Digital audio data transmission system based on the information content of an audio signal
First Claim
1. Apparatus for encoding digital audio information formed of audio signals including speech signals and non-speech signals, comprising:
- means for generating a selection signal indicative of the speech signal and the non-speech signal;
means for separately encoding the speech and non-speech signals present in the audio information with optimum compression based on the energy contents of the signals;
means responsive to the selection signal for providing an identification signal indicative of the audio signals for inclusion with selected audio signals; and
means for intermingling the encoded speech signal, and the encoded non-speech signal and the identification signal in response to the selection signal.
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Accused Products
Abstract
The data rate of speech and non-speech audio is selectively reduced by respective compression techniques based upon the information content of the type of signal. A composite audio information signal formed of speech and non-speech audio is applied to both a voice encoder and a wide-band audio compression encoder. An audio-type detection circuit examines the speech spectrum as well as the entire frequency spectrum and dynamic range of the audio information and generates a selection signal indicating whether the signal is speech or non-speech audio. A composite encoded audio signal is produced by intermingling the outputs of the encoders in response to the selection signal. The composite encoded audio signal and an identification signal indicative of the audio signal type are transmitted to respective receivers at the reduced data rates for storage, and subsequent decoding and retrieval by a listener as an audible signal in response to the transmitted identification signal.
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Citations
108 Claims
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1. Apparatus for encoding digital audio information formed of audio signals including speech signals and non-speech signals, comprising:
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means for generating a selection signal indicative of the speech signal and the non-speech signal; means for separately encoding the speech and non-speech signals present in the audio information with optimum compression based on the energy contents of the signals; means responsive to the selection signal for providing an identification signal indicative of the audio signals for inclusion with selected audio signals; and means for intermingling the encoded speech signal, and the encoded non-speech signal and the identification signal in response to the selection signal. - View Dependent Claims (2, 3, 4, 5)
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6. Apparatus for encoding digital audio information formed of audio signals including speech signals and non-speech signals, comprising:
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means responsive to a selection signal for providing an identification signal indicative of the audio signals for inclusion with selected audio signals; means for intermingling the speech signal, the non-speech signal, and the identification signal in response to the selection signal; first means for generating a first signal indicative of a speech signal; logic for generating the selection signal in response to the first signal and a second signal; a filter for passing a passband signal in a frequency range which contains maximum speech energy; means responsive to the passband signal and the audio information for providing a third signal representing a level of frequency components outside a range of the speech signal; and means responsive to the third signal and to a predetermined threshold level for producing the second signal indicative of a level of energy in the third signal. - View Dependent Claims (7, 8, 9, 10)
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11. Apparatus for encoding digital audio information formed of audio signals including speech signals and non-speech signals, comprising:
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means for generating a selection signal indicative of the speech signal and the non-speech signal; means responsive to the selection signal for providing an identification signal indicative of the audio signals for inclusion with selected audio signals; means for intermingling encoded speech signal, the encoded non-speech signal, and the identification signal in response to the selection signal; a voice encoder for encoding the speech signal; and a wide-band audio compression encoder for encoding the non-speech signal.
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12. Apparatus for encoding digital audio information formed of audio signals including speech signals and non-speech signals, comprising:
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means for generating a selection signal indicative of the speech signal and the non-speech signal; means responsive to the selection signal for providing an identification signal indicative of the audio signals for inclusion with selected audio signals; means for intermingling the speech signal, the non-speech signal, and the identification signal in response to the selection signal; a timing generator means responsive to the selection signal for synchronizing the identification signal with the occurrence of the audio signals; and a latch responsive to the timing generator means for providing the identification signal. - View Dependent Claims (13)
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14. Apparatus for encoding digital audio information formed of audio signals including speech signals and non-speech signals, comprising:
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means responsive to a selection signal for providing an identification signal indicative of the audio signals for inclusion with selected audio signals; and means for intermingling the speech signal, the non-speech signal, and the identification signal in response to the selection signal; a voice encoder for receiving and compressing the audio signals; means for generating reconstructed voice coded signals from the compressed audio signals; means for comparing the accuracy of the reconstructed voice coded signals with the audio signals; and means for generating the selection signal indicative of a speech signal in response to an accurate comparison between the reconstructed audio signals and the audio signals and for generating a selection signal indicative of a non-speech signal in response to a significant inaccuracy in the comparison. - View Dependent Claims (15)
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16. Apparatus for reducing the transmission data rate of digital audio information formed of speech signals and non-speech signals, comprising:
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means for detecting whether the information is a speech or a non-speech signal and for generating a selection signal indicative thereof; means for separately encoding the speech and non-speech signals with respective optimum compression based on the information energy content of the signals; means responsive to the detecting and generating means for producing a signal identifying the speech signal and the non-speech signal; and means for intermingling the encoded speech signal and the encoded non-speech signal in response to the selection signal, for transmission at said reduced data rate. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. Apparatus for decoding digital audio information formed of signals such as speech signals and non-speech signals, the audio information including a signal identifying the speech and non-speech signals, comprising:
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means for receiving combined speech, non-speech and identifying signals; means for separating the identifying signal from the speech and non-speech signals; and a decoder for separately decoding the speech and non-speech signals into a reassembled audio signal in response to the identifying signal, for audible presentation of the reassembled audio. - View Dependent Claims (27, 28)
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29. Apparatus for encoding digital audio information formed of audio signals such as speech signals and non-speech signals, comprising:
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a generator which provides a selection signal indicative of the speech signal and the non-speech signal; an encoder that separately encodes the speech and non-speech signals present in the audio information with optimum compression based on the information energy content of the signals; a circuit responsive to the selection signal that provides an identification signal indicative of the audio signals for inclusion with selected audio signals; and a multiplexer coupled to receive the encoded speech signal, the encoded non-speech signal, and the identification signal that intermingles the encoded speech signal, the encoded non-speech signal and the identification signal in response to the selection signal. - View Dependent Claims (30, 31, 32, 33)
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34. Apparatus for encoding digital audio information formed of audio signals including speech signals and non-speech signals, comprising:
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a generator coupled to receive first and second signals that generates a selection signal indicative of speech and non-speech signals; a circuit responsive to the selection signal that provides an identification signal indicative of the audio signals for inclusion with selected audio signals; a multiplexer coupled to receive the speech signal, the non-speech signal, and the identification signal that intermingles the speech signal, the non-speech signal, and the identification signal in response to the selection signal; a first circuit that generates the first signal indicative of a speech signal; a filter that passes a passband signal in a frequency range which contains maximum speech energy; a third circuit responsive to the passband signal and the audio information that provides a third signal representing a level of frequency components outside the range of the speech signal; and a logic responsive to the third signal and to a predetermined threshold level for producing the second signal indicative of the level of energy in the third signal. - View Dependent Claims (35, 36, 37, 38)
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39. Apparatus for encoding digital audio information formed of audio signals such as speech signals and non-speech signals, comprising:
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a generator which provides a selection signal indicative of the speech signal and the non-speech signal; a circuit responsive to the selection signal that provides an identification signal indicative of the audio signals for inclusion with selected audio signals; a multiplexer coupled to receive an encoded speech signal, an encoded non-speech signal, and the identification signal that intermingles the encoded speech signal, the encoded non-speech signal, and the identification signal in response to the selection signal; a voice encoder that encodes the speech signal; a wide-band audio compression encoder that encodes the non-speech signal.
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40. Apparatus for encoding digital audio information formed of audio signals such as speech signals and non-speech signals, comprising:
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a generator which provides a selection signal indicative of the speech signal and the non-speech signal; a circuit responsive to the selection signal that provides an identification signal indicative of the audio signals for inclusion with selected audio signals; a multiplexer coupled to receive the speech signal, the non-speech signal, and the identification signal that intermingles the speech signal, the non-speech signal, and the identification signal in response to the selection signal; a timing generator that synchronizes the identification signal with the occurrence of the speech and non-speech signals; and a latch responsive to the timing generator that provides the identification signal. - View Dependent Claims (41)
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42. Apparatus for encoding digital audio information formed of audio signals such as speech signals and non-speech signals, comprising:
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a circuit responsive to a selection signal that provides an identification signal indicative of the audio signals for inclusion with selected audio signals; a multiplexer coupled to receive the speech signal, the non-speech signal, and the identification signal that intermingles the speech signal, the non-speech signal, and the identification signal in response to a selection signal; a voice encoder that receives and compresses the audio signals; a comparator that compares the accuracy of reconstructed voice coded signals generated from the compressed audio signals with the audio signals; and a generator that generates the selection signal indicative of a speech signal in response to an accurate comparison between the reconstructed audio signals and the audio signals and that generates the selection signal indicative of a non-speech signal in response to a significant inaccuracy in the comparison. - View Dependent Claims (43)
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44. Method for encoding digital audio information formed of audio signals including speech signals and non-speech signals, comprising the steps:
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generating a selection signal indicative of the speech signal and the non-speech signal; separately encoding the speech and non-speech signals present in the audio information with optimum compression based on the energy contents of the signals; providing an identification signal indicative of the audio signals for inclusion with selected audio signals in response to the selection signal; and intermingling the encoded speech signal, the encoded non-speech signal, and the identification signal in response to the selection signal. - View Dependent Claims (45, 46, 47)
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48. Method for encoding digital audio information formed of audio signals including speech signals and non-speech signals, comprising the steps of:
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generating a first signal indicative of the speech signal; filtering out signals except a passband signal in a frequency range which contains maximum speech energy; providing a third signal responsive to the passband signal and the audio information representing a level of frequency components outside the range of the speech signal; generating a second signal responsive to the third signal indicative of the non-speech signal; generating a selection signal indicative of the speech signal and the non-speech signal in response to the first and second signals; separately encoding the speech and non-speech signals present in the audio information with optimum compression based on the energy contents of the signals; providing an identification signal indicative of the audio signals for inclusion with selected audio signals in response to the selection signal; and intermingling the encoded speech signal, the encoded non-speech signal, and the identification signal in response to the selection signal. - View Dependent Claims (49, 50, 51, 52)
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53. Method for encoding digital audio information formed of audio signals including speech signals and non-speech signals, the steps comprising:
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generating a selection signal indicative of the speech signal and the non-speech signal; voice encoding the speech signal; wide-band compression encoding the non-speech signal; providing an identification signal indicative of the audio signals for inclusion with selected audio signals in response to the selection signal; and intermingling the encoded speech signal, the encoded non-speech signal, and the identification signal in response to the selection signal.
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54. Method for encoding digital audio information formed of audio signals including speech signals and non-speech signals, the steps comprising:
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generating a selection signal indicative of the speech signal and the non-speech signal; providing an identification signal indicative of the audio signals for inclusion with selected audio signals in response to the selection signal; generating a timing signal responsive to the selection signal for synchronizing the identification signal with the speech and non-speech signals; synchronizing the identification signal with the speech and non-speech signals by use of a latch responsive to the timing signal; and intermingling the speech signal, the non-speech signal, and the identification signal in response to the selection signal. - View Dependent Claims (55)
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56. Method for encoding digital audio information formed of audio signals including speech signals and non-speech signals, the steps comprising:
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voice encoding the audio signals; reconstructing audio signals from the voice encoded audio signals; comparing the accuracy of the reconstructed audio signals with the audio signals; generating a selection signal indicative of a speech signal in response to an accurate reproduction of the audio signals;
orgenerating a selection signal indicative of a non-speech signal in response to an inaccurate reproduction of the audio signals; providing an identification signal indicative of the audio signals for inclusion with selected audio signals in response to the selection signal; and intermingling the speech signal, the non-speech signal, and the identification signal in response to the selection signal. - View Dependent Claims (57)
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58. Apparatus for reducing the transmission data rate of digital audio information formed of speech signals and non-speech signals, comprising:
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a detector coupled to receive the audio information that detects whether the information is a speech or a non-speech signal and generates a selection signal indicative thereof; an encoder coupled to receive the speech and non-speech signals that separately encodes the speech and non-speech signals with respective optimum compression based on the information energy content of the signals; an identifier which is responsive to the selection signal that produces a signal identifying the presence of the speech signal and the non-speech signal in the audio information; and a multiplexer coupled to receive the encoded speech and non-speech signals that intermingles the encoded speech signal and the encoded non-speech signal in response to the selection signal, for transmission at said reduced data rate. - View Dependent Claims (59, 60, 61, 62, 63, 64, 65, 66, 67)
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68. Method of decoding digital audio information formed of speech signals and non-speech signals, the audio information including a signal identifying the speech and non-speech signals, the steps including:
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receiving combined speech and non-speech signals and the identifying signal; separating the identifying signal from the speech and non-speech signals; and intermingling the speech and non-speech signals into a reassembled audio signal in response to the identifying signal, for audible presentation of the reassembled audio. - View Dependent Claims (69, 70)
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71. Apparatus for decoding digital audio information formed of signals such as speech signals and non-speech signals, the audio information including a signal identifying the speech and non-speech signals, comprising:
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a receiver that receives combined speech, non-speech and identifying signals; an identification signal decoder coupled to receive the combined speech, non-speech and identifying signals which separates the identifying signal; and a switch coupled to receive the speech and non-speech signals that reassembles the speech and non-speech signals in response to the identifying signal into an audio signal, for audible presentation. - View Dependent Claims (72, 73)
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74. Apparatus for encoding digital audio information formed of audio signals such as speech signals and music signals, comprising:
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a generator which provides a selection signal indicative of the speech signal and the music signal; a circuit responsive to the selection signal that provides an identification signal indicative of the audio signals for inclusion with selected audio signals; and a multiplexer coupled to receive the speech signal, the music signal, and the identification signal that intermingles the speech signal, the music signal and the identification signal in response to the selection signal. - View Dependent Claims (75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88)
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89. Method for encoding digital audio information formed of audio signals including speech signals and music signals, comprising the steps:
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generating a selection signal indicative of the speech signal and the music signal; providing an identification signal indicative of the audio signals for inclusion with selected audio signals in response to the selection signal; and intermingling the speech signal, the music signal, and the identification signal in response to the selection signal. - View Dependent Claims (90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102)
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103. Apparatus for decoding digital audio information formed of signals such as speech signals and music signals, the audio information including a signal identifying the speech and music signals, comprising:
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a receiver that receives combined speech, music, and identifying signals; an identification signal decoder coupled to receive the combined speech, music and identifying signals which separates the identifying signal; and a switch coupled to receive the speech and music signals that reassembles the speech and music signals in response to the identifying signal into an audio signal, for audible presentation. - View Dependent Claims (104, 105)
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106. Method of decoding digital audio information formed of speech signals and music signals, the audio information including a signal identifying the speech and music signals, the steps including:
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receiving combined speech and music signals and the identifying signal; separating the identifying signal from the speech and music signals; and intermingling the speech and music signals into a reassembled audio signal in response to the identifying signal, for audible presentation of the reassembled audio. - View Dependent Claims (107, 108)
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Specification