You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: compression_hdl_lowpower.m
    path of file: ./repos/microshift_compression/matlab code
    
    the code of the file until where you have to start completion: function [bitstream_ready, bitstream_length_output, subimage_index_output, bitstream_output, hStart_output, hEnd_output, vStart_output, vEnd_output, valid_output] ...
    = compression_hdl_lowpower(pixelIn, hStart, hEnd, vStart, vEnd, valid, mode)
% mode = 0: no compression;
% mode = 1: compression without psd;
% mode = 2: compression with psd; (only this mode in low power version)
% mode = 3: dump mode

% effective size: 48*64
width = uint16(216);
porch = uint16(20);
numCols = width + porch; % total number of columns, modify according to the testbench!

    
function [bitstream_ready, bitstream_length_output, subimage_index_output, bitstream_output, hStart_output, hEnd_output, vStart_output, vEnd_output, valid_output] ...
    = compression_hdl_lowpower(pixelIn, hStart, hEnd, vStart, vEnd, valid, mode)
% mode = 0: no compression;
% mode = 1: compression without psd;
% mode = 2: compression with psd; (only this mode in low power version)
% mode = 3: dump mode

% effective size: 48*64
width = uint16(216);
porch = uint16(20);
numCols = width + porch; % total number of columns, modify according to the testbench!
% F = fimath('OverflowAction','Wrap','RoundingMethod','Floor','SumMode','KeepLSB','SumWordLength',3);

persistent range;
if isempty(range)
    range = int8(8);
end