Method of system for video coding using intra block copy mode

A method of video coding system using coding modes including an Inter prediction mode and an Intra Block Copy (IntraBC) mode, comprising:

• determining a variable to indicate whether two versions of a reconstructed current image unit are needed, wherein determining the variable comprises extracting one or more syntax elements in a picture level, a slice level, or both the picture level and the slice level of a video bitstream;
• if the variable indicates that two versions of the reconstructed current image unit are needed, allowing a loop-filtered version of the reconstructed current image unit and a non-loop-filter version of the reconstructed current image unit to be stored and used as reference data;
• if the variable indicates that two versions of the reconstructed current image unit are not needed, storing only one version of the reconstructed current image unit as the reference data;
• and
• encoding or decoding according to the stored reference data, wherein the variable is determined based on one or more syntax elements in a picture level, a slice level, or both the picture level and the slice level of a bitstream, and wherein said one or more syntax elements are selected from a group of syntax elements comprising a first syntax element in the picture level of the bitstream indicating whether the IntraBC mode is enabled for a current picture, a second syntax element in the slice level indicating whether luma SAO (Sample Adaptive Offset) is enabled for a current luma slice, a third syntax element in the slice level indicating whether chroma SAO is enabled for a current chroma slice, and a fourth syntax element in the slice level indicating whether deblocking-filter is disabled for a current slice.

A method of video coding system using coding modes including an Inter prediction mode and an Intra Block Copy (IntraBC) mode, comprising:

• determining a variable to indicate whether two versions of a reconstructed current image unit are needed, wherein determining the variable comprises extracting one or more syntax elements in a picture level, a slice level, or both the picture level and the slice level of a video bitstream;
• if the variable indicates that two versions of the reconstructed current image unit are needed, allowing a loop-filtered version of the reconstructed current image unit and a non-loop-filter version of the reconstructed current image unit to be stored and used as reference data;
• if the variable indicates that two versions of the reconstructed current image unit are not needed, storing only one version of the reconstructed current image unit as the reference data;
• and
• encoding or decoding according to the stored reference data;
• comprising if the variable indicates that two versions of the reconstructed current image unit are needed, converting a high-bandwidth bi-prediction mode into a uni-prediction mode;
• wherein the high-bandwidth bi-prediction mode corresponds to an 8×8 bi-prediction mode.

A video coding system using coding modes including an Inter prediction mode and an Intra Block Copy (IntraBC) mode, comprising one or more electronic circuits arranged to:

• determine a variable in a bitstream to indicate whether two versions of a reconstructed current image unit are needed, wherein determining the variable comprises extracting one or more syntax elements in a picture level, a slice level, or both the picture level and the slice level of a video bitstream;
• if the syntax element indicates that two versions of the reconstructed current image unit are needed, allow a loop-filtered version of the reconstructed current image unit and a non-loop-filter version of the reconstructed current image unit to be stored and used as reference data;
• if the syntax element indicates that two versions of the reconstructed current image unit are not needed, store only one version of the reconstructed current image unit as the reference data;
• and
• encode or decode according to the stored reference data,
• wherein the syntax element is determined based on one or more syntax elements in a picture level of a bitstream and wherein said one or more syntax elements are selected from a group of syntax elements comprising a first syntax element indicating whether the IntraBC mode is enabled for a current picture, a second syntax element indicating whether SAO (Sample Adaptive Offset) is enabled, a third syntax element indicating whether deblocking-filter is disabled, and a fourth syntax element indicating whether deblocking-filter-override is enabled.