Variable-frame speech coding/decoding apparatus and method
First Claim
1. A speech coding apparatus comprising:
- an input speech classification unit classify the input speech into several class such as a transition segment and a stationary segment;
a variable rate speech coding unit coding the input speech using a frame sizes, quantizer structures, and bit assignment methods determined by the class information; and
a multiplexing unit outputting a bit string of coding parameters, which has been extracted in the variable frame size.
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Abstract
There is provided a speech coding/decoding apparatus and method, in which the input speech signals are classified into several classes in accordance with characteristics of the input speech signals and the input speech signals are coded using frame sizes, quantizer structures, and bit assignment methods corresponding to the determined classes, or in which the frame sizes can be adjusted in accordance with network conditions or codec type of a counter part. Therefore, by optimally adjusting the frame size, the quantizer structure, and the bit assignment method in accordance with the characteristics of input speech, it is possible to improve the performance of the speech coding apparatus, and by adjusting the frame size in accordance with the speech codec type of a counter part, it is also possible to reduce the total end-to-end delay.
38 Citations
20 Claims
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1. A speech coding apparatus comprising:
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an input speech classification unit classify the input speech into several class such as a transition segment and a stationary segment;
a variable rate speech coding unit coding the input speech using a frame sizes, quantizer structures, and bit assignment methods determined by the class information; and
a multiplexing unit outputting a bit string of coding parameters, which has been extracted in the variable frame size. - View Dependent Claims (2, 3)
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4. A speech coding method comprising:
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(a) classify the input speech into a several class such as transition segment and a stationary segment;
(b) variably coding the input speech using different frame sizes, quantizer structures, and bit assignment methods in accordance with the determined classes; and
(c) output the bit strings of the coding parameter which extracted in a variable frame size.
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5. A speech decoding apparatus comprising:
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a demultiplexing unit receiving bit strings coded with frame sizes, quantizer structures, and bit assignment methods corresponding to the input speech class and extracting parameters for decoding from the bit strings;
a variable rate speech decoding unit has information for every class, the variable rate speech decoding unit reconstruct the speech signal in accordance with the classes information for received bit strings; and
a temporary storage unit temporarily storing the decoded speech to continuously output the reconstructed speech.
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6. A speech decoding method comprising:
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(a) receiving bit strings coded using frame sizes, quantizer structures, and bit assignment methods in accordance with input speech class and extracting parameter information necessary for decoding from the bit strings;
(b) variably decoding the received parameters in accordance with the classes of the received parameters; and
(c) temporarily storing the decoded speech to continuously output the reconstructed speech.
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7. A speech coding apparatus comprising:
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a frame determining unit determining the frame sizes and the number of frames per packet for transmission of input speech on the basis of a network delay or codec type of a counter part;
a variable rate speech coding unit variably coding the input speech in accordance with the frame sizes and the number of frames determined; and
a multiplexing unit outputting bit strings of the coding parameters extracted in a variable frame size. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A speech coding method comprising:
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(a) determining frame sizes and the number of frames per packet for coding speech signals on the basis of network delay information or codec type of a counter part;
(b) coding the speech signals in accordance with the frame sizes and the number of frames having been determined; and
(c) outputting bit strings of the speech signals coded in a variable frame size.
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14. A speech decoding apparatus comprising:
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a demultiplexing unit receiving bit strings for speech signals coded on the basis of network delay information and extracting parameters necessary for reconstruct the speech signal from the bit strings;
variable speech decoding units have the every information for decoding the received parameters, each variable speech decoding unit variably decoding the received speech signals in accordance with the frame sizes of the received speech signals; and
a temporary storage unit temporarily storing the decoded speech signals to continuously output the decoded speech signals.
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15. A speech decoding method comprising:
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(a) receiving bit strings of speech signals coded on the basis of network delay information and extracting parameter information necessary for decoding from the bit strings;
(b) variably decoding the received coding parameters in accordance with the frame sizes of the received signals; and
(c) temporarily storing the decoded speech signals to continuously output the decoded speech signals.
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16. A speech coding apparatus comprising:
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a variable coding unit determining frame sizes for coding on the basis of any one of a characteristic of input speech, network delay information, and speech codec type of a counter part, and coding the input speech on the basis of the determined frame size; and
a frame transmitting unit transmitting the coded frames at a constant transmission interval. - View Dependent Claims (17, 18, 19)
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20. A speech coding method comprising:
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determining frame sizes for coding on the basis of any one of a characteristic of input speech, network delay information, and speech codec type of a counter part, and coding the input speech on the basis of the determined frame sizes; and
transmitting the coded parameters at a constant transmission interval.
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Specification