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swscale.h
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1 /*
2  * Copyright (C) 2001-2011 Michael Niedermayer <michaelni@gmx.at>
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 lsws
27  * external API header
28  */
29 
30 /**
31  * @defgroup lsws Libswscale
32  * @{
33  */
34 
35 #include <stdint.h>
36 
37 #include "libavutil/avutil.h"
38 #include "libavutil/log.h"
39 #include "libavutil/pixfmt.h"
40 #include "version.h"
41 
42 /**
43  * Return the LIBSWSCALE_VERSION_INT constant.
44  */
45 unsigned swscale_version(void);
46 
47 /**
48  * Return the libswscale build-time configuration.
49  */
50 const char *swscale_configuration(void);
51 
52 /**
53  * Return the libswscale license.
54  */
55 const 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 chrominace 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 
86 #if FF_API_SWS_CPU_CAPS
87 /**
88  * CPU caps are autodetected now, those flags
89  * are only provided for API compatibility.
90  */
91 #define SWS_CPU_CAPS_MMX 0x80000000
92 #define SWS_CPU_CAPS_MMXEXT 0x20000000
93 #define SWS_CPU_CAPS_MMX2 0x20000000
94 #define SWS_CPU_CAPS_3DNOW 0x40000000
95 #define SWS_CPU_CAPS_ALTIVEC 0x10000000
96 #define SWS_CPU_CAPS_BFIN 0x01000000
97 #define SWS_CPU_CAPS_SSE2 0x02000000
98 #endif
99 
100 #define SWS_MAX_REDUCE_CUTOFF 0.002
101 
102 #define SWS_CS_ITU709 1
103 #define SWS_CS_FCC 4
104 #define SWS_CS_ITU601 5
105 #define SWS_CS_ITU624 5
106 #define SWS_CS_SMPTE170M 5
107 #define SWS_CS_SMPTE240M 7
108 #define SWS_CS_DEFAULT 5
109 
110 /**
111  * Return a pointer to yuv<->rgb coefficients for the given colorspace
112  * suitable for sws_setColorspaceDetails().
113  *
114  * @param colorspace One of the SWS_CS_* macros. If invalid,
115  * SWS_CS_DEFAULT is used.
116  */
117 const int *sws_getCoefficients(int colorspace);
118 
119 // when used for filters they must have an odd number of elements
120 // coeffs cannot be shared between vectors
121 typedef struct SwsVector {
122  double *coeff; ///< pointer to the list of coefficients
123  int length; ///< number of coefficients in the vector
124 } SwsVector;
125 
126 // vectors can be shared
127 typedef struct SwsFilter {
132 } SwsFilter;
133 
134 struct SwsContext;
135 
136 /**
137  * Return a positive value if pix_fmt is a supported input format, 0
138  * otherwise.
139  */
141 
142 /**
143  * Return a positive value if pix_fmt is a supported output format, 0
144  * otherwise.
145  */
147 
148 /**
149  * Allocate an empty SwsContext. This must be filled and passed to
150  * sws_init_context(). For filling see AVOptions, options.c and
151  * sws_setColorspaceDetails().
152  */
153 struct SwsContext *sws_alloc_context(void);
154 
155 /**
156  * Initialize the swscaler context sws_context.
157  *
158  * @return zero or positive value on success, a negative value on
159  * error
160  */
161 int sws_init_context(struct SwsContext *sws_context, SwsFilter *srcFilter, SwsFilter *dstFilter);
162 
163 /**
164  * Free the swscaler context swsContext.
165  * If swsContext is NULL, then does nothing.
166  */
167 void sws_freeContext(struct SwsContext *swsContext);
168 
169 #if FF_API_SWS_GETCONTEXT
170 /**
171  * Allocate and return an SwsContext. You need it to perform
172  * scaling/conversion operations using sws_scale().
173  *
174  * @param srcW the width of the source image
175  * @param srcH the height of the source image
176  * @param srcFormat the source image format
177  * @param dstW the width of the destination image
178  * @param dstH the height of the destination image
179  * @param dstFormat the destination image format
180  * @param flags specify which algorithm and options to use for rescaling
181  * @return a pointer to an allocated context, or NULL in case of error
182  * @note this function is to be removed after a saner alternative is
183  * written
184  * @deprecated Use sws_getCachedContext() instead.
185  */
187  int dstW, int dstH, enum AVPixelFormat dstFormat,
188  int flags, SwsFilter *srcFilter,
189  SwsFilter *dstFilter, const double *param);
190 #endif
191 
192 /**
193  * Scale the image slice in srcSlice and put the resulting scaled
194  * slice in the image in dst. A slice is a sequence of consecutive
195  * rows in an image.
196  *
197  * Slices have to be provided in sequential order, either in
198  * top-bottom or bottom-top order. If slices are provided in
199  * non-sequential order the behavior of the function is undefined.
200  *
201  * @param c the scaling context previously created with
202  * sws_getContext()
203  * @param srcSlice the array containing the pointers to the planes of
204  * the source slice
205  * @param srcStride the array containing the strides for each plane of
206  * the source image
207  * @param srcSliceY the position in the source image of the slice to
208  * process, that is the number (counted starting from
209  * zero) in the image of the first row of the slice
210  * @param srcSliceH the height of the source slice, that is the number
211  * of rows in the slice
212  * @param dst the array containing the pointers to the planes of
213  * the destination image
214  * @param dstStride the array containing the strides for each plane of
215  * the destination image
216  * @return the height of the output slice
217  */
218 int sws_scale(struct SwsContext *c, const uint8_t *const srcSlice[],
219  const int srcStride[], int srcSliceY, int srcSliceH,
220  uint8_t *const dst[], const int dstStride[]);
221 
222 /**
223  * @param dstRange flag indicating the while-black range of the output (1=jpeg / 0=mpeg)
224  * @param srcRange flag indicating the while-black range of the input (1=jpeg / 0=mpeg)
225  * @param table the yuv2rgb coefficients describing the output yuv space, normally ff_yuv2rgb_coeffs[x]
226  * @param inv_table the yuv2rgb coefficients describing the input yuv space, normally ff_yuv2rgb_coeffs[x]
227  * @param brightness 16.16 fixed point brightness correction
228  * @param contrast 16.16 fixed point contrast correction
229  * @param saturation 16.16 fixed point saturation correction
230  * @return -1 if not supported
231  */
232 int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4],
233  int srcRange, const int table[4], int dstRange,
234  int brightness, int contrast, int saturation);
235 
236 /**
237  * @return -1 if not supported
238  */
239 int sws_getColorspaceDetails(struct SwsContext *c, int **inv_table,
240  int *srcRange, int **table, int *dstRange,
241  int *brightness, int *contrast, int *saturation);
242 
243 /**
244  * Allocate and return an uninitialized vector with length coefficients.
245  */
246 SwsVector *sws_allocVec(int length);
247 
248 /**
249  * Return a normalized Gaussian curve used to filter stuff
250  * quality = 3 is high quality, lower is lower quality.
251  */
252 SwsVector *sws_getGaussianVec(double variance, double quality);
253 
254 /**
255  * Allocate and return a vector with length coefficients, all
256  * with the same value c.
257  */
258 SwsVector *sws_getConstVec(double c, int length);
259 
260 /**
261  * Allocate and return a vector with just one coefficient, with
262  * value 1.0.
263  */
265 
266 /**
267  * Scale all the coefficients of a by the scalar value.
268  */
269 void sws_scaleVec(SwsVector *a, double scalar);
270 
271 /**
272  * Scale all the coefficients of a so that their sum equals height.
273  */
274 void sws_normalizeVec(SwsVector *a, double height);
276 void sws_addVec(SwsVector *a, SwsVector *b);
277 void sws_subVec(SwsVector *a, SwsVector *b);
278 void sws_shiftVec(SwsVector *a, int shift);
279 
280 /**
281  * Allocate and return a clone of the vector a, that is a vector
282  * with the same coefficients as a.
283  */
285 
286 /**
287  * Print with av_log() a textual representation of the vector a
288  * if log_level <= av_log_level.
289  */
290 void sws_printVec2(SwsVector *a, AVClass *log_ctx, int log_level);
291 
292 void sws_freeVec(SwsVector *a);
293 
294 SwsFilter *sws_getDefaultFilter(float lumaGBlur, float chromaGBlur,
295  float lumaSharpen, float chromaSharpen,
296  float chromaHShift, float chromaVShift,
297  int verbose);
299 
300 /**
301  * Check if context can be reused, otherwise reallocate a new one.
302  *
303  * If context is NULL, just calls sws_getContext() to get a new
304  * context. Otherwise, checks if the parameters are the ones already
305  * saved in context. If that is the case, returns the current
306  * context. Otherwise, frees context and gets a new context with
307  * the new parameters.
308  *
309  * Be warned that srcFilter and dstFilter are not checked, they
310  * are assumed to remain the same.
311  */
312 struct SwsContext *sws_getCachedContext(struct SwsContext *context,
313  int srcW, int srcH, enum AVPixelFormat srcFormat,
314  int dstW, int dstH, enum AVPixelFormat dstFormat,
315  int flags, SwsFilter *srcFilter,
316  SwsFilter *dstFilter, const double *param);
317 
318 /**
319  * Convert an 8-bit paletted frame into a frame with a color depth of 32 bits.
320  *
321  * The output frame will have the same packed format as the palette.
322  *
323  * @param src source frame buffer
324  * @param dst destination frame buffer
325  * @param num_pixels number of pixels to convert
326  * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
327  */
328 void sws_convertPalette8ToPacked32(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
329 
330 /**
331  * Convert an 8-bit paletted frame into a frame with a color depth of 24 bits.
332  *
333  * With the palette format "ABCD", the destination frame ends up with the format "ABC".
334  *
335  * @param src source frame buffer
336  * @param dst destination frame buffer
337  * @param num_pixels number of pixels to convert
338  * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
339  */
340 void sws_convertPalette8ToPacked24(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
341 
342 /**
343  * Get the AVClass for swsContext. It can be used in combination with
344  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
345  *
346  * @see av_opt_find().
347  */
348 const AVClass *sws_get_class(void);
349 
350 /**
351  * @}
352  */
353 
354 #endif /* SWSCALE_SWSCALE_H */