Method and device for indicating quantizer parameters in a video coding system
DCFirst Claim
1. A method of decoding an encoded digital video sequence for use in a video decoding application to produce a decoded digital video sequence, the digital video sequence comprising a number of frames, each frame of said sequence comprising an array of pixels divided into a plurality of blocks, each block comprising a certain number of said pixels, frames of the digital video sequence encoded by:
- applying motion compensated prediction to blocks of pixels for producing corresponding blocks of prediction error values;
applying a transform coding technique to said blocks of prediction error valves to produce sets of transform coefficient values representative of said blocks of prediction error values; and
applying a level of quantization to said sets of transform coefficient values to yield sets of quantized transform coefficient values representative of said blocks of prediction error values, wherein an indication of said level of quantization is provided in the encoded bit-stream including the encoded digital video sequence, said decoding method comprising;
selecting a default level of inverse quantization for use in decoding of the encoded digital video sequence to inverse quantize the sets of quantized transform coefficient values, said default level selected based on the indication of said level of quantization provided in the encoded bit-stream.
2 Assignments
Litigations
1 Petition
Accused Products
Abstract
A method and device for coding of digital video sequence, wherein an indication of quantization parameter (QP) is provided in the encoded bit-stream for decoding purposes. The QP related information is indicated by introducing a sequence level quantization parameter value SQP. More specifically, instead of coding the absolute values of picture/slice QPs, an indication of the difference ΔQP between the sequence level quantization parameter SQP and the picture/slice QP is provided. This eliminates the need to transmit a full QP for every picture/slice, and enables a statistically smaller difference value to be transmitted, thus providing a reduction in transmission bit-rate. The difference value is subsequently used in a corresponding decoder to reconstruct the picture/slice QP.
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Citations
10 Claims
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1. A method of decoding an encoded digital video sequence for use in a video decoding application to produce a decoded digital video sequence, the digital video sequence comprising a number of frames, each frame of said sequence comprising an array of pixels divided into a plurality of blocks, each block comprising a certain number of said pixels, frames of the digital video sequence encoded by:
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applying motion compensated prediction to blocks of pixels for producing corresponding blocks of prediction error values; applying a transform coding technique to said blocks of prediction error valves to produce sets of transform coefficient values representative of said blocks of prediction error values; and applying a level of quantization to said sets of transform coefficient values to yield sets of quantized transform coefficient values representative of said blocks of prediction error values, wherein an indication of said level of quantization is provided in the encoded bit-stream including the encoded digital video sequence, said decoding method comprising; selecting a default level of inverse quantization for use in decoding of the encoded digital video sequence to inverse quantize the sets of quantized transform coefficient values, said default level selected based on the indication of said level of quantization provided in the encoded bit-stream. - View Dependent Claims (2, 3, 4)
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5. A video decoder for decoding an encoded digital video sequence to produce a decoded digital video sequence, the digital video sequence comprising a number of frames, each frame of said sequence comprising an array of pixels divided into a plurality of blocks, each block comprising a certain number of said pixels, frames of the digital video sequence encoded by:
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applying motion compensated prediction to blocks of pixels for producing corresponding blocks of prediction error values; applying a transform coding technique to said blocks of prediction error values to produce sets of transform coefficient values representative of said blocks of prediction error values; and applying a level of quantization to said sets of transform coefficient values to yield sets of quantized transform coefficient values representative of said blocks of prediction error values, wherein an indication of said level of quantization is provided in the encoded bit-stream including the encoded digital video sequence, said video decoder comprising; means for retrieving the encoded digital video sequence from the encoded bit-stream; and means for selecting a default level of inverse quantization for use in decoding of the encoded digital video sequence to inverse quantize the sets of quantized transform coefficient values, said default level of inverse quantization selected based on said indication of said level of quantization provided in the encoded bit-stream. - View Dependent Claims (6, 7, 8, 9)
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10. A video decoder for decoding an encoded digital video sequence to produce a decoded digital video sequence, the digital video sequence comprising a number of frames, each frame of said sequence comprising an array of pixels divided into a plurality of blocks, each block comprising a certain number of said pixels, frames of the digital video sequence encoded by:
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applying motion compensated prediction to blocks of pixels for producing corresponding blocks of prediction error values; applying a transform coding technique to said blocks of prediction error values to produce sets of transform coefficient values representative of said blocks of prediction error values; and applying a level of quantization to said sets of transform coefficient values to yield sets of quantized transform coefficient values representative of said blocks of prediction error values, wherein an indication of said level of quantization is provided in the encoded bit-stream including the encoded digital video sequence, said video decoder comprising; a module for retrieving the encoded digital video sequence from the encoded bit-stream; and a module for selecting a default level of inverse quantization for use in decoding of the encoded digital video sequence to inversely quantize the sets of quantized transform coefficient values, said default level of inverse quantization selected based on said indication of said level of quantization provided in the encoded bit-stream.
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Specification