WO2007138825A1

WO2007138825A1 - Digital audio data processing device and processing method

Info

Publication number: WO2007138825A1
Application number: PCT/JP2007/059585
Authority: WO
Inventors: Seiji Harada
Original assignee: Pioneer Corporation
Priority date: 2006-05-25
Filing date: 2007-05-09
Publication date: 2007-12-06
Also published as: JPWO2007138825A1; JP4551472B2

Abstract

[PROBLEMS] To reduce uncomfortable feeling of an operator even when an error has occurred in a stream. [MEANS FOR SOLVING PROBLEMS] A high-band component pseudo generation unit (13) pseudo-wise generates high-band component data having a higher reproduction band than decoded data in a Base Codec unit and outputs the decoded Base Codec data together with the pseudo-wise generated high-band component data. Thus, as compared to a case when a soundless state continues until next header information is acquired after an error has occurred or when only Base Codec data is outputted after decoding, it is possible to reduce the soundless state and output a higher-band component, thereby reducing the uncomfortable feeling for sense of hearing.

Description

Specification

Digital audio data processing apparatus and processing method

Technical field

[0001] The present invention relates to a digital audio data processing apparatus and processing method for digitally processing encoded data.

Background art

[0002] Digital broadcasting for digitizing and multiplex-transmitting image data (video data) and audio data (audio data) using, for example, a digital or Internet broadcast receiver has already been started. In this digital broadcasting, a predetermined compression encoding method (for example, MPEG; Moving Picture Experts Group method, etc.) is employed, and the data power of a plurality of programs (for example, MPEG transport stream). Stream; MPEG-TS, etc.) The multiplexed data transmitted as a stream is selectively extracted by transmitting it to the receiver side that has received the data.

[0003] In recent years, with the progress of broadbandization, digital or Internet broadcast receivers having a relatively simple structure such as mobile phones and other mobile terminals (so-called third-generation mobile terminals, in-vehicle terminals, mopile devices), etc. It is planned to provide a simple video distribution service.

[0004] In this case, SBR (Spectral Band Replication) technology has been applied to audio data (audio data) in addition to the AAC (Advanced Audio Coding) standard standardized by MPEG, which has been widely used in the past. Encoding has already been proposed (see, for example, Patent Document 1).

[0005] That is, in general, in the encoding of audio data, it is difficult to allocate sufficient bits for encoding high frequency components, and as the compression rate increases, the upper limit of the reproduction band is increased. The frequency tends to decrease and the sound quality tends to deteriorate. The above SBR technology compensates for the lack of such high-frequency components. Auxiliary information for predicting high-frequency components from low-frequency components is stored in advance in the stream, and band expansion processing is performed during playback. In this way, it is possible to reproduce high-quality sound by generating a high-frequency component by expanding the bandwidth in a pseudo manner.

[0006] An encoding method in which SBR is added in addition to the conventional AAC is called AAC-plus, and one frame of data includes AAC encoded data (BaseCodec) and SBR encoded data. It consists of. Note that even conventional decryption means compatible only with AAC can decrypt only AAC data by skipping SBR data.

[0007] Patent Document 1: Japanese Patent Laid-Open No. 2006-50387

Disclosure of the invention

Problems to be solved by the invention

[0008] In the encoding method using SBR, as described above, auxiliary information for predicting a high frequency component from a low frequency component is subjected to band expansion processing during reproduction to generate a high frequency component. It is. At this time, a frame (reference frame) having an SBR header is generated every predetermined frame data unit (for example, several frames, several tens of frames) (for example, irregularly) based on the data transmission amount restriction described above. It has been entered. In addition, frames that do not have an SBR header other than this frame (non-reference frames) are included, and all frames create a calculation table from the information (header information) stored in the SBR header. Based on the table, the band expansion process is performed to generate a high frequency component.

[0009] In this case, the header information of the SBR header is always required for decoding the SBR data as described above (although there is an advantage that the total transmission amount can be reduced). If the part is lost (= error occurred) (because the header information may have changed in the meantime), decoding cannot be performed until the next SBR header information is obtained. For this reason, once an error occurs, only the AAC data (that is, the low frequency band) is decoded and output until the next SBR header information is acquired, and the high frequency is not reproduced. Was supposed to give a sense of incongruity

[0010] The problems to be solved by the present invention include the above-described problems as an example. Means for solving the problem

[0011] In order to solve the above-described problem, the invention according to claim 1 is encoded data including a plurality of framed frame sequences, and the plurality of frame sequences include a reference frame and a non-reference. The non-reference frame includes non-reference first data obtained by encoding speech information and non-reference first data obtained by encoding band expansion information for expanding the reproduction band of the non-reference first data. Second reference data, and the reference frame is configured by encoding reference first data obtained by encoding audio information and band expansion information for expanding the reproduction band of the reference first data, A digital audio data processing device for processing a stream, including reference second data having a processing header including header information for performing arithmetic processing of the non-reference second data, wherein the reference frame A header information acquisition unit for acquiring the header information of the processing header provided in the reference second data, and decoding the reference first data or the non-reference first data of the reference frame or the non-reference frame The first decoding means for generating first decoded data, and the reference second data or the non-reference second data of the reference frame or the non-reference frame is obtained by the header information obtaining means. When the header information cannot be acquired by the second decoding means for decoding using the header information and generating second decoded data, and the header information acquisition means, the first decoding is performed. A high-frequency component pseudo-generating means for pseudo-generating high-frequency component data having a reproduction band higher than that of the first decoded data based on the first decoded data decoded by the encoding means; 1 Decryption Hide And output control means for outputting the high-frequency component data together.

[0012] Further, the invention according to claim 4 is code data including a plurality of framed frames, and the plurality of frame sequences includes a plurality of frames including a reference frame and a non-reference frame. And the non-reference frame includes non-reference first data obtained by encoding audio information, and non-reference second data obtained by encoding band expansion information for expanding the reproduction band of the non-reference first data. And the reference frame is configured by encoding reference first data in which audio information is encoded and band expansion information for expanding a reproduction band of the reference first data. Digital processing stream, including reference second data having a processing header with header information for performing arithmetic processing An audio data processing method, an error determination procedure for determining whether or not a part of the stream has been lost, and a header for acquiring the header information of the processing header provided in the reference second data of the reference frame An information acquisition procedure; first decoding means for decoding the reference first data or the non-reference first data of the reference frame or the non-reference frame to generate first decoded data; and the reference frame Alternatively, the second reference data or the second non-reference data of the non-reference frame is decoded using the header information acquired in the header information acquisition procedure to generate second decoded data. And when the header information cannot be acquired by the header information acquisition procedure, based on the first decoding data decoded by the first decoding procedure, High-frequency component data with a higher regeneration zone than 1 decodes data generated in a pseudo manner, and outputs before Symbol the high frequency component data together with the first decryption data.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment is an embodiment when applied to a mobile phone as an example of a digital audio data processing apparatus.

FIG. 1 is a perspective view showing the overall appearance of the mobile phone according to the present embodiment. In FIG. 1, this mobile phone 1 as a digital audio data processing apparatus acquires and outputs content data including audio data, video data, data for data broadcasting, etc. distributed as TS (Transport Stream). It is compatible with terrestrial digital broadcasting using the TS system.

[0015] In this example, the cellular phone 1 is provided with a main body casing 2, an operation unit 3 provided at a lower portion of the main body casing 2, and provided with a telephone number input key, various function buttons, and the like, and a base end portion thereof. Open / close cover 4 pivotally supported at the lower end of main casing 2 and attached to main casing 2 so as to be openable / closable, display 5 for various displays, and antenna 6 for data transmission / reception via wireless communication A speaker 7 that emits sound, a lever switch 8 for opening and closing operation, a microphone 9, and a broadcasting antenna 10 that receives broadcast waves such as terrestrial digital broadcasts and satellite digital broadcasts (not shown, described later) Etc.).

FIG. 2 is a functional block diagram showing a functional configuration of the mobile phone 1. Figure 2 Odor After the radio wave transmitted from the broadcasting station or other mobile phone is received by the antennas 6 and 10, the demodulated received signal is demodulated by the transmission / reception unit 100 connected to the antennas 6 and 10. The signal processing unit 101 performs predetermined signal processing (details will be described later) for reproduction. The signal processed by the signal processing unit 101 is reproduced as sound by the speaker 7.

At this time, the transmission / reception unit 100 includes a TS reception unit (not shown), and the broadcasting antenna 10 (which may also be used as the antenna 6) is connected to the TS reception unit. . Under the control of the signal processing unit 101, the TS receiving unit acquires a TS corresponding to the content selected by the user from, for example, a plurality of TSs transmitted as digital signals from the broadcasting antenna 10. Then, the acquired TS is output to the signal processing unit 101 as a TS signal.

On the other hand, the conversation of the speaker is input to the microphone 9 and converted into an audio signal. The audio signal is subjected to signal processing for transmission in the signal processing unit 101. The transmission / reception unit 100 modulates the audio signal from the signal processing unit 101 and supplies the modulated signal to the antenna 6. The antenna 6 transmits the audio signal. As a radio wave.

[0019] Note that the operation of each of the above-described components is controlled by the control unit 102 including a CPU and the like.

[0020] FIG. 3 is a schematic diagram conceptually showing an extracted portion related to audio in the TS stream received by the antenna 10 provided in the mobile phone 1 of the present embodiment.

[0021] FIG. 3 shows a state in which an audio stream extracted from the multiplexed stream received by the antenna 10 (ie, Elementary Stream) includes a plurality of frames along the time axis. Yes. These multiple frames consist of a reference frame SF and other non-reference frame IF.

[0022] Non-reference frame IF is a BaseCodec (non-reference number

1 data) and SBR data (non-reference second data, which does not include the SBR header) encoded with band expansion information for expanding the reproduction band of this BaseCodec.

[0023] The reference frame SF is configured by encoding BaseCodec (reference first data) obtained by encoding audio information according to the AAC standard and band expansion information for expanding the reproduction band of the BaseCodec, as described above. To perform processing of SBR data without SBR header SBR data (standard second data) with SBR header (processing header) with header information. By using the header information of the SBR header, a table for the above arithmetic processing is created, and band expansion processing can be performed based on this table to generate high frequency components.

FIG. 4 is a functional block diagram showing a configuration related to the reproduction processing of the audio signal in the signal processing unit 101.

In FIG. 4, the signal processing unit 101 includes a BaseCodecDecode unit 11, an error processing unit 12, a high frequency component pseudo generation processing unit 13, an SBRDecode unit 14, and a BaseCodecDecode unit 1

Switch 15 (output control means) that is switched by a switching control signal from 1.

[0026] The BaseCodecDecode unit 11 has a plurality of functions. First, as the first function, the audio signal stream (Elementary Stream) described above with reference to FIG. 3 is input, and the BaseCodec part included in the reference frame SF and the non-reference frame IF is decoded (decoded) ( First decoding means).

[0027] In addition, as a second function, the BaseCodecDecode unit 11 determines whether each frame has an SBR-header (in other words, a reference frame SF or a non-reference frame IF force). At the same time, if the frame is the reference frame SF, the header information of the SBR header provided in the SBR data is acquired (header information acquisition means).

[0028] Further, as a third function, the BaseCodecDecode unit 11 also performs error determination of whether or not a part of the ES (Elementary Stream) has disappeared (= error generation force (error determination means)). The determination method may be determined to be an error when a failure occurs in the ES decoding process in the BaseCodecDecode unit 11, or when an ES is input, error information about the ES is separately received from the outside. You may make it judge

Here, in the present embodiment, as described above, the switch 15 is based on the switching control signal from the BaseCodecDecode unit 11, based on the error processing unit 12, the high frequency component pseudo generation processing unit 13, and the S BRDecode unit 14. The output from either of these is selected and output to the speaker 7 side. Figure 5 shows the processing executed by the BaseCodecDecode unit 11 for each frame. It is a flowchart showing a procedure.

[0030] In FIG. 5, first, in step S5, the header information acquisition (flag Fh = 0 indicating whether or not the header information could be acquired is set. Then, in step S10, the above error is detected. Judgment is made as to whether or not an error has occurred by the function as a judgment means (judgment procedure) If part of the ES has disappeared and an error has occurred in the frame, the judgment is satisfied, and in step S55 After setting the flag Fh = 0, proceed to Step S60.

[0031] In step S60, the error processing unit 12 is instructed to output predetermined error data, and a switching control signal for switching the switch 15 to the error processing unit 12 side is output. In response to this, the error processing unit 12 outputs, as error data, a mute signal for making a silent state (or data before and after the data force may be interpolated by an appropriate method) (error data generation means, Error data generation procedure), output from switch 15 to speaker 7 side.

[0032] On the other hand, if it is determined in step S10 that an error has not occurred, the determination is not satisfied, and the routine goes to step S15. In step S15, the header information of the SBR header is acquired from the frame by the function as the header information acquisition means described above (header information acquisition procedure). Thereafter, in step S20, it is determined whether or not there is an SBR header (in other words, whether or not a header information calculation table has been created). If the header information has been acquired and the calculation table has been created, the determination is satisfied, and after setting the flag Fh = l in step S25, the process proceeds to step S30. If there is no SBR header in step S20, the determination is not satisfied, and the routine goes directly to step S30.

[0033] In step S30, it is determined whether or not the flag Fh = 1 (in other words, the force with which the header information is obtained and the calculation table is created. If the determination is satisfied, the process proceeds to step S35, and The decoding data of the BaseCodec part decoded by the function as the first decoding means and the Syntax of the SBR part (retained at this point) (the table based on the header information in other words) In addition to outputting to the SBRDecode unit 14, it outputs a switching control signal for switching the switch 15 to the SBRDecode unit 14. In response, the SBRDecode unit 14 receives the decoded data of the BaseCodec unit received from the BaseCodecDecode unit 11 as follows: In addition, decryption processing is performed using a table based on the syntax information of the SBR section described above. The decoding data generated by the SBR section is collected and output to the switch 15 (second decoding procedure), and output from the switch 15 to the speaker 7 side.

[0034] If the determination in step S30 is not satisfied, the process proceeds to step S40. In step S40, the decoded data of the BaseCodec part decoded by the function as the first decoding means described above is output to the high-frequency component pseudo-generation processing unit 13 and the switch 15 is pseudo-generated. A switching control signal for switching to the processing unit 13 is output. In response to this, the high-frequency component pseudo-generation processing unit 13 up-samples the decoded data of the BaseCodec unit received from the BaseCodecDecode unit 11 twice and uses a known method (for example, described in Japanese Patent No. 3140273). The high-frequency component data is generated based on the decoded data of the BaseCodec part, which is a low frequency by the above method), and the decrypted data including the generated high-frequency component data is output to the switch 15, and the switch 15 Output to the side.

[0035] When step S35, step S40, and step S60 are completed, the process returns to step S10 and the same procedure is repeated.

[0036] As in the above flow, in the present embodiment, when the header information of the SBR header cannot be acquired (in other words, when a calculation table is not created), a known high-frequency component simulation generation method is used. The high frequency component data is generated in a pseudo manner based on the decoded data of the BaseCodec part decoded in this way, and the generated high frequency component data is added to the decoded data of the BaseCodec part for output.

[0037] As described above, the digital audio data processing device 1 according to the present embodiment is encoded data composed of a plurality of framed frame sequences, and the plurality of frame sequences include the reference frame SF and the non-frame data. The reference frame IF includes multiple frames, and the non-reference frame IF expands the playback band of the non-reference first data (BaseCodec in this example) that encodes audio information and the non-reference first data BaseCodec. Non-reference second data (in this example, SBR) that encodes the bandwidth expansion information for encoding, and the reference frame SF is the reference first data (in this example, BaseCodec) that encodes the voice information, A processing header (this header, which includes header information for performing arithmetic processing of the non-standard second data SBR, is configured by encoding the band expansion information for expanding the reproduction band of the reference first data BaseCodec. In the example Is a digital audio data processing device 1 for processing a stream including reference second data (in this example, SBR) having SBR headers, and is a processing header provided in reference second data SBR of reference frame SF Header information acquisition means (BaseCodecDecode section 11 in this example) for acquiring the header information of the first frame and the first reference data BaseCodec or the first non-reference first data BaseCodec of the reference frame SF or the non-reference frame IF. The first decoding means (BaseCodecDecode unit 11 in this example) that generates data (BaseCodec data after decoding) in this example, and the reference second data SBR or non-reference data of the reference frame SF or non-reference frame IF 2 The second decoding means for decoding the data SBR using the header information acquired by the header information acquisition means 11 and generating the second decrypted data (in this example, the decoded SBR data) In this example, if the header information cannot be acquired by the SBRDecode unit 14) and the header information acquisition means 11, the first decoded data (BaseCodec after decoding) decoded by the first decoding means 11 High-frequency component pseudo-generation means (in this example, a high-frequency component) that artificially generates high-frequency component data having a higher reproduction and reproduction band than the first decoded data (decoded BaseCodec data). A pseudo-generation processing unit 13) and output control means (switch 15 in this example) for outputting the first decoded key data (BaseCodec data after decoding) and high-frequency component data together. It is a sign.

[0038] In the present embodiment, the reference frame SF including the force standard first data BaseCodec and the reference second data SBR of each of the plurality of frames provided in the stream, and the non-standard first data BaseCodec and the non-standard second data. It is composed of non-reference frame IF including data SBR. Among them, the reference first data BaseCodec and the non-reference first data BaseCodec are decoded by the first decoding means 11 to generate the first decoded data (Base Codec data after decoding), while the reference first data 2 The data SBR and the non-reference second data SBR are decrypted by the _second decryption means 14 using the header information obtained by the header information obtaining means 11, and the second decrypted data ( _SBR data after decoding) ) Is generated.

[0039] At this time, when header information cannot be acquired by the header information acquisition unit 11 due to, for example, a part of the stream disappeared (= an error has occurred), the first decoding unit 11 performs the decoding. Based on the first decoded data (BaseCodec data after decoding) The pseudo-generation means 13 generates pseudo high frequency component data. Then, the output control means 15 outputs the first decoded data (decoded BaseCodec data) together with the generated high frequency component data. As a result, the silence state can be shortened and the high-frequency component can be reduced compared to the case where the silence state is obtained until the next header information can be obtained after the error occurs or only the first decoded data (decoded BaseCodec data) is output. By outputting, it is possible to reduce the sense of incongruity in hearing.

Further, the digital audio data processing method using the digital audio data processing device 1 of the present embodiment is encoded data consisting of a plurality of framed frames, and the plurality of frame sequences are It includes multiple frames consisting of a reference frame SF and a non-reference frame IF, and the non-reference frame IF expands the playback bandwidth of the non-reference first data BaseCodec that encodes audio information and the non-reference first data BaseCodec. The reference frame SF includes the reference first data BaseCodec encoded voice information and the reproduction band of the reference first data BaseCodec. Reference second data SB, which is configured by encoding band expansion information for expansion and has a processing header (SBR header) with header information for performing calculation processing of non-reference second data SBR A digital audio data processing method for processing a stream including R, and a header information acquisition procedure for acquiring the header information of the processing header provided in the reference second data SBR of the reference frame SF (in this example, FIG. 5). Step S15) and the reference first data BaseCodec or non-reference first data BaseCodec of the reference frame SF or non-reference frame IF are decoded to generate first decoded data (decoded BaseCodec data). 1 Decoding procedure (BaseCodec decoding procedure by BaseCodecDecode section 11 in this example) and reference second data SBR or non-reference second data SBR of reference frame SF or non-reference frame IF were acquired in header information acquisition procedure S 15 The second decoding procedure (in this example, step S35 in FIG. 5) for decoding the header information to generate the second decoded data (decoded SBR data), and the header information acquisition procedure If header information cannot be obtained in order S15, the high-frequency component is based on the first decoded data (BaseCodec data after decoding) decoded in the first decoding procedure (BaseCodec decoding procedure by BaseCodecDecode section 11). Data is generated and the first decrypted data (BaseCodec data after decoding) and high The band component data is also output together.

[0041] In the digital audio data processing method of the present embodiment, the header information acquisition procedure S 1

If header information could not be obtained in step 5, high frequency component data is generated based on the decoded first decoded data (BaseCodec data after decoding), and the first decoded data (after decoding) BaseCodec data) and the generated high-frequency component data are output together. As a result, the silence state can be shortened and the high frequency component can be output compared to the case where the silence state is obtained until the next header information can be acquired after an error occurs or only the first decoded data (decoded BaseCodec data) is output. By doing this, you can reduce the sense of incongruity in hearing.

[0042] The digital audio data processing apparatus 1 in the above embodiment has error determination means (BaseCodecDecode section 11 in this example) for determining whether or not a part of the stream has been lost. Is characterized by generating high-frequency component data when it is determined by the error determination means 11 that the non-reference frame IF has disappeared.

In this embodiment, when the error determination means 11 determines that the non-reference frame IF has disappeared, the high frequency component pseudo generation means 13 generates high frequency component data. As a result, silence occurs compared to when silence occurs until the next header information can be acquired after an error in which the non-reference frame IF is lost, or when only the first decoded data (decoded BaseCodec data) is output. And a sense of discomfort in hearing can be reduced by outputting a high frequency component.

[0044] The digital audio data processing method according to the present embodiment further includes an error determination procedure (in this example, step S10 in Fig. 5) for determining whether or not a part of the stream has been lost. High frequency component data is generated when it is determined in S10 that the non-reference frame IF has disappeared.

In the present embodiment, high frequency component data is generated when it is determined that the non-reference frame IF has disappeared. As a result, silence occurs compared to when silence occurs until the next header information can be obtained after an error that the non-reference frame IF is lost, or when only the first decoded data (decoded BaseCodec data) is output. Can be shortened, and discomfort in hearing can be reduced by outputting a high frequency component. In the digital audio data processing device 1 in the above embodiment, when it is determined by the error determination unit 11 that the non-reference frame IF has been lost, a predetermined error corresponding to the lost non-reference frame IF is used. It is characterized by having error data generation means (in this example, error processing unit 12) for generating data (in this example, mute data).

[0047] Thereby, it is possible to output predetermined error data corresponding to when an error occurs.

[0048] Also, in the digital audio data processing method in the above embodiment, when it is determined that the non-reference frame IF has been lost in the error determination procedure S10, a predetermined error corresponding to the lost non-reference frame IF is used. It is characterized by having an error data generation procedure (in this example, step S60) for generating data (in this example, mute data).

[0049] Thereby, it is possible to output predetermined error data corresponding to when an error occurs.

FIGS. 6 to 8 are explanatory diagrams for specifically explaining the effects of the present embodiment listed above. In the figure, the horizontal axis represents the time axis, FIG. 6 shows an example of the behavior of each frame in the input stream, and FIG. 7 shows the digital audio data processing apparatus 1 of the present embodiment corresponding to FIG. Fig. 8 shows the output behavior of the comparative example in which only the first decoded data (BaseCodec data after decoding) is output after the error occurs.

[0051] In FIG. 7 and FIG. 8, when the reference frame SF with the SBR header can be received (without error), and the subsequent non-reference frame IF without the SBR header can be received without error. If this is the case, this is the same as in this embodiment and the comparative example, and both the BaseCo dec part and the SBR part can be decoded, and the first decoded decoded data and the second decoded data (referred to as “SBR decode”). Can be output together.

[0052] In addition, even when an error occurs in a certain frame (at least a part of the frame is lost), there is predetermined error data (in this example, in a silent state) that does not differ between this embodiment and the comparative example. A certain mute) can be output.

On the other hand, the frame after the frame in which the error has occurred (until the frame before the next SBR header can be acquired) differs between the comparative example and the present embodiment. That is, As shown in Fig. 8, in the above comparative example, if an error occurs, the SBR part cannot be decoded until the header information of the SBR header is newly acquired thereafter, and the low frequency band of only the BaseCodec part cannot be obtained. Output decrypted data.

On the other hand, as shown in FIG. 7, in the present embodiment, on the basis of the decoded code data of the BaseCodec part, high frequency component data having a reproduction band higher than the BaseCodec data is generated in a pseudo manner, Since the decoded BaseCodec data and the pseudo high frequency component data are output together, it is possible to reduce the sense of discomfort in the sense of hearing.

[0055] Note that the above has been described by taking as an example a case where the present invention is applied to a mobile phone that supports terrestrial digital broadcasting (for example, broadcasting using so-called lSegment), but is not limited thereto, and other mobile terminals, mopile devices, etc. It can be applied to. This is particularly effective when applied to in-vehicle terminals where errors frequently occur.

[0056] The digital audio data processing device 1 according to the above embodiment is code data including a plurality of framed frames, and the plurality of frame sequences are a plurality of frames including a reference frame SF and a non-reference frame IF. The non-reference frame IF includes the BaseCodec that encodes the audio information and the SBR that encodes the band expansion information for expanding the playback band of this BaseCodec, and the reference frame SF Includes BaseCodec that encodes information, and SBR that has SBR header that is configured by encoding band expansion information for expanding the playback band of BaseCodec, and includes header information for performing SBR calculation processing A digital audio data processing device 1 for processing a stream, and a BaseCodeDecode unit 11 for obtaining header information of a processing header provided in an SBR of a reference frame SF; BaseCodecDecode unit 11 that decodes BaseCodec of quasi-frame SF or non-reference frame IF and generates decoded BaseCodec data, and header obtained by BaseCodecDecode unit 11 for SBR of base frame SF or non-reference frame IF When the header information cannot be obtained by the SBRDecode unit 14 that generates the SBR data after decoding using the information, and the BaseCodecDecode unit 11, the BaseCodecDecode unit 11 A high-frequency component pseudo-generation processing unit 13 that artificially generates high-frequency component data having a reproduction band higher than that of BaseCodec data, and a switch 15 for outputting BaseCodec and high-frequency component data together are provided. To do.

[0057] In the present embodiment, the frame includes a reference frame SF including an SBR having a base codec and an SBR header, and a non-reference frame IF including a base codec and an SBR, respectively. Among them, BaseCodec is decoded by Base CodecDecode unit 11 to generate BaseCodec data, while SBR is decoded by SBRDecode unit 14 using the header information acquired by BaseCodecDecode unit 11 to generate SBR data .

[0058] At this time, for example, when header information cannot be acquired by the Base CodecDecode unit 11 due to loss of part of the stream (= an error has occurred), the BaseCodecDecode unit 11 decodes the BaseCodec data Based on this, the high frequency component pseudo generation processing unit 13 generates high frequency component data in a pseudo manner. Then, the switch 15 outputs BaseCodec data together with the generated high frequency component data. This makes it possible to reduce the silence and reduce the sense of incongruity by outputting high-frequency components, compared to the case where silence is maintained until the next header information can be acquired after an error occurs, and only BaseCodec is output. can do.

[0059] In addition, the digital audio data processing method using the digital audio data processing device 1 of the present embodiment is encoded data including a plurality of framed frames, and includes a plurality of frames. The column includes a plurality of frames composed of a reference frame SF and a non-reference frame IF. The non-reference frame IF force encodes base codec that encodes audio information and band expansion information for expanding the playback band of this base codec. This is composed of BaseCodec, which encodes the reference frame SF power audio information, and the band expansion information for expanding the playback band of this BaseCodec. A digital audio data processing method for processing a stream including an SBR having an SBR header with header information, the header of the SBR header provided in the SBR of the reference frame SF. Step S15 for obtaining information, and decoding the BaseCodec of the reference frame SF or non-reference frame IF, and generating the BaseCodec data The BaseCodec decoding procedure by the BaseCodecDecode unit 11 and the reference frame SF or non-reference frame IF SBR is decrypted using the header information obtained in step S15, and SBR data If the header information could not be acquired in step S35 and step S15, a higher playback bandwidth than that of the BaseCodec data is obtained based on the BaseCodec data decoded by BaseCodec decoding by the BaseCodecDecode 咅 11. The pseudo high frequency component data is generated and BaseCodec data and high frequency component data are output together.

[0060] In the digital audio data processing method of the present embodiment, when header information cannot be acquired in step S15, high frequency component data is generated based on the decoded BaseCodec data, and BaseCodec data and The generated high frequency component data is also output. This makes it possible to reduce the silence and reduce the sense of incongruity by outputting high-frequency components, compared to the case in which silence is maintained until the next header information can be acquired after an error occurs, and only BaseCodec data is output. Can do.

Brief Description of Drawings

FIG. 1 is a perspective view showing the overall appearance of a mobile phone according to an embodiment of the present invention.

2 is a functional block diagram showing a functional configuration of the mobile phone shown in FIG.

FIG. 3 is a schematic diagram conceptually showing a portion related to audio extracted from a stream.

4 is a functional block diagram showing a configuration related to audio signal reproduction processing in the signal processing section shown in FIG.

FIG. 5 is a flowchart showing the processing procedure executed by the BaseCodecDecode part for each frame.

FIG. 6 is an explanatory diagram for specifically explaining each effect of the embodiment of the present invention.

FIG. 7 is an explanatory diagram for specifically explaining each effect of the embodiment of the present invention.

FIG. 8 is an explanatory diagram for specifically explaining each effect of the embodiment of the present invention. Explanation of symbols

[0062] 1 Mobile phone (digital audio data processing device)

11 BaseCodecDecode part (error determination means, header information acquisition means, first decoding means, second decoding means, analysis means, verification means)

12 Error processing section (error data generation means)

13 High-frequency component pseudo-generation processing unit (high-frequency component pseudo-generation means)

15 Switch (output control means) Non-reference frame Reference frame

Claims

The scope of the claims

[1] Code data consisting of a plurality of framed frames,

The plurality of frame sequences includes a reference frame and a non-reference frame;

The non-reference frame includes non-reference first data obtained by encoding audio information, and non-reference second data obtained by encoding band expansion information for expanding the reproduction band of the non-reference first data;

The reference frame is configured by encoding reference first data obtained by encoding audio information and band expansion information for expanding a reproduction band of the reference first data, and calculating the non-reference second data. Digital audio data processing apparatus for processing a stream, including reference second data having a processing header having header information for performing the processing, wherein the processing header provided in the reference second data of the reference frame Header information acquisition means for acquiring the header information of

First decoding means for decoding the reference first data or the non-reference first data of the reference frame or the non-reference frame and generating first decoded data;

The reference second data or the non-reference second data of the reference frame or the non-reference frame is decoded using the header information acquired by the header information acquisition means, and second decoded data is generated. A second decryption means;

When the header information cannot be obtained by the header information obtaining means, a higher reproduction band than the first decoded data is obtained based on the first decoded data decoded by the first decoding means. High-frequency component pseudo-generation means for generating pseudo-high-frequency component data,

An output control means for outputting the first decoded data and the high-frequency component data together;

A digital audio data processing apparatus comprising:

[2] In the digital audio data processing device according to claim 1,

An error determination unit that determines whether a part of the stream has been lost, and the high-frequency component pseudo-generation unit, when the error determination unit determines that the non-reference frame has been lost, A digital device characterized by generating high-frequency component data Le voice data processing device.

[3] The digital audio data processing device according to claim 2,

When the error determination means determines that the non-reference frame has been lost, error data generation means for generating predetermined error data corresponding to the lost non-reference frame

A digital audio data processing apparatus comprising:

[4] Coded data composed of a plurality of framed frames,

The plurality of frame sequences includes a plurality of frames including a reference frame and a non-reference frame,

The reference frame is configured by encoding reference first data obtained by encoding audio information and band expansion information for expanding a reproduction band of the reference first data, and calculating the non-reference second data. A digital audio data processing method for processing a stream, including reference second data having a processing header with header information for performing the processing, wherein the processing header provided in the reference second data of the reference frame Header information acquisition procedure for acquiring the header information of

A first decoding procedure for decoding the reference first data or the non-reference first data of the reference frame or the non-reference frame to generate first decoded data;

The reference second data or the non-reference second data of the reference frame or the non-reference frame is decoded using the header information acquired in the header information acquisition procedure to generate second decoded data. A second decryption procedure,

If the header information cannot be acquired by the header information acquisition procedure, the reproduction information has a higher reproduction band than the first decoded data based on the first decoded data decoded by the first decoding procedure. A digital audio data processing method, characterized in that high-frequency component data is generated in a pseudo manner, and the first decoded data and the high-frequency component data are output together.

[5] The digital audio data processing method according to claim 4,

An error determination procedure for determining whether or not a part of the stream has been lost, and the high-frequency component data is generated when the error determination procedure determines that the non-reference frame has been lost. Digital audio data processing method.

[6] The digital audio data processing method according to claim 5,

An error data generation procedure for generating predetermined error data corresponding to the lost non-reference frame when the error determination procedure determines that the non-reference frame has been lost.

A digital audio data processing method comprising: