Video bitstream coding
A method of decoding JVET video includes receiving a bitstream indicating how a coding tree unit was partitioned into coding units, and parsing said bitstream to generate at least one predictor based on an intra prediction mode signaled in the bitstream. The predictor may be generated by interpolating neighboring pixels for each pixel within a coding block. The computation may be more accurate by deriving a value for a bottom right neighboring pixel.
1. A method for predicting pixel values for a current coding block from neighboring pixels that form a first array of horizontal pixels on an upper side of the current coding block and vertical pixels on a left side of the current coding block the method configured to:
calculate an intensity value of a bottom right neighboring pixel of the current coding block;
using an intensity value of at least one neighboring pixel from the first array and the calculated intensity value of the bottom right neighboring pixel, calculate intensity values for neighboring pixels in a second array of horizontal pixels along the lower side of the current coding block and vertical pixels in a column along the right side of the current coding block;
calculate a first predictor for a pixel in the current coding block by interpolating between an intensity value of at least one pixel in the first array and at least one pixel in the second array;
calculate a second predictor, different from the first predictor, for the pixel in the current coding block by interpolating between an intensity value of at least one pixel in the first array and at least one pixel in the second array; and
derive a prediction pixel value from the first and second predictors, wherein a plurality of prediction pixel values make up a prediction block.
2. The method of claim 1 , wherein deriving the prediction pixel value comprises averaging the first and second predictors.
3. The method of claim 1 , wherein a top right corner neighboring pixel is used to calculate the intensity values for neighboring pixels in a column along the right side of the current coding block.
4. The method of claim 1 , wherein a bottom left corner neighboring pixel is used to calculate the intensity values for neighboring pixels in a column along the left side of the current coding block.
5. The method of claim 1 , wherein calculating the intensity value of the bottom right neighboring pixel comprises calculating a weighted average of intensity values of two or more reconstructed neighboring pixels.
6. The method of claim 5 , wherein the intensity value of at least one of the neighboring pixels is filtered for use in the weighted average calculation of the intensity values.