A method of decoding video data includes generating a prediction block for a current block of the video data and decoding a residual block for the current block of the video data. The method includes combining the prediction block and the residual block to generate a reconstructed block of the video data and determining a variable M×N sample pattern based on a block size of the current block. The method includes estimating a local luma level for samples of the reconstructed block using the variable M×N sample pattern and applying, based on the estimated local luma level, a deblocking filter to the samples of the reconstructed block to generate filtered samples. The method includes generating final samples of the video data based on the filtered samples.