US20040230427A1 - Audio signal compression - Google Patents
Audio signal compression Download PDFInfo
- Publication number
- US20040230427A1 US20040230427A1 US10/868,258 US86825804A US2004230427A1 US 20040230427 A1 US20040230427 A1 US 20040230427A1 US 86825804 A US86825804 A US 86825804A US 2004230427 A1 US2004230427 A1 US 2004230427A1
- Authority
- US
- United States
- Prior art keywords
- audio signal
- compressing
- signal
- compression gain
- recording
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M7/00—Conversion of a code where information is represented by a given sequence or number of digits to a code where the same, similar or subset of information is represented by a different sequence or number of digits
- H03M7/30—Compression; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
- H03M7/3002—Conversion to or from differential modulation
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M3/00—Conversion of analogue values to or from differential modulation
- H03M3/30—Delta-sigma modulation
- H03M3/458—Analogue/digital converters using delta-sigma modulation as an intermediate step
- H03M3/478—Means for controlling the correspondence between the range of the input signal and the range of signals the converter can handle; Means for out-of-range indication
- H03M3/48—Means for controlling the correspondence between the range of the input signal and the range of signals the converter can handle; Means for out-of-range indication characterised by the type of range control, e.g. limiting
- H03M3/482—Means for controlling the correspondence between the range of the input signal and the range of signals the converter can handle; Means for out-of-range indication characterised by the type of range control, e.g. limiting by adapting the quantisation step size
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10L—SPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
- G10L19/00—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/00007—Time or data compression or expansion
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10527—Audio or video recording; Data buffering arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B14/00—Transmission systems not characterised by the medium used for transmission
- H04B14/02—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation
- H04B14/06—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation using differential modulation, e.g. delta modulation
- H04B14/062—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation using differential modulation, e.g. delta modulation using delta modulation or one-bit differential modulation [1DPCM]
- H04B14/064—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation using differential modulation, e.g. delta modulation using delta modulation or one-bit differential modulation [1DPCM] with adaptive feedback
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/00007—Time or data compression or expansion
- G11B2020/00014—Time or data compression or expansion the compressed signal being an audio signal
- G11B2020/00065—Sigma-delta audio encoding
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M3/00—Conversion of analogue values to or from differential modulation
- H03M3/30—Delta-sigma modulation
- H03M3/39—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators
- H03M3/402—Arrangements specific to bandpass modulators
- H03M3/404—Arrangements specific to bandpass modulators characterised by the type of bandpass filters used
- H03M3/406—Arrangements specific to bandpass modulators characterised by the type of bandpass filters used by the use of a pair of integrators forming a closed loop
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M3/00—Conversion of analogue values to or from differential modulation
- H03M3/30—Delta-sigma modulation
- H03M3/39—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators
- H03M3/412—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators characterised by the number of quantisers and their type and resolution
- H03M3/422—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators characterised by the number of quantisers and their type and resolution having one quantiser only
- H03M3/43—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators characterised by the number of quantisers and their type and resolution having one quantiser only the quantiser being a single bit one
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M3/00—Conversion of analogue values to or from differential modulation
- H03M3/30—Delta-sigma modulation
- H03M3/39—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators
- H03M3/436—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators characterised by the order of the loop filter, e.g. error feedback type
- H03M3/438—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators characterised by the order of the loop filter, e.g. error feedback type the modulator having a higher order loop filter in the feedforward path
- H03M3/452—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators characterised by the order of the loop filter, e.g. error feedback type the modulator having a higher order loop filter in the feedforward path with weighted feedforward summation, i.e. with feedforward paths from more than one filter stage to the quantiser input
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M3/00—Conversion of analogue values to or from differential modulation
- H03M3/30—Delta-sigma modulation
- H03M3/458—Analogue/digital converters using delta-sigma modulation as an intermediate step
- H03M3/478—Means for controlling the correspondence between the range of the input signal and the range of signals the converter can handle; Means for out-of-range indication
- H03M3/488—Means for controlling the correspondence between the range of the input signal and the range of signals the converter can handle; Means for out-of-range indication using automatic control
- H03M3/49—Means for controlling the correspondence between the range of the input signal and the range of signals the converter can handle; Means for out-of-range indication using automatic control in feedback mode, i.e. by determining the range to be selected from one or more previous digital output values
Definitions
- International Patent Application WO 98/16014 discloses a data compression apparatus for data compressing an audio signal.
- the data compression apparatus comprises an input terminal for receiving the audio signal, a 1-bit A/D converter for A/D converting the audio signal so as to obtain a bitstream signal, a lossless coder for carrying out a lossless data compression step on the bit-stream signal so as to obtain a data compressed bit-stream signal, and an output terminal for supplying the data compressed bit-stream signal.
- a recording apparatus and a transmitter apparatus comprising the data compression apparatus are disclosed.
- a data expansion apparatus for data expanding the data compressed bit-stream signal supplied by the data compression apparatus is disclosed, as well as a reproducing apparatus and a receiver apparatus comprising the data expansion apparatus.
- the invention provides a method and device for estimating a compression gain, a recording apparatus and a transmitter as defined in the independent claims.
- Advantageous embodiments are defined in the dependent claims.
- a compression gain estimation can be used in authoring and/or editing of audio signal sequences such as music pieces. It may be used for control of signal processing parameters, such as adaptive control of the compression ratio by compressive encoding, to allow recording of the content of e.g. a music piece within the limited maximum storage content of a recording medium such as a Super Audio Compact Disc (SACD) by providing a quick estimate of the amount of data that can be stored or recorded on the storage or recording medium.
- SACD Super Audio Compact Disc
- an advantageous estimate of the obtainable compression gain is obtained by extraction of a signal power contained in a selected frequency band of the audio signal and obtaining said estimate by correlation with the extracted signal power.
- This aspect of the invention is based on the insight that a quick estimate of the compression ratio or coding gain can be obtained by using a correlation between the signal power of an audio signal and the compression gain.
- This aspect is especially advantageous in losslessly compressing 1 bit bit-stream signals e.g. in Direct Stream Digital format.
- FIG. 1 is a graphic representation of the relationship between compression gain and signal power in a selected frequency band of an audio signal
- FIG. 2 is a simplified block diagram of a digital audio signal recording or transmission chain incorporating an embodiment of a signal processing apparatus according to the invention.
- FIG. 3 a simplified topology diagram of a 5th order sigma-delta modulator for use in the signal processor in the block diagram in FIG. 2.
- an input audio signal which may be an analog or a digital signal is supplied to a signal processor 1 , in which the input audio signal is processed in dependence of at least one variable processing parameter determined by a parameter control device 2 .
- the control signal generated by the control device 2 controls adaptation of an adaptive sigma-delta modulator 3 , which produces a data-stream signal in the so-called DSD (Direct Stream Digital) format, such as a 1 bit bit-stream signal, as output signal from the signal processor 1 to be sup-plied to the lossless encoder 4 .
- DSD Direct Stream Digital
- the compression gain obtained in the encoder 4 may be significantly affected by variation of the variable parameter used for control of the signal processor 1 , which in result may strongly affect the amount of data that can be recorded or stored by the recording medium, which is represented in FIG. 2 by a SACD recording on a DVD disc 5 .
- a correlation as represented in FIG. 1 between the signal power of the bit-stream signal in the DSD format and the compression gain is used to provide a quick and accurate estimate of the coding gain.
- the signal power may be extracted from the bit-stream signal by an extraction and correlation device 6 connected with the output from the signal processor 1 and supplying the compression ratio or coding gain estimate as an input control signal to the parameter control device 2 .
- the parameter controlled component of the signal processor 1 may typically be an adaptive sigma-delta modulator 3 and several approaches can be used for adaptation or modification of the structure of such a sigma-delta modulator such as shifting between sigma-delta modulator structures of different order or creation of structure in the high frequency noise of the modulator.
- the diagram in FIG. 3 shows a preferred topology of a 5th order sigma-delta modulator for use in the signal processor 1 in FIG. 2.
- the illustrated topology is based on a multiple resonator structure, in which the coefficients c 1 , c 2 , . . . c 5 in the feed-back loops of resonators R 1 , R 2 , . . . R 5 determine the poles of the loop filters (or zeroes of the noise transfer function).
- the illustrated topology is for a 5th order modulator the same topology may be used for a 7th order modulator just by adding another resonator structure.
- poles will normally be positioned in the audio band, According to the invention it is preferred, however, to have at least one pole positioned outside the audio band to create additional structure in the—otherwise almost flat—high frequency part of the sigma-delta spectrum.
- the last pole is, in accordance with the invention, preferably shifted from the 20 kHz region to a higher frequency region, e.g. around 300 kHz or higher, which may lead to a significant increase of compression gain. Although this may be accompanied by a slight decrease of the signal-to-noise performance, this would normally be quite acceptable, because the extra noise is introduced on the high side of the frequency band, where the human ear is less sensitive.
- the shifting of the pole position from the 20 kHz region towards higher frequencies can be effected by addition of a separate extra band pass filter to the existing modulator structure, e.g. in parallel to the low-pass loop filter.
- a separate extra band pass filter to the existing modulator structure, e.g. in parallel to the low-pass loop filter.
- a 2nd order Butter-worth band pass filter for such a parallel filter a significant increase of compression gain can be realized with the resulting modulator remaining stable for large inputs and the signal-to-noise performance in the audio band remaining virtually unchanged with respect to an unmodified modulator.
- a fixed sigma-delta modulator may be incorporated as a final processing device be-fore the lossless encoder 4 as shown by the block 7 drawn in dashed lines in FIG. 2.
- the signal power should preferably be extracted from the signal supplied from the fixed sigma-delta modulator 7 to the lossless encoder 4 .
- an adaptive sigma-delta modulator is used to adapt or modify the compression ratio or coding gain in response to the correlation obtained from the signal power of the bit-stream signal
- other approaches such as reduction of the signal level of incorporation of a bandwidth limiting low-pass filter in the signal processor before a sigma-delta modulator, that may be adaptive or fixed, may be used either separately or in combination.
- a signal processing apparatus for carrying out the method according to embodiments of the invention need not by itself comprise compressive encoding means, in as much as the estimate of the compression ratio obtainable in subsequent compressive encoding may be used separately, e.g. in a studio environment for pure evaluation, formatting, authoring and/or editing of an audio signal sequence.
Abstract
Estimating a compression gain obtainable in compressing a given audio signal, comprising extracting a signal power in a selected frequency band of the given audio signal, and obtaining an estimation of the compression gain by correlation with the extracted signal power.
Description
- International Patent Application WO 98/16014 discloses a data compression apparatus for data compressing an audio signal. The data compression apparatus comprises an input terminal for receiving the audio signal, a 1-bit A/D converter for A/D converting the audio signal so as to obtain a bitstream signal, a lossless coder for carrying out a lossless data compression step on the bit-stream signal so as to obtain a data compressed bit-stream signal, and an output terminal for supplying the data compressed bit-stream signal. Further, a recording apparatus and a transmitter apparatus comprising the data compression apparatus are disclosed. In addition, a data expansion apparatus for data expanding the data compressed bit-stream signal supplied by the data compression apparatus is disclosed, as well as a reproducing apparatus and a receiver apparatus comprising the data expansion apparatus.
- It is an object of the invention to provide advantageous compression gain estimation in audio compressing. To this end the invention provides a method and device for estimating a compression gain, a recording apparatus and a transmitter as defined in the independent claims. Advantageous embodiments are defined in the dependent claims.
- A compression gain estimation can be used in authoring and/or editing of audio signal sequences such as music pieces. It may be used for control of signal processing parameters, such as adaptive control of the compression ratio by compressive encoding, to allow recording of the content of e.g. a music piece within the limited maximum storage content of a recording medium such as a Super Audio Compact Disc (SACD) by providing a quick estimate of the amount of data that can be stored or recorded on the storage or recording medium.
- Theoretically, to produce such an estimate it could be envisaged to use the average actual compression ratio or coding gain for a small fraction of an audio signal sequence such as a piece of music as an indication of the compression ratio for the entire sequence. Such an approach would suffer, however, from the problem that typical audio signal sequences in the form of music pieces have a rather wide variation of compression ratios or coding gains with significant short-time correlations, whereby a very significant fraction of the signal sequence would have to be used for obtaining a compression ratio estimate having the required level of precision or accuracy. Due to the required time for computation such a solution would in practice not be acceptable.
- According to a first aspect of the invention an advantageous estimate of the obtainable compression gain is obtained by extraction of a signal power contained in a selected frequency band of the audio signal and obtaining said estimate by correlation with the extracted signal power. This aspect of the invention is based on the insight that a quick estimate of the compression ratio or coding gain can be obtained by using a correlation between the signal power of an audio signal and the compression gain. This aspect is especially advantageous in losslessly compressing 1 bit bit-stream signals e.g. in Direct Stream Digital format.
- It is noted that from standard PCM coding it is known that the attainable coding gain is directly related to the degree of structure (flatness) in the signal power. However, in the above aspect of the invention the signal power itself is used, not its structure.
- In the following the invention will be further explained with reference to the accompanying drawings, in which
- FIG. 1 is a graphic representation of the relationship between compression gain and signal power in a selected frequency band of an audio signal,
- FIG. 2 is a simplified block diagram of a digital audio signal recording or transmission chain incorporating an embodiment of a signal processing apparatus according to the invention, and
- FIG. 3 a simplified topology diagram of a 5th order sigma-delta modulator for use in the signal processor in the block diagram in FIG. 2.
- Whereas investigations for a lossless encoder have demonstrated that in the audio signal band itself, e.g. up to 20 kHz a relatively flat response curve exists for the compression ratio as function of the signal power, a significant steep response of the compression gain cg in dependence of the signal power sp is obtained for a signal band outside the audio signal band, e.g. as illustrated in FIG. 1 for the signal band from 20 to 50 kHz.
- In the signal processing apparatus represented by the block diagram in FIG. 2 this distinctive correlation is used to obtain an estimate of the compression ratio or coding gain obtained by lossless encoding. An input audio signal, which may be an analog or a digital signal is supplied to a signal processor1, in which the input audio signal is processed in dependence of at least one variable processing parameter determined by a
parameter control device 2. In the example illustrated, the control signal generated by thecontrol device 2 controls adaptation of an adaptive sigma-delta modulator 3, which produces a data-stream signal in the so-called DSD (Direct Stream Digital) format, such as a 1 bit bit-stream signal, as output signal from the signal processor 1 to be sup-plied to thelossless encoder 4. The compression gain obtained in theencoder 4 may be significantly affected by variation of the variable parameter used for control of the signal processor 1, which in result may strongly affect the amount of data that can be recorded or stored by the recording medium, which is represented in FIG. 2 by a SACD recording on aDVD disc 5. Reference is made to co-pending application of the same applicant entitled ‘Audio signal processing’ having the same priority date as this application. - According to an embodiment of the invention a correlation as represented in FIG. 1 between the signal power of the bit-stream signal in the DSD format and the compression gain is used to provide a quick and accurate estimate of the coding gain. As shown the signal power may be extracted from the bit-stream signal by an extraction and
correlation device 6 connected with the output from the signal processor 1 and supplying the compression ratio or coding gain estimate as an input control signal to theparameter control device 2. - As shown the parameter controlled component of the signal processor1 may typically be an adaptive sigma-delta modulator 3 and several approaches can be used for adaptation or modification of the structure of such a sigma-delta modulator such as shifting between sigma-delta modulator structures of different order or creation of structure in the high frequency noise of the modulator.
- Thus, by shifting between modulator structures of the 3rd, 5th or 7th order compression ratios may be obtained ranging typically from about 3.7 for a 3rd order structure down to only 2.3 or lower for a 7th order structure and this can be used to shape the amount of data in the compressed bit-stream signal from the
encoder 4 to fit within the limited record-ing or storage capacity of the recording medium such as theDVD disc 5. - The diagram in FIG. 3 shows a preferred topology of a 5th order sigma-delta modulator for use in the signal processor1 in FIG. 2. The illustrated topology is based on a multiple resonator structure, in which the coefficients c1, c2, . . . c5 in the feed-back loops of resonators R1, R2, . . . R5 determine the poles of the loop filters (or zeroes of the noise transfer function). Whereas the illustrated topology is for a 5th order modulator the same topology may be used for a 7th order modulator just by adding another resonator structure.
- In ordinary design of a such a sigma-delta modulator the poles will normally be positioned in the audio band, According to the invention it is preferred, however, to have at least one pole positioned outside the audio band to create additional structure in the—otherwise almost flat—high frequency part of the sigma-delta spectrum.
- Thus, whereas in standard designs of sigma-delta modulators the poles are typically positioned at 8.7, 15.7 and 19.5 kHz, the last pole is, in accordance with the invention, preferably shifted from the 20 kHz region to a higher frequency region, e.g. around 300 kHz or higher, which may lead to a significant increase of compression gain. Although this may be accompanied by a slight decrease of the signal-to-noise performance, this would normally be quite acceptable, because the extra noise is introduced on the high side of the frequency band, where the human ear is less sensitive.
- The shifting of the pole position from the 20 kHz region towards higher frequencies can be effected by addition of a separate extra band pass filter to the existing modulator structure, e.g. in parallel to the low-pass loop filter. By use of a 2nd order Butter-worth band pass filter for such a parallel filter a significant increase of compression gain can be realized with the resulting modulator remaining stable for large inputs and the signal-to-noise performance in the audio band remaining virtually unchanged with respect to an unmodified modulator.
- To take account of the fact that shifting between different sigma-delta modulator structures may cause variation in the relation between the signal power in a certain frequency band of the bit-stream signal and the compression ratio or coding gain and may thereby affect the correlation used as basis for the estimation of the compression ratio, it may be advantageous to use an initial calibration process to fix the correlation.
- For this purpose a fixed sigma-delta modulator may be incorporated as a final processing device be-fore the
lossless encoder 4 as shown by theblock 7 drawn in dashed lines in FIG. 2. Thereby, the signal power should preferably be extracted from the signal supplied from the fixed sigma-delta modulator 7 to thelossless encoder 4. - Whereas in the signal processor embodiment described above and shown in FIG. 2 an adaptive sigma-delta modulator is used to adapt or modify the compression ratio or coding gain in response to the correlation obtained from the signal power of the bit-stream signal other approaches, such as reduction of the signal level of incorporation of a bandwidth limiting low-pass filter in the signal processor before a sigma-delta modulator, that may be adaptive or fixed, may be used either separately or in combination.
- Moreover, a signal processing apparatus for carrying out the method according to embodiments of the invention need not by itself comprise compressive encoding means, in as much as the estimate of the compression ratio obtainable in subsequent compressive encoding may be used separately, e.g. in a studio environment for pure evaluation, formatting, authoring and/or editing of an audio signal sequence.
- It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other elements or steps than those listed in a claim. The invention can be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
Claims (11)
1. A method of estimating a compression gain obtainable in compressing a given audio signal, the method comprising the steps of:
extracting a signal power in a selected frequency band of the given audio signal, and
obtaining an estimation of the compression gain by correlation with the extracted signal power.
2. A method as claimed in claim 1 , wherein the audio signal is a 1-bit noise shaped digital signal.
3. A method as claimed in claim 1 , wherein the compressing is lossless.
4. A method as claimed in claim 1 , wherein said selected frequency band is above 20 kHz.
5. A method as claimed in claim 4 , wherein said selected frequency band is from 20 to 50 kH.
6. A method of recording an audio signal on a recording medium, the method comprising the steps of:
compressing the audio signal to obtain a compressed audio signal,
recording the compressed audio signal on the recording medium,
the method further comprising:
estimating a compression gain obtainable in the compressing step by extracting a signal power in a selected frequency band of the audio signal, and obtaining an estimation of the compression gain by correlation with the extracted signal power,
controlling said compressing depending on said estimated compression gain.
7. A method as claimed in claim 6 , wherein said compressing step comprises:
converting the audio signal into a digital signal by an adaptive noise-shaping modulation in response to the estimated compression gain,
8. A method of transmitting an audio signal, the method comprising the steps of:
compressing the audio signal to obtain a compressed audio signal,
transmitting the compressed audio signal over a transmission medium,
the method further comprising:
estimating a compression gain obtainable in the compressing step by extracting a signal power in a selected frequency band of the audio signal, and obtaining an estimation of the compression gain by correlation with the extracted signal power,
controlling said compressing depending on said estimated compression gain.
9. A device for estimating a compression gain obtainable in compressing a given audio signal, the device comprising:
means for extracting a signal power in a selected frequency band of the given audio signal, and
means for obtaining an estimation of the compression gain by correlation with the extracted signal power.
10. A recording apparatus for recording an audio signal on a recording medium, the recording apparatus comprising:
means for compressing the audio signal to obtain a compressed audio signal,
means for recording the compressed audio signal on the recording medium,
the recording apparatus further comprising:
a device as claimed in claim 9 for estimating a compression gain obtainable in the compressing,
means for controlling said compressing depending on said estimated compression gain.
11. A transmitter for transmitting an audio signal, the transmitter comprising:
means for compressing the audio signal to obtain a compressed audio signal,
means for transmitting the compressed audio signal over a transmission medium,
the transmitter further comprising:
a device as claimed in claim 9 for estimating a compression gain obtainable in the compressing,
means for controlling said compressing depending on said estimated compression gain.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP00203097 | 2000-09-08 | ||
EP00203097.1 | 2000-09-08 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20040230427A1 true US20040230427A1 (en) | 2004-11-18 |
Family
ID=8171989
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/129,695 Expired - Fee Related US6819275B2 (en) | 2000-09-08 | 2001-09-06 | Audio signal compression |
US10/129,692 Abandoned US20020165631A1 (en) | 2000-09-08 | 2001-09-06 | Audio signal processing with adaptive noise-shaping modulation |
US10/868,258 Abandoned US20040230427A1 (en) | 2000-09-08 | 2004-06-15 | Audio signal compression |
Family Applications Before (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/129,695 Expired - Fee Related US6819275B2 (en) | 2000-09-08 | 2001-09-06 | Audio signal compression |
US10/129,692 Abandoned US20020165631A1 (en) | 2000-09-08 | 2001-09-06 | Audio signal processing with adaptive noise-shaping modulation |
Country Status (8)
Country | Link |
---|---|
US (3) | US6819275B2 (en) |
EP (2) | EP1328938A1 (en) |
JP (2) | JP2004508755A (en) |
KR (2) | KR20020051933A (en) |
CN (2) | CN1308949C (en) |
AU (1) | AU2001285936A1 (en) |
BR (1) | BR0107191A (en) |
WO (2) | WO2002021525A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130060803A1 (en) * | 2010-05-17 | 2013-03-07 | Green Sql Ltd | Database translation system and method |
US10193565B2 (en) | 2015-03-03 | 2019-01-29 | Sony Corporation | Compressive encoding apparatus, compressive encoding method, decoding apparatus, decoding method, and program |
RU2756042C2 (en) * | 2013-09-30 | 2021-09-24 | Конинклейке Филипс Н.В. | Resampling of an audio signal for low-latency encoding/decoding |
Families Citing this family (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20020051933A (en) * | 2000-09-08 | 2002-06-29 | 요트.게.아. 롤페즈 | Audio signal processing with adaptive noise-shaping modulation |
EP1520361A1 (en) * | 2002-06-28 | 2005-04-06 | Koninklijke Philips Electronics N.V. | Adaptive rate matching method |
US8718298B2 (en) * | 2003-12-19 | 2014-05-06 | Lear Corporation | NVH dependent parallel compression processing for automotive audio systems |
CA2457988A1 (en) * | 2004-02-18 | 2005-08-18 | Voiceage Corporation | Methods and devices for audio compression based on acelp/tcx coding and multi-rate lattice vector quantization |
US7009540B1 (en) * | 2005-01-04 | 2006-03-07 | Faraday Technology Corp. | Method for designing a noise shaper with a single loop distributed feedback delta-sigma modulator |
US20070147518A1 (en) * | 2005-02-18 | 2007-06-28 | Bruno Bessette | Methods and devices for low-frequency emphasis during audio compression based on ACELP/TCX |
US8249861B2 (en) * | 2005-04-20 | 2012-08-21 | Qnx Software Systems Limited | High frequency compression integration |
US8086451B2 (en) | 2005-04-20 | 2011-12-27 | Qnx Software Systems Co. | System for improving speech intelligibility through high frequency compression |
US7813931B2 (en) * | 2005-04-20 | 2010-10-12 | QNX Software Systems, Co. | System for improving speech quality and intelligibility with bandwidth compression/expansion |
WO2006129215A2 (en) * | 2005-05-30 | 2006-12-07 | Koninklijke Philips Electronics N.V. | Direct stream digital audio with minimal storage requirement |
US7289050B1 (en) * | 2005-06-27 | 2007-10-30 | Qualcomm Incorporated | Amplification method and apparatus |
KR101001115B1 (en) * | 2005-06-27 | 2010-12-14 | 퀄컴 인코포레이티드 | Methods and apparatus for implementing and using amplifiers for performing various amplification related operations |
US20080000431A1 (en) * | 2006-06-29 | 2008-01-03 | Stephen Longo | Dog leash assembly |
JP2010513940A (en) * | 2006-06-29 | 2010-04-30 | エヌエックスピー ビー ヴィ | Noise synthesis |
TW200813816A (en) * | 2006-09-11 | 2008-03-16 | Princeton Technology Corp | Optimal parameter adjusting method and system |
BRPI0720266A2 (en) * | 2006-12-13 | 2014-01-28 | Panasonic Corp | AUDIO DECODING DEVICE AND POWER ADJUSTMENT METHOD |
CN101179716B (en) * | 2007-11-30 | 2011-12-07 | 华南理工大学 | Audio automatic gain control method for transmission data flow of compression field |
BR112018073621A2 (en) * | 2016-05-24 | 2019-02-26 | Sony Corporation | apparatus and method of compression / coding, program, and apparatus and method of decoding |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5594598A (en) * | 1992-10-19 | 1997-01-14 | Canon Kabushiki Kaisha | Information recording apparatus having variable compression ratio |
US5835043A (en) * | 1996-04-24 | 1998-11-10 | Sony Corporation | Signal processing apparatus, signal recording apparatus, and signal reproducing apparatus |
US6097824A (en) * | 1997-06-06 | 2000-08-01 | Audiologic, Incorporated | Continuous frequency dynamic range audio compressor |
US6426934B1 (en) * | 1998-10-09 | 2002-07-30 | Sony Corporation | One-bit data reproducing system having controllable low pass filter characteristics |
US20030081804A1 (en) * | 2001-08-08 | 2003-05-01 | Gn Resound North America Corporation | Dynamic range compression using digital frequency warping |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2744006B2 (en) * | 1988-03-15 | 1998-04-28 | 株式会社東芝 | Nonlinear A / D conversion circuit and non-linear A / D conversion method |
JPH0311811A (en) * | 1989-06-09 | 1991-01-21 | Fujitsu Ltd | Adaptive type noise shaping filter |
JP3465401B2 (en) * | 1994-03-03 | 2003-11-10 | ソニー株式会社 | Audio signal processing device and audio recording device |
US5608400A (en) * | 1995-08-24 | 1997-03-04 | Martin Marietta Corporation | Selectable intermediate frequency sigma-delta analog-to-digital converter |
US6434246B1 (en) * | 1995-10-10 | 2002-08-13 | Gn Resound As | Apparatus and methods for combining audio compression and feedback cancellation in a hearing aid |
US6269338B1 (en) * | 1996-10-10 | 2001-07-31 | U.S. Philips Corporation | Data compression and expansion of an audio signal |
PT1603244E (en) * | 1996-11-07 | 2007-11-23 | Koninkl Philips Electronics Nv | Transmitting of a bitstream signal |
JP3328532B2 (en) * | 1997-01-22 | 2002-09-24 | シャープ株式会社 | Digital data encoding method |
JP2001501421A (en) * | 1997-06-04 | 2001-01-30 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | Data compression and expansion of n-level information signal |
JP3807036B2 (en) * | 1997-07-17 | 2006-08-09 | ソニー株式会社 | Digital data processing apparatus and method |
US6218972B1 (en) * | 1997-09-11 | 2001-04-17 | Rockwell Science Center, Inc. | Tunable bandpass sigma-delta digital receiver |
US6311153B1 (en) * | 1997-10-03 | 2001-10-30 | Matsushita Electric Industrial Co., Ltd. | Speech recognition method and apparatus using frequency warping of linear prediction coefficients |
US5966688A (en) * | 1997-10-28 | 1999-10-12 | Hughes Electronics Corporation | Speech mode based multi-stage vector quantizer |
GB2341763B (en) * | 1998-09-15 | 2000-09-13 | 3Com Technologies Ltd | Data receiver including hybrid decision feedback equalizer |
US6326912B1 (en) * | 1999-09-24 | 2001-12-04 | Akm Semiconductor, Inc. | Analog-to-digital conversion using a multi-bit analog delta-sigma modulator combined with a one-bit digital delta-sigma modulator |
KR20020051933A (en) | 2000-09-08 | 2002-06-29 | 요트.게.아. 롤페즈 | Audio signal processing with adaptive noise-shaping modulation |
-
2001
- 2001-09-06 KR KR1020027005952A patent/KR20020051933A/en not_active Application Discontinuation
- 2001-09-06 CN CNB01802646XA patent/CN1308949C/en not_active Expired - Fee Related
- 2001-09-06 WO PCT/EP2001/010336 patent/WO2002021525A1/en not_active Application Discontinuation
- 2001-09-06 JP JP2002525656A patent/JP2004508755A/en not_active Withdrawn
- 2001-09-06 EP EP01978350A patent/EP1328938A1/en not_active Withdrawn
- 2001-09-06 JP JP2002525655A patent/JP4950407B2/en not_active Expired - Fee Related
- 2001-09-06 WO PCT/EP2001/010340 patent/WO2002021526A1/en active Application Filing
- 2001-09-06 BR BR0107191-2A patent/BR0107191A/en not_active IP Right Cessation
- 2001-09-06 KR KR1020027005886A patent/KR20020052203A/en not_active Application Discontinuation
- 2001-09-06 US US10/129,695 patent/US6819275B2/en not_active Expired - Fee Related
- 2001-09-06 CN CN01802647A patent/CN1388965A/en active Pending
- 2001-09-06 US US10/129,692 patent/US20020165631A1/en not_active Abandoned
- 2001-09-06 AU AU2001285936A patent/AU2001285936A1/en not_active Abandoned
- 2001-09-06 EP EP01965265A patent/EP1317754A1/en not_active Withdrawn
-
2004
- 2004-06-15 US US10/868,258 patent/US20040230427A1/en not_active Abandoned
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5594598A (en) * | 1992-10-19 | 1997-01-14 | Canon Kabushiki Kaisha | Information recording apparatus having variable compression ratio |
US5835043A (en) * | 1996-04-24 | 1998-11-10 | Sony Corporation | Signal processing apparatus, signal recording apparatus, and signal reproducing apparatus |
US6097824A (en) * | 1997-06-06 | 2000-08-01 | Audiologic, Incorporated | Continuous frequency dynamic range audio compressor |
US6426934B1 (en) * | 1998-10-09 | 2002-07-30 | Sony Corporation | One-bit data reproducing system having controllable low pass filter characteristics |
US20030081804A1 (en) * | 2001-08-08 | 2003-05-01 | Gn Resound North America Corporation | Dynamic range compression using digital frequency warping |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130060803A1 (en) * | 2010-05-17 | 2013-03-07 | Green Sql Ltd | Database translation system and method |
US9135297B2 (en) * | 2010-05-17 | 2015-09-15 | Green Sql Ltd. | Database translation system and method |
RU2756042C2 (en) * | 2013-09-30 | 2021-09-24 | Конинклейке Филипс Н.В. | Resampling of an audio signal for low-latency encoding/decoding |
US10193565B2 (en) | 2015-03-03 | 2019-01-29 | Sony Corporation | Compressive encoding apparatus, compressive encoding method, decoding apparatus, decoding method, and program |
Also Published As
Publication number | Publication date |
---|---|
KR20020052203A (en) | 2002-07-02 |
JP4950407B2 (en) | 2012-06-13 |
EP1317754A1 (en) | 2003-06-11 |
CN1388964A (en) | 2003-01-01 |
WO2002021525A1 (en) | 2002-03-14 |
AU2001285936A1 (en) | 2002-03-22 |
US20020163455A1 (en) | 2002-11-07 |
US6819275B2 (en) | 2004-11-16 |
EP1328938A1 (en) | 2003-07-23 |
CN1308949C (en) | 2007-04-04 |
WO2002021526A1 (en) | 2002-03-14 |
KR20020051933A (en) | 2002-06-29 |
US20020165631A1 (en) | 2002-11-07 |
JP2004508755A (en) | 2004-03-18 |
JP2004508598A (en) | 2004-03-18 |
BR0107191A (en) | 2002-07-16 |
CN1388965A (en) | 2003-01-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6819275B2 (en) | Audio signal compression | |
KR100603894B1 (en) | Apparatus and method for data compression and restoration of audio signals | |
CA2418722A1 (en) | Modulating one or more parameters of an audio or video perceptual coding system in response to supplemental information | |
KR101207110B1 (en) | A method of encoding scalable lossless bitstream | |
US6778965B1 (en) | Data compression and expansion of an audio signal | |
EP1259956B1 (en) | Method of and apparatus for converting an audio signal between data compression formats | |
US5706308A (en) | Signal processing apparatus and method for sigma-delta modulated signals including gain adjustment | |
US20070118362A1 (en) | Audio compression/decompression device | |
KR100577464B1 (en) | Transmission Apparatus and Reproduction Apparatus | |
JPH0738437A (en) | Codec device | |
JPH1083198A (en) | Digital signal processing method and device therefor | |
JP2007181208A (en) | Apparatus for data compression and expansion of audio signal | |
JPH05160742A (en) | Audio signal coder | |
JP2000113655A (en) | Signal level meter and signal processor equipped with signal level meter | |
JPH03265308A (en) | Data compression coding device | |
KR20070020584A (en) | Apparatus for writing and playing audio and audio coding method in the apparatus |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |