Frequency Envelope Vector Quantization With Partitioned Codebooks
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Solution Overview
Problem
Existing frequency envelope quantization methods face challenges with insufficient quantization precision and excessive complexity due to limited bits in the codebook and a large number of frequency envelopes, particularly when scalar quantization is used.
Innovation Solution
The proposed method divides frequency envelopes into fewer-dimensional vectors and uses a codebook with a smaller number of bits by partitioning the codebook into parts, allowing for efficient vector quantization by determining the appropriate codebook based on the quantized vector's code word, thereby reducing complexity and ensuring quantization quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If scalar quantization is used for each frequency envelope, then quantization can be performed simply, but a large quantity of bits is consumed
Solution Approach 1:
The patent combines multiple frequency envelopes into vectors for joint quantization. Specifically, it divides N frequency envelopes into N1 vectors, where each vector contains M frequency envelopes. This merging approach allows the system to quantify multiple frequency envelopes simultaneously using a shared codebook, thereby reducing the total bits consumed while maintaining quantization effectiveness.
2Measurement precision
If vector quantization is used with a codebook of length 2^B, then quantization precision can be improved, but complexity increases exponentially with B
Solution Approach 1:
The patent segments the codebook into multiple sub-codebooks based on the quantized values of the first vector. After quantizing the first vector and obtaining its code word, the system determines which sub-codebook to use for quantizing subsequent vectors. This segmentation strategy reduces the search space for each quantization operation, thereby降低ing complexity while maintaining overall quantization precision.
Solution Approach 2:
The patent performs preliminary quantization of the first vector before quantizing subsequent vectors. By quantizing the first vector first and using its result to determine the appropriate sub-codebook, the system prepares the quantization process in advance. This preliminary action reduces the complexity of subsequent quantization operations by limiting the search space to a specific sub-codebook rather than the entire codebook.
3Device complexity
If the codebook is divided into 2^B1 portions, then complexity for subsequent vectors is reduced, but quantization precision may be compromised
Solution Approach 1:
The patent uses the quantization result of the first vector as a preliminary step to select the appropriate sub-codebook. By determining which portion of the divided codebook to use based on the first vector's code word, the system ensures that subsequent quantization operations are performed in the most appropriate sub-space, thereby maintaining precision while reducing complexity.
Solution Approach 2:
The patent dynamically selects different sub-codebooks for quantizing different vectors based on the quantization results of previous vectors. This dynamic selection process allows the system to adapt the quantization process to the specific characteristics of each vector, maintaining high precision while keeping the complexity of individual quantization operations manageable through codebook division.
Data Source
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AI summary
Embodiments of the present invention proposes a frequency envelope vector quantization method and apparatus, where the method comprises: dividing N frequency envelopes in one frame into N1 vectors, where each vector in the N1 vectors comprises M frequency envelopes; quantizing a first vector in the N1 vectors by using a first codebook, to obtain a code word corresponding to the quantized first vector, where the first codebook is divided into 2B1 parts; determining, according to the code word of the quantized first vector, that the quantized first vector is associated with the ith part in the 2B1 parts of the first codebook; determining a second codebook according to the codebook of the ith part; and quantizing a second vector in the N1 vectors based on the second codebook. In the embodiments of the present invention, frequency envelopes are divided into a plurality of vectors with fewer dimensions, so that vector quantization can be performed on frequency envelope vectors by using a codebook with a smaller quantity of bits. Therefore, complexity of vector quantization can be reduced, and an effect of vector quantization can also be ensured.