Moving image decoding device and moving image decoding method
Encoding and decoding are uniformly carried out for a plurality of chroma formats. Based on a control signal for providing a chroma format type of an input moving image signal, in the case of a chroma format of 4:2:0 or 4:2:2, a first intra prediction mode deciding unit and a first intra prediction image generation unit are applied to a luminance component of the input moving image signal, and a second intra prediction mode deciding unit and a second intra prediction image generation unit are applied to a chrominance component. In the case of a chroma format of 4:4:4, the first intra prediction mode deciding unit and the first intra prediction image generation unit are applied to all color components to carry out encoding, and a variable length encoding unit multiplexes the control signal as encoding data to be applied to a moving image sequence unit on a bit stream.
1. A moving image decoding device for decoding a digital moving image signal, based on an input of a bit stream generated by subjecting the digital moving image signal to compression encoding in which the digital moving image signal is transformed and quantized on a block basis, the moving image decoding device comprising:
a decoding unit for decoding chroma format identification information for designating a chroma format of an input video signal to be encoded, common encoding or independent encoding identification information indicating which of encoding through a common encoding process and encoding through an independent encoding process is to be executed, and intra only encoding instruction information indicating whether or not to intra encode all pictures corresponding to the digital moving image signal, wherein the decoding unit generates a decoded image in which a deblocking filter provided at each boundary between blocks serving as units of the transform and quantization is disabled when the intra only encoding instruction information indicates that all the pictures corresponding to the digital moving image signal are to be intra encoded;
the decoding unit decodes using an intra prediction mode which is different regarding luminance components and chrominance components when the chroma formats are 4:2:0 and 4:2:2 based on chroma format identification information;
the decoding unit decodes using an intra prediction image of each color component generated based on a unique intra prediction mode common to all the color components when the chroma format is 4:4:4 and the common encoding or independent encoding identification information indicates common encoding processing; and
the decoding unit decodes using an intra prediction image of each color component generated based on an individual intra prediction mode for each color component when the chroma format is 4:4:4 and the common encoding or independent encoding identification information indicates independent encoding processing.
2. A moving image decoding method for decoding a digital moving image signal, based on an input of a bit stream generated by subjecting the digital moving image signal to compression encoding in which the digital moving image signal is transformed and quantized on a block basis, the moving image decoding method comprising:
a decoding step for decoding chroma format identification information for designating a chrome format of an input video signal to be encoded, common encoding or independent encoding identification information indicating which of encoding through a common encoding process and encoding through an independent encoding process is to be executed, and intra only encoding instruction information indicating whether or not to intra encode all pictures corresponding to the digital moving image signal, wherein the decoding step generates a decoded image in which a deblocking filter provided at each boundary between blocks serving as units of the transform and quantization is when the intra only encoding instruction information indicates that all the pictures corresponding to the digital moving image signal are to be intra encoded;
the decoding step decodes using an intra prediction mode which is different regarding luminance components and chrominance when the chrome formats are 4:2:0 and 4:2:2 based on chrome format identification information;
the decoding step decodes using an intra prediction image of each color component generated based on a unique intra prediction mode common to all the color components when the chrome format is 4:4:4 and the common encoding or independent encoding identification information indicates common encoding processing; and
the decoding step decodes using an intra prediction image of each color component generated based on an individual intra prediction mode for each dolor component when the chrome format is 4:4:4 and the common encoding or independent encoding identification information indicates independent encoding processing.