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/*
FreeRDP: A Remote Desktop Protocol client.
RemoteFX Codec Library - DWT
Copyright 2011 Vic Lee
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "rfx_dwt.h"
void
rfx_dwt_2d_decode_block(sint16 * buffer, sint16 * idwt, int subband_width)
{
sint16 * dst, * l, * h;
sint16 * l_dst, * h_dst;
sint16 * hl, * lh, * hh, * ll;
int total_width;
int x, y;
int n;
total_width = subband_width << 1;
/* Inverse DWT in horizontal direction, results in 2 sub-bands in L, H order in tmp buffer idwt. */
/* The 4 sub-bands are stored in HL(0), LH(1), HH(2), LL(3) order. */
/* The lower part L uses LL(3) and HL(0). */
/* The higher part H uses LH(1) and HH(2). */
ll = buffer + subband_width * subband_width * 3;
hl = buffer;
l_dst = idwt;
lh = buffer + subband_width * subband_width;
hh = buffer + subband_width * subband_width * 2;
h_dst = idwt + subband_width * subband_width * 2;
for (y = 0; y < subband_width; y++)
{
/* Even coefficients */
l_dst[0] = ll[0] - ((hl[0] + hl[0] + 1) >> 1);
h_dst[0] = lh[0] - ((hh[0] + hh[0] + 1) >> 1);
for (n = 1; n < subband_width; n++)
{
x = n << 1;
l_dst[x] = ll[n] - ((hl[n-1] + hl[n] + 1) >> 1);
h_dst[x] = lh[n] - ((hh[n-1] + hh[n] + 1) >> 1);
}
/* Odd coefficients */
for (n = 0; n < subband_width-1; n++)
{
x = n << 1;
l_dst[x + 1] = (hl[n] << 1) + ((l_dst[x] + l_dst[x + 2]) >> 1);
h_dst[x + 1] = (hh[n] << 1) + ((h_dst[x] + h_dst[x + 2]) >> 1);
}
x = n << 1;
l_dst[x + 1] = (hl[n] << 1) + (l_dst[x]);
h_dst[x + 1] = (hh[n] << 1) + (h_dst[x]);
ll += subband_width;
hl += subband_width;
l_dst += total_width;
lh += subband_width;
hh += subband_width;
h_dst += total_width;
}
/* Inverse DWT in vertical direction, results are stored in original buffer. */
for (x = 0; x < total_width; x++)
{
/* Even coefficients */
for (n = 0; n < subband_width; n++)
{
y = n << 1;
dst = buffer + y * total_width + x;
l = idwt + n * total_width + x;
h = l + subband_width * total_width;
dst[0] = *l - (((n > 0 ? *(h - total_width) : *h) + (*h) + 1) >> 1);
}
/* Odd coefficients */
for (n = 0; n < subband_width; n++)
{
y = n << 1;
dst = buffer + y * total_width + x;
l = idwt + n * total_width + x;
h = l + subband_width * total_width;
dst[total_width] = (*h << 1) + ((dst[0] + dst[n < subband_width - 1 ? 2 * total_width : 0]) >> 1);
}
}
}
void
rfx_dwt_2d_decode(sint16 * buffer, sint16 * dwt_buffer_8, sint16 * dwt_buffer_16, sint16 * dwt_buffer_32)
{
rfx_dwt_2d_decode_block(buffer + 3840, dwt_buffer_8, 8);
rfx_dwt_2d_decode_block(buffer + 3072, dwt_buffer_16, 16);
rfx_dwt_2d_decode_block(buffer, dwt_buffer_32, 32);
}
void
rfx_dwt_2d_encode_block(sint16 * buffer, sint16 * dwt, int subband_width)
{
sint16 * src, * l, * h;
sint16 * l_src, * h_src;
sint16 * hl, * lh, * hh, * ll;
int total_width;
int x, y;
int n;
total_width = subband_width << 1;
/* DWT in vertical direction, results in 2 sub-bands in L, H order in tmp buffer dwt. */
for (x = 0; x < total_width; x++)
{
for (n = 0; n < subband_width; n++)
{
y = n << 1;
l = dwt + n * total_width + x;
h = l + subband_width * total_width;
src = buffer + y * total_width + x;
/* H */
*h = (src[total_width] - ((src[0] + src[n < subband_width - 1 ? 2 * total_width : 0]) >> 1)) >> 1;
/* L */
*l = src[0] + (n == 0 ? *h : (*(h - total_width) + *h) >> 1);
}
}
/* DWT in horizontal direction, results in 4 sub-bands in HL(0), LH(1), HH(2), LL(3) order, stored in original buffer. */
/* The lower part L generates LL(3) and HL(0). */
/* The higher part H generates LH(1) and HH(2). */
ll = buffer + subband_width * subband_width * 3;
hl = buffer;
l_src = dwt;
lh = buffer + subband_width * subband_width;
hh = buffer + subband_width * subband_width * 2;
h_src = dwt + subband_width * subband_width * 2;
for (y = 0; y < subband_width; y++)
{
/* L */
for (n = 0; n < subband_width; n++)
{
x = n << 1;
/* HL */
hl[n] = (l_src[x + 1] - ((l_src[x] + l_src[n < subband_width - 1 ? x + 2 : x]) >> 1)) >> 1;
/* LL */
ll[n] = l_src[x] + (n == 0 ? hl[n] : (hl[n - 1] + hl[n]) >> 1);
}
/* H */
for (n = 0; n < subband_width; n++)
{
x = n << 1;
/* HH */
hh[n] = (h_src[x + 1] - ((h_src[x] + h_src[n < subband_width - 1 ? x + 2 : x]) >> 1)) >> 1;
/* LH */
lh[n] = h_src[x] + (n == 0 ? hh[n] : (hh[n - 1] + hh[n]) >> 1);
}
ll += subband_width;
hl += subband_width;
l_src += total_width;
lh += subband_width;
hh += subband_width;
h_src += total_width;
}
}
void
rfx_dwt_2d_encode(sint16 * buffer, sint16 * dwt_buffer_8, sint16 * dwt_buffer_16, sint16 * dwt_buffer_32)
{
rfx_dwt_2d_encode_block(buffer, dwt_buffer_32, 32);
rfx_dwt_2d_encode_block(buffer + 3072, dwt_buffer_16, 16);
rfx_dwt_2d_encode_block(buffer + 3840, dwt_buffer_8, 8);
}
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