A method for cross-component prediction of a block of video data, the method comprising: down-sampling a reconstructed luma block to obtain a down-sampled luma block, the reconstructed luma block corresponding to a chroma block; obtaining first down-sampled luma samples of reconstructed top neighboring luma samples that are above the reconstructed luma block and second down-sampled luma samples of reconstructed left neighboring luma samples that are left to the reconstructed luma block, wherein the reconstructed top neighboring luma samples are in a single row being adjacent to the reconstructed luma block and the reconstructed left neighboring luma samples are in three columns being adjacent to the reconstructed luma block, wherein the video data is in the YUV4:2:0 format, wherein the first down-sampled luma samples are obtained by applying a three tap downsampling filter to the reconstructed top neighboring luma samples according to A[i] = (A1 *2 + A1[2i-1] + A1[2i+1] + 2) >> 2, wherein A1[i] is the ith reconstructed top neighboring luma sample in the single row being adjacent to the reconstructed luma block and A[i] is the ith down-sampled luma sample of the reconstructed top neighboring luma samples, wherein the second down-sampled luma samples are obtained by applying a six tap downsampling filter to the reconstructed left neighboring luma samples according to L[i] = (L2 *2 + L1 + L3 + L2[2i+1]*2 + L1[2i+1] + L3[2i+1] + 4) » 3, wherein L1[i], L2[ i] and L3[i] are the ith reconstructed left neighboring luma sample in the three columns being adjacent to the reconstructed luma block, respectively, and L[i] is the ith down-sampled luma sample of reconstructed left neighboring luma samples; deriving parameters of a linear model, LM, from - the first down-sampled luma samples and the second down-sampled luma samples, and - reconstructed neighboring chroma samples that are above the chroma block and reconstructed neighboring chroma samples that are left to the chroma block; and generating predicted chroma values of the chroma block based on the parameters of the LM and the downsampled luma block, wherein the LM is a linear model of the cross-component linear model, CCLM, mode, wherein the predicted chroma values of the chroma block are determined according to pred c (i,j) = α·rec L '(i,j) + β, wherein pred c (i,j) are the predicted chroma values of the chroma block, rec L '(i,j) are the down-sampled luma samples of the down-sampled luma block, and α and β are the parameters of the LM. down-sampling a reconstructed luma block to obtain a down-sampled luma block, the reconstructed luma block corresponding to a chroma block; obtaining first down-sampled luma samples of reconstructed top neighboring luma samples that are above the reconstructed luma block and second down-sampled luma samples of reconstructed left neighboring luma samples that are left to the reconstructed luma block, wherein the reconstructed top neighboring luma samples are in a single row being adjacent to the reconstructed luma block and the reconstructed left neighboring luma samples are in three columns being adjacent to the reconstructed luma block, wherein the video data is in the YUV4:2:0 format, wherein the first down-sampled luma samples are obtained by applying a three tap downsampling filter to the reconstructed top neighboring luma samples according to A[i] = (A1 *2 + A1[2i-1] + A1[2i+1] + 2) >> 2, wherein A1[i] is the ith reconstructed top neighboring luma sample in the single row being adjacent to the reconstructed luma block and A[i] is the ith down-sampled luma sample of the reconstructed top neighboring luma samples, wherein the second down-sampled luma samples are obtained by applying a six tap downsampling filter to the reconstructed left neighboring luma samples according to L[i] = (L2 *2 + L1 + L3 + L2[2i+1]*2 + L1[2i+1] + L3[2i+1] + 4) » 3, wherein L1[i], L2[ i] and L3[i] are the ith reconstructed left neighboring luma sample in the three columns being adjacent to the reconstructed luma block, respectively, and L[i] is the ith down-sampled luma sample of reconstructed left neighboring luma samples; deriving parameters of a linear model, LM, from - the first down-sampled luma samples and the second down-sampled luma samples, and - reconstructed neighboring chroma samples that are above the chroma block and reconstructed neighboring chroma samples that are left to the chroma block; and - the first down-sampled luma samples and the second down-sampled luma samples, and - reconstructed neighboring chroma samples that are above the chroma block and reconstructed neighboring chroma samples that are left to the chroma block; and generating predicted chroma values of the chroma block based on the parameters of the LM and the downsampled luma block, wherein the LM is a linear model of the cross-component linear model, CCLM, mode, wherein the predicted chroma values of the chroma block are determined according to pred c (i,j) = α·rec L '(i,j) + β, wherein pred c (i,j) are the predicted chroma values of the chroma block, rec L '(i,j) are the down-sampled luma samples of the down-sampled luma block, and α and β are the parameters of the LM.