/** * FreeRDP: A Remote Desktop Protocol Implementation * 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. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <stdio.h> #include <stdlib.h> #include <string.h> #include "rfx_dwt.h" static void rfx_dwt_2d_decode_block(INT16* buffer, INT16* idwt, int subband_width) { INT16 *dst, *l, *h; INT16 *l_dst, *h_dst; INT16 *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(INT16* buffer, INT16* dwt_buffer) { rfx_dwt_2d_decode_block(&buffer[3840], dwt_buffer, 8); rfx_dwt_2d_decode_block(&buffer[3072], dwt_buffer, 16); rfx_dwt_2d_decode_block(&buffer[0], dwt_buffer, 32); } static void rfx_dwt_2d_encode_block(INT16* buffer, INT16* dwt, int subband_width) { INT16 *src, *l, *h; INT16 *l_src, *h_src; INT16 *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(INT16* buffer, INT16* dwt_buffer) { rfx_dwt_2d_encode_block(&buffer[0], dwt_buffer, 32); rfx_dwt_2d_encode_block(&buffer[3072], dwt_buffer, 16); rfx_dwt_2d_encode_block(&buffer[3840], dwt_buffer, 8); }