Method and system for generating a transform size syntax element for video decoding
View Patent ↗In a video processing system, a method and system for generating a transform size syntax element for video decoding are provided. For high profile mode video decoding operations, the transform sizes may be selected based on the prediction macroblock type and the contents of the macroblock. A set of rules may be utilized to select from a 4×4 or an 8×8 transform size during the encoding operation. Dynamic selection of transform size may be performed on intra-predicted macroblocks, inter-predicted macroblocks, and/or direct mode inter-predicted macroblocks. The encoding operation may generate a transform size syntax element to indicate the transform size that may be used in reconstructing the encoded macroblock. The transform size syntax element may be transmitted to a decoder as part of the encoded video information bit stream.
1. A method for video signal processing, the method comprising:
enabling an 8×8 inverse transform size in a video decoder;
receiving a coded macroblock from a video information stream;
receiving a transform size syntax element from the video information stream, wherein the transform size syntax element indicates a transform size of the coded macroblock;
determining a macroblock type of the coded macroblock;
selecting an inverse transform size based on the received transform size syntax element and a selection rule corresponding to the macroblock type of the coded macroblock, wherein for at least one macroblock type the selected inverse transform size does not correspond to a transform size indicated by the received transform size syntax element;
inverse transforming the coded macroblock to determine an inverse transformed block based on the selected inverse transform size; and
generating a reconstructed output based on the inverse transformed block.
2. The method of claim 1 , wherein receiving the coded macroblock from the video information stream further comprises:
determining that the coded macroblock is intra-coded.
3. The method of claim 1 ,
wherein the transform size syntax element indicates that the transform size of the coded macroblock is 4×4, and
wherein selecting the inverse transform size further comprises selecting a 4×4 inverse transform size as the inverse transform size based on the transform size syntax element.
4. The method of claim 3 ,
wherein inverse transforming the coded macroblock further comprises inverse transforming the coded macroblock using a 4×4 spatial prediction and a 4×4 inverse transform.
5. The method of claim 1 ,
wherein the transform size syntax element indicates that the transform size of the coded macroblock is 8×8, and
wherein selecting the inverse transform size comprises selecting the 8×8 inverse transform size as the inverse transform size based on the transform size syntax element.
6. The method of claim 5 ,
wherein inverse transforming the coded macroblock further comprises inverse transforming the coded macroblock using a 8×8 spatial prediction and a 8×8 inverse transform.
7. A method for video signal processing, the method comprising:
enabling an 8×8 inverse transform size in a video decoder;
receiving a coded macroblock and a transform size syntax element from a video stream;
determining a coded macroblock type for the coded macroblock, comprising determining whether the coded macroblock is an intra coded macroblock or an inter coded macroblock;
selecting an inverse transform size based on a selection rule corresponding to the determined coded macroblock type and the transform size syntax element, wherein for at least one coded macroblock type the selected inverse transform size does not correspond to a transform size indicated by the received transform size syntax element; and
inverse transforming the coded macroblock according to the selected transform size.
8. The method of claim 7 ,
wherein the at least one coded macroblock type is an intra-coded macroblock type.