diff options
Diffstat (limited to 'libfreerdp/codec/rfx_dwt.c')
| -rw-r--r-- | libfreerdp/codec/rfx_dwt.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/libfreerdp/codec/rfx_dwt.c b/libfreerdp/codec/rfx_dwt.c new file mode 100644 index 0000000..e79e9da --- /dev/null +++ b/libfreerdp/codec/rfx_dwt.c @@ -0,0 +1,218 @@ +/** + * 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. + */ + +#include <freerdp/config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "rfx_dwt.h" + +static void rfx_dwt_2d_decode_block(INT16* buffer, INT16* idwt, size_t subband_width) +{ + INT16* dst = NULL; + INT16* l = NULL; + INT16* h = NULL; + INT16* l_dst = NULL; + INT16* h_dst = NULL; + INT16* hl = NULL; + INT16* lh = NULL; + INT16* hh = NULL; + INT16* ll = NULL; + + const size_t 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 (size_t 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 (size_t n = 1; n < subband_width; n++) + { + const size_t 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 */ + size_t n = 0; + for (; n < subband_width - 1; n++) + { + const size_t 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); + } + + const size_t 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 (size_t x = 0; x < total_width; x++) + { + l = idwt + x; + h = idwt + x + subband_width * total_width; + dst = buffer + x; + + *dst = *l - ((*h * 2 + 1) >> 1); + + for (size_t n = 1; n < subband_width; n++) + { + l += total_width; + h += total_width; + + /* Even coefficients */ + dst[2 * total_width] = *l - ((*(h - total_width) + *h + 1) >> 1); + + /* Odd coefficients */ + dst[total_width] = (*(h - total_width) << 1) + ((*dst + dst[2 * total_width]) >> 1); + + dst += 2 * total_width; + } + + dst[total_width] = (*h << 1) + ((*dst * 2) >> 1); + } +} + +void rfx_dwt_2d_decode(INT16* buffer, INT16* dwt_buffer) +{ + WINPR_ASSERT(buffer); + WINPR_ASSERT(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, UINT32 subband_width) +{ + INT16* src = NULL; + INT16* l = NULL; + INT16* h = NULL; + INT16* l_src = NULL; + INT16* h_src = NULL; + INT16* hl = NULL; + INT16* lh = NULL; + INT16* hh = NULL; + INT16* ll = NULL; + + const UINT32 total_width = subband_width << 1; + + /* DWT in vertical direction, results in 2 sub-bands in L, H order in tmp buffer dwt. */ + for (UINT32 x = 0; x < total_width; x++) + { + for (UINT32 n = 0; n < subband_width; n++) + { + UINT32 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 (UINT32 y = 0; y < subband_width; y++) + { + /* L */ + for (UINT32 n = 0; n < subband_width; n++) + { + UINT32 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 (UINT32 n = 0; n < subband_width; n++) + { + UINT32 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) +{ + WINPR_ASSERT(buffer); + WINPR_ASSERT(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); +} |