1/*
2 * Copyright (C) 2001-2011 Michael Niedermayer <[email protected]>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#ifndef SWSCALE_SWSCALE_H
22#define SWSCALE_SWSCALE_H
23
24/**
25 * @file
26 * @ingroup libsws
27 * external API header
28 */
29
30#include <stdint.h>
31
32#include "libavutil/avutil.h"
33#include "libavutil/log.h"
34#include "libavutil/pixfmt.h"
35#include "version.h"
36
37/**
38 * @defgroup libsws libswscale
39 * Color conversion and scaling library.
40 *
41 * @{
42 *
43 * Return the LIBSWSCALE_VERSION_INT constant.
44 */
45unsigned swscale_version(void);
46
47/**
48 * Return the libswscale build-time configuration.
49 */
50const char *swscale_configuration(void);
51
52/**
53 * Return the libswscale license.
54 */
55const char *swscale_license(void);
56
57/* values for the flags, the stuff on the command line is different */
58#define SWS_FAST_BILINEAR 1
59#define SWS_BILINEAR 2
60#define SWS_BICUBIC 4
61#define SWS_X 8
62#define SWS_POINT 0x10
63#define SWS_AREA 0x20
64#define SWS_BICUBLIN 0x40
65#define SWS_GAUSS 0x80
66#define SWS_SINC 0x100
67#define SWS_LANCZOS 0x200
68#define SWS_SPLINE 0x400
69
70#define SWS_SRC_V_CHR_DROP_MASK 0x30000
71#define SWS_SRC_V_CHR_DROP_SHIFT 16
72
73#define SWS_PARAM_DEFAULT 123456
74
75#define SWS_PRINT_INFO 0x1000
76
77//the following 3 flags are not completely implemented
78//internal chrominance subsampling info
79#define SWS_FULL_CHR_H_INT 0x2000
80//input subsampling info
81#define SWS_FULL_CHR_H_INP 0x4000
82#define SWS_DIRECT_BGR 0x8000
83#define SWS_ACCURATE_RND 0x40000
84#define SWS_BITEXACT 0x80000
85#define SWS_ERROR_DIFFUSION 0x800000
86
87#define SWS_MAX_REDUCE_CUTOFF 0.002
88
89#define SWS_CS_ITU709 1
90#define SWS_CS_FCC 4
91#define SWS_CS_ITU601 5
92#define SWS_CS_ITU624 5
93#define SWS_CS_SMPTE170M 5
94#define SWS_CS_SMPTE240M 7
95#define SWS_CS_DEFAULT 5
96#define SWS_CS_BT2020 9
97
98/**
99 * Return a pointer to yuv<->rgb coefficients for the given colorspace
100 * suitable for sws_setColorspaceDetails().
101 *
102 * @param colorspace One of the SWS_CS_* macros. If invalid,
103 * SWS_CS_DEFAULT is used.
104 */
105const int *sws_getCoefficients(int colorspace);
106
107// when used for filters they must have an odd number of elements
108// coeffs cannot be shared between vectors
109typedef struct SwsVector {
110 double *coeff; ///< pointer to the list of coefficients
111 int length; ///< number of coefficients in the vector
112} SwsVector;
113
114// vectors can be shared
115typedef struct SwsFilter {
116 SwsVector *lumH;
117 SwsVector *lumV;
118 SwsVector *chrH;
119 SwsVector *chrV;
120} SwsFilter;
121
122struct SwsContext;
123
124/**
125 * Return a positive value if pix_fmt is a supported input format, 0
126 * otherwise.
127 */
128int sws_isSupportedInput(enum AVPixelFormat pix_fmt);
129
130/**
131 * Return a positive value if pix_fmt is a supported output format, 0
132 * otherwise.
133 */
134int sws_isSupportedOutput(enum AVPixelFormat pix_fmt);
135
136/**
137 * @param[in] pix_fmt the pixel format
138 * @return a positive value if an endianness conversion for pix_fmt is
139 * supported, 0 otherwise.
140 */
141int sws_isSupportedEndiannessConversion(enum AVPixelFormat pix_fmt);
142
143/**
144 * Allocate an empty SwsContext. This must be filled and passed to
145 * sws_init_context(). For filling see AVOptions, options.c and
146 * sws_setColorspaceDetails().
147 */
148struct SwsContext *sws_alloc_context(void);
149
150/**
151 * Initialize the swscaler context sws_context.
152 *
153 * @return zero or positive value on success, a negative value on
154 * error
155 */
156av_warn_unused_result
157int sws_init_context(struct SwsContext *sws_context, SwsFilter *srcFilter, SwsFilter *dstFilter);
158
159/**
160 * Free the swscaler context swsContext.
161 * If swsContext is NULL, then does nothing.
162 */
163void sws_freeContext(struct SwsContext *swsContext);
164
165/**
166 * Allocate and return an SwsContext. You need it to perform
167 * scaling/conversion operations using sws_scale().
168 *
169 * @param srcW the width of the source image
170 * @param srcH the height of the source image
171 * @param srcFormat the source image format
172 * @param dstW the width of the destination image
173 * @param dstH the height of the destination image
174 * @param dstFormat the destination image format
175 * @param flags specify which algorithm and options to use for rescaling
176 * @param param extra parameters to tune the used scaler
177 * For SWS_BICUBIC param[0] and [1] tune the shape of the basis
178 * function, param[0] tunes f(1) and param[1] f´(1)
179 * For SWS_GAUSS param[0] tunes the exponent and thus cutoff
180 * frequency
181 * For SWS_LANCZOS param[0] tunes the width of the window function
182 * @return a pointer to an allocated context, or NULL in case of error
183 * @note this function is to be removed after a saner alternative is
184 * written
185 */
186struct SwsContext *sws_getContext(int srcW, int srcH, enum AVPixelFormat srcFormat,
187 int dstW, int dstH, enum AVPixelFormat dstFormat,
188 int flags, SwsFilter *srcFilter,
189 SwsFilter *dstFilter, const double *param);
190
191/**
192 * Scale the image slice in srcSlice and put the resulting scaled
193 * slice in the image in dst. A slice is a sequence of consecutive
194 * rows in an image.
195 *
196 * Slices have to be provided in sequential order, either in
197 * top-bottom or bottom-top order. If slices are provided in
198 * non-sequential order the behavior of the function is undefined.
199 *
200 * @param c the scaling context previously created with
201 * sws_getContext()
202 * @param srcSlice the array containing the pointers to the planes of
203 * the source slice
204 * @param srcStride the array containing the strides for each plane of
205 * the source image
206 * @param srcSliceY the position in the source image of the slice to
207 * process, that is the number (counted starting from
208 * zero) in the image of the first row of the slice
209 * @param srcSliceH the height of the source slice, that is the number
210 * of rows in the slice
211 * @param dst the array containing the pointers to the planes of
212 * the destination image
213 * @param dstStride the array containing the strides for each plane of
214 * the destination image
215 * @return the height of the output slice
216 */
217int sws_scale(struct SwsContext *c, const uint8_t *const srcSlice[],
218 const int srcStride[], int srcSliceY, int srcSliceH,
219 uint8_t *const dst[], const int dstStride[]);
220
221/**
222 * @param dstRange flag indicating the while-black range of the output (1=jpeg / 0=mpeg)
223 * @param srcRange flag indicating the while-black range of the input (1=jpeg / 0=mpeg)
224 * @param table the yuv2rgb coefficients describing the output yuv space, normally ff_yuv2rgb_coeffs[x]
225 * @param inv_table the yuv2rgb coefficients describing the input yuv space, normally ff_yuv2rgb_coeffs[x]
226 * @param brightness 16.16 fixed point brightness correction
227 * @param contrast 16.16 fixed point contrast correction
228 * @param saturation 16.16 fixed point saturation correction
229 * @return -1 if not supported
230 */
231int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4],
232 int srcRange, const int table[4], int dstRange,
233 int brightness, int contrast, int saturation);
234
235/**
236 * @return -1 if not supported
237 */
238int sws_getColorspaceDetails(struct SwsContext *c, int **inv_table,
239 int *srcRange, int **table, int *dstRange,
240 int *brightness, int *contrast, int *saturation);
241
242/**
243 * Allocate and return an uninitialized vector with length coefficients.
244 */
245SwsVector *sws_allocVec(int length);
246
247/**
248 * Return a normalized Gaussian curve used to filter stuff
249 * quality = 3 is high quality, lower is lower quality.
250 */
251SwsVector *sws_getGaussianVec(double variance, double quality);
252
253/**
254 * Scale all the coefficients of a by the scalar value.
255 */
256void sws_scaleVec(SwsVector *a, double scalar);
257
258/**
259 * Scale all the coefficients of a so that their sum equals height.
260 */
261void sws_normalizeVec(SwsVector *a, double height);
262
263#if FF_API_SWS_VECTOR
264attribute_deprecated SwsVector *sws_getConstVec(double c, int length);
265attribute_deprecated SwsVector *sws_getIdentityVec(void);
266attribute_deprecated void sws_convVec(SwsVector *a, SwsVector *b);
267attribute_deprecated void sws_addVec(SwsVector *a, SwsVector *b);
268attribute_deprecated void sws_subVec(SwsVector *a, SwsVector *b);
269attribute_deprecated void sws_shiftVec(SwsVector *a, int shift);
270attribute_deprecated SwsVector *sws_cloneVec(SwsVector *a);
271attribute_deprecated void sws_printVec2(SwsVector *a, AVClass *log_ctx, int log_level);
272#endif
273
274void sws_freeVec(SwsVector *a);
275
276SwsFilter *sws_getDefaultFilter(float lumaGBlur, float chromaGBlur,
277 float lumaSharpen, float chromaSharpen,
278 float chromaHShift, float chromaVShift,
279 int verbose);
280void sws_freeFilter(SwsFilter *filter);
281
282/**
283 * Check if context can be reused, otherwise reallocate a new one.
284 *
285 * If context is NULL, just calls sws_getContext() to get a new
286 * context. Otherwise, checks if the parameters are the ones already
287 * saved in context. If that is the case, returns the current
288 * context. Otherwise, frees context and gets a new context with
289 * the new parameters.
290 *
291 * Be warned that srcFilter and dstFilter are not checked, they
292 * are assumed to remain the same.
293 */
294struct SwsContext *sws_getCachedContext(struct SwsContext *context,
295 int srcW, int srcH, enum AVPixelFormat srcFormat,
296 int dstW, int dstH, enum AVPixelFormat dstFormat,
297 int flags, SwsFilter *srcFilter,
298 SwsFilter *dstFilter, const double *param);
299
300/**
301 * Convert an 8-bit paletted frame into a frame with a color depth of 32 bits.
302 *
303 * The output frame will have the same packed format as the palette.
304 *
305 * @param src source frame buffer
306 * @param dst destination frame buffer
307 * @param num_pixels number of pixels to convert
308 * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
309 */
310void sws_convertPalette8ToPacked32(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
311
312/**
313 * Convert an 8-bit paletted frame into a frame with a color depth of 24 bits.
314 *
315 * With the palette format "ABCD", the destination frame ends up with the format "ABC".
316 *
317 * @param src source frame buffer
318 * @param dst destination frame buffer
319 * @param num_pixels number of pixels to convert
320 * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
321 */
322void sws_convertPalette8ToPacked24(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
323
324/**
325 * Get the AVClass for swsContext. It can be used in combination with
326 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
327 *
328 * @see av_opt_find().
329 */
330const AVClass *sws_get_class(void);
331
332/**
333 * @}
334 */
335
336#endif /* SWSCALE_SWSCALE_H */
337

source code of include/x86_64-linux-gnu/libswscale/swscale.h