Embodiment
See also the signaling process figure of Fig. 1 for first embodiment of a kind of coding/decoding method of the present invention.
The embodiment of the invention is used in the ultra broadband codec.The input signal of scrambler is the 32kHz sampling rate, and the processing frame length is 20ms.Input signal is carried out after branch frequency band, down-sampling handle, 320 sampled points are arranged, 320 sampled points are arranged corresponding to the signal of 8~16kHz frequency band corresponding to the signal of 0~8kHz frequency band.Wherein the signal in 0~8kHz frequency band is handled by core encoder, and core encoder can be a codec G.729.1, also can be other broadband signal codec.
For the time-domain signal in 8~16kHz frequency band y_hi (0), y_hi (1) ..., y_hi (319) }; Through having obtained one group of MDCT coefficient after the MDCT conversion, the frequency-region signal that promptly this frequency band is corresponding y_swb (0), y_swb (1) ... Y_swb (319) } because the ultra broadband part is only handled the signal in 8~14kHz frequency band, so frequency-region signal is only handled { y_swb (0); Y_swb (1) ..., y_swb (239) }.Can this be organized frequency-region signal at coding side and be divided into N subband; Extract the frequency domain envelope and the quantification of each subband; Obtain one group of frequency domain envelope { spec_env (0) after the quantification; Spec_env (1);, spec_env
}, this group envelope arrives decoding end through coding transmission.
For the broadband core encoder G.729.1,7~8kHz part signal not within its process range, in order to ensure the continuity at decoding end decoded signal frequency spectrum, need extract the characteristic parameter of 7~8kHz part signal at coding side.Because G.729.1 scrambler has carried out the MDCT conversion to the signal of 4~8kHz, corresponding frequency-region signal { y_wb (0), y_wb (1);, y_wb (159) }, the frequency-region signal that wherein 7~8kHz is corresponding is { y_wb (120); Y_wb (121) ..., y_wb (159) }; At coding side it is divided into M subband, extracts the frequency domain envelope and the quantification of each subband, obtain one group of frequency domain envelope { spec_env_extra (0) after the quantification; Spec_env_extra (1);, spec_env_extra
}, this group envelope arrives decoding end through coding transmission.N=15 in the present embodiment, M=3.
This frequency expansion method embodiment comprises coding method and coding/decoding method: extract the tonality feature parameter by coding side earlier, and send to decoding end, by the profile information reconstruct high band signal of decoding end according to tonality feature parameter and original high band signal.Specifically may further comprise the steps:
Step 101: coding side sends the tonality feature parameter of extraction to decoding end;
To the frequency-region signal of ultra broadband part spec (0), spec (1) ..., spec (239) } and carry out the tonality feature analysis, extract the tonality feature parameter, and said tonality feature parameter is carried out quantization encoding, coding transmission is arrived decoding end.
Concrete steps are following:
Autocorrelation function
nP [MIN of 1a, calculating ultra broadband part frequency-region signal; MAX], MIN=5MAX=70 in the present embodiment.
The tonality feature parameter of 1b, ultra broadband part is
1c, tonality feature parametric t ona is quantized the tonality feature parametric t ona after obtaining quantizing
q, with its coding transmission to decoding end.
Step 102: the decoding end decoding obtains the tonality feature parameter;
Decoding end obtains tonality feature parametric t ona after the coding that receives is decoded
q
Step 103: decoding end generates excitation spectrum according to the tonality feature parameter;
Specifically can may further comprise the steps:
Step 103A: decoding end generates the initial excitation spectrum;
Be specially narrow-band spectrum and the wideband spectrum generation initial excitation spectrum of decoding end according to decoding and reconstituting; Can add random noise when generating the initial excitation spectrum and obtain
Step 103B: decoding end can be carried out albefaction to the initial excitation spectrum, makes the energy distribution of initial excitation spectrum balanced;
After decoding end is extracted the spectrum envelope of initial excitation spectrum E, the initial excitation spectrum is carried out albefaction, concrete steps are following:
A is divided into 7 subbands with the initial excitation spectrum; Calculate the average energy of each subband; Be spectrum envelope,
B has better continuity in order to make the initial excitation spectrum after the albefaction, can also carry out inserting in level and smooth to spectrum envelope, obtain one group of normalized factor β (0), β (1) ... β (279) }.The process of inserting in level and smooth is following:
wherein w is one 40 point symmetry window function.
C carries out albefaction to the initial excitation spectrum, and the initial excitation spectrum after the albefaction is:
103C: decoding end is carried out the tone shaping according to the original frequency band signal spectrum to the initial excitation spectrum and is obtained excitation spectrum; Need to prove that if the initial excitation spectrum has been passed through the albefaction operation of 103B, the initial excitation spectrum of this step input is the initial excitation spectrum after the albefaction.
Concrete steps are following:
a According to the formula
by the E 'to calculate the initial excitation spectra Pseudospectra
B adopts following method to calculate the tonality feature parameter T of the puppet spectrum SE of initial excitation spectrum.
Calculate autocorrelation function
nP [MIN of pseudo-spectrum SE frequency-region signal; MAX], MIN=5MAX=70 in the present embodiment.
The tonality feature parameter
of the puppet spectrum SE of initial excitation spectrum
c calculation tone shaping factor
In this embodiment
D utilizes tone shaping factor pair initial excitation spectrum to adjust.Be specially: if
Be tona
q TMT, the tone characteristic of promptly original ultra broadband frequency spectrum is eager to excel than the tone characteristic of initial excitation spectrum, then the initial excitation spectrum is carried out the sharpening adjustment, promptly
Obtain the excitation spectrum after the tone shaping
If α } 0, i.e. tona
qμ T a little less than the tone characteristic of the tone characteristic of promptly original ultra broadband frequency spectrum than the initial excitation spectrum, then composes adaptive adding noise to initial excitation, smoothly adjusts, and adjustment process is following:
Generate random noise Noise={noise (0), noise (1) ..., noise (279) }.
Calculate the energy of pumping signal and noise signal,
knows
According to following formula pumping signal is carried out the tone adjustment,
get tone shaping excitation spectrum
The tone characteristic of the tone characteristic of the excitation spectrum after the tone shaping and original ultra-broadband signal spectrum is mated more.
Step 104: decoding end can be carried out the frequency band adjustment to the excitation spectrum of final generation, to obtain the accurate more excitation spectrum of frequency band;
Concrete steps are following:
corresponds to 7 ~ 8kHz excitation signal.
corresponds to 8 ~ 14kHz excitation signal.Wherein START is pumping signal reference position parameter, START=30 in the present embodiment.
Step 105: decoding end generates the high band signal of reconstruct according to the profile information (like the frequency domain envelope information) in said excitation spectrum and the original high band signal.Promptly excitation spectrum is carried out the adjustment of energy level coupling and obtain the high band signal of reconstruct; Concrete steps are following:
5a obtains the frequency domain envelope (being the frequency domain energy in the present embodiment) of excitation spectrum, promptly according to the sub-band division identical with coding side, extracts the sub belt energy of excitation spectrum, and the excitation spectrum sub belt energy of 7~8kHz part is:
{ excit_energy_extra (0), excit_energy_extra (1), excit_energy_extra (2) }, the excitation spectrum sub belt energy of 8~14kHz part be excit_energy (0), excit_energy (1) ..., excit_energy (14) }.The computation process of sub belt energy is:
promptly asks quadratic sum to the spectral coefficient in each subband.
The 5b decoding obtains original high-band signal frequency-domain envelope information:
{ spec_env_extra (0), spec_env_extra (1), spec_env_extra (2) } and spec_env (0), spec_env (1) ..., spec_env (14) }.Because the frequency domain envelope has been represented the average energy of this subband; Can obtain original high-band signal frequency-domain energy so the frequency domain envelope multiply by the number of the spectral coefficient in this subband: { orig_energy_extra (0); Orig_energy_extra (1), orig_energy_extra (2) } and { orig_energy (0), orig_energy (1);, orig_energy (14) }.
5c can be to the frequency domain energy and the original high-band signal frequency-domain energy of excitation spectrum; Tonality feature parameter according to original high band signal is carried out smoothing processing, obtains frequency domain energy { excit_energy_extra_sm (0), the excit_energy_extra_sm (1) of the excitation spectrum after level and smooth; Excit_energy_extra_sm (2) }, { excit_energy_sm (0); Excit_energy_sm (1) ..., excit_energy_sm (14) } and original high-band signal frequency-domain energy
{orig_energy_extra_sm(0),orig_energy_extra_sm(1),orig_energy_extra_sm(2)}、{orig_energy_sm(0),orig_energy_sm(1),……,orig_energy_sm(14)}。
5d is certain according to the energy level coupling gain factor
that the frequency domain energy after level and smooth calculates each subband; If do not carry out smoothing processing, input be the frequency domain energy among 5a, the 5b.
5e carries out the shaping of energy level coupling to excitation spectrum: the spectral coefficient to the excitation spectrum of each subband multiply by the corresponding energy level coupling of this subband gain factor; Promptly
obtains the high-band excitation spectrum of reconstruct, comprises reconstruct spectrum { y_re_extra (0), the y_re_extra (1) of 7~8kHz part; Y_re_extra (39) }, reconstruct spectrum { y_re (0), the y_re (1) of 8~14kHz part; Y_re (239) }, the high band signal of promptly final reconstruct is accomplished the expansion of frequency band.
Decoding end is carried out the adjustment of energy level coupling to excitation spectrum, and the energy envelope of synthetic spectrum and original ultra broadband spectrum are close.
The embodiment of the invention is employed in the key characterization parameter that coding side extracts original high band signal: the tonality feature parameter, carry out coding transmission with few bit resource.In decoding end, generate the excitation spectrum of the high band signal of control reconstruct according to the tonality feature parameter, and finally generate the high band signal of reconstruct according to the profile information (for example frequency domain envelope) of original high band signal, realize band spread.Because when decoding end is carried out the reconstruct of high band signal; Minutia based on original high band signal is that the tonality feature parameter is operated; The high band signal of reconstruct except profile and original high band signal near; Coupling is preferably arranged on details, just can reach auditory effect preferably through less bit resource consumption.
See also the signaling process figure of Fig. 2 for second embodiment of a kind of coding/decoding method of the present invention.
The embodiment of the invention is used in the ultra broadband codec.The input signal of scrambler is the 32kHz sampling rate, and the processing frame length is 20ms.Input signal is carried out after branch frequency band, down-sampling handle, 320 sampled points are arranged, 320 sampled points are arranged corresponding to the signal of 8~16kHz frequency band corresponding to the signal of 0~8kHz frequency band.Wherein the signal in 0~8kHz frequency band is handled by core encoder, and core encoder can be a codec G.729.1, also can be other broadband signal codec.
For the time-domain signal in 8~16kHz frequency band y_hi (0), y_hi (1) ..., y_hi (319) }; Through having obtained one group of MDCT coefficient after the MDCT conversion, the frequency-region signal that promptly this frequency band is corresponding y_swb (0), y_swb (1) ... Y_swb (319) } because the ultra broadband part is only handled the signal in 8~14kHz frequency band, so frequency-region signal is only handled { y_swb (0); Y_swb (1) ..., y_swb (239) }.Can this be organized frequency-region signal at coding side and be divided into N subband; Extract the frequency domain envelope and the quantification of each subband; Obtain one group of frequency domain envelope { spec_env (0) after the quantification; Spec_env (1);, spec_env
}, this group envelope arrives decoding end through coding transmission.
For the broadband core encoder G.729.1,7~8kHz part signal not within its process range, in order to ensure the continuity at decoding end decoded signal frequency spectrum, need extract the characteristic parameter of 7~8kHz part signal at coding side.Because G.729.1 scrambler has carried out the MDCT conversion to the signal of 4~8kHz, corresponding frequency-region signal { y_wb (0), y_wb (1);, y_wb (159) }, the frequency-region signal that wherein 7~8kHz is corresponding is { y_wb (120); Y_wb (121) ..., y_wb (159) }; At coding side it is divided into M subband, extracts the frequency domain envelope and the quantification of each subband, obtain one group of frequency domain envelope after the quantification
{ spec_env_extra (0); Spec_env_extra (1); Spec_env_extra
}, this group envelope arrives decoding end through coding transmission.N=15 in the present embodiment, M=3.
This frequency expansion method embodiment comprises coding method and coding/decoding method: extract the tonality feature parameter by coding side earlier, and send to decoding end, by the profile information reconstruct high band signal of decoding end according to tonality feature parameter and original high band signal.Specifically may further comprise the steps:
Step 201: coding side sends the tonality feature parameter of extraction to decoding end;
To the frequency-region signal of ultra broadband part spec (0), spec (1) ..., spec (239) } and carry out the tonality feature analysis, extract the tonality feature parameter, and, be transferred to decoding end this parameter quantification coding.
Concrete leaching process is following:
(1) calculates the tonality feature parameter of each subband
A (1) with frequency-region signal spec (0), spec (1) ..., spec (239) } and be divided into K subband, in the present embodiment, and K=4, i group frequency-region signal is:
Maximal value in every group of frequency-region signal of B (1) search
And record maximal value position p
i
C (1) calculates p
iThe average of the frequency domain envelope in the oL scope, that is:
be L=7 in the present embodiment.
The tonality feature parameter of this subband of D (1) is
(2) comprehensively extract G tonality feature parameter, the G=2 in the present embodiment that characterizes whole ultra broadband partial tone characteristic.Be specially
Tona wherein
0Corresponding to spec (0), spec (1) ..., spec (119) } part tonality feature, tona
1Corresponding to spec (120), spec (121) ..., spec (239) } part tonality feature.
(3) with tonality feature parametric t ona
iQuantize the tonality feature parameter after obtaining quantizing
, with its coding transmission to decoding end.
Coding side is to tona
iDuring quantification, can be limited within 1.125~4.5 scopes its span.
When coding side extracted the tonality feature parameter, the parameter that uses can have multiple source, and concrete CALCULATION OF PARAMETERS also can have multiple computing method.For example:
A wherein the frequency-region signal of ultra broadband part spec (0), spec (1) ... Spec (239) } can directly take absolute value to original frequency-region signal and obtain | y_swb (0) |, | y_swb (1) | ... | y_swb (239) | }, also can be pseudo-spectrum signal { s (0), the s (1) that calculates through following formula (1) by original frequency-region signal;, s (239) }:
B is in step (1), and the calculating of average also can be to obtain
according to computes
In step (1), subband tonality feature CALCULATION OF PARAMETERS also can be to obtain
according to computes
C in step (2), the tonality feature parameter comprehensively also can obtain
according to computes
In step (2), the tonality feature parameter comprehensively also can obtain
according to computes
Step 202: the decoding end decoding obtains the tonality feature parameter;
Decoding tonality feature parameter obtains
Know
If at coding side to tona
iDuring quantification, its span is limited within 1.125~4.5 scopes, can carries out nonlinear enhancing to it by following formula in decoding end,
In the present embodiment
Through the tonality feature nonlinearity in parameters is strengthened, can better control the synthetic of ultra broadband spectrum.Can certainly not carry out non-linear enhancing.
Step 203: decoding end generates excitation spectrum according to the tonality feature parameter; Specifically can may further comprise the steps:
Step 203A: decoding end generates the initial excitation spectrum;
Can generate excitation spectrum
in several ways in decoding end can adopt for example following mode to obtain excitation spectrum:
Time-domain signal in 0~4kHz frequency band of decoding end reconstruct is done the MDCT conversion, obtain in 0~4kHz frequency band frequency-region signal y_lo (0), y_lo (1) ..., y_lo (159) }; And the frequency-region signal in the 4~7kHz frequency band that obtains of decoding y_h (0), y_h (1) ..., y_h (119) }; With this two parts spectrum constitute original excitation spectrum y_lo (0), y_lo (1) ..., y_lo (159); Y_h (0), y_h (1) ..., y_h (119) }.
Owing to need reconstruct the frequency spectrum of 7~8kHz in decoding end, so in excitation spectrum, need comprise the excitation information of 7~8kHz, V=280 in the present embodiment.
Step 203B is because excitation spectrum itself has the tone characteristic, for the tone characteristic of the tone characteristic that makes excitation spectrum and original ultra-broadband signal spectrum is complementary, can carry out the tone shaping to the initial excitation spectrum, and concrete steps are following:
A calculates the puppet spectrum of excitation spectrum according to formula (1):
B adopts the tonality feature parameter T that obtains two subbands of pseudo-spectrum with coding side step (1), (2) identical method respectively
0And T
1
C is divided into two subbands with excitation spectrum and pseudo-spectrum,
Calculate the tone energy parameter of pseudo-spectrum:
D calculates the tone shaping factor:
C utilizes tone shaping factor pair initial excitation spectrum to adjust.Be specially: order
Tone characteristic T according to excitation spectrum
iTone characteristic tona with original ultra broadband spectrum
iBetween relation excitation spectrum is adjusted,
Obtain the excitation spectrum after the tone shaping
Step 203C: decoding end can be carried out albefaction to the excitation spectrum after the tone shaping, makes the energy distribution of excitation spectrum balanced, helps follow-up energy level coupling adjustment;
The spectrum envelope that decoding end is extracted the excitation spectrum Y after the tone shaping carries out albefaction to excitation spectrum.Concrete steps are following:
A is divided into 7 subbands with excitation spectrum; Calculate the average energy of each subband; Be spectrum envelope,
B has better continuity in order to make the spectrum after the albefaction, and spectrum envelope is carried out inserting in level and smooth, obtains one group of normalized factor { β (0), β (1), β (279) }.The process of inserting in level and smooth is following:
wherein w is one 40 point symmetry window function.
C carries out albefaction to excitation spectrum, and the excitation spectrum after the albefaction is:
The albefaction process is:
At this moment, just generated final excitation spectrum.Can certainly not carry out albefaction, directly use excitation spectrum after the tone shaping as final excitation spectrum.
Step 204: decoding end can be carried out the frequency band adjustment to the excitation spectrum of final generation, to obtain the accurate more excitation spectrum of frequency band;
Decoding end is carried out the frequency band adjustment to excitation spectrum and is adopted formula,
corresponds to 7 ~ 8kHz excitation signal.
corresponds to 8 ~ 14kHz excitation signal.Wherein START is pumping signal reference position parameter, START=30 in the present embodiment.
Step 205: decoding end can add noise spectrum in excitation spectrum;
In order to make the frequency spectrum of excitation spectrum more approaching original ultra broadband on the spectrum details; Under the tonality feature parameter control of original ultra-broadband signal, add noise spectrum, excitation spectrum
detailed process that obtains adding after making an uproar is following:
5a with the tonality feature parameter maps of original ultra-broadband signal in 0~1 interval range,
5b calculating energy gain factor ener, in the present embodiment
5c adds noise spectrum to the pumping signal of 7~8kHz:
wherein noise is the random number within the o0.5 scope, i.e. a noise spectrum.
5d adds noise spectrum to the pumping signal of 8~14kHz:
wherein noise is the random number within the o0.5 scope, i.e. a noise spectrum; Tona is comprehensive tonality feature parameter, is provided with as follows:
Step 206: decoding end generates the high band signal of reconstruct according to the profile information (like the frequency domain envelope information) in said excitation spectrum and the original high band signal.Be that decoding end is carried out the high band signal that the adjustment of energy level coupling obtains reconstruct to excitation spectrum.
Excitation spectrum is carried out the adjustment of energy level coupling, the energy envelope of synthetic spectrum and original ultra broadband spectrum are close.Concrete steps are following:
6a obtains the frequency domain envelope (being the frequency domain energy in the present embodiment) of excitation spectrum, promptly according to the sub-band division identical with coding side, extracts the sub belt energy of excitation spectrum, and the excitation spectrum sub belt energy of 7~8kHz part does
{ excit_energy_extra (0), excit_energy_extra (1), excit_energy_extra (2) }, the excitation spectrum sub belt energy of 8~14kHz part does
{excit_energy(0),excit_energy(1),……,excit_energy(14)}。The computation process of sub belt energy is:
promptly asks quadratic sum to the spectral coefficient in each subband.
The 6b decoding obtains original high-band signal frequency-domain envelope information:
{ spec_env_extra (0), spec_env_extra (1), spec_env_extra (2) } and spec_env (0), spec_env (1) ..., spec_env (14) }.Because the frequency domain envelope has been represented the average energy of this subband; Can obtain original high-band signal frequency-domain energy so the frequency domain envelope multiply by the number of the spectral coefficient in this subband: { orig_energy_extra (0); Orig_energy_extra (1), orig_energy_extra (2) } and { orig_energy (0), orig_energy (1);, orig_energy (14) }.
6c can be to the frequency domain energy and the original high-band signal frequency-domain energy of excitation spectrum; Tonality feature parameter according to original high band signal is carried out smoothing processing, obtains frequency domain energy { excit_energy_extra_sm (0), the excit_energy_extra_sm (1) of the excitation spectrum after level and smooth; Excit_energy_extra_sm (2) }, { excit_energy_sm (0); Excit_energy_sm (1) ..., excit_energy_sm (14) } and original high-band signal frequency-domain energy
{orig_energy_extra_sm(0),orig_energy_extra_sm(1),orig_energy_extra_sm(2)}、{orig_energy_sm(0),orig_energy_sm(1),……,orig_energy_sm(14)}。The concrete processing as follows:
Frequency domain energy to 7~8kHz part:
Wherein
N
iBeing the number of the spectral coefficient in each subband, is 8,16,16 in the present embodiment.
Parts for 8 ~ 14kHz frequency domain energy:
where
6d is certain according to the energy level coupling gain factor
that the frequency domain energy after level and smooth calculates each subband; If do not carry out smoothing processing, input be the frequency domain energy among 6a, the 6b.
6e carries out the shaping of energy level coupling to excitation spectrum: the spectral coefficient to the excitation spectrum of each subband multiply by the corresponding energy level coupling of this subband gain factor; Promptly
obtains the high-band excitation spectrum of reconstruct, comprises reconstruct spectrum { y_re_extra (0), the y_re_extra (1) of 7~8kHz part; Y_re_extra (39) }, reconstruct spectrum { y_re (0), the y_re (1) of 8~14kHz part; Y_re (239) }, the high band signal of promptly final reconstruct is accomplished the expansion of frequency band.
The embodiment of the invention is employed in the key characterization parameter that coding side extracts original high band signal: the tonality feature parameter, carry out coding transmission with few bit resource.In decoding end, generate the excitation spectrum of the high band signal of control reconstruct according to the tonality feature parameter, and finally generate the high band signal of reconstruct according to the profile information (for example frequency domain envelope) of original high band signal, realize band spread.Because when decoding end is carried out the reconstruct of high band signal; Minutia based on original high band signal is that the tonality feature parameter is operated; The high band signal of reconstruct except profile and original high band signal near; Coupling is preferably arranged on details, just can reach auditory effect preferably through less bit resource consumption.
See also the structural drawing of Fig. 3 for an embodiment of a kind of coding method of the present invention;
Step 301: the frequency-region signal to the ultra broadband part carries out tonality feature analysis extraction tonality feature parameter;
Concrete steps are following:
301A with frequency-region signal spec (0), spec (1) ..., spec (239) } and be divided into K subband, K=4 in the present embodiment, i group frequency-region signal is:
Maximal value in each subband frequency-region signal of 301B search
And record maximal value position p
i
301C calculates p
iThe average of the frequency domain envelope in the oL scope, that is:
be L=7 in the present embodiment.
The calculating of average also can be to obtain
according to computes
The tonality feature parameter of this subband of 301D is
Subband tonality feature CALCULATION OF PARAMETERS also can be to obtain
according to computes
Comprehensive each the subband tonality feature parameter of 301E obtains the tonality feature parameter.
Extract G tonality feature parameter, G=2 in the present embodiment characterizing whole ultra broadband partial tone characteristic.Be specially
Tona wherein
0Corresponding to spec (0), spec (1) ..., spec (119) } part tonality feature, tona
1Corresponding to spec (120), spec (121) ..., spec (239) } part tonality feature.
The tonality feature parameter comprehensively also can obtain
according to computes
Step 301 can also adopt following manner to accomplish,
Calculate the autocorrelation function of ultra broadband part frequency-region signal;
Calculate autocorrelation function
nP [MIN of ultra broadband part frequency-region signal; MAX], MIN=5MAX=70 in the present embodiment.
The tonality feature parameter is
Step 302: said tonality feature parameter is carried out quantization encoding.
See also the structural drawing of Fig. 4 for an embodiment of a kind of band spread of the present invention system;
Coding side 401 is used to send original high band signal and tonality feature parameter;
The frequency-region signal of 401 pairs of ultra broadband parts of coding side spec (0), spec (1) ..., spec (239) } and carry out the tonality feature analysis, extract the tonality feature parameter, and said pitch parameters is carried out quantization encoding, coding transmission is arrived decoding end.
Concrete steps are following:
Autocorrelation function
nP [MIN of a, calculating ultra broadband part frequency-region signal; MAX], MIN=5MAX=70 in the present embodiment.
The tonality feature parameter of b, ultra broadband part is
C, tonality feature parametric t ona is quantized the tonality feature parametric t ona after obtaining quantizing
q, with its coding transmission to decoding end.
Decoding end 402 is used for tonality feature parameter and original high band signal that received code end 401 sends; Generate excitation spectrum according to said tonality feature parameter; Generate the high band signal of reconstruct according to the profile information in said excitation spectrum and the said original high band signal.
Decoding end 402 further can comprise:
Receiving element 40201 is used for tonality feature parameter and original high band signal that received code end 401 sends;
Excitation spectrum generation unit 40202 is used for the excitation spectrum according to the high band signal of said tonality feature parameter generation reconstruct;
High band signal generation unit 40203 is used for generating the high band signal of reconstruct according to the profile information of said excitation spectrum and said original high band signal;
Excitation spectrum generation unit 40202 further can comprise: excitation spectrum shaping unit 40202a, be used to generate the initial excitation spectrum, and said initial excitation spectrum is carried out the excitation spectrum after shaping obtains the tone shaping.
Excitation spectrum generation unit 40202 further can comprise:
Albefaction unit 40202b is used for the excitation spectrum after said initial excitation spectrum or the tone shaping is carried out the excitation spectrum after albefaction obtains albefaction.
Decoding end 402 further can comprise:
Frequency band adjustment unit 40204 is used for the excitation spectrum that generates is carried out the frequency band adjustment.
Noise adds unit 40205, is used for adding the noise spectrum that makes the more approaching original high-band signal spectrum structure of excitation spectrum at said excitation spectrum.
Said high band signal generation unit 40203 further can also comprise:
Spectrum envelope extraction unit 40203a is used to extract the spectrum envelope of excitation spectrum;
Smooth unit 40203b is used for the spectrum envelope and the original high-band signal decoding spectrum envelope of excitation spectrum are carried out the level and smooth interior continuous frequency domain envelope of generation of inserting;
Gain factor computing unit 40203c is used for calculating the gain factor that energy level matees according to said frequency domain envelope;
Generation unit 40203d is used for according to said gain factor excitation spectrum being carried out shaping, generates the high band signal of reconstruct.
See also the structural drawing of implementing row of Fig. 5 for a kind of band spread decoding end of the present invention; Comprise:
Receiving element 501 is used for tonality feature parameter and original high band signal that the received code end sends;
Excitation spectrum generation unit 502 is used for the excitation spectrum according to the high band signal of said tonality feature parameter generation reconstruct;
High band signal generation unit 503 is used for generating reconstruct high-band signal frequency-domain information according to the profile information of said excitation spectrum and said original high band signal.
Said excitation spectrum generation unit 502 further comprises:
Excitation spectrum shaping unit 502a is used for according to said Pood's property the excitation spectrum that generates being carried out shaping.
Albefaction unit 502b is used for the excitation spectrum that generates is carried out albefaction.
Said decoding end can also comprise:
Frequency band adjustment unit 504 is used for excitation spectrum is carried out the frequency band adjustment.
Noise adds unit 505, is used for adding the noise spectrum that makes the more approaching original high-band signal spectrum structure of excitation spectrum at said excitation spectrum.
Said high band signal generation unit 403 further can comprise:
Spectrum envelope extraction unit 503a is used to extract the spectrum envelope of excitation spectrum;
Smooth unit 503b is used for the spectrum envelope and the original high-band signal decoding spectrum envelope of excitation spectrum are carried out the level and smooth interior continuous frequency domain envelope of generation of inserting;
Gain factor computing unit 503c is used for calculating the gain factor that energy level matees according to said frequency domain envelope;
Generation unit 503d is used for according to said gain factor excitation spectrum being carried out shaping, generates the high band signal of reconstruct.
See also the structural drawing of Fig. 6 for an embodiment of a kind of band spread coding side of the present invention; This coding side can be applied in the system shown in Figure 4, and it comprises:
Tonality feature parameter extraction unit 601 is used for the frequency-region signal of ultra broadband part is carried out tonality feature analysis extraction tonality feature parameter;
Concrete steps are following:
With frequency-region signal spec (0), spec (1) ..., spec (239) } and be divided into K subband, K=4 in the present embodiment, i group frequency-region signal is:
Search for the maximal value in each subband frequency-region signal
And record maximal value position p
i
Calculate p
iThe average of the frequency domain envelope in the oL scope, that is:
be L=7 in the present embodiment.
The calculating of average also can be to obtain
according to computes
The tonality feature parameter of this subband is
Subband tonality feature CALCULATION OF PARAMETERS also can be to obtain
according to computes
Comprehensive each subband tonality feature parameter obtains the tonality feature parameter.
Extract G tonality feature parameter, G=2 in the present embodiment characterizing whole ultra broadband partial tone characteristic.Be specially
Tona wherein
0Corresponding to spec (0), spec (1) ..., spec (119) } part tonality feature, tona
1Corresponding to spec (120), spec (121) ..., spec (239) } part tonality feature.
The tonality feature parameter comprehensively also can obtain
according to computes
Can also adopt following manner to accomplish:
Calculate the autocorrelation function of ultra broadband part frequency-region signal;
Calculate autocorrelation function
nP [MIN of ultra broadband part frequency-region signal; MAX], MIN=5MAX=70 in the present embodiment.
The tonality feature parameter is
Quantifying unit 602 is used for that said tonality feature parameter is carried out quantization encoding and sends said tonality feature parameter.
Wherein, tonality feature parameter extraction unit 601 can comprise:
Autocorrelation function unit 601a is used for obtaining the tonality feature parameter through the autocorrelation function that calculates ultra broadband part frequency-region signal.
Tonality feature parameter extraction unit 601 can comprise:
Computing unit 601b is used to calculate each subband frequency-region signal tonality feature parameter;
Extraction unit 601c comprehensively extracts the tonality feature parameter that characterizes whole ultra broadband partial tone characteristic.
One of ordinary skill in the art will appreciate that all or part of step in the whole bag of tricks of the foregoing description is to instruct relevant hardware to accomplish through program; This program can be stored in the computer-readable recording medium, and storage medium can comprise: ROM, RAM, disk or CD etc.
More than frequency expansion method that the embodiment of the invention provided and system and equipment have been carried out detailed introduction; Used concrete example among this paper principle of the present invention and embodiment are set forth, the explanation of above embodiment just is used for helping to understand method of the present invention and core concept thereof; Simultaneously, for one of ordinary skill in the art, according to thought of the present invention, the part that on embodiment and range of application, all can change, in sum, this description should not be construed as limitation of the present invention.