Variable Length Coding and Decoding Methods and Devices for Grouped Pixels
AssigneeASPEED Technology Inc.
InventorChung-Yen LU
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Abstract
A variable length coder is disclosed. The variable length coder comprises a size determining unit and a first residual coder. The size determining unit determines a maximum size based on sizes of quantized residuals in a current group and determines whether to enable the first residual coder according to the maximum size. When the maximum size is equal to 1, the first residual coder is enabled to encode the quantized residuals as one symbol to generate a first encoded suffix according to a variable length coding scheme.
Claims22
A variable length coder, comprising:
- a size determining unit for determining a maximum size based on sizes of quantized residuals in a current group and determining whether to enable the first residual coder according to the maximum size;
- and
- the first residual coder, enabled when the maximum size is one, that encodes the quantized residuals of the current group as one symbol to generate a first encoded suffix according to a variable length coding scheme.
A variable length coding method applied in a spatial prediction coding system, comprising:
- determining a maximum size based on sizes of quantized residuals in a current group;
- and
- when the maximum size is one, encoding the quantized residuals of the current group as one symbol according to a variable length coding scheme to obtain a first encoded suffix.
A variable length decoder, comprising:
- a size decoding unit for receiving an encoded bit stream comprising an encoded prefix and an encoded suffix, and decoding the encoded prefix into a reconstructed maximum size of a current group to enable one of a first residual decoder, a second residual decoder and a third residual decoder;
- the first residual coder, enabled when the reconstructed maximum size is one, that decodes the encoded suffix as one codeword into N decoded quantized residuals of the current group according to a variable length decoding scheme;
- the second residual decoder that is enabled when the reconstructed maximum size is two, wherein the second residual decoder decodes the encoded suffix as one codeword into N decoded quantized residuals of the current group according to the variable length decoding scheme, and then sequentially decodes each two-bit code in the encoded suffix into a decimal value if the variable length decoding scheme fails to decode the encoded suffix;
- and
- the third residual decoder, enabled when the reconstructed maximum size is three, that sequentially decodes each codeword in the encoded suffix according to the variable length decoding scheme;
- wherein N>=2.
A variable length decoding method applied in a spatial prediction decoding system, comprising:
- receiving an encoded bit stream comprising an encoded prefix and an encoded suffix;
- decoding the encoded prefix into a reconstructed maximum size of a current group;
- when the reconstructed maximum size is one, decoding the encoded suffix as one codeword into N decoded quantized residuals of the current group according to a variable length decoding scheme;
- when the reconstructed maximum size is two, decoding the encoded suffix as one codeword into N decoded quantized residuals of the current group according to the variable length decoding scheme, and sequentially decodes each two-bit code in the encoded suffix into a decimal value if the variable length decoding scheme fails to decode the encoded suffix;
- and
- when the reconstructed maximum size is three, sequentially decoding each codeword in the encoded suffix according to the variable length decoding scheme;
- wherein N>=2.
Dependencies are inferred from the claim text.