ffmpeg/libavcodec/jpeg2000dwt.h
2024-11-08 08:30:07 -08:00

70 lines
2.3 KiB
C

/*
* Discrete wavelet transform
* Copyright (c) 2007 Kamil Nowosad
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_JPEG2000DWT_H
#define AVCODEC_JPEG2000DWT_H
/**
* @file
* Discrete wavelet transform
*/
#include <stdint.h>
#define FF_DWT_MAX_DECLVLS 32 ///< max number of decomposition levels
#define F_LFTG_K 1.230174104914001f
#define F_LFTG_X 0.812893066115961f
#define I_PRESHIFT 8
enum DWTType {
FF_DWT97,
FF_DWT53,
FF_DWT97_INT,
FF_DWT_NB
};
typedef struct DWTContext {
/// line lengths { horizontal, vertical } in consecutive decomposition levels
int linelen[FF_DWT_MAX_DECLVLS][2];
uint8_t mod[FF_DWT_MAX_DECLVLS][2]; ///< coordinates (x0, y0) of decomp. levels mod 2
uint8_t ndeclevels; ///< number of decomposition levels
uint8_t type; ///< 0 for 9/7; 1 for 5/3
int32_t *i_linebuf; ///< int buffer used by transform
float *f_linebuf; ///< float buffer used by transform
} DWTContext;
/**
* Initialize DWT.
* @param s DWT context
* @param border coordinates of transformed region {{x0, x1}, {y0, y1}}
* @param decomp_levels number of decomposition levels
* @param type 0 for DWT 9/7; 1 for DWT 5/3
*/
int ff_jpeg2000_dwt_init(DWTContext *s, int border[2][2],
int decomp_levels, int type);
int ff_dwt_encode(DWTContext *s, void *t);
int ff_dwt_decode(DWTContext *s, void *t);
void ff_dwt_destroy(DWTContext *s);
#endif /* AVCODEC_JPEG2000DWT_H */