio encoding method currently used, the recordable time, the remaining battery level, and the like are separately displayed in the lower left corner of the screen.

  While viewing the setting screen shown in FIGS. 3 and 4, the user uses the keys and buttons included in the operation unit 13 to select items corresponding to the desired encoding method from the screens shown in FIGS. 3 and 4. ,decide. This determination instruction is detected by the CPU 1 as an encoding system change instruction (step S111).

  When an instruction to change the encoding method is input from the operation unit 13, the CPU 1 transmits a change to the encoding method corresponding to the selected item to the DSP 9. Further, the file division instruction unit 3 transmits a file division instruction to the DSP 9, the memory 10, and the signal processing ECC circuit 18.

  In the DSP 9, when the encoding change instruction signal is received from the CPU 1, the encoding method before the change instruction is continuously used until the file being recorded can be closed. Specifically, the encoding method is not changed until the recording frame (recording sector, recording data unit) of data to be recorded on the recording medium 25 generated by the signal processing ECC circuit 18 and the modem 19 is completed (step S115). Then, when a recording frame using only encoded data according to the current encoding method can be generated, the file is closed and the encoding method is changed to the instructed method (step S117). Then, the encoded data generated by the changed encoding method starts recording as a new file.

  As shown in FIG. 5, the encoded moving image data and the encoded audio data are supplied from the memory 10 to the signal processing ECC circuit 18, and the encoding scheme identification is added from the CPU 1 in addition to the encoding scheme change instruction signal. Management information for specifying an encoding method of recording data such as information and management information for specifying file division are input. Then, a recording frame is generated from the encoded moving image data, the encoded audio data, and the management information data.

  The generated recording frame is recorded on the recording medium 25 by the servo head control unit 22 and the motor control unit 23 controlling the head 21 and the spindle motor 24 in accordance with an instruction from the CPU 1.

  As described above, in this embodiment, when there is an instruction to change the encoding method during creation of a recording frame, the encoding method is not changed until the end of the recording frame. Furthermore, even if the recording frame ends, it is possible to perform encoding up to the last frame constituting the encoding unit corresponding to the current encoding method. In this case, when the encoding process and recording of the data of the last encoding unit are completed, the file is temporarily closed at that time. For example, when the encoding method before the change is the MPEG2 method, the encoding is performed in a unit called GOP, so here, up to the last frame of the GOP being encoded when the encoding method change instruction is given. Performs encoding using the encoding method before the change. After that, the data encoding and recording process by the changed encoding method is started (step S117). At this time, the encoded data to which the changed encoding method is applied is recorded as a new file. Thereafter, the process returns to step S103 to continue recording.

  In addition to recording management information for specifying the encoding method in the recording frame and recording it on the recording medium, information indicating the correspondence between the recording frame and the recording encoding method is also recorded in the management information recording area of the recording medium. It is also possible to record a table or the like. Thus, by recording the management information at a plurality of locations on the recording medium, it is possible to improve the reliability during reproduction. In addition, by storing the encoding method after the change of the encoding method in the management information of the file before the change, when these two files are reproduced continuously, the corresponding decoding circuit can be switched smoothly. .

  If an instruction to change the encoding method is not input from the operation unit 13 in step S111, the recording process continues while waiting for the instruction until a predetermined time elapses, and there is no change instruction even if the predetermined time elapses (step S113). , N), the setting screen is deleted (step S114), and the recording process is continued. Even when there is a cancel instruction on the setting screen, the setting screen is deleted and the recording process is continued as in the case where there is no instruction for a predetermined time.

  Note that when reproducing moving image data recorded on the recording medium 25, management information is read to acquire information such as an encoding method, and the moving image data and audio data are decoded based on this information. Therefore, even when the encoding method is changed during reproduction, it is possible to correctly decode.

  As described above, according to the present embodiment, it is possible to easily change the encoding method while recording. At this time, by presenting the recordable time in association with the selectable encoding method, the user can easily perform the encoding method in consideration of the recording time. Since the data recorded before the encoding method change and the data recorded after the change are managed as separate files, even a device that supports only a part of the encoding method reproduces this It becomes possible.

  In addition, by storing information about the encoding method in a file and recording it, the decoding method can be recognized in advance even when playing back, and even a moving image whose encoding method has been changed in the middle can be encoded. Smooth decoding and playback are possible even when there is a switching point of the conversion method.

  In the present embodiment, only the change of the encoding method has been described for ease of explanation and understanding. However, after selecting an encoding method, an image quality setting screen for the encoding method can be displayed, and the image quality setting can also be set by the user. In this case, in addition to the instruction to switch the encoding method, the CPU 1 is notified of the image quality setting to the DSP 9, the signal processing ECC circuit 18, and the like.

It is a block diagram which shows the structural example of the video camera as an example of the recording device which concerns on embodiment which concerns on embodiment of this invention. It is a flowchart for demonstrating the imaging | photography / recording processing operation in the video camera which concerns on embodiment. It is a figure which shows the example of a setting screen of a moving image encoding system in the video camera which concerns on embodiment. It is a figure which shows the example of a setting screen of the audio | voice encoding system in the video camera which concerns on embodiment. It is a figure which shows typically the operation | movement of a signal processing ECC circuit and the flow of data in the video camera which concerns on embodiment.

Claims (6)

Encoding means for applying any one of a plurality of encoding methods to input data, and outputting the encoded data as encoded data;
Generating means for generating a recording frame including a predetermined amount of the encoded data and information indicating an encoding method used for encoding the encoded data;
Recording means for recording the recording frame on a recording medium;
During the recording by the recording means, it has an accepting means for accepting an instruction to change the encoding method and notifying the encoding means of the changed encoding method,
The recording apparatus, wherein the encoding means performs encoding using the notified changed encoding method from input data included in a new recording frame. First detecting means for detecting a recordable capacity of the recording medium;
Storage means for storing information relating to the amount of generated data stored in advance for each of the plurality of encoding methods;
Calculating means for calculating a recordable time for each of the plurality of encoding methods from the recordable capacity and the information on the generated data amount;
The recording apparatus according to claim 1, further comprising display means for displaying the recordable time calculated by the calculation means in association with an encoding method. Furthermore, it has a 2nd detection means to detect the power capacity of a power supply,
The storage means stores information related to power consumption density for each of the plurality of encoding methods,
The recording apparatus according to claim 2, wherein the calculation unit calculates the recordable time by further using the power capacity value and the power consumption density.   The recording apparatus according to claim 1, wherein the plurality of encoding methods include at least a plurality of encoding methods for image data.   Encoding is performed using the applied encoding method until the last recording frame constituting the encoding unit of the applied encoding method at the time when the encoding means receives the change instruction. 5. The recording apparatus according to claim 1, wherein encoding is performed using the notified changed encoding method. 5.   6. The recording apparatus according to claim 1, wherein the recording unit records a recording frame in which the encoding method after the change is changed as a new file.

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