Adding second enhancement layer to CELP based core layer
First Claim
1. A method of transmitting an input audio signal with a scalable codec by an audio access device comprising a processor, the method comprising:
- encoding, by the processor, a low frequency band signal having an inner core layer coding;
encoding, by the processor, a first coding error of the inner core layer coding having a first enhancement layer on the low frequency band of the low frequency band signal;
encoding, by the processor, a second coding error of the first enhancement layer by using a second enhancement layer on the low frequency band of the low frequency band signal after the first enhancement layer, encoding the second coding error comprising coding fine spectrum coefficients of the second coding error to produce coded fine spectrum coefficients, and coding a spectral envelope of the second coding error to produce a coded spectral envelope; and
transmitting the coded fine spectrum coefficients and the coded spectral envelope.
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Abstract
In an embodiment, a method of transmitting an input audio signal is disclosed. A first coding error of the input audio signal with a scalable codec having a first enhancement layer is encoded, and a second coding error is encoded using a second enhancement layer after the first enhancement layer. Encoding the second coding error includes coding fine spectrum coefficients of the second coding error to produce coded fine spectrum coefficients, and coding a spectral envelope of the second coding error to produce a coded spectral envelope. The coded fine spectrum coefficients and the coded spectral envelope are transmitted.
67 Citations
22 Claims
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1. A method of transmitting an input audio signal with a scalable codec by an audio access device comprising a processor, the method comprising:
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encoding, by the processor, a low frequency band signal having an inner core layer coding; encoding, by the processor, a first coding error of the inner core layer coding having a first enhancement layer on the low frequency band of the low frequency band signal; encoding, by the processor, a second coding error of the first enhancement layer by using a second enhancement layer on the low frequency band of the low frequency band signal after the first enhancement layer, encoding the second coding error comprising coding fine spectrum coefficients of the second coding error to produce coded fine spectrum coefficients, and coding a spectral envelope of the second coding error to produce a coded spectral envelope; and transmitting the coded fine spectrum coefficients and the coded spectral envelope. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of transmitting an input audio signal with a scalable codec by an audio access device comprising a processor, the method comprising:
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encoding, by the processor, a low frequency band signal having an inner core layer coding; encoding, by the processor, a first coding error of the inner core layer coding having a first modified discrete cosine transform (MDCT) enhancement layer on the low frequency band of the low frequency band signal; determining if a second MDCT enhancement layer is needed on the low frequency band of the low frequency band signal; and if the second MDCT enhancement layer is needed based on the determining, encoding, by the processor, a second coding error by using the second MDCT enhancement layer after the first modified MCDT enhancement layer. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A system for transmitting an input audio signal with a scalable codec, the system comprising:
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a transmitter comprising an audio coder, the audio coder comprising an inner core layer coding with a code-excited linear prediction (CELP) codec configured to encode a low frequency band signal, a first modified discrete cosine transform (MDCT) enhancement layer configured to encode a first coding error of the inner core layer coding of CELP on the low frequency band of the low frequency band signal, and a second MDCT enhancement layer configured to encode a second coding error of the first MDCT enhancement layer on the low frequency band of the low frequency band signal, encode fine spectrum coefficients of the second coding error, and encode a spectral envelope of the second coding error. - View Dependent Claims (20, 21, 22)
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Specification