Technical field
[0001]This technique, signal processing apparatus, signal processing method, and a program, in particular, a single DSD signal, the signal processor also outputs a PCM signal to be able to correspond, a signal processing method, and a program.
BACKGROUND
[0002]In recent years, music has come to be carried out by high-resolution sound source is the audio data of sound quality that exceeds the music CD (CD-DA).
[0003]
　Delta-sigma modulated digital signal by 1bit signal (hereinafter, DSD (Direct Stream Digital) signal also referred to.) In the music distribution using, sampling frequency 44.1kHz for CD which is used by Super Audio CD (SACD) 64 not only multiple of DSD signal (64DSD signal), 128 times the DSD signal (128DSD signal) and also the delivery of 256 times the DSD signal (256DSD signal) have been made experimentally.
[0004]
　DSD signal, the sampling frequency is higher than PCM (Pulse Code Modulation) signal, the communication capacity is large compared to the PCM signal for performing streaming distribution. For example, the data capacity of 64DSD signal when the 3 seconds 1 frame signal of the stereo (2 channels) is approximately 2.8Mbit / frame.
[0005]
　The present applicant, in Patent Document 1 proposes a compression method for transmitting reversibly compress the DSD signal first.
[0006]
　On the other hand, as a coping method in accordance with the state of the communication path, for example, MPEG-DASH - as in (Moving Picture Experts Group Dynamic Adaptive Streaming over HTTP), a plurality of encoded data representing the same content at different bit rates the may be stored in the content server, the client apparatus, from the plurality of encoded data in accordance with the communication capacity of the network, there is a technique for streaming receiving the desired encoded data.
[0007]
　The applicant has in Patent Document 2, in the music delivery using DSD signal, using a streaming method, such as MPEG-DASH, signals of different bit rates at the same content, for example, 64DSD signal, 128DSD signal, 256DSD signal from among, in accordance with the communication bandwidth, it has proposed a method of dynamically selecting view better quality DSD signal. Incidentally, DSD signal, be compressed by using a compression method Patent Document 1, since compared with PCM signal bit rate increases, it is preferable to prepare such can be delivered in a PCM signal.
CITATION
Patent Document
[0008]
Patent Document 1: WO 2016/140071 Patent
Patent Document 2: International Publication No. WO 2016/199596
Summary of the Invention
Problems that the Invention is to Solve
[0009]
　However, in order to effectively utilize the delivery side resources, the type of data to be prepared in the delivery side is desirably 1 type.
[0010]
　This technology has been made in view of such circumstances, a single DSD signal, the output of the PCM signal is also intended to be compatible.
Means for Solving the Problems
[0011]
　Signal processing apparatus according to an embodiment of the present technology, when generating a PCM signal having a predetermined sampling frequency from DSD signal, especially in samples of a predetermined interval determined by said predetermined sampling frequency, the samples of a predetermined number includes an extraction unit that extracts from the DSD signal, by filtering the samples of said predetermined number is extracted, and a filtering unit for generating a PCM signal of the predetermined sampling frequency.
[0012]
　Signal processing method according to an embodiment of the present technology, the signal processing apparatus for generating a PCM signal having a predetermined sampling frequency from DSD signal is centered on the sample of a predetermined interval determined by said predetermined sampling frequency, the number of predetermined samples were extracted from the DSD signal, by filtering the samples of the predetermined number are extracted, including the step of generating a PCM signal of the predetermined sampling frequency.
[0013]
　A program according to an embodiment of the present technology, the computer, to generate a PCM signal having a predetermined sampling frequency from DSD signal, especially in samples of a predetermined interval determined by said predetermined sampling frequency, a predetermined number of samples the, the extract from DSD signal, by filtering the samples of said predetermined number is extracted, is intended for executing a process of generating a PCM signal of the predetermined sampling frequency.
[0014]
　In one aspect of the present technology, when generating a PCM signal having a predetermined sampling frequency from DSD signal, especially in samples of a predetermined interval determined by said predetermined sampling frequency, a predetermined number of samples is, the DSD It is extracted from the signal, by filtering the extracted sample of the predetermined number of, PCM signals of the predetermined sampling frequency is generated.
[0015]
　The signal processing apparatus according to an embodiment of the present technology may be realized by causing a computer to execute a program.
[0016]
　Program can be transmitted via a transmission medium or by being recorded on a recording medium, it can be provided.
[0017]
　The signal processing apparatus may be an independent apparatus or may be an internal block constituting one apparatus.
The invention's effect
[0018]
　According to one aspect of the present technology, a single DSD signal, the output of the PCM signal can be accommodated.
[0019]
　Here, the advantages described in the present invention is not necessarily limited, it may be any of the effects described in the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020]
It is a block diagram showing a configuration example of an embodiment of a reproduction system to which the FIG. 1 present technology.
[2] the distribution apparatus is a diagram illustrating a transmission mode of audio data to be transmitted.
Is a block diagram illustrating a detailed configuration example of FIG. 3] PCM conversion unit.
Is a diagram illustrating a FIG. 4 sampling extraction process.
Is a diagram illustrating a FIG. 5 sampling extraction process.
Is a diagram illustrating a FIG. 6 filtering.
Is a diagram illustrating a FIG. 7 filtering.
Is a flowchart illustrating a FIG. 8 audio data transmission process.
9 is a block diagram illustrating a detailed configuration example of a playback apparatus.
It is a block diagram showing a configuration example of FIG. 10 reproducing apparatus.
11 is a flowchart for explaining the audio data reproduction process.
It is a block diagram showing a configuration example of an embodiment of FIG. 12] PCM signal converting apparatus according to the present technology.
13 is a block diagram showing a configuration example of an embodiment of a computer to which the present technology is applied.
DESCRIPTION OF THE INVENTION
[0021]
　Hereinafter, embodiments of the present technology (hereinafter, referred to as embodiments) will be described. The description will be made in the following order.
1. Configuration of the reproduction system Example
2. Submit form of playback audio data
3. Detailed configuration of the PCM conversion unit Example
4. Description of PCM conversion processing
5. Audio data transmission process
6. Detailed Configuration of reproducing apparatus example
7. Form and transmits DSD data and PCM_AAC data simultaneously
8. Audio data playback processing
9. PCM signal converter
10. Computer configuration example
[0022]
<1. Configuration Example> Reproducing System
　FIG. 1 is a block diagram showing a configuration example of an embodiment of a reproduction system according to the present technology.
[0023]
　Reproduction system 1 of Figure 1 comprises at least a delivery device 11 and the playback device 12 is a system reproducing apparatus 12 acquires and reproduces audio data from the delivery device 11.
[0024]
　The distribution device 11, a plurality of contents each sound collected by the microphone 21, the audio data obtained by delta-sigma modulation are stored.
[0025]
　More specifically, the audio signal of a predetermined sound source picked up by the microphone 21 (e.g., content A) is amplified by an amplifier (AMP) 22, it is supplied to a delta-sigma (.DELTA..SIGMA) modulator 23.
[0026]
　Delta-sigma modulator 23, the delta-sigma modulation, and converts the analog audio signal input to the digital signal (AD conversion). For example, the delta-sigma modulator 23, the analog audio signal input, CD and delta-sigma modulation at 64 times the sampling frequency of the sampling frequency 44.1kHz of (Compact Disc), delivery device DSD signal obtained as a result 11 to be stored in. DSD signal obtained by delta-sigma modulation at 64 times the sampling frequency of the 44.1kHz, since the bit rate of 2.8MMbps, in the following, also referred to as 2.8M DSD data.
[0027]
　Delivery device 11 stores 2.8M DSD data of a plurality of contents that are generated as described above.
[0028]
　Reproducing apparatus 12, when requesting audio data of a predetermined content to the delivery unit 11, an audio data of itself is a format reproducible, or 2.8M DSD data, or PCM_AAC selects one of the data Te, and requests the distribution device 11. Alternatively, the reproducing apparatus 12, in accordance with the communication capacity of the network 24, or 2.8M DSD data, or PCM_AAC selects either of the data, may request the delivery device 11.
[0029]
　Here, PCM_AAC data, sampling frequency 192kHz (44.1kx4Hz), a PCM signal quantized bits 16bit, it is AAC (Advanced Audio Coding) compression encoded signal by encoding scheme.
[0030]
　Distribution device 11, in response to a request from the playback device 12, a 2.8M DSD data or PCM_AAC data of the specified content, transmitted to the reproducing apparatus 12.
[0031]
　Delivery device 11 includes a control unit 31, storage unit 32, PCM conversion section 33, the encoding unit 34, and the transmission unit 35.
[0032]
　Control unit 31 obtains the transmission request of the content from the reproduction apparatus 12 via the transmitter 35, to transmit the audio data of the requested content, and controls each unit of the delivery device 11.
[0033]
　More specifically, for example, from the reproducing apparatus 12, as the audio data of the content A, when a request for 2.8M DSD data, the control unit 31, 2.8M DSD of the content A stored in the storage unit 32 to supply the data to the transmission unit 35, it is transmitted from the transmitter 35 to the reproducing apparatus 12.
[0034]
　Further, for example, as an audio data of the content A, when a request for PCM_AAC data from the reproducing apparatus 12, the control unit 31 operates the PCM conversion unit 33 and the encoding unit 34, are stored in the storage unit 32 from 2.8M DSD data of the content a, to generate PCM_AAC data, it is transmitted from the transmitter 35 to the reproducing apparatus 12.
[0035]
　Storage unit 32 stores each of 2.8M DSD data multiple contents.
[0036]
　PCM conversion section 33 supplies the 2.8M DSD data supplied from the storage unit 32 sampling frequency 192 kHz, by converting the PCM signal quantized bits 16bit, it generates a PCM signal, the encoding unit 34. The sampling frequency and quantization bit number of the PCM signal to be produced is an example, not limited to this.
[0037]
　Encoding unit 34, a PCM signal supplied from the PCM conversion unit 33, and compression-encoded by the encoding scheme of AAC (Advanced Audio Coding), and supplies the PCM_AAC data obtained as a result, the transmitter 35.
[0038]
　Transmitter 35 is transmitted from the reproducing apparatus 12 via the network 24, it receives a request for transmission of audio data, and supplies the control unit 31.
[0039]
　The transmission section 35, the audio data of a predetermined content supplied from the storage unit 32 or the encoding unit 34, and transmits to the playback apparatus 12 via the network 24. From the storage unit 32 is supplied with 2.8M DSD data as audio data, from the encoding unit 34, PCM_AAC data is supplied.
[0040]
　Reproducing apparatus 12 receives the digital audio data transmitted from the distribution device 11, into an analog signal, and outputs the analog LPF 25.
[0041]
　Analog LPF (low pass filter) 25 performs a filtering process for removing high frequency components, and outputs the signal after filtering processing to the power amplifier 26.
[0042]
　Power amplifier 26 amplifies the analog audio signal outputted from the analog LPF 25, and outputs to the speaker 27. Speaker 27 outputs the audio signal supplied from the power amplifier 26 as sound.
[0043]
　Analog LPF 25, a power amplifier 26 and, an analog output section consisting of the speaker 27 may be incorporated as part of the reproduction apparatus 12.
[0044]
<2. Transmission mode> audio playback data
　2, delivery device 11 indicates the transmission mode of audio data to be transmitted to the reproducing apparatus 12.
[0045]
　Transmission form of the audio data distribution device 11 transmits to the playback device 12, depending on the configuration of the reproducing apparatus 12 can take several forms.
[0046]
　For example, the reproducing apparatus 12 is playable audio data, 2.8M DSD data, or if it is fixed in one of PCM_AAC data distribution device 11, as shown in A of FIG. 2, the reproducing apparatus 12 There transmits one of 2.8M DSD data or PCM_AAC data playable. If the playback device 12 is a known data format of the audio data can be reproduced, only the content to be reproduced is specified to the delivery device 11 from the reproducing apparatus 12. In FIG. 2, for simplicity, 2.8M DSD data is described as DSD data, PCM_AAC data is described as PCM data.
[0047]
　Further, for example, the reproducing apparatus 12, in the middle of a playback of a single piece of content even if the 2.8M DSD data and PCM_AAC data of the same content, a device capable of reproducing switched as necessary, the distribution device 11 , as shown in B in FIG. 2, in response to a request of the reproducing apparatus 12, transmits to switch the 2.8M DSD data and PCM_AAC data of the same content seamlessly. 2.8M DSD data is larger but are data amount with high quality, PCM_AAC data, the sound quality is inferior as compared with 2.8M DSD data but the data amount is small. Thus, for example, the reproducing apparatus 12, in accordance with the communication capacity of the network 24, or 2.8M DSD data, or appropriately selecting the PCM_AAC data plays while switching.
[0048]
　In the case of seamless playback while switching 2.8M DSD data and PCM_AAC data, PCM_AAC data includes PCM data conversion processing by the PCM conversion unit 33, delay only time the compression encoding process by the encoding unit 34 generates . Delivery device 11 can transmit the delay value in advance reproducing apparatus 12 as metadata, reproduction apparatus 12 can be switched 2.8M DSD data and PCM_AAC data based on the delay value seamlessly.
[0049]
　Client device, from among the stored plurality of coded data, in accordance with the communication capacity of the network, as standard method for streaming receiving a desired coded data, MPEG-DASH (Moving Picture Experts Group - Dynamic Adaptive Streaming over HTTP) there is. Delivery device 11 in the form conforming to the standard of the MPEG-DASH, transmits switched as necessary 2.8M DSD data and PCM_AAC data reproducing apparatus 12, receives and reproduces it.
[0050]
　Delivery device 11, it is possible to transmit both 2.8M DSD data and PCM_AAC data at the same time. For example, as shown in C of FIG. 2, the front right and front left audio data is transmitted in 2.8M DSD data of a high sound quality, the rear right and rear left audio data, the data amount is small PCM_AAC it is possible to transmit the data.
[0051]
　As described above, the delivery device 11, as the audio data for delivery, only stores one DSD data 2.8M DSD data, may correspond to the transmission of both 2.8M DSD data and PCM_AAC data it can.
[0052]
<3. Detailed Configuration Example> of PCM conversion section
　3 is a block diagram illustrating a detailed configuration example of a PCM conversion unit 33.
[0053]
　PCM conversion section 33, an extraction unit 41, a filtering unit 42, a 2.8M DSD data into PCM signals of a predetermined sampling frequency. In the present embodiment, PCM conversion section 33 converts the PCM signal having a sampling frequency 192 kHz.
[0054]
　Extraction unit 41, at predetermined intervals determined by the sampling frequency 192kHz of the PCM signal, a predetermined number of sampling data, extracted from 2.8M DSD data supplied from the storage unit 32.
[0055]
　Filtering unit 42 filters the predetermined number of sampling data extracted at predetermined intervals in the extraction unit 41 to generate a PCM signal, and outputs to the encoding part 34.
[0056]
<4. Description of the PCM conversion process>
　Referring to FIGS. 4 to 7, a description will be given of PCM conversion by the PCM conversion unit 33.
[0057]
(Sampling extraction process by the extraction unit 41)
　First, with reference to FIGS. 4 and 5, the sampling extraction process by the extraction unit 41 will be described.
[0058]
　Now, each sampling data of 2.8M DSD data before PCM conversion of a given content,
　　　D [0], D [1], D [2], D [3], · · ·, D [n], · ...
and, each sampling data of the PCM data after PCM conversion,
　　　PCM [0], PCM [1], PCM [2], PCM [3], · · ·, PCM [n], · · ·
and .
[0059]
　2.8M each sampling data D DSD data [n] is "1" or "0" is represented by 1bit signal, in operation of the signal processing is represented by a "0" to "-1", " It is calculated by the 1 "or" -1 ". In the following, the sampling data, simply referred to as a sample.
[0060]
　1 Sample 2.8M DSD data, 1 / (44.1 * 64k) is [sec], one sample of the PCM data of the sampling frequency 192kHz are the 1 / 192k [sec], PCM conversion section 33, ( 44.1 * 64) /192=14.7 on a sample-by-sample basis, and it outputs the data.
[0061]
　Therefore, the extraction unit 41, a sample of 2.8M DSD data, 14.7 sample interval, to extract a predetermined number of samples. In this embodiment, the number of samples extractor 41 is extracted, and 256 samples. Thus, the extraction unit 41, a sample of 2.8M DSD data, 14.7 samples (the m non-negative integer) of m times to extract before and after 256 samples such that each sample position of the center sample, the filtering unit 42 supplied to.
[0062]
　Figure 4 is a sample of 2.8M DSD data extracting unit 41 extracts, shows the correspondence between the PCM data PCM after PCM conversion [n].
[0063]
　14.7 m times of the samples, 0,14.7,29.4,44.1,58.5, ..., 1470,1484.7,1499.4,1514.1, since a., The center position samples extracted sample for each PCM [n] is, 0,15,29,44,59, ..., 1470,1485,1499,1514, and ....
[0064]
　Since 256 samples around the respective central positions sample is extracted, the extraction sample, D [0] D around the [-127] to D [128] becomes corresponding to PCM [0], PCM [ extracting samples corresponding to 1], D centered on D [15] [-112] to D [143], and the extracted samples corresponding to the PCM [2] is, D centered on D [29] [ -98] to the D [157]. However, n is negative D "n", the data of the content is not present, - is treated as "1".
[0065]
　As an example of n it does not include negative D "n", for example, as shown in FIG. 4, the extraction samples corresponding to PCM [100] is, D [1470] D [1343] around the through D [ 1598], and extraction samples corresponding to PCM [101] is, D [1485] D [1358] to D [1613] around the next, the extracted sample that corresponds to PCM [102] is, D [1499] center the D [1372] to D [1627] which was.
[0066]
　5, PCM [100] to PCM [104] for each show the center position samples 2.8M DSD data, the 256 samples of relationships extracted.
[0067]
　A predetermined interval determined by the sampling frequency of the PCM signal, the maximum error between the center position samples that actually extracted, since a half of the sampling period of the DSD signal, in the case of 2.8M DSD data, 0.5 / (44.1k * 64) = 0.18 a [μsec]. The time resolution of the human hearing are said to be 5 [μsec] degree, frequency conversion of 0.18 [μsec] is a 5.6MHz, the frequency conversion of the 5 [μsec] is a 200kHz, error of 0.18 [μsec] It should not be an error of about a great influence on the sound quality.
[0068]
　Extraction unit 41, as described above, a sample of 2.8M DSD data supplied from the storage unit 32, around a predetermined interval (14.7 samples) determined by the sampling frequency 192kHz of the PCM signal, a predetermined number of samples (256 samples) are extracted, and outputs the filtering unit 42.
[0069]
　The above-described example, a 2.8M DSD data is an example of converting a PCM signal having a sampling frequency 192 kHz, it can be converted into PCM signal of an arbitrary sampling frequency. As for the DSD data, not limited to 2.8M DSD data, and 5.6 M DSD data sampling frequency twice that, or the like may be used 11.2 M. DSD data for the four times the sampling frequency. The bit rate or DSD data, when the sampling frequency of the PCM signal has changed, it is possible to cope with only by changing the spacing of the center position samples in accordance with the sampling ratio.
[0070]
　Also, to be extracted how much the number of samples around the center position samples can be determined arbitrarily depending on the accuracy and the processing load of the PCM signal to be converted.
[0071]
(Filtering process by the filtering unit 42)
　Next, with reference to FIGS. 6 and 7, will be described filtering process by the filtering unit 42.
[0072]
　2.8M DSD data, because as described above, "1" or "0" (signal processing on the operation "1" or "-1") is a binary signal of the filtering unit 42, normal rather than product-sum operation like filtering of the PCM signal, by addition only, it may perform the filtering process.
[0073]
　Now, the 256 sample to be extracted around a predetermined central position sample supplied from the extraction unit 41, expressed in DA [0] to DA [255], the filtering unit against DA [0] to DA [255] When 42 the filter coefficients of 256 taps is applied to the K [0] to K [255], the filter operation by the filtering unit 42 is expressed by ΣDA [n] * K [n] (n = 0 to 255). Since DA [n] is "1" or "-1", the filter operation expression, multiplication is not required, it is easy to see can be calculated in addition only.
[0074]
　May be carried out addition by detecting the data bit by bit, but because the redundancy as the processing of the CPU, the filtering unit 42, for example, a 256-bit data DA [0] to DA [255], 8 bits dividing each performs a calculation using a plurality of partial sum table prepared in advance in 8-bit units.
[0075]
　For example, as shown in FIG. 6, the D [1343] to D [1598] is an extraction samples corresponding to the PCM [100], a description will be given of an example of filter operation.
[0076]
　First, PCM [100] D [1343] supplied from the extraction unit 41 as the extraction samples corresponding to or D [1598] is a DA [0] to DA [255] is a data filtering target.
[0077]
　The DA [0] to DA [255] is, DA [0] to DA [7], DA [8] to DA [15], DA [16] to DA [23], ····, DA [240 ] to DA [247], and are divided into 8-bit DA [248] to DA [255].
[0078]
　Filtering unit 42, the DA [0] to DA [7] which is the first eight bits and holds the partial sum table BT0 shown in FIG.
[0079]
　Partial sum table BT0 in Figure 7, pre-operation and bit patterns of the DA [0] to 256 patterns that can take the DA [7], ΣDA at that time [n] * K [n] a (n = 0 to 7) the operation result C 0 to C 255 are stored in association with each other.
[0080]
　Filtering unit 42 refers to the partial sum table BT0 7 stored therein, by determining the operation result corresponding to the real data of the DA [0] to DA [7], calculates the partial sum T0 to. Partial sum T0 is, C 0 to C 255 becomes either.
[0081]
　Returning to FIG. 6, the filtering unit 42 are other data divided every 8 bits, DA [8] to DA [15], DA [16] to DA [23], ····, DA [240 ] to DA [247], the same applies to the DA [248] to DA [255], by referring to the partial sum table BT1 to BT31, determining the partial sum T1 to T31.
[0082]
　That is, the filtering unit 42 refers to the partial sum table BT1, calculates the partial sum T1 corresponding to the real data of DA [8] to DA [15], with reference to the partial sum table BT2, DA [16] to calculating a partial sum T2 corresponding to the actual data of the DA [23], similarly, refers to the partial sum table BT31, calculates the partial sum T31 corresponding to the actual data DA [248] to DA [255].
[0083]
　Finally, the filtering unit 42, 32 partial sum table BT0 to BT31 calculates the sum of the partial sums T0 to T31 correspond to the respective calculates a PCM [100].
[0084]
　Therefore, the filtering unit 42, only addition and 32 times of the table reference, extracted sample D [1343] to be able to calculate the PCM data corresponding to D [1598].
[0085]
　Incidentally, the delay value of the transmission data for the DSD data when transmitting the PCM data, if determining the number of taps of the filtering portion 42 can be pre-computed.
[0086]
　In the example described above, for simplicity of explanation, the extraction unit 256 samples is extracted around the respective central positions samples at 41, it has been described for an example of a 256 tap taps filtering unit 42.
[0087]
　In fact, from 2.8M DSD data, for example, to generate a PCM signal of 100 [dB] approximately in the accuracy of the sampling frequency 192kHz, it is necessary approximately 4500 taps as the number of taps of the filtering unit 42. In this case, by creating a partial sum table of 12-bit units can be calculated by only addition and 375 times the table reference. Assuming addition of one clock, 192k * 375 = 72MIPS becomes a processable level, even mobile system CPU, is sufficient feasible.
[0088]
<5. Audio data transmission process>
　Next, with reference to the flowchart of FIG. 8, in response to a request of the reproducing apparatus 12, the audio data distribution device 11 to be transmitted by switching seamlessly 2.8M DSD data and PCM_AAC data of a predetermined content the transmission process will be described.
[0089]
　First, in step S1, the control unit 31 of the distribution device 11 supplies the transmitting section 35 a delay value PCM_AAC data to transmit to the playback device 12 to the transmitter 35 as metadata.
[0090]
　In step S2, the control unit 31 receives via the transmission unit 35 a transmission request of the content transmitted from the reproducing apparatus 12, audio data of content being requested is determined whether the PCM_AAC data.
[0091]
　In step S2, if the audio data being requested is determined to be PCM_AAC data, the process proceeds to step S3, the extraction unit 41 of the PCM converter 33, stores 2.8M DSD data of the requested content unit obtained from 32, from the obtained 2.8M DSD data, extracts a sample of a predetermined number at predetermined intervals determined by the sampling frequency of the PCM signal. In this embodiment, when generating a PCM signal having a sampling frequency 192 kHz, 256 samples centered position samples each sample corresponding to m times of 14.7 samples are sequentially extracted.
[0092]
　In step S4, the filtering unit 42 filters the samples of a predetermined number of extracted at predetermined intervals in the extraction unit 41 to generate a PCM signal, and outputs to the encoding part 34. In this embodiment, the filtering unit 42, to the 256 samples supplied from the extraction unit 41, using the 32 partial sum table BT0 to BT31, by performing addition and 32 times of the table reference, PCM generate one sample of the signal, and outputs to the encoding part 34.
[0093]
　In step S5, the coding unit 34, a PCM signal supplied from the filtering unit 42, and compression-encoded by the encoding method of the AAC, supplies PCM_AAC data obtained as a result, the transmitter 35.
[0094]
　In step S6, the transmission unit 35, a PCM_AAC data obtained by compression coding by the coding section 34, and transmits to the playback device 12.
[0095]
　On the other hand, in step S2, the audio data being requested is not a PCM_AAC data, i.e., if the audio data being requested is determined to be a 2.8M DSD data, the process proceeds to step S7, the transmission unit 35 acquires 2.8M DSD data of the requested content from the storage unit 32, and transmits to the playback device 12.
[0096]
　In step S8, the transmission unit 35 determines whether the transmission of audio data is completed. For example, transmitter 35 determines that the audio data from either memory unit 32 and coding unit 34 may no longer supplied, the transmission of audio data is completed.
[0097]
　In step S8, if it is determined not yet finished the transmission of audio data, the process returns to step S2, the processing of steps S2 to S8 is repeated.
[0098]
　On the other hand, in step S8, when transmission of the audio data is determined to have ended, the audio data transmission process is terminated.
[0099]
　As described above, the delivery device 11, when the PCM_AAC data is requested from the reproduction device 12 as the audio data of the content, generates a PCM signal from 2.8M DSD data stored in the storage unit 32, reproduction it can be transmitted to the device 12. That is, the distribution device 11, the audio data of one content, in response to a request of the reproducing apparatus 12 can transmit switch between DSD data and PCM_AAC data.
[0100]
　The distribution device 11, the time required for conversion processing for converting into PCM signal, and transmits to the pre-reproduction apparatus 12 as a delay value, it is possible to realize a full synchronization of DSD data and PCM_AAC data reproducing apparatus 12 in, it can be reproduced by switching seamlessly DSD data and PCM_AAC data.
[0101]
　For example, as in MPEG-DASH, in response to a request from the client device, the delivery device for transmitting a predetermined coded data, in general, both of the encoded data of synchronizing the sampling frequency DSD signal and PCM signal generated in advance, it is necessary to store.
[0102]
　According to the distribution device 11 using this technique, since it is sufficient to store only DSD data as audio data of the contents in the storage unit 32, only one of the DSD signal, also correspond to the transmission of PCM signals it can.
[0103]
　Incidentally, the storage unit 32 of the distribution device 11, so as to store the 11.2 M. DSD data obtained by delta-sigma modulation at 256 times the sampling frequency of the sampling frequency 44.1kHz for CD, the delivery device 11, or transmitted to generate a 5.6 M DSD data or 2.8M DSD data from 11.2 M. DSD data downsampling, transmitted from 11.2 M. DSD data, to generate a PCM signal of an arbitrary sampling frequency, such as 44.1kHz or 48kHz configuration that is also possible.
[0104]
　Incidentally, the audio data transmission process described above is an example of processing in the transmission mode of audio data shown in B in FIG 2. The transmission mode of audio data shown in A of FIG. 2, when transmitting PCM_AAC data, the processing of steps S3 to S6 is executed, and when transmitting a 2.8M DSD data, executing the process of step S7 good.
[0105]
<6. Detailed Configuration Example> of the playback apparatus
　9 is a block diagram illustrating a detailed configuration example of a playback apparatus 12 of FIG. 1.
[0106]
　Reproducing apparatus of FIG. 9 12 is a reproducing apparatus capable to switch seamlessly 2.8M DSD data and PCM_AAC data of a predetermined content.
[0107]
　Reproducing apparatus 12 includes a control unit 50, a communication unit 51, decoding unit 52, PCM up-sampling unit 53, a delta sigma (.DELTA..SIGMA) modulator 54, switching unit 55, the clock supply unit 56, and, a delta-sigma demodulator 57 .
[0108]
　Control unit 50 controls the reproducing device 12 the overall operation. For example, the control unit 50, not in the illustrated operation unit, when the reproduction of the predetermined content stored in the distribution device 11 is instructed by the user, reproduced indicated two audio data (DSD data and corresponding to the content from among PCM_AAC data), in accordance with the communication capacity of the network 24 selects one of audio data, via the communication unit 51 requests the distribution device 11. In FIG. 9, the illustration of the control signal to each unit are omitted from the control unit 50.
[0109]
　Control unit 50, as streaming data of a content, to acquire the audio data according to MPEG-DASH, acquires the MPD file first, based on the acquired MPD file, access to the communication unit 51 to a predetermined address of the delivery device 11 by, to obtain the desired audio data to the communication unit 51. MPD The file, for example, includes information about the delay value PCM_AAC data.
[0110]
　The communication unit 51 based on an instruction of the control unit 50, the audio data reproduction instruction content of (DSD data and AAC data), requests the distribution device 11. The DSD data and AAC data as the first and second audio data, when switching from the first audio data into second audio data, the communication unit 51, the before and after switching two first and second audio data simultaneously acquired, when there is no need to switch acquires one of the audio data.
[0111]
　The communication unit 51 acquires the digital audio data transmitted from the delivery device 11. Communication unit 51, when the acquired audio data is 2.8M DSD data supplies 2.8M DSD data obtained, the switching unit 55. On the other hand, if the acquired audio data is PCM_AAC data communication unit 51, a PCM_AAC data acquired, and supplies the decoding section 52.
[0112]
　Decoding unit 52, a PCM_AAC data supplied from the communication unit 51, using a decoding scheme corresponding to the encoding scheme, and outputs a PCM signal obtained by the decoded into PCM up-sampling unit 53.
[0113]
　PCM upsampling unit 53, the PCM signal supplied from the decoding unit 52, and up-sampled to the same frequency as the sampling frequency of 2.8M DSD data, and outputs the delta sigma modulator 54. Specifically, PCM upsampling unit 53 upsamples the PCM signal of 2.8 MHz, and outputs the delta sigma modulator 54.
[0114]
　Delta-sigma modulation section 54, the up-sampled PCM signal, and delta-sigma modulation, and generates a 2.8M DSD data, and outputs to the switching unit 55.
[0115]
　Switching unit 55 is an output of the communication unit 51 2.8M DSD data, or selects one of 2.8M DSD data which is the output of the delta-sigma modulator 54, a 2.8M DSD data selected, subsequent output of the delta-sigma demodulator 57.
[0116]
　The switching unit 55, the delay value which has been transmitted from the distribution device 11 is supplied. Switching unit 55, from 2.8M DSD data which is the output of the communication unit 51, when switching to the 2.8M DSD data which is the output of the delta-sigma modulator 54, and delay value sent from the delivery device 11, the decoding unit 52 or after only by delaying the value of the combined delay value by the processing of the delta sigma modulator 54 is switched. Thus, even during the playback of the content, seamless switching is possible.
[0117]
　Clock supply unit 56 supplies a clock signal CLK2 corresponding to 2.8M DSD data to the delta-sigma demodulator 57. In this embodiment, the clock supply 56 generates a clock signal CLK2 of 2.8 MHz, supplied to a delta-sigma demodulator 57.
[0118]
　Delta sigma demodulator 57, a 2.8M DSD data supplied from the switching unit 55, and demodulated using the clock signal CLK2 supplied from the clock supply section 56 (delta sigma demodulator), a demodulation result, the subsequent analog LPF25 output (FIG. 1). Delta sigma demodulator 57, for example, can be composed of a digital filter of FIR (finite impulse response).
[0119]
　Reproducing apparatus 12, the above structure can be reproduced by switching seamlessly 2.8M DSD data and PCM_AAC data of a predetermined content.
[0120]
<7. Form and transmits DSD data and PCM_AAC data simultaneously>
　There will be described the configuration for transmitting both 2.8M DSD data and PCM_AAC data at the same time.
[0121]
　For example, as shown in C of FIG. 2, the distribution device 11, for the front right and front left audio data transmits 2.8M DSD data of a high sound quality, the rear right and rear left audio data, transmitting the data amount is small PCM_AAC data.
[0122]
　The storage unit 32 converts, for the rear right and rear left audio data is stored in 2.8M DSD data, when transmitting the PCM data, the PCM data 2.8M DSD data by PCM conversion section 33 It is, are transmitted to the reproducing apparatus 12. 2.8M DSD data reception right and front left side, in parallel with the rear right and rear left of the PCM data is transmitted to the reproducing apparatus 12. Construction of the distribution device 11 is the same as that described with reference to FIG.
[0123]
　Needless to say, the communication capacity of the capacity and network 24 of the reproducing apparatus 12, when a predetermined condition is satisfied, for also the rear right and rear left audio data, similarly to the front right and front left, 2.8M DSD data may be directly sent to.
[0124]
　Figure 10 is a front right and front left 2.8M DSD data, and receives the rear right and rear left PCM_AAC data at the same time, construction of a reproducing apparatus 12 for outputting a sound from the front right and front left two loudspeakers example is a block diagram showing the.
[0125]
　10, the portions corresponding to FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.
[0126]
　Reproducing apparatus 12 includes a communication unit 51, decoding unit 52, a delta sigma (.DELTA..SIGMA) modulator 54, a clock supply unit 56, the delta-sigma demodulator 57, a delay unit 71, the surround processor 72, and includes a mixer 73. The mixer 73 includes an adder 81 and 82, and a delta-sigma modulation section 83.
[0127]
　Communication unit 51, DSD_FL data is 2.8M DSD data reception left transmitted from the distribution device 11, and receives DSD_FR data which is the front right side of 2.8M DSD data, and supplies to the delay unit 71.
[0128]
　The communication unit 51, AAC_RL data is PCM_AAC data of the rear left transmitted from the distribution device 11, and receives AAC_RR data is PCM_AAC data of the rear right, and supplies the decoding section 52.
[0129]
　Delay unit 71, the DSD_FL data and DSD_FR data supplied from the communication unit 51, and the delay value sent from the delivery device 11, the delay due to processing of the decoding unit 52, the surround processor 72 and the delta-sigma modulator 54, only the value of the combined value by delay, and supplies to the mixer 73. DSD_FL data outputted from the delay unit 71 is supplied to the adder 81 of the mixer 73 as DSD_FL1 data, DSD_FR data output from the delay unit 71 is supplied to the adder 82 of the mixer 73 as DSD_FR1 data.
[0130]
　Decoding unit 52, AAC_RL data is PCM_AAC data of the rear left, and decodes the AAC_RR data is PCM_AAC data of the rear right, respectively, PCM_RL data, and to obtain PCM_RR data. Resulting PCM_RL data, and, PCM_RR data are supplied to the surround processor 72.
[0131]
　Surround processing unit 72 is supplied from the decoding unit 52, PCM_RL data is PCM data of the rear left, and, for each of PCM_RR data is PCM data of the rear right, even when the output from the front side loudspeaker, performing surround conversion processing as come hear from the rear side. Surround conversion process, PCM_RL data of the rear left is converted into left front PCM_FL data, PCM_RR data of the rear right side are converted into right front PCM_FR data is supplied to the delta-sigma modulator 54.
[0132]
　Delta-sigma modulation section 54, PCM_FL data is the left front of the PCM signal, and the PCM_FR data which is the front right of the PCM signal, respectively delta-sigma modulation. DSD_FL2 data left front PCM_FL data obtained by the delta-sigma modulation is supplied to the adder 81 of the mixer 73. DSD_FR2 data right front PCM_FR data obtained by the delta-sigma modulation is supplied to the adder 82 of the mixer 73.
[0133]
　Adding unit 81 of the mixer 73, and DSD_FL1 data from the delay unit 71 adds the DSD_FL2 data from the delta sigma modulator 54, and supplies the DSD_FLa data is the addition result to the delta sigma modulation section 83.
[0134]
　Adding unit 82 of the mixer 73, and DSD_FR1 data from the delay unit 71 adds the DSD_FR2 data from the delta sigma modulator 54, and supplies the DSD_FRa data is the addition result to the delta sigma modulation section 83.
[0135]
　Delta-sigma modulation section 83, a DSD_FLa data from the adder 81 to the delta sigma modulation, and supplies the DSD_FLb data is DSD data after modulation to the delta-sigma demodulator 57. Further, the delta-sigma modulation section 83, a DSD_FRa data from the adder 82 to the delta sigma modulation, and supplies the DSD_FRb data is DSD data after modulation to the delta-sigma demodulator 57.
[0136]
　Delta sigma demodulator 57, a DSD_FLb data supplied from the delta-sigma modulation section 83, and demodulated using the clock signal CLK2 supplied from the clock supply section 56 (delta sigma demodulator), an analog front-left a demodulation result the signal Front_L, and outputs the analog LPF 25 (FIG. 1).
[0137]
　Further, the delta-sigma demodulator 57, a DSD_FRb data supplied from the delta-sigma modulation section 83, and demodulated using the clock signal CLK2 supplied from the clock supply section 56 (delta sigma demodulator), a front right is demodulated result outputs of the analog signal Front_R, the analog LPF 25 (FIG. 1).
[0138]
<8. Audio data reproducing processing>
　Next, with reference to the flowchart of FIG. 11, both PCM_AAC data of two channels for two-channel 2.8M DSD data and rear for the front simultaneously received, only two front speakers output from the audio data reproduction process by the reproduction device 12 of FIG. 10 will be described.
[0139]
　Initially, supply in step S10, the communication unit 51 from the delivery device 11 receives a delay value sent as meta data, the control unit 50.
[0140]
　In step S11, the communication unit 51 receives a 2.8M DSD data of two channels for reception and two channels PCM_AAC data for the rear.
[0141]
　More specifically, the communication unit 51 receives DSD_FL data is 2.8M DSD data reception left transmitted from the distribution device 11, and the DSD_FR data which is the front right side of 2.8M DSD data, the delay unit It supplies it to the 71. The communication unit 51, AAC_RL data is PCM_AAC data of the rear left transmitted from the distribution device 11, and receives AAC_RR data is PCM_AAC data of the rear right, and supplies the decoding section 52.
[0142]
　In step S12, the delay unit 71, the DSD_FL data and DSD_FR data supplied from the communication unit 51, and only by delaying a predetermined time, and supplies to the mixer 73. Here the delay time in the the delay value which has been transmitted from the distribution device 11 corresponds to the sum of the delay value by the processing of the decoding unit 52, the surround processor 72 and the delta-sigma modulator 54,.
[0143]
　In step S13, the decoding section 52, rear left AAC_RL data supplied from the communication unit 51, and decodes the AAC_RR data of the rear right. PCM_RL data obtained by the decoding, and, PCM_RR data are supplied to the surround processor 72.
[0144]
　In step S14, the surround processor 72, supplied from the decoding section 52, the rear left PCM_RL data, and, for each of PCM_RR data of the rear right, executes surround conversion process. Surround conversion process, PCM_RL data of the rear left is converted into left front PCM_FL data, PCM_RR data of the rear right side are converted into right front PCM_FR data is supplied to the delta-sigma modulator 54.
[0145]
　In step S15, the delta-sigma modulator 54, the front left PCM_FL data, and, the front right PCM_FR data, respectively delta-sigma modulation. DSD_FL2 data obtained by delta-sigma modulation is supplied to the adder 81 of the mixer 73, DSD_FR2 data is supplied to the adder 82 of the mixer 73.
[0146]
　The processing of step S12, the processing of steps S13 to S15 are executed in parallel. In step S12, the output timing of DSD_FL data and DSD_FR data is output as DSD_FL1 data and DSD_FR1 data from the delay unit 71, in step S15, DSD_FL2 data and DSD_FR2 data, and an output timing that is outputted from the delta sigma modulator 54 match.
[0147]
　In step S16, each adding unit 81 and 82 of the mixer 73 adds the first DSD data from the delay unit 71, the second DSD data from the delta sigma modulator 54. More specifically, the addition unit 81, and DSD_FL1 data from the delay unit 71 adds the DSD_FL2 data from the delta sigma modulator 54, and supplies the DSD_FLa data is the addition result to the delta sigma modulation section 83. Addition unit 82, and DSD_FR1 data from the delay unit 71 adds the DSD_FR2 data from the delta sigma modulator 54, and supplies the DSD_FRa data is the addition result to the delta sigma modulation section 83.
[0148]
　In step S17, the delta-sigma modulation section 83, the addition result to the delta sigma modulation. In other words, the delta-sigma modulation section 83, a DSD_FLa data from the adder 81 by delta-sigma modulation, and supplies the DSD_FLb data after modulation to the delta-sigma demodulator 57. Further, the delta-sigma modulation section 83, a DSD_FRa data from the adder 82 by delta-sigma modulation, and supplies the DSD_FRb data after modulation to the delta-sigma demodulator 57.
[0149]
　In step S18, the delta-sigma demodulator 57, the DSD_FLb data and DSD_FRb data after the delta-sigma modulation supplied from the delta-sigma modulation section 83, and a delta-sigma demodulator using a clock signal CLK2 supplied from the clock supply section 56 the analog signal Front_L and the front right of the analog signal Front_R front left a demodulation result, and outputs the analog LPF 25, and terminates the audio data reproduction process.
[0150]
　The audio data reproducing process described above, the reproducing apparatus 12, both PCM_AAC data of two channels for 2.8M DSD data and rear two channels for reception received simultaneously converted into signals of two front speakers it is possible to output Te.
[0151]
　In the example described above, the reproducing apparatus 12 side, but the received DSD data provided a delay unit 71 for a predetermined time delay, the delay section 71 provided in the distribution device 11 is a delivery side, which is a predetermined time delay DSD it may be configured in which data is supplied.
[0152]
<9. PCM signal converter>
　In the above embodiment, the distribution device 11 server apparatus, the reproduction apparatus 12 as a client device, the DSD data or PCM_AAC data as audio data, configuration of the server-client system for delivering via the network 24 It was described.
[0153]
　However, the present technology is not limited to server-client system, for example, the DSD data stored in the storage unit 32 is converted into PCM data, BD (Blu-ray (registered trademark) Disc) or DVD (Digital Versatile in such PCM signal conversion apparatus for recording on a recording medium Disc) or the like can be applied.
[0154]
　Figure 12 is a block diagram showing a configuration example of a PCM signal converter. 12, portions corresponding to the distribution device 11 of FIG. 1 are denoted by the same reference numerals, and a description thereof will be omitted.
[0155]
　PCM signal converter 90 of FIG. 12, in place of the transmission portion 35 of the distribution device 11 of FIG. 1, drive 91 is provided.
[0156]
　Drive 91 drives a recording medium 92 such as a BD or as DVD, audio data of the content, and 2.8M DSD data supplied from the storage unit 32, a PCM_AAC data supplied from the encoding unit 34, recording medium 92 It is recorded in the.
[0157]
　The storage unit 32, the audio data of the content, and importance of the sound quality, are stored in DSD data. For example, the audio data for combination with the video, be generated in PCM signals, consider a scene to be recorded on the recording medium 92.
[0158]
　DSD signals are 64 times the sampling frequency 44.1kHz for CD, 128-fold, or 256-fold such but the sampling frequency is used, the video sampling frequency of 48kHz are generally used.
[0159]
　In general, when generating a PCM signal 48kHz from 2.8M DSD data, simply, first downconverts 2.8M DSD data into PCM signal of about 44.1 * 8 kHz, then that generates the data in a linear interpolation or the like Although it is customary, the sound quality is degraded to accompany the interpolation. Further, when priority is given to audio quality, like a 2.8M DSD data down-converts the PCM signal 44.1 * 8 kHz, up-converts the signal after the down-converted to 40-fold, further down-converts it to 1/147 methods are conceivable. However, this method, although it accurately converted into PCM signals 96kHz, the process is not heavily practical.
[0160]
　In contrast, according to the PCM signal converter 90 generates a PCM signal accurately easily 48kHz from DSD data, can be recorded on a recording medium 92 such as a BD or DVD.
[0161]
<10. Computer Configuration Example>
　distribution device 11 described above, the reproducing apparatus 12, and a series of processes by the signal processing apparatus such as a PCM signal converter 90 is executed, can be executed by hardware, it is executed by software It can also be. In the case of executing the series of processes by software, a program constituting the software is installed in a computer. Here, the computer includes or micro computer incorporated in dedicated hardware, by installing various programs, which can execute various functions include, for example, such as a general-purpose personal computer.
[0162]
　Figure 13 is a block diagram showing a configuration example of hardware of a computer that executes the series of processes described above.
[0163]
　In the computer, CPU (Central Processing Unit) 101, ROM (Read Only Memory) 102, RAM (Random Access Memory) 103 are connected to each other via a bus 104.
[0164]
　The bus 104 further input and output interface 105 is connected. Output interface 105, an input unit 106, output unit 107, storage unit 108, a communication unit 109, and a drive 110 are connected.
[0165]
　Input unit 106 includes a keyboard, a mouse, a microphone, a touch panel, consisting of an input terminal. The output unit 107 includes a display, a speaker, so forth output terminal. Storage unit 108, a hard disk, RAM disk, made of a nonvolatile memory. The communication unit 109 includes a network interface. Drive 110 drives the magnetic disk, optical disk, magneto-optical disk or a removable recording medium 111 such as a semiconductor memory.
[0166]
　Audio In the computer configured as described above, CPU 101 is, for example, a program stored in the storage unit 108, output interface 105 and the bus 104 and executes the loaded into RAM 103, the above-mentioned a series of processes such as data transmission processing and the audio data reproduction processing is performed. Also in RAM 103, CPU 101 is appropriately stores data necessary in the execution of various processes.
[0167]
　In the computer, by mounting the removable recording medium 111 into the drive 110, it can be installed via the input and output interface 105, the storage unit 108. Further, the program may be a local area network, the Internet, or digital satellite broadcasting, via a wired or wireless transmission medium and received by the communication unit 109, installed in the storage unit 108. Alternatively, the program may be in the ROM102 and the storage unit 108 installed in advance.
[0168]
　The program which the computer executes may be a program in which processes are performed in time series in the order described herein, at a necessary timing such as when the parallel or call was made processing may be a program to be carried out.
[0169]
　In the present specification, the system includes a plurality of components (devices, modules (components) or the like) means a set of, it does not matter whether or not there is in the same housing all components. Therefore, housed in a separate enclosure, a plurality of devices connected via a network, and one device in which a plurality of modules within a single casing is housed, both of which the system .
[0170]
　Embodiments of the present technology is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present disclosure.
[0171]
　For example, it is possible to employ the appropriate combination form all or part of the above-described embodiment.
[0172]
　For example, the present technology, sharing one function by a plurality of devices via a network, it is possible to adopt a configuration of cloud computing which processes jointly.
[0173]
　Further, each step described in the above flowcharts may be executed by one device, it can be performed by allocating a plurality of apparatuses.
[0174]
　Further, when a plurality of processes are included in one step, the plurality of processes included in the one step may be executed by one device, it can be performed by allocating a plurality of apparatuses.
[0175]
　Note that the effect described herein is not limited to a merely illustrative, there may be effects other than those described herein.
[0176]
　The present technology may also be configured as below.
(1)
　when generating a PCM signal having a predetermined sampling frequency from DSD signal, it extracts the center samples of a predetermined interval determined by said predetermined sampling frequency, the samples of a predetermined number are extracted from the DSD signal parts and,
　by filtering the extracted sample of the predetermined number, and a filtering unit for generating a PCM signal of the predetermined sampling frequency
　signal processing apparatus comprising a.
(2)
　the filtering unit includes a extracted the obtained predetermined number of samples taken data, includes a table that associates the calculation results at that time, by referring to the table, extracted the predetermined number of by obtaining the calculation results corresponding to the sample, to filter the samples of the predetermined number of extracted
　signal processing apparatus according to (1).
(3)
　The table is comprised of a plurality of partial sum table divided by bits of a predetermined number,
　the filtering unit, with reference to the partial sum table, corresponding to the sample of the predetermined number of bits calculated partial sums, and addition of the partial sum of said plurality of partial sum table to determine the operation result
　signal processing apparatus according to (2).
(4)
　a storage unit for storing the DSD signal,
　A transmission unit for transmitting at least one other device of the DSD signal or the PCM signal
　further comprises a
　signal processing device according to any one of (1) to (3).
(5)
　and the transmission unit, the delay value of the PCM signal to the DSD signal is also transmitted to the other device
　a signal processing apparatus according to (4).
(6)
　and the transmission unit, it switches the PCM signal and the DSD signals of the same content transmitted to the other device
　a signal processing apparatus according to (4).
(7)
　and the transmission unit transmits both the DSD signal and the PCM signal to the other device
　a signal processing apparatus according to (4).
(8)
　and the transmission unit, when transmitting the DSD signal to the other device, and transmits delayed by delay value of said PCM signal to the DSD signal
　signal processing apparatus according to (7).
(9)
　the DSD signals are audio data of the front side,
　the PCM signal is an audio data of the rear-side
　signal processing apparatus according to (7) or (8).
(10)
　Signal processing apparatus for generating a PCM signal having a predetermined sampling frequency from DSD signal,
　mainly in samples of a predetermined interval determined by said predetermined sampling frequency, the samples of a predetermined number, and extracted from the DSD signal,
　extracting by filtering the samples of the predetermined number which is to generate a PCM signal of the predetermined sampling frequency
　signal processing method comprising the steps.
(11)
　to the computer,
　when generating a PCM signal having a predetermined sampling frequency from DSD signal, especially in samples of a predetermined interval determined by said predetermined sampling frequency, the samples of a predetermined number, from the DSD signal extracting,
　by filtering a sample of said predetermined number is extracted, it generates a PCM signal of the predetermined sampling frequency
　program for executing the process.
DESCRIPTION OF SYMBOLS
[0177]
　1 reproduction system, 11 distribution device, 12 reproducing apparatus, 31 control unit, 32 storage unit, 33 PCM conversion section, 34 encoding section, 35 sending section, 41 extracting unit, 42 filtering unit, 50 control unit, 51 communication unit, 52 decoding unit, 53 PCM upsampling unit, 54 a delta sigma modulation section, 55 switching unit, 57 a delta-sigma demodulator, 71 a delay unit, 72 surround processing unit, 73 a mixer, 90 PCM signal converter, 91 drive, 92 a recording medium , 101 CPU, 102 ROM, 103 RAM, 106 input unit, 107 output unit, 108 storage unit, 109 communication unit, 110 drive

The scope of the claims

[Requested item 1]When generating a PCM signal having a predetermined sampling frequency from DSD signal, especially in samples of a predetermined interval determined by said predetermined sampling frequency, an extraction unit of a predetermined number of samples, extracted from the DSD signal,
　by filtering the extracted sample of the predetermined number, and a filtering unit for generating a PCM signal of the predetermined sampling frequency
　signal processing apparatus comprising a.
[Requested item 2]
　The filtering unit includes a extracted the obtained predetermined number of samples taken data, includes a table that associates the calculation results at that time, by referring to the table, which is extracted corresponding to the predetermined number of samples by determining the calculation result of, filtering samples of said predetermined number of extracted
　signal processing apparatus according to claim 1.
[Requested item 3]
　The table is composed of a plurality of partial sum table divided by bits of a predetermined number,
　the filtering unit, with reference to the partial sum table, a partial sum corresponding to the sample of the predetermined number of bits It determined, and addition of partial sum of said plurality of partial sum table to determine the operation result
　signal processing apparatus according to claim 2.
[Requested item 4]
　Wherein a storage unit for storing a DSD signal,
　a transmitter for transmitting at least one of the DSD signal or the PCM signal to another device
　, further comprising a
　signal processing apparatus according to claim 1.
[Requested item 5]
　And the transmission unit, the delay value of the PCM signal to the DSD signal is also transmitted to the other device
　a signal processing apparatus according to claim 4.
[Requested item 6]
　And the transmission unit, switches the PCM signal and the DSD signals of the same content transmitted to the other device
　a signal processing apparatus according to claim 4.
[Requested item 7]
　The transmission unit transmits both the DSD signal and the PCM signal to the other device
　a signal processing apparatus according to claim 4.
[Requested item 8]
　And the transmission unit, the time of transmitting the DSD signal to the other device, and transmits delayed by delay value of said PCM signal to the DSD signal
　signal processing apparatus according to claim 7.
[Requested item 9]
　The DSD signal is audio data of the front side,
　the PCM signal is an audio data of the rear-side
　signal processing apparatus according to claim 7.
[Requested item 10]
　Signal processing apparatus for generating a PCM signal having a predetermined sampling frequency from DSD signal,
　mainly in samples of a predetermined interval determined by said predetermined sampling frequency, the samples of a predetermined number, and extracted from the DSD signal,
　extracting by filtering the samples of the predetermined number which is to generate a PCM signal of the predetermined sampling frequency
　signal processing method comprising the steps.
[Requested item 11]
　The computer,
　to generate a PCM signal having a predetermined sampling frequency from DSD signal, especially in samples of a predetermined interval determined by said predetermined sampling frequency, the samples of a predetermined number, and extracted from the DSD signal,
　by filtering the samples of the predetermined number are extracted to generate a PCM signal of the predetermined sampling frequency
　program for executing the process.