Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 ** AlacDecodeUtils.java
 **
 ** Copyright (c) 2011 Peter McQuillan
 **
 ** All Rights Reserved.
 **                       
 ** Distributed under the BSD Software License (see license.txt)  
 **
 */

public class Main {
    static int[] predictor_decompress_fir_adapt(int[] error_buffer, int output_size, int readsamplesize,
            int[] predictor_coef_table, int predictor_coef_num, int predictor_quantitization) {
        int buffer_out_idx = 0;
        int[] buffer_out;
        int bitsmove = 0;

        /* first sample always copies */
        buffer_out = error_buffer;

        if (predictor_coef_num == 0) {
            if (output_size <= 1)
                return (buffer_out);
            int sizeToCopy = 0;
            sizeToCopy = (output_size - 1) * 4;
            System.arraycopy(error_buffer, 1, buffer_out, 1, sizeToCopy);
            return (buffer_out);
        }

        if (predictor_coef_num == 0x1f) // 11111 - max value of predictor_coef_num
        {
            /* second-best case scenario for fir decompression,
             * error describes a small difference from the previous sample only
             */
            if (output_size <= 1)
                return (buffer_out);

            for (int i = 0; i < (output_size - 1); i++) {
                int prev_value = 0;
                int error_value = 0;

                prev_value = buffer_out[i];
                error_value = error_buffer[i + 1];

                bitsmove = 32 - readsamplesize;
                buffer_out[i + 1] = (((prev_value + error_value) << bitsmove) >> bitsmove);
            }
            return (buffer_out);
        }

        /* read warm-up samples */
        if (predictor_coef_num > 0) {
            for (int i = 0; i < predictor_coef_num; i++) {
                int val = 0;

                val = buffer_out[i] + error_buffer[i + 1];

                bitsmove = 32 - readsamplesize;

                val = ((val << bitsmove) >> bitsmove);

                buffer_out[i + 1] = val;
            }
        }

        /* general case */
        if (predictor_coef_num > 0) {
            buffer_out_idx = 0;
            for (int i = predictor_coef_num + 1; i < output_size; i++) {
                int j;
                int sum = 0;
                int outval;
                int error_val = error_buffer[i];

                for (j = 0; j < predictor_coef_num; j++) {
                    sum += (buffer_out[buffer_out_idx + predictor_coef_num - j] - buffer_out[buffer_out_idx])
                            * predictor_coef_table[j];
                }

                outval = (1 << (predictor_quantitization - 1)) + sum;
                outval = outval >> predictor_quantitization;
                outval = outval + buffer_out[buffer_out_idx] + error_val;
                bitsmove = 32 - readsamplesize;

                outval = ((outval << bitsmove) >> bitsmove);

                buffer_out[buffer_out_idx + predictor_coef_num + 1] = outval;

                if (error_val > 0) {
                    int predictor_num = predictor_coef_num - 1;

                    while (predictor_num >= 0 && error_val > 0) {
                        int val = buffer_out[buffer_out_idx]
                                - buffer_out[buffer_out_idx + predictor_coef_num - predictor_num];
                        int sign = ((val < 0) ? (-1) : ((val > 0) ? (1) : (0)));

                        predictor_coef_table[predictor_num] -= sign;

                        val *= sign; // absolute value

                        error_val -= ((val >> predictor_quantitization) * (predictor_coef_num - predictor_num));

                        predictor_num--;
                    }
                } else if (error_val < 0) {
                    int predictor_num = predictor_coef_num - 1;

                    while (predictor_num >= 0 && error_val < 0) {
                        int val = buffer_out[buffer_out_idx]
                                - buffer_out[buffer_out_idx + predictor_coef_num - predictor_num];
                        int sign = -((val < 0) ? (-1) : ((val > 0) ? (1) : (0)));

                        predictor_coef_table[predictor_num] -= sign;

                        val *= sign; // neg value

                        error_val -= ((val >> predictor_quantitization) * (predictor_coef_num - predictor_num));

                        predictor_num--;
                    }
                }

                buffer_out_idx++;
            }
        }
        return (buffer_out);
    }
}