Semiconductor device

Abstract

A semiconductor device includes a hash generator, a reference hash list, a frame mode determination unit, and an intra prediction unit. The hash generator generates a hash value of a target frame to be encoded. The reference hash list is to record the hash value generated by the hash generator. The frame mode determination unit compares the hash value generated by the hash generator and the hash value in the reference hash list. The intra prediction unit performs intra prediction for the target frame to be encoded. When the hash value of the target frame to be encoded coincides with any of the hash values in the reference hash list, the intra prediction unit skips an encoding process, and outputs encoded information corresponding to any of the hash values in the reference hash list.

What is claimed is: 
     
         1 . A semiconductor device comprising:
 a hash generator which generates a hash value of a target frame to be encoded;   a reference hash list for recording the hash value generated by the hash generator; and   a frame mode generation unit which compares the hash value generated by the hash generator with any of hash values in the reference hash list,   wherein, when the hash value of the target frame to be encoded coincides with any of the hash values in the reference hash list, the semiconductor device skips process for encoding the target frame to be encoded, and   wherein, when the hash value of the target frame to be encoded does not coincide with any of the hash values in the reference hash list, the semiconductor device performs the process for encoding the target frame to be encoded.   
     
     
         2 . The semiconductor device according to  claim 1 ,
 wherein, when the hash value of the target frame to be encoded coincides with any of the hash values in the reference hash list, the semiconductor device refers a reference frame represented by the coincident reference hash value.   
     
     
         3 . The semiconductor device according to  claim 1 , further comprising an intra prediction unit,
 wherein, when the hash value of the target frame to be encoded does not coincide with any of the hash values in the reference hash list, the intra prediction unit performs intra-frame prediction for the target frame to be encoded.   
     
     
         4 . The semiconductor device according to  claim 3 , further comprising an inter prediction unit,
 wherein, when the hash value of the target frame to be encoded does not coincide with any of the hash values in the reference hash list, the inter prediction unit performs inter-frame prediction using a physical reference frame stored in a frame memory.   
     
     
         5 . The semiconductor device according to  claim 4 , further comprising a prediction mode determination unit which compares an inter prediction error generated by the inter prediction unit with an intra prediction error generated by the intra prediction unit, selects a lower prediction error as an encoding mode, and selects prediction error data of the selected mode as a selection prediction error. 
     
     
         6 . The semiconductor device according to  claim 1 ,
 wherein the hash generator generates hash values, independently in accordance with generation units of the hash values, either in association with luminance and color differences, in association with encoding units of slice, or in association with a region of interest and a region of non-interest.   
     
     
         7 . The semiconductor device according to  claim 1 , further comprising a hash filter which smoothes the target frame to be encoded, preceding the hash generator. 
     
     
         8 . The semiconductor device according to  claim 1 ,
 wherein the hash generator, the reference hash list, the frame mode determination unit, and the intra prediction unit are formed over one semiconductor substrate.   
     
     
         9 . The semiconductor device according to  claim 1 , further comprising:
 a subtracter which calculates a difference in prediction image data, which is generated from image data of the target frame to be encoded and encoded image data;   an orthogonal transformation unit which transforms difference data calculated by the subtracter to a frequency domain;   a quantization unit which quantizes the data transformed to the frequency domain by the orthogonal transformation unit;   an encoding unit which transforms the data quantized by the quantization unit into a variable length code;   an inverse quantization unit which inverse-quantizes the data quantized by the quantization unit; and   an inverse orthogonal transformation unit which performs inverse orthogonal transform of the data inverse-quantized by the inverse quantization unit.   
     
     
         10 . The semiconductor device according to  claim 1 ,
 wherein, when the hash value of the target frame to be encoded coincides with any of the hash values in the reference hash list, processes of the subtracter, the orthogonal transformation unit, the quantization unit, the inverse quantization unit, and the inverse orthogonal transformation unit are stopped.   
     
     
         11 . The semiconductor device according to  claim 1 ,
 wherein, when the hash value of the target frame to be encoded coincides with any of the hash values in the reference hash list, the semiconductor device outputs encoded information corresponding to any of the hash values in the reference hash list.