CN1598926A - Audio coding method and equipment with noise restaining - Google Patents
Audio coding method and equipment with noise restaining Download PDFInfo
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Abstract
The invention discloses a frequency ciphering apparatus with bandwidth encoder (13) and noise killer (12). The encoder (13) includes the high frequency encoder (131) and the low frequency encoder (130). The low frequency encoder (130) includes the low frequency noise killer (203). When the high frequency encoder (131) is forbidden, the noise killer (12) also is forbidden and the digital frequency signal passes through the noise killer (12) and transfers the signal to the encoder (13). When the high frequency encoder (131) is working, the low noise killer (203) is forbidden and the digital frequency signal passes through the low frequency noise killer (203).
Description
Technical field
The present invention relates generally to be applicable to the audio signal processing apparatus of the digital audio communication system in the moving communicating field of pocket telephone etc. for example, more particularly, relate to noise suppressing function or echo inhibit feature in the audio coding.
Background technology
In general, in the moving communicating field of for example pocket telephone, the Applied Digital audio communication system.The digital audio communication system adopts audio coding (compressed encoding) to transmit the voice data of compression.
In moving communicating field, typical audio coding method is the low bitrate coding method that is called CELP (Code Excited Linear Prediction).When audio coding adopts this method, sound signal not only usually, and comprise that the sound signal of the noise component that is called the high frequency environment noise also often is encoded.
As known, when the sound signal that comprises noise and echo component is encoded, produce second-rate coding audio data.For this reason, the audio coding circuit adopts the noise suppression circuit that is called noise eliminator, so that only export the sound signal that has suppressed noise component.In addition, echo suppression circuit is used to import the sound signal that has suppressed echo component such as echo eliminator, voice switch.
Noise eliminator determines wherein not import any sound signal, the i.e. state of an input environment noise signal.Noise eliminator is analyzed the feature of ambient noise signal under this state.Subsequently, during sound signal and noise component mixing, noise eliminator utilizes this feature to suppress noise component.
Echo eliminator determines that wherein sound signal arrives the take over party, but does not export the state of any sound signal, i.e. take over party's single session state from transmit leg.Echo eliminator is understood under this state, returns the sound property of transmit leg from the take over party.Subsequently, by utilizing the sound property of understanding, noise eliminator suppresses to be blended in the echo component in the transmit leg signal.Voice switch compares the signal power of take over party and transmit leg, by the lower side of loss power input, suppresses echo component.
The audio coding scheme of using in the present pocket telephone is confined to the frequency band that sound signal mainly exists.In recent years, carrying out in the frequency band of being wider than the sound signal frequency band, realizing the standardization effort of the wideband encoding scheme of audio coding.This wideband encoding scheme adopts CELP, needs noise eliminator and echo eliminator or voice switch.
Using noise eliminator and adopting in the audio signal processor of wideband encoding scheme, be divided into through the digital audio and video signals of noise eliminator that power is lower than sound signal and unessential high-frequency audio signal component and other low-frequency audio signal component with regard to information.Under the specified coding mode, the high-frequency audio signal component is optional, and it is known to remove the method for this component from coding audio data.For example, AMR-WB (AMR-WB) coder by 3GPP (third generation cooperative relationship project) standard code can be used as coded system.
In fact, in a coded system of the coding audio data of output low frequency audio signal components (for example, transfer rate is different from the 23.85kbps among the AMR-WB) under, noise eliminator does not need that the digital audio and video signals component of the full range band of exporting from A/D converter 11 is carried out squelch and handles, and only needs low-frequency audio signal component execution squelch is handled.
Usually, noise eliminator comprises digital signal processor (DSP).So, when noise eliminator is handled the digital audio and video signals component of full range band, when realizing the noise eliminator function,, need excessive data processing amount and memory capacity for DSP.
This is suitable for echo eliminator equally, wishes to realize required data processing amount and the memory capacity of echo inhibit feature improving Audio Signal Processing efficient by reducing.
Note having proposed a kind of method that reduces calculated amount and essential memory capacity, wherein only carry out the Echo Cancellation of low-frequency audio signal component, and do not carry out the Echo Cancellation (for example, referring to Japanese patent application KOKAI open No.8-65211) of full range audio signal components.But this method is not still eliminated the high frequency echo component.
Summary of the invention
According to one embodiment of present invention, the purpose of this invention is to provide a kind ofly, can improve the audio coding equipment of audio coding treatment effeciency by reducing required data processing amount and the memory capacity of noise eliminator in the audio coding.
Audio coding equipment comprises the high-frequency audio scrambler to the high-frequency audio component coding of digital audio and video signals, reduce following sampling (downsampling) unit of the sampling frequency of the digital audio and video signals identical with the digital audio and video signals of high-frequency audio coder processes, suppress to be included in down the noise suppressor of the noise component in the signal that sampling unit handles and to the low frequency audio coder of the signal encoding of noise suppressor processing.
Description of drawings
The accompanying drawing that is included in the instructions and constitutes an instructions part illustrates currently preferred embodiment of the present invention, and and the generality that provides above describe and DETAILED DESCRIPTION OF THE PREFERRED given below, principle of the present invention is described together.
Fig. 1 is the block scheme of expression according to the major part of the audio codec of first embodiment of the invention;
Fig. 2 is the block scheme of expression according to the structure of the low frequency audio coder of first embodiment;
Fig. 3 is the block scheme of expression according to the major part of the audio codec of second embodiment of the invention;
Fig. 4 is the block scheme of expression according to the structure of the scrambler of second embodiment;
Fig. 5 A and 5B are the block scheme of explanation according to the vad function of second embodiment;
Fig. 6 is the block scheme of the modification of expression second embodiment;
Fig. 7 is the block scheme of expression according to the major part of the audio codec of third embodiment of the invention;
Fig. 8 A and 8B are the block scheme of expression according to the structure of the low frequency audio coder of the 3rd embodiment;
Fig. 9 is the block scheme of expression according to the major part of the audio codec of fourth embodiment of the invention;
Figure 10 is the block scheme of expression according to the structure of the scrambler of the 4th embodiment;
Figure 11 is the block scheme of the modification of expression the 4th embodiment;
Figure 12 is the block scheme of expression according to the major part of the audio codec of fifth embodiment of the invention;
Figure 13 A and 13B are the block scheme of expression according to the structure of the low frequency audio coder of the 5th embodiment;
Figure 14 is the block scheme of expression according to the major part of the audio codec of sixth embodiment of the invention;
Figure 15 A and 15B are the block scheme of expression according to the structure of the scrambler of the 6th embodiment;
Figure 16 A-16D is the block scheme of expression basic scheme of the present invention.
Embodiment
Basic scheme of the present invention is divided into four kinds of patterns, as shown in Figure 16 A-16D.
Under first kind of pattern, as shown in Figure 16 A, band divides (BD) unit 1 that digital audio and video signals is divided into a plurality of frequency bands.Corrector 2 is proofreaied and correct the low-frequency audio signal after band divides, and correction signal is exported to low frequency scrambler 3.High-frequency audio signal coding after 4 pairs of bands of high frequency encoder divide.
Under second kind of pattern, as shown in Figure 16 B, band divides the low-frequency audio signal after (BD) unit 1 divides band to export to low frequency scrambler 3, and high-frequency audio signal is exported to high frequency encoder 4.Corrector 2 is proofreaied and correct the high-frequency audio code of high frequency encoder 4 codings.
Under the third pattern, as shown in Figure 16 C, when proofreading and correct the low-frequency audio signal of being with after dividing, corrector 2 is with reference to the decoded signal from 5 outputs of low frequency demoder.
Under the 4th kind of pattern, as shown in Figure 16 D, when proofreading and correct the high-frequency audio signal of being with after dividing, corrector is with reference to the decoded signal from 6 outputs of high frequency demoder.
By these scheme modes, can before being lower than, be with under the sampling rate of dividing and carry out treatment for correcting, and can reduce data processing amount and memory capacity.
Below with reference to description of drawings the preferred embodiments of the present invention.
(first embodiment)
Fig. 1 is the block scheme of expression according to the major part of the audio codec of first embodiment.
As shown in fig. 1, in general, the equipment of present embodiment is made of coded system and playback system (decode system), coded system produces coding audio data (TX) according to digital audio and video signals, playback system is decoded to the coding audio data (TX) that is generally held in the storer 15, thereby obtains initial sound signal.
Coded system has the A/D converter 11 that the sound signal by microphone 10 inputs is converted to digital audio and video signals, noise eliminator 12, scrambler 13 and multiplexer (data multiplex unit) 14.On the other hand, playback system has loudspeaker 20, D/A converter 21, demoder (audio decoding circuit) 22 and demultiplexer 23.Notice that the playback system shown in Fig. 1 is identical with conventional system, so omit explanation to it.In coded system, noise eliminator 12, scrambler 13 and multiplexer 14 are realized by digital signal processor (DSP) usually.
Scrambler 13 is the compressed encodings that utilize pre-defined algorithm (for example CELP) combine digital sound signal, and produces the audio coding circuit of coding audio data.Scrambler 13 is broadband (for example AMR-WB) audio coding circuit, and is divided into low frequency audio coder 130 and high-frequency audio scrambler (below be also referred to as the H scrambler) 131.Multiplexer 14 converts the coding audio data that scrambler 13 produces to conform to the characteristic of transmission path, modulator-demodular unit, error correction unit etc. form, and the data after the conversion are exported to storer 15.
According to the mode signal (HM) of the operator scheme that scrambler 13 is set, the noise suppressing function of noise eliminator 12 is enabled/is forbidden in control.This mode signal is from, for example CPU 100 of pocket telephone output, and is used to determine whether to enable high-frequency audio scrambler (H scrambler) 131.For for simplicity, suppose when " HM=1 " (for example, when transfer rate is 23.85kbps among the AMR-WB), H scrambler 131 is activated, when " HM=0 " (for example, when transfer rate is different from 23.85kbps among the AMR-WB), H scrambler 131 is disabled.
When " HM=1 ", noise eliminator 12 is activated, and suppresses from the noise component of the digital audio and video signals of A/D converter 11 outputs.On the other hand, when " HM=0 ", noise eliminator 12 is skipped noise suppression process, allows digital audio and video signals (VS) from A/D converter 11 outputs through noise eliminator.
Low frequency audio coder 130 has module 200 and the noise eliminator 203 that comprises take a sample down (downsample) unit 201 and low frequency scrambler (L scrambler) 202, as shown in Figure 2.
201 times samplings of following sampling unit reduce the sample of predetermined number, so that the digital audio and video signals (VS) from A/D converter 11 outputs is carried out the low frequency processing.
When " HM=0 ", the digital audio and video signals (VS) of 201 times samplings of 203 pairs of following sampling units of noise eliminator carries out squelch to be handled, and the signal after handling is exported to L scrambler 202.On the other hand, when " HM=1 ", noise eliminator 203 is skipped the squelch of the digital audio and video signals (VS) of 201 times samplings of sampling unit is down handled, and directly described digital audio and video signals (VS) is passed to L scrambler 202.
(operation of first embodiment)
The operation of the coded system of present embodiment is described below with reference to Fig. 1 and 2.
For example, the CPU of pocket telephone output is provided with the mode signal HM of the operator scheme (HM=0/1) of scrambler 13.A/D converter 11 converts the sound signal by microphone 10 inputs to digital audio and video signals.
Suppose the operator scheme (HM=1) enable high-frequency audio scrambler (H scrambler) 131 (for example, when transfer rate is 23.85kbps among the AMR-WB) is set.When " HM=1 ", noise eliminator 12 is activated, and suppresses from the noise component of the digital audio and video signals of A/D converter 11 outputs, and this signal is exported to scrambler 13.
In scrambler 13,131 pairs of high-frequency audio signals of H scrambler carry out encoding process.On the other hand, in low frequency audio coder 130, when " HM=1 ", noise eliminator 203 is skipped the squelch of the digital audio and video signals (VS) of 201 times samplings of sampling unit is down handled, and directly it is passed to L scrambler 202.The squelch of the noise eliminator 12 that sampling digital audio and video signals (VS) has experienced previous stage under noting is handled.The output of H scrambler 131 and L scrambler 202 (coding audio data) is multiplexed by multiplexer 14, and multiplexed data is stored in the storer 15.
On the other hand, suppose forbidding high-frequency audio scrambler (H scrambler) 131 operator scheme (HM=0) of (for example, when transfer rate is different from 23.85kbps among the AMR-WB) is set.When " HM=0 ", noise eliminator 12 is skipped squelch and is handled, and allows digital audio and video signals (VS) from A/D converter 11 outputs by it.H scrambler 131 is disabled.
In low frequency audio coder 130, when " HM=0 ", the digital audio and video signals (VS) of 201 times samplings of 203 pairs of following sampling units of noise eliminator carries out squelch to be handled, and the signal after handling is exported to L scrambler 202.L scrambler 202 produces the low frequency coding audio data, and outputs it to multiplexer 14.
As mentioned above, according to present embodiment, when the operator scheme forbidding H of coded system scrambler 131 (HM=0), the noise eliminator 12 that inserted before scrambler 13 is also disabled.So, pass through noise eliminator 12 from the digital audio and video signals (VS) of A/D converter 11 outputs, and be provided for the low frequency audio coder 130 of scrambler 13.
In low frequency audio coder 130, when " HM=0 ", noise eliminator 203 is activated, and the digital audio and video signals (VS) of 201 times samplings of sampling unit is down carried out squelch handle, and the signal after handling is exported to L scrambler 202.In this manner, low frequency audio coder 130 produces the low frequency coding audio data according to the low frequency digital sound signal that suppresses noise component.
So under the operator scheme of forbidding high-frequency audio scrambler 131, the noise eliminator 12 that inserted before scrambler 13 is disabled.Thereby, can reduce the data processing amount and the memory capacity that realize among the required DSP of noise eliminator function.On the other hand, in low frequency audio coder 130,, therefore can under the situation that does not reduce sound quality, produce the low frequency coding audio data because low-frequency noise canceller 203 is activated.In this case, 203 pairs of following sampling digital audio and video signals of low-frequency noise canceller (its sample number is reduced) carry out the squelch processing.Thereby, and enable high frequency noise canceller 12 and compare, can further reduce data processing amount and memory capacity among the required DSP of the function that realizes noise eliminator 203.
(second embodiment)
Fig. 3 is the block scheme of expression according to the major part of the audio codec of second embodiment.
The coded system of present embodiment does not have any independently high frequency noise canceller, comprise scrambler 300 with low frequency audio coding 300 and high-frequency audio scrambler 301, low frequency audio coder 300 comprises a low-frequency noise canceller (LNC), and high-frequency audio scrambler 301 comprises a high frequency noise canceller (HNC).Notice that playback system (decode system) is identical with the playback system (referring to Fig. 1) among first embodiment, so omission is to its explanation.
In scrambler 30, low frequency audio coder 300 has low frequency scrambler (L scrambler) 400, following sampling unit 401 and low-frequency noise canceller (LNC) 402, as shown in Figure 4.401 times samplings of following sampling unit reduce the sample of predetermined number, so that handle carrying out low frequency from the digital audio-frequency data (VS) of A/D converter 11 outputs.LNC 402 carries out squelch and handles, the main low frequency environments noise that suppresses from the digital audio and video signals (VS) of taking a sample down.L scrambler 400 produces the low frequency coding audio data, and outputs it to multiplexer 14 according to the digital audio and video signals (following sampled signal) that experiences the squelch of LNC 402.
On the other hand, high-frequency audio scrambler 301 has high frequency encoder (H scrambler) 500 and high frequency noise canceller (HNC) 501.Operator scheme (HM=1/0) according to previous mode signal HM is provided with determines whether to enable H scrambler 500.That is, when " HM=1 ", H scrambler 500 is activated (for example, when transfer rate is 23.85kbps among the AMR-WB), and the high-frequency audio signal from the digital audio and video signals (VS) of A/D converter 11 outputs is carried out encoding process.
HNC 501 carries out squelch and handles, so that suppress the high frequency environment noise.The output of HNC501 and L scrambler 400 (coding audio data) is multiplexed by multiplexer 14, and multiplexed data is stored in the storer 15.
When " HM=0 ", H scrambler 500 disabled (for example, when transfer rate is different from 23.85kbps among the AMR-WB).Under this operator scheme, low frequency audio coder 300 is enabled separately, and the output encoder voice data is as 14 the output from L scrambler 400 to multiplexer.
As mentioned above, according to present embodiment, when the operator scheme forbidding H of coded system scrambler 500 (HM=0), high-frequency audio scrambler 301 is disabled, and low frequency audio coder 301 is enabled separately.Thereby, when " HM=0 ", only enable the LNC 402 that is included in the low frequency audio coder 300, the digital audio and video signals (VS) of 401 times samplings of sampling unit is down carried out squelch handle.So, under the operator scheme of forbidding high-frequency audio scrambler 301, can reduce the data processing amount and the memory capacity that realize among the required DSP of noise eliminator function.
(vad function)
Low frequency audio coder 300 has according to digital audio and video signals (VS), and detecting input voice periods is sound period or the VAD in noiseless period (voice activity detection) function.When detecting noiseless period, scrambler 300 is to high-frequency audio scrambler 301 output predetermined flag (VADF).
In high-frequency audio scrambler 301, the output of H scrambler 500 is main coding audio datas relevant with the high-frequency gain of sound signal.HNC 501 is only by handling this coding audio data, the high frequency noise canceller of elimination noise.
When detecting noiseless period (VADF=0), HNC 501 determines that high-frequency gain is the high-frequency gain of noise signal (noise), deducts from the output signal of H scrambler 500 and this gain value corresponding, and difference is exported to multiplexer 14.On the other hand, when detecting sound period (VADF=1), HNC 501 deducts the numerical value that deducts in noiseless period (VADF=0) from the input of H scrambler 500, and difference is exported to multiplexer 14.
In low frequency audio coder 300, L scrambler 400 comprises vad function.More particularly, L scrambler 400 has VAD unit 50, and sound cell encoder 51 and noiseless cell encoder 52 are as shown in Fig. 5 A.When the sign (VADF=0) in noiseless period was indicated in 50 outputs of VAD unit, noiseless cell encoder 52 was activated.When the sign (VADF=1) in sound period was indicated in 50 outputs of VAD unit, sound cell encoder 51 was activated.Sign (VADF=1/0) is exported to the HNC 501 of high-frequency audio scrambler 301 in VAD unit 50.
(modification)
Fig. 6 is the block scheme of the modification of expression second embodiment.
In the scheme of this modification, according to for example from the operator scheme signal (MS) of the CPU 100 of pocket telephone, the operation of HNC 501 in the control high-frequency audio scrambler 301.More particularly, operator scheme signal (MS) is corresponding to the set handling signal of the pattern of the sound signal of music for example.
In high-frequency audio scrambler 301, when to carrying out high-frequency coding from the sound signal of the music of CPU 100 when handling, HNC 501 is according to operator scheme signal (MS=1) operation, and carries out the high frequency noise that is applicable to music and suppress to handle.
The operator scheme signal (MS) that attention CPU 100 is provided with is not limited to this concrete pattern about music, can be used for being provided with other various patterns on the contrary.
(the 3rd embodiment)
Fig. 7 is the block scheme of expression according to the major part of the audio codec of the 3rd embodiment.Fig. 8 A and 8B are the block schemes of the structure of low frequency audio coder 172 in the presentation graphs 7 and low frequency audio decoder.
In the present embodiment, comparison diagram 1 and 7 and Fig. 2 and 8A can find out, noise eliminator among first embodiment is replaced by echo eliminator, increased received audio signal (BR signal) input, increased the LBR signal input of from low frequency audio decoder 222 to low frequency audio coder 172 (echo eliminator 204) from scrambler 22 to wideband echoes canceller 16.
One in the echo eliminator 16 and 204 is activated: when high-frequency audio scrambler 171 is activated (for example, when transfer rate is 23.85kbps among the AMR-WB), echo eliminator 16 is enabled separately; When scrambler 171 is disabled (for example, when transfer rate is different from 23.85kbps among the AMR-WB), echo eliminator 204 is enabled separately.So, when high-frequency audio scrambler 171 is disabled, can reduce data processing amount and memory capacity among the required DSP of the function that realizes echo eliminator.
(the 4th embodiment)
Fig. 9 is the block scheme of expression according to the major part of the audio codec of the 4th embodiment.Figure 10 is the block scheme of the structure of scrambler 31 in the presentation graphs 9.
In the present embodiment, comparison diagram 3 and 9 and Fig. 4 and 10 can find out, noise eliminator among second embodiment is replaced by echo eliminator, increase the LBR signal input of from low frequency audio decoder 222 to low frequency audio coder 310 (low frequency echo eliminator 403), increased the HBR signal input of from high-frequency audio scrambler 221 to high-frequency audio scrambler 311 (high frequency echo eliminator 502).
When high-frequency audio scrambler 500 is disabled (for example, when transfer rate is different from 23.85kbps among the AMR-WB), high frequency echo eliminator 502 is disabled, and low frequency echo eliminator 403 is enabled separately.Thereby, when high-frequency audio scrambler 500 is disabled, can reduce data processing amount and memory capacity among the required DSP of the function that realizes echo eliminator.
(modification)
Figure 11 is the block scheme of the modification of the 4th embodiment.
In the scheme of this modification, according to from, the operator scheme signal (RBT) of the CPU 100 of pocket telephone for example, the operation of HEC 502 in the control high-frequency audio scrambler 311.More particularly, operator scheme signal (RBT) is provided for handling the signal with extreme frequency skew of telephone set, the pattern of for example push tone, calling out tune, warning tone etc.
The operator scheme signal (RBT) that attention is provided with from CPU 100 is not limited to be used to handle this concrete pattern of pushing tone, calling out tune, warning tone etc., can be used for being provided with other various patterns on the contrary, for example coding mode or the like.
In addition, by replace the echo eliminator among Fig. 7-10 with voice switch, can realize the embodiment among Figure 12-15B.In Figure 12,13A and 13B, low frequency voice switch (LVS) 81 and high frequency voice switch (HVS) 82 are combined.
In Figure 14,15A and 15B, high frequency voice switch and low frequency voice switch are combined.In arbitrary embodiment, (for example, when transfer rate is different from 23.85kbps among the AMR-WB) only enables the low frequency voice switch when the high-frequency audio scrambler is disabled, so that reduce data processing amount and memory capacity.
(other embodiment)
Among Fig. 4, high-frequency audio scrambler 500 is inserted in high frequency noise and eliminated before 501.On the other hand, high frequency noise canceller 501 can be inserted in before the high-frequency audio scrambler 500.In this case, when high-frequency audio scrambler 500 is activated, after handling, the noise removing of high-frequency signal finishes the high-frequency audio coding.The equivalent modifications of this scheme is applicable to Figure 10 and 15A.
That is, high frequency echo eliminator 502 or high frequency attenuator can be inserted in before the high-frequency audio scrambler 500.In this case, when high-frequency audio scrambler 500 is activated, after the high frequency echo is eliminated processing or the processing of high frequency voice switch, finish the high-frequency audio coding.
Among Fig. 9, be used as the reference signal of high ripple echo eliminator from the output signal of high-frequency audio demoder 221.On the other hand, the input signal of high-frequency audio demoder 221 can be used as reference signal.In this case, the high-frequency signal power in the incoming bit stream of high frequency echo eliminator use high-frequency audio demoder 221 is as reference signal.
Among Figure 14, the attenuator of high frequency voice switch 80 is inserted in after the high-frequency audio demoder 221.On the other hand, this attenuator can be inserted in before the high-frequency audio demoder 221.In this case, the high-frequency signal power in the incoming bit stream of 80 pairs of high-frequency audio demoders 221 of high frequency voice switch is carried out the loss control processing.
In Figure 12-15, the loss control device of each voice switch comprises an attenuator, comprises an ON/OFF switch but also can change into.
As mentioned above, according to the foregoing description, especially has wideband audio coding circuit (scrambler), in one or more audio codec in noise eliminator, echo eliminator and the voice switch, can under the situation that does not reduce sound quality, reduce especially in coded system, to realize the required data processing amount and the memory capacity of function of noise eliminator, echo eliminator or voice switch.
So, thereby can improve the audio coding treatment effeciency.More particularly, the audio coding of high-frequency audio signal component is handled, and when low-frequency signal components carried out audio coding, can be carried out the noise that is included in the low-frequency audio signal component or the inhibition of echo component and handle when skipping.So,, under the pattern of skipping the high-frequency audio encoding process, can reduce required data processing amount and the memory capacity of function that realizes noise eliminator, echo eliminator or voice switch utilizing DSP to carry out in the scheme of noise or echo inhibition processing.
Those skilled in the art is easy to expect additional advantages and modifications.So scope of the present invention is not limited to detail and the exemplary embodiments representing and describe here.Therefore, not breaking away from by accessory claim and being equal under the situation of spirit or scope of the general inventive principle that limits, can make various modifications.
Claims (14)
1, a kind of audio coding equipment is characterized in that comprising:
High-frequency audio scrambler (131) to the high-frequency audio component coding of digital audio and video signals;
Reduce the following sampling unit (201) of the sampling frequency of the digital audio and video signals identical with the digital audio and video signals of high-frequency audio coder processes;
Suppress to be included in down the noise suppressor (203) of the noise component in the signal of sampling unit (201) processing; With
The low frequency audio coder (202) of the signal encoding that noise suppressor (203) is handled.
2, according to the described equipment of claim 1, it is characterized in that also being included in digital audio and video signals by before high-frequency audio scrambler (131) and following sampling unit (201) processing, suppress second noise suppressor (12) of the high frequency noise components of digital audio and video signals.
3, according to the described equipment of claim 1, it is characterized in that when high-frequency audio scrambler (131) is disabled, the inhibition that second noise suppressor (12) is skipped high frequency noise components, and allow digital audio and video signals by it.
4, according to the described equipment of claim 1, it is characterized in that when high-frequency audio scrambler (131) when being activated, the inhibition that noise suppressor (203) is skipped the low-frequency noise component, and digital audio and video signals input low frequency audio decoder (202).
5,, it is characterized in that high-frequency audio scrambler (301) comprises the high frequency noise rejector (501) of the noise component in the high-frequency audio signal that suppresses to be included in coding according to the described equipment of claim 1.
6, according to the described equipment of claim 1, it is characterized in that low frequency audio coder (300) from the no acoustical signal of digital audio and video signals identification, and the signal of the no acoustical signal of indication is exported to high-frequency audio scrambler (301),
High-frequency audio scrambler (301) comprise the noise component in the high-frequency audio signal that suppresses to be included in coding high frequency noise rejector (501) and
High frequency noise rejector (501) deducts and does not have the gain value corresponding of acoustical signal according to no acoustical signal from the high-frequency audio signal of coding.
7, according to the described equipment of claim 1, it is characterized in that high-frequency audio scrambler (301) comprises the high frequency noise rejector (501) of the noise component in the high-frequency audio signal that suppresses to be included in coding, and
This equipment also comprises:
According to the coding mode of digital audio and video signals, the CPU (100) of the function of high frequency noise rejector (501) is enabled or forbids in control.
8, a kind of audio coding equipment is characterized in that comprising:
First echo suppressor (16) that suppresses the high frequency echo component of digital audio and video signals;
The high-frequency audio scrambler (171) of the signal encoding that first echo suppressor (16) is handled;
Reduce the following sampling unit (201) of the sampling frequency of the digital audio and video signals identical with the digital audio and video signals of first echo suppressor processing;
Suppress to be included in down second echo suppressor (204) of the echo component in the signal of sampling unit (201) processing; With
The low frequency audio coder (202) of the signal encoding that second echo suppressor (204) is handled.
9, according to the described equipment of claim 8, it is characterized in that when high-frequency audio scrambler (171) is disabled, the inhibition that first echo suppressor (16) is skipped echo component, and allow digital audio and video signals by it.
10, according to the described equipment of claim 8, it is characterized in that when high-frequency audio scrambler (171) when being activated, the inhibition that second echo suppressor (204) is skipped echo component, and digital audio and video signals input low frequency audio decoder (202).
11,, it is characterized in that high-frequency audio scrambler (311) comprises the high frequency echo suppressor (502) of the echo component in the high-frequency audio signal that suppresses to be included in coding according to the described equipment of claim 8.
12, according to the described equipment of claim 8, it is characterized in that high-frequency audio scrambler (311) comprises the high frequency echo suppressor (502) of the echo component in the high-frequency audio signal that suppresses to be included in coding, and
This equipment also comprises:
According to the coding mode of digital audio and video signals, the CPU (100) of the function of the second high frequency echo suppressor (502) is enabled or forbids in control.
13, a kind of audio coding method is characterized in that comprising:
High fdrequency component coding to digital audio and video signals;
To the sampling down of uncoded digital audio and video signals;
Suppress to be included in down the noise component in the sampling digital audio and video signals; With
To the repressed digital audio signal coding of its noise component.
14, a kind of audio coding method is characterized in that comprising:
Suppress to be included in the echo component in the high-frequency range of digital audio and video signals;
To the repressed high-frequency digital audio-frequency signal coding of its echo component;
To the sampling down of not repressed digital audio and video signals;
Suppress the echo component of sampling digital audio and video signals down; With
The low frequency digital audio-frequency signal coding that its echo component is suppressed.
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| CNA031588859A CN1598926A (en) | 2003-09-16 | 2003-09-16 | Audio coding method and equipment with noise restaining |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8060363B2 (en) | 2007-02-13 | 2011-11-15 | Nokia Corporation | Audio signal encoding |
| CN101185124B (en) * | 2005-04-01 | 2012-01-11 | 高通股份有限公司 | Method and apparatus for dividing frequency band coding of voice signal |
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2003
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101185124B (en) * | 2005-04-01 | 2012-01-11 | 高通股份有限公司 | Method and apparatus for dividing frequency band coding of voice signal |
| CN101185120B (en) * | 2005-04-01 | 2012-05-30 | 高通股份有限公司 | Systems, methods, and apparatus for highband burst suppression |
| US8060363B2 (en) | 2007-02-13 | 2011-11-15 | Nokia Corporation | Audio signal encoding |
| CN101611441B (en) * | 2007-02-13 | 2012-12-26 | 诺基亚公司 | Audio signal encoding |
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