JP2011259466A - Recording reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a power consumed by a memory, used by encoding processing and decoding processing, and to realize low power consumption as a recording reproducing device.SOLUTION: An encoder 113 and decoders 111 and 112 have memories 14 and 15 for holding intermediate data, when the encoder 113 and the decoders 111 and 112 are operated. A clock control section 115 controls so as to supply only the memory which is used by the memory with a clock, or controls a frequency of the clock supplied to the memory. A memory power-supply control section 18 controls so as to supply only the memory which is used by the memory with a power supply. When a battery is used as the power supply supplied to a recording reproducing device and trans-coding processing is performed, the clock control section 115 stops supplying of the clock to the memory.

Description

  The present invention relates to a recording / reproducing apparatus for encoding and recording / reproducing a video / audio signal.

  In recent years, digital recorders and video cameras for digitally encoding (encoding) video and audio signals on a recording medium such as a hard disk (HDD) or an optical disk (DVD) have been commercialized. In these recording devices, for example, a plurality of recording media such as HDDs and DVDs are mounted, and a recording function (encoding process) for these media and a reproducing function (decoding process) from these media are provided. Furthermore, in order to back up data that has been recorded once or to store it for a long time, it has a function of dubbing the recorded data between two media. In this dubbing, the encoding method of the original compressed video / audio signal is converted and re-encoded for the purpose of changing the compression rate or because the compression encoding standard differs between media. Transcode processing is often performed.

  For example, Patent Document 1 discloses how to divide a file (code stream) to be supplied to a plurality of transcoding devices in a method of performing parallel processing using a plurality of transcoding devices in order to perform this transcoding processing at high speed. And how to read out.

JP 2001-86460 A

  In particular, recording / playback apparatuses for mobile use are required to further reduce power consumption as the recording time increases. In the encoding / decoding process at the time of recording and reproduction, and the transcoding process at the time of dubbing, the process is performed while storing the intermediate data in the memory, but a large amount of power is consumed to drive the memory device. Further, the required memory capacity varies depending on the operation mode, and more efficient use of the memory in consideration of power consumption is required. Conventionally, including Patent Document 1, sufficient consideration has not been given to reducing power consumption in memory devices.

  An object of the present invention is to realize a reduction in power consumption of a recording / reproducing apparatus by reducing power consumed in a memory used in encoding processing and decoding processing during recording and reproduction.

  According to the present invention, in a recording / reproducing apparatus in which the first and second recording media are mounted and the video / audio signal is recorded and reproduced on the first and second recording media, the input video / audio signal is compressed and encoded to the first or second recording medium. An encoding unit for recording, a decoding unit for reproducing and decompressing and outputting a video / audio signal from the first or second recording medium, and a decompression decoding of the video / audio signal reproduced from the first recording medium, A transcode unit that is compression-coded again and recorded on the second recording medium, a plurality of memories that hold intermediate data when the encode unit, the decode unit, and the transcode unit operate, and a clock that is supplied to the memory A clock control unit for controlling the clock control unit in a memory used by an operating unit among the encoding unit, the decoding unit, and the transcoding unit. To control the supplying of a clock.

  In addition, a memory power control unit that controls the power supplied to the memory is provided, and the memory power control unit controls the power supply only to the memory used by the operating unit among the encoding unit, the decoding unit, and the transcoding unit. To do.

  And a power determining unit that determines whether the power supplied to the device is a battery or an external power source. When the supplied power is a battery and the transcoding unit operates, the clock control The unit stops supplying the clock to the memory.

  The present invention relates to a recording / reproducing apparatus in which the first and second recording media are mounted and the video / audio signals are recorded and reproduced on the first and second recording media, and the input video / audio signals are compressed and recorded on the first or second recording media. An encoding unit, a decoding unit that reproduces a video / audio signal from the first or second recording medium, decompresses and outputs the signal, and decompresses and decodes the video / audio signal reproduced from the first recording medium. Controls the transcoding part that is compressed and encoded and recorded on the second recording medium, the memory that holds intermediate data when the encoding part, decoding part, and transcoding part operate, and the frequency of the clock supplied to the memory A clock control unit, and the clock control unit lowers the frequency of the supplied clock when the encoding unit or the decoding unit operates, When de unit to operate controls to increase the frequency of the clock supplied.

  The present invention relates to a recording / reproducing apparatus in which the first and second recording media are mounted and the video / audio signals are recorded and reproduced on the first and second recording media, and the input video / audio signals are compressed and recorded on the first or second recording media. An encoding unit, a decoding unit that reproduces a video / audio signal from the first or second recording medium, decompresses and outputs the signal, and decompresses and decodes the video / audio signal reproduced from the first recording medium. A transcoding unit for compressing and encoding and recording on a second recording medium; the encoding unit and the transcoding unit commonly have an encoder for compressing and encoding a video / audio signal; and the decoding unit and the transcoding unit are Independently owns a decoder for decompressing and decoding video and audio signals.

  Here, the decoding unit reproduces the video / audio signal from the first recording medium, decompresses and decodes and outputs it, and the transcoding unit decompresses and decodes the video / audio signal reproduced from the first recording medium. After that, the dubbing process of compressing and encoding again and recording on the second recording medium is executed in parallel in time.

  According to the present invention, it is possible to reduce wasteful power consumption in each operation mode of the recording / reproducing apparatus, and particularly to prevent battery consumption when the power source is driven by a battery.

1 is a block diagram illustrating a recording / reproducing apparatus according to an embodiment of the present invention (first embodiment). FIG. The figure which shows the operation mode with which the recording / reproducing apparatus of a present Example is provided. The figure which shows the relationship between an operation mode and clock supply. The figure which shows the relationship between an operation mode and a clock frequency. The block block diagram which shows the other Example of the recording / reproducing apparatus by this invention (Example 2). The figure which shows the relationship between the operation mode in a present Example, and the power supply which can be used. FIG. 10 is a diagram showing an example of dubbing processing of the recording / reproducing apparatus according to the present invention (Example 3). The figure which shows an example of the dubbing setting screen by a user.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an embodiment of a recording / reproducing apparatus according to the present invention. The recording / reproducing apparatus 1 includes a hard disk drive (HDD) 12 and a Blu-ray Disc (BD) drive 13 as recording media. A digital audio signal and a digital video signal (hereinafter referred to as AV signal) input from the input terminal 16 are compression-encoded by the compression / decompression unit 11 and recorded on these recording media. Also, the data recorded on the recording medium is reproduced, decompressed and decoded by the compression / decompression unit 11, output from the output terminal 17, and output to an external display device. Further, as a dubbing operation, a transcoding process is performed in which data recorded in the HDD 12 is re-recorded in the BD drive 13 while converting the bit rate and resolution. When transcoding, the compression / decompression unit 11 performs both decompression decoding and compression coding.

  The compression / decompression unit 11 is configured as an LSI, and includes an encoding unit, a decoding unit, and a transcoding unit. The encoder includes an encoder 113 that compresses and encodes an AV signal, the decoder includes a decoder 111 that decompresses and decodes the AV signal, and the transcode includes a decoder 112 and an encoder 113. Furthermore, a media interface (media IF) 110 that is an interface with each recording medium, a selector 114 that selects a signal source, and a clock control unit 115 are provided. The memories 14 and 15 are, for example, SDRAMs provided outside the LSI, and hold intermediate data during processing by the decoders 111 and 112 and the encoder 113, respectively. The clock control unit 115 and the memory power supply control unit 18 control clock supply and power supply to the memories 14 and 15.

  FIG. 2 is a diagram showing an operation mode provided in the recording / reproducing apparatus of the present embodiment. Starting from the standby state (M200), the recording / playback modes include HDD recording (M201), HDD playback (M202), BD recording (M203), and BD playback (M204). Further, as a dubbing mode, transcoding from HDD to BD (M205), transcoding from HDD to BD, and reproduction of HDD (M206) are possible. The arrows in the figure indicate that transition between the modes is possible.

Each operation mode will be described below.
<Recording mode>
A case where the AV signal input from the input terminal 16 is recorded on the HDD or BD (M201, M203) will be described. The AV signal input from the input terminal 16 is input to the encoder 113 via the signal selector 114. In the encoder 113, for example, the MPEG standard or the H.264 standard. Compression encoding such as H.264 standard is performed. At this time, processing is performed while intermediate data is held in the memory 15 connected to the outside.

  The encoder 113 transfers AV data converted into a bit stream and packetized to the media IF 110 while writing and reading intermediate data to and from the memory 15. The media IF 110 converts the transferred data into a communication protocol (for example, a signal standard such as ATA / ATAPI) to the HDD 12 or the BD drive 13 and records it on the medium selected as the recording destination.

<Playback mode>
A case where data recorded on the HDD or BD is reproduced (M202, M204) will be described. Data recorded in the HDD 12 or the BD drive 13 is read out via the media IF 110 and transferred to the decoder 111. The decoder 111 performs decompression decoding of the encoded data while holding the intermediate data being processed in the memory 14 connected to the outside. The expanded AV signal is output to the external terminal 17 as a digital video signal such as REC656 or a PCM audio signal, and the video and audio signals are reproduced by a display device and a speaker device connected to the outside.

  In the compression encoding and decompression decoding processing in the recording / reproducing mode, the compression / decompression processing is performed using the correlation between the image frames. Therefore, each of the memories 15 and 14 connected to the outside needs to hold a plurality of frames of image data, and therefore a memory device having a large capacity of several megabytes to several tens of megabytes is used. Furthermore, a memory device having a high access speed is required to compare a portion having a high correlation between frames for each small pixel area called a macro block (MB). A memory area for storing the input image once and storing the created bit stream is also required. For this reason, SDRAM is suitable as the memory device.

<Transcode mode>
A case where the data recorded on the HDD is transcoded and dubbed to the BD (M205) will be described. First, the encoded data recorded in the HDD 12 is read out via the media IF 110 and decompressed and decoded by the decoder 112 in the same way as during reproduction. At this time, intermediate data necessary for processing is held in the external memory 14. The decoded data is transferred to the encoder 113 via the selector 114, and compression-encoded again while converting the bit rate and resolution. The encoded data is sent to the BD drive 13 via the media IF 110 and recorded on the BD.

  In the configuration of the present embodiment, when the AV signal input from the input terminal 16 is recorded on the medium and when transcoding is performed between the media, the encoder 113 is used in common. As for the external memory, the memory 15 used by the encoder 113 is made independent, and the memory used by the decoder 111 in the reproduction mode and the decoder 112 in the transcoding is made common (memory 14). This is because more memory capacity is required than when decoding in order to perform motion prediction during compression encoding.

  As the above-described memories 14 and 15, for example, when handling an image of HD standard (High Definition, resolution = horizontal pixel 1920 × vertical pixel number 1080), a DDR-SDRAM (Double Data Rate-SDRAM) having a 16-bit width of 266 MHz or more. ) Etc. are used. As the image size for compression encoding / decoding increases, the memory capacity and data rate (clock frequency) tend to increase. For this reason, among the factors that increase the power consumption of the recording / reproducing apparatus, the power for driving each memory is a major factor. Further, when the compression / decompression unit 11 is made into an LSI, the power consumption required at the connection terminal with the external memory becomes one of the dominant factors of the LSI power consumption. This power consumption is proportional to the bit width and the operation clock. Generally, in the case of accessing the SDRAM, about several hundreds mW of power is consumed.

  Also, the power consumption of the external SDRAM-IC occupies a large proportion in the apparatus. For example, when the DDR-SDRAM is operated at a usage rate of 80%, if the current required for one command is about 80 to 125 mA and the internal voltage is 1.8 V, about 115 to 180 mA per memory device. Consume power. These power consumptions are almost proportional to the access rate to the SDRAM and the clock frequency. Even in the idling state, power of about 20 mW is required except for the power-down mode in which the clock stops.

  In the present embodiment, in order to reduce the power consumption, as described above, the memory for storing the intermediate data for each encoder and decoder is allocated separately. Furthermore, the clock control unit 115 and the memory power supply control unit 18 control the supply of the clock and power necessary for operating each memory so as to stop according to the operating state of the device, thereby reducing power consumption. Plan.

  FIG. 3 is a diagram illustrating the relationship between the operation mode and the clock supply. For example, in a mode in which recording is performed on a HDD or BD medium (M201 and M203 in FIG. 2), the supply to the decoder memory 14 is stopped only by supplying the clock to the encoder memory 15. In the mode (M202, M204) in which playback is performed from the HDD or BD media, the supply to the encoder memory 15 is stopped only by supplying the clock to the decoder memory 14. In the mode of transcoding from HDD to BD (M205, M206), clocks are supplied to both memories 14,15. As described above, the number of memories operating in accordance with the operation mode is increased or decreased, and the number of memories is increased in the transcode mode.

  By stopping the clock supply to the memory that is not used by the encoder or decoder by the clock control unit 115, useless power consumption can be reduced. Furthermore, not only the clock supply is stopped, but also the power supply to the memory is stopped by the memory power supply control unit 18, so that the power consumption can be further reduced.

  In general, the transcode operation is necessary only when performing backup from the HDD to the BD, and the operation ratio is very low in the operation of the apparatus. On the other hand, the operation ratio is high in the recording or reproducing mode, and operating only the memory necessary for the mode greatly contributes to the reduction of power consumption.

  In this embodiment, the clock supply and power supply to the memory are controlled (stopped) in accordance with the operation state of the apparatus. As another method, the clock frequency supplied to the memory is controlled by the memory clock control unit 115. It is good also as a method to do.

  FIG. 4 is a diagram showing the relationship between the operation mode and the clock frequency. That is, in the recording / reproducing mode (M201 to M204 in FIG. 2), the frequency of the clock supplied to the memories 14 and 15 is lowered, and in the transcode mode (M205 and M206 in FIG. 2), the clocks are supplied to the memories 14 and 15. Increase the clock frequency. This makes it possible to reduce power consumption during recording / reproduction on a normal medium. In this case, the memory 14 and the memory 15 may be shared.

  In this embodiment, when the operation mode is recording, reproduction, and transcoding processing, how to control the supply of the clock and power to the memory has been described, but the present invention is not limited to this. That is, the operation mode can take various forms other than the above depending on the application of the apparatus, and the required memory changes accordingly. Therefore, the power consumption of the apparatus can be reduced by controlling the supply of the clock and power to only the memory required in each operation mode, or setting the necessary clock frequency.

  In this embodiment, the control circuit is used to suppress the supply of the clock and power to the non-operating memory. However, a command for setting the non-operating memory to the power down mode may be issued. Then, by canceling the power down mode again when the operation resumes, the same effect as in the present embodiment can be obtained.

  FIG. 5 is a block diagram showing another embodiment of the recording / reproducing apparatus according to the present invention, in which the apparatus of the first embodiment is applied to a video camera. In this embodiment, instead of the input terminal 16, an imaging unit 21 and a camera signal processing unit 22 are connected as a camera input unit, and the input AV signal is recorded and reproduced. In addition, although the power source used is a battery drive system, an external power source (AC power source or the like) can be connected and used. The power source discrimination unit 19 discriminates the power source to be used, and the control unit 20 controls the operation of the apparatus according to the discrimination result. Other components are the same as those in the first embodiment.

  Since the power source of a mobile device such as a video camera is a battery-driven system, it is particularly required to prevent battery consumption. Therefore, in this embodiment, usable power sources are limited according to the operation mode.

  FIG. 6 is a diagram showing the relationship between the operation mode and the usable power supply in this embodiment. The recording / reproducing operation can be executed with either an external power source or a battery, but the transcoding operation is prohibited when the battery is driven, and can be executed only when driven by the external power source. As described above, the power consumption is larger during the transcode operation than during the recording / reproduction operation. Therefore, transcoding processing can be performed only with an external power supply, and power consumption from the battery is reduced. Since recording and playback processing is often performed outdoors, battery operation is essential. However, transcoding processing is usually performed at home or office after shooting, so it is limited to an external power supply (AC power supply). There are few obstacles. Thereby, it is possible to prevent the battery from being inadvertently consumed when the user performs the transcoding operation.

  In order to inhibit the transcoding operation, the method described in the first embodiment can be used. That is, the control unit 20 controls the clock control unit 115 and the memory power supply control unit 18 to stop the clock supply to the memory used for transcoding, further stop the power supply, or lower the clock frequency to be supplied. For example, the transcoding process is disabled.

  In addition, when the user gives an operation instruction to change from the standby state (M200 in FIG. 2) to the transcode state (M205), the power supply determination unit 19 determines which power supply is connected to the external power supply. It is possible to make a transition to the transcode state (M205) only when the power is connected, and to notify the user that the transition is prohibited when the battery is connected.

  FIG. 7 is a diagram showing an example of the dubbing process (transcode process) of the recording / reproducing apparatus according to the present invention. In this embodiment, the dubbing setting operation by the user and the actual dubbing process by the apparatus are executed in a time-overlapping manner, and FIG. 7 shows their time relationship. Reference numerals 301, 302, and 303 accept three setting operations (setting 1 to setting 3) in a dubbing operation setting period by the user. Reference numerals 311, 312, and 313 denote periods of dubbing processes 1 to 3 executed according to the respective settings 1 to 3. When the dubbing setting 1 (301) is completed, the dubbing process 1 (311) set by the dubbing process 1 is continuously executed. While the dubbing process 1 is being executed, the next setting 2 (302) and setting 3 (303) are accepted. be able to. Conventionally, the dubbing setting operation and the actual dubbing process are performed alternately. However, in this embodiment, the total time required for performing the dubbing process a plurality of times can be shortened by performing these operations in parallel. .

  FIG. 8 is a diagram showing an example of the dubbing setting screen 400 by the user. Here, for example, it is assumed that dubbing from the HDD 12 of FIG.

  The AV source group recorded on the dubbing source (HDD 12) is displayed as a sequence group 401 (seq1 to seq5). The user selects, for example, seq3 as a candidate for dubbing 402 using an external remote controller or the like. The playback time of the selected candidate 402 is displayed on the time axis 403. The user determines the start point 406 and end point 207 of the portion to be dubbed. Further, in order to confirm the contents of the dubbing, the preview screen 408 reproduces (decodes) the dubbing source AV data at the position 405 on the time axis and displays the video.

  When the source and period of the dubbing target are determined, the dubbing list 409 is additionally displayed as a target list sequentially. For example, list1 and list2 are already determined as dubbing targets, and list3 is added as a determined portion 410 that is currently being edited. When the dubbing list 409 is completed, the user instructs to start dubbing.

  In accordance with the dubbing list 409, the recording / reproducing apparatus sequentially reads out the dubbing target portion from the HDD 12, performs transcode processing, and then records it on the BD 13. When it is desired to set a new dubbing process during the dubbing process, the user can activate the setting screen of FIG. 8 again and perform the next dubbing setting in parallel.

  As described above, in this embodiment, as shown in the operation mode (M206) of FIG. 2, playback processing (preview) from the dubbing source (HDD) can be performed simultaneously during dubbing processing (transcoding processing). How to perform such parallel operation will be described using the apparatus configuration of FIG.

  First, at the time of dubbing processing, the AV stream read from the HDD 12 is sent to the decoder 112 via the media IF unit 110 to be a decoded AV digital signal. This AV signal is sent to the encoder 113 via the selector 114, and is compression-coded again to obtain an AV stream. This AV stream is dubbed and recorded on the BD 13 via the media IF 110.

  Next, in the reproduction process (preview screen output), a preview AV stream is read from the HDD 12 via the media IF 110 and sent to the decoder 111. The decoder 111 decodes the AV stream into an AV signal, outputs the video to a preview screen of a display device (not shown) via the AV output terminal 17, and the user confirms this.

  As described above, in this embodiment, since the dubbing (transcoding) decoder 112 and the preview reproduction decoder 111 are provided independently, simultaneous processing of dubbing and preview reproduction is possible. Thereby, as shown in FIG. 7, a new dubbing setting process can be advanced by overlapping with the dubbing process. As a result, when the dubbing process is performed in a plurality of times, the total time required for dubbing can be shortened.

  In each of the above embodiments, the HDD and the BD are described as examples of the recording medium, but the present invention is not limited to these. For example, it is obvious that the same effect can be obtained even with a removable HDD, other optical disk media (DVD, CD, etc.), and a removable memory device.

DESCRIPTION OF SYMBOLS 1 ... Recording / reproducing apparatus 11 ... Compression / decompression part 12 ... Hard disk drive 13 ... BD drive 14, 15 ... Memory 16 ... AV signal input terminal 17 ... AV signal output terminal 18 ... Memory power supply control part 19 ... Power supply discrimination | determination part 20 ... Control part 21 ... Imaging unit 22 ... Camera signal processing unit 110 ... Media IF
111, 112 ... Decoder 113 ... Encoder 114 ... Selector 115 ... Clock control unit.

Claims (5)

In a recording / reproducing apparatus in which first and second recording media are mounted and a video / audio signal is recorded and reproduced on the recording medium,
An encoding unit that compresses and encodes an input video / audio signal and records the compressed signal on the first or second recording medium;
A decoding unit that reproduces a video / audio signal from the first or second recording medium, decompresses and outputs the signal, and outputs;
A transcoding unit that decompresses and decodes a video / audio signal reproduced from the first recording medium, and then compresses and encodes the video / audio signal again and records the encoded signal on the second recording medium;
A memory that holds intermediate data when the encoding unit, the decoding unit, and the transcoding unit operate;
A clock control unit for controlling a frequency of a clock supplied to the memory;
The clock control unit controls to lower the frequency of the supplied clock when the encoding unit or the decoding unit operates, and to increase the frequency of the supplied clock when the transcoding unit operates. A characteristic recording / reproducing apparatus. The recording / reproducing apparatus according to claim 1,
In addition, the power supply determination unit for determining whether the power supplied to the device is a battery or an external power supply,
When the supplied power is a battery, the clock control unit controls the frequency of the supplied clock to be lowered even when the transcoding unit operates. In a recording / reproducing apparatus in which first and second recording media are mounted and a video / audio signal is recorded and reproduced on the recording medium,
An encoding unit that compresses and encodes an input video / audio signal and records the compressed signal on the first or second recording medium;
A decoding unit that reproduces a video / audio signal from the first or second recording medium, decompresses and outputs the signal, and outputs;
A transcoding unit that decompresses and decodes the video / audio signal reproduced from the first recording medium, and then compresses and encodes the video / audio signal again and records the encoded signal on the second recording medium;
The encoding unit and the transcoding unit commonly have an encoder for compressing and encoding a video / audio signal,
The recording / reproducing apparatus, wherein the decoding unit and the transcoding unit independently have a decoder for decompressing and decoding a video / audio signal. The recording / reproducing apparatus according to claim 3,
A playback process for playing back a video / audio signal from the first recording medium, decompressing and decoding the video / audio signal by the decoding unit;
A dubbing process in which the transcoding unit decompresses and decodes the video / audio signal reproduced from the first recording medium, and then compresses and decodes the video / audio signal again and records it on the second recording medium, in parallel in time. And a recording / reproducing apparatus. In a recording / reproducing apparatus in which a recording medium is mounted and a video / audio signal is recorded and reproduced on the recording medium
An encoder that compresses and encodes an input video / audio signal to record it on the recording medium;
A decoder for decompressing and decoding a video / audio signal reproduced from the recording medium;
A memory for holding intermediate data when the encoder and the decoder operate;
A memory control unit for controlling the memory;
The memory control unit controls the supply of a clock or power to the memory or changes the frequency of the supplied clock according to the operating state of the encoder or the decoder.

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