System and method for error concealment in digital audio transmission
First Claim
Patent Images
1. A method comprising:
- (a) formatting a stream of audio data provided by a audio source into a sequence of audio data intervals;
(b) transform encoding the sequence of audio data intervals to form a sequence of encoded audio data intervals, each of the encoded audio data intervals having a plurality of transform coefficients;
(c) analyzing the transform coefficients of the sequence of encoded audio data intervals in the sequence so as to identify encoded transient audio data intervals, each of the encoded transient audio data intervals including a short transient signal having first transient signal characteristics; and
(d) embedding ancillary data into encoded audio data intervals preceding the encoded transient audio data intervals, the ancillary data providing notification that the encoded transient audio data intervals include the short transient signals.
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Abstract
A beat-pattern based error concealment system and method which detects drum-like beat patterns of music signals on the encoder side of the system and embeds the beat information as data ancillary to a preceding audio data interval in the transmitted compressed bitstream. The embedded information is then used to perform an error concealment task on the decoder side of the system. The beat detector functions as part of an error concealment system in an audio decoding section used in audio information transfer and audio download-streaming system terminal devices such as mobile phones. The disclosed sender-based method improves error concealment performance while reducing decoder complexity.
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Citations
39 Claims
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1. A method comprising:
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(a) formatting a stream of audio data provided by a audio source into a sequence of audio data intervals; (b) transform encoding the sequence of audio data intervals to form a sequence of encoded audio data intervals, each of the encoded audio data intervals having a plurality of transform coefficients; (c) analyzing the transform coefficients of the sequence of encoded audio data intervals in the sequence so as to identify encoded transient audio data intervals, each of the encoded transient audio data intervals including a short transient signal having first transient signal characteristics; and (d) embedding ancillary data into encoded audio data intervals preceding the encoded transient audio data intervals, the ancillary data providing notification that the encoded transient audio data intervals include the short transient signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method comprising:
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(a) receiving transform-encoded audio data intervals of a sequence of transform-encoded audio data intervals, each of the intervals having a plurality of transform coefficients, wherein less than all of the intervals are transient intervals, and wherein each of the transient intervals corresponds to an audio segment that includes a beat; (b) receiving ancillary data identifying the transient intervals; (c) identifying transient intervals of the sequence that are defective; and (d) replacing transform coefficients of the defective transient intervals with transform coefficients from received transient intervals not identified as defective. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A device comprising:
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a decoder configured to perform steps that include (a) receiving transform-encoded audio data intervals of a sequence of transform-encoded audio data intervals, each of the intervals having a plurality of transform coefficients, wherein less than all of the intervals are transient intervals, and wherein each of the transient intervals corresponds to an audio segment that includes a beat, (b) retrieving ancillary data identifying the transient intervals, and (c) identifying transient intervals of the sequence that are defective; and
an error concealment unit configured to perform a step that includes(d) providing replacement transform coefficients for defective transient intervals, wherein the replacement transform coefficients are obtained from received transient intervals not identified as defective, and wherein the decoder is further configured to perform steps that include (e) as to each of the defective transient intervals, (e1) matching a window type of the defective transient interval with a window type of a received transient interval not identified as defective, and (e2) replacing transform coefficients of the defective transient interval with transform coefficients from the matching non-defective received transient interval. - View Dependent Claims (26, 27)
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28. A system comprising:
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an audio source for providing audio streaming information, the audio source including an encoder for converting the audio streaming information into a sequence of coded audio data intervals, each of the coded audio data intervals having a plurality of frequency domain transform coefficients, and a transient detector for classifying, by analysis of frequency domain transform coefficients, coded audio data intervals of the sequence that have a short transient signal as transient coded audio data intervals; and a receiving terminal for converting the sequence of coded audio data intervals into the audio sample, the receiving terminal including an error concealment unit for replacing frequency domain transform coefficients of a defective transient audio data interval with frequency domain transform coefficients from a received transient audio data interval found to be error-free. - View Dependent Claims (29, 30, 31, 32, 33, 34)
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35. A device comprising:
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a decoder configured to perform steps that include (a) receiving transform-encoded audio data intervals of a sequence of transform-encoded audio data intervals, each of the intervals having a plurality of transform coefficients, wherein less than all of the intervals are transient intervals, and wherein each of the transient intervals corresponds to an audio segment that includes a beat, (b) retrieving ancillary data identifying the transient intervals, and (c) identifying transient intervals of the sequence that are defective; and
an error concealment unit configured to perform a step that includes(d) providing replacement transform coefficients for defective transient intervals, wherein the replacement transform coefficients are obtained from received transient intervals not identified as defective, and wherein the decoder is further configured to perform steps that include (e) identifying each of multiple transient intervals received in step (a) by a type of beat in the audio segment to which that transient interval corresponds, and (f) as to each of the defective transient intervals, (f1) matching the beat type of the defective transient interval with the beat type of a non-defective received transient interval, and (f3) replacing transform coefficients of the defective transient interval with transform coefficients from the matching non-defective received transient interval.
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36. A device comprising:
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a decoder configured to perform steps that include (a) receiving transform-encoded audio data intervals of a sequence of transform-encoded audio data intervals, each of the intervals having a plurality of transform coefficients, wherein less than all of the intervals are transient intervals, and wherein each of the transient intervals corresponds to an audio segment that includes a beat, (b) retrieving ancillary data identifying the transient intervals, and (c) identifying transient intervals of the sequence that are defective; and
an error concealment unit configured to perform a step that includes(d) providing replacement transform coefficients for defective transient intervals, wherein the replacement transform coefficients are obtained from received transient intervals not identified as defective, and wherein the decoder is further configured to perform steps that include (e) identifying each of multiple transient intervals received in step (a) by a type of beat in the audio segment to which that transient interval corresponds, and (f) as to each of the defective transient intervals, (f1) matching a window type and the beat type of the defective transient interval with a window type and the beat type of a non-defective received transient interval, (f2) replacing transform coefficients of the defective transient interval with transform coefficients from the matching non-defective received transient interval.
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37. A device comprising:
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a decoder configured to perform steps that include (a) receiving transform-encoded audio data intervals of a sequence of transform-encoded audio data intervals, each of the intervals having a plurality of transform coefficients, wherein less than all of the intervals are transient intervals, and wherein each of the transient intervals corresponds to an audio segment that includes a beat, (b) retrieving ancillary data identifying the transient intervals, and (c) identifying transient intervals of the sequence that are defective; and an error concealment unit configured to perform a step that includes (d) providing replacement transform coefficients for defective transient intervals, wherein the replacement transform coefficients are obtained from received transient intervals not identified as defective, and wherein the decoder is further configured to perform steps that include (e) as to each of the defective transient intervals, (e1) replacing transform coefficients for a low-frequency band and for a high-frequency band with transform coefficients from a received transient interval not identified as defective, and (e2) replacing transform coefficients for a mid-frequency band with transform coefficients from a received interval other than the interval supplying the replacement coefficients in step (e1). - View Dependent Claims (38, 39)
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Specification