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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 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 Color conversion and scaling
39  * @{
40  *
41  * Return the LIBSWSCALE_VERSION_INT constant.
42  */
43 unsigned swscale_version(void);
44 
45 /**
46  * Return the libswscale build-time configuration.
47  */
48 const char *swscale_configuration(void);
49 
50 /**
51  * Return the libswscale license.
52  */
53 const char *swscale_license(void);
54 
55 /* values for the flags, the stuff on the command line is different */
56 #define SWS_FAST_BILINEAR 1
57 #define SWS_BILINEAR 2
58 #define SWS_BICUBIC 4
59 #define SWS_X 8
60 #define SWS_POINT 0x10
61 #define SWS_AREA 0x20
62 #define SWS_BICUBLIN 0x40
63 #define SWS_GAUSS 0x80
64 #define SWS_SINC 0x100
65 #define SWS_LANCZOS 0x200
66 #define SWS_SPLINE 0x400
67 
68 #define SWS_SRC_V_CHR_DROP_MASK 0x30000
69 #define SWS_SRC_V_CHR_DROP_SHIFT 16
70 
71 #define SWS_PARAM_DEFAULT 123456
72 
73 #define SWS_PRINT_INFO 0x1000
74 
75 //the following 3 flags are not completely implemented
76 //internal chrominace subsampling info
77 #define SWS_FULL_CHR_H_INT 0x2000
78 //input subsampling info
79 #define SWS_FULL_CHR_H_INP 0x4000
80 #define SWS_DIRECT_BGR 0x8000
81 #define SWS_ACCURATE_RND 0x40000
82 #define SWS_BITEXACT 0x80000
83 #define SWS_ERROR_DIFFUSION 0x800000
84 
85 #if FF_API_SWS_CPU_CAPS
86 /**
87  * CPU caps are autodetected now, those flags
88  * are only provided for API compatibility.
89  */
90 #define SWS_CPU_CAPS_MMX 0x80000000
91 #define SWS_CPU_CAPS_MMXEXT 0x20000000
92 #define SWS_CPU_CAPS_MMX2 0x20000000
93 #define SWS_CPU_CAPS_3DNOW 0x40000000
94 #define SWS_CPU_CAPS_ALTIVEC 0x10000000
95 #if FF_API_ARCH_BFIN
96 #define SWS_CPU_CAPS_BFIN 0x01000000
97 #endif
98 #define SWS_CPU_CAPS_SSE2 0x02000000
99 #endif
100 
101 #define SWS_MAX_REDUCE_CUTOFF 0.002
102 
103 #define SWS_CS_ITU709 1
104 #define SWS_CS_FCC 4
105 #define SWS_CS_ITU601 5
106 #define SWS_CS_ITU624 5
107 #define SWS_CS_SMPTE170M 5
108 #define SWS_CS_SMPTE240M 7
109 #define SWS_CS_DEFAULT 5
110 
111 /**
112  * Return a pointer to yuv<->rgb coefficients for the given colorspace
113  * suitable for sws_setColorspaceDetails().
114  *
115  * @param colorspace One of the SWS_CS_* macros. If invalid,
116  * SWS_CS_DEFAULT is used.
117  */
118 const int *sws_getCoefficients(int colorspace);
119 
120 // when used for filters they must have an odd number of elements
121 // coeffs cannot be shared between vectors
122 typedef struct SwsVector {
123  double *coeff; ///< pointer to the list of coefficients
124  int length; ///< number of coefficients in the vector
125 } SwsVector;
126 
127 // vectors can be shared
128 typedef struct SwsFilter {
133 } SwsFilter;
134 
135 struct SwsContext;
136 
137 /**
138  * Return a positive value if pix_fmt is a supported input format, 0
139  * otherwise.
140  */
142 
143 /**
144  * Return a positive value if pix_fmt is a supported output format, 0
145  * otherwise.
146  */
148 
149 /**
150  * @param[in] pix_fmt the pixel format
151  * @return a positive value if an endianness conversion for pix_fmt is
152  * supported, 0 otherwise.
153  */
155 
156 /**
157  * Allocate an empty SwsContext. This must be filled and passed to
158  * sws_init_context(). For filling see AVOptions, options.c and
159  * sws_setColorspaceDetails().
160  */
161 struct SwsContext *sws_alloc_context(void);
162 
163 /**
164  * Initialize the swscaler context sws_context.
165  *
166  * @return zero or positive value on success, a negative value on
167  * error
168  */
169 int sws_init_context(struct SwsContext *sws_context, SwsFilter *srcFilter, SwsFilter *dstFilter);
170 
171 /**
172  * Free the swscaler context swsContext.
173  * If swsContext is NULL, then does nothing.
174  */
175 void sws_freeContext(struct SwsContext *swsContext);
176 
177 /**
178  * Allocate and return an SwsContext. You need it to perform
179  * scaling/conversion operations using sws_scale().
180  *
181  * @param srcW the width of the source image
182  * @param srcH the height of the source image
183  * @param srcFormat the source image format
184  * @param dstW the width of the destination image
185  * @param dstH the height of the destination image
186  * @param dstFormat the destination image format
187  * @param flags specify which algorithm and options to use for rescaling
188  * @return a pointer to an allocated context, or NULL in case of error
189  * @note this function is to be removed after a saner alternative is
190  * written
191  */
193  int dstW, int dstH, enum AVPixelFormat dstFormat,
194  int flags, SwsFilter *srcFilter,
195  SwsFilter *dstFilter, const double *param);
196 
197 /**
198  * Scale the image slice in srcSlice and put the resulting scaled
199  * slice in the image in dst. A slice is a sequence of consecutive
200  * rows in an image.
201  *
202  * Slices have to be provided in sequential order, either in
203  * top-bottom or bottom-top order. If slices are provided in
204  * non-sequential order the behavior of the function is undefined.
205  *
206  * @param c the scaling context previously created with
207  * sws_getContext()
208  * @param srcSlice the array containing the pointers to the planes of
209  * the source slice
210  * @param srcStride the array containing the strides for each plane of
211  * the source image
212  * @param srcSliceY the position in the source image of the slice to
213  * process, that is the number (counted starting from
214  * zero) in the image of the first row of the slice
215  * @param srcSliceH the height of the source slice, that is the number
216  * of rows in the slice
217  * @param dst the array containing the pointers to the planes of
218  * the destination image
219  * @param dstStride the array containing the strides for each plane of
220  * the destination image
221  * @return the height of the output slice
222  */
223 int sws_scale(struct SwsContext *c, const uint8_t *const srcSlice[],
224  const int srcStride[], int srcSliceY, int srcSliceH,
225  uint8_t *const dst[], const int dstStride[]);
226 
227 /**
228  * @param dstRange flag indicating the while-black range of the output (1=jpeg / 0=mpeg)
229  * @param srcRange flag indicating the while-black range of the input (1=jpeg / 0=mpeg)
230  * @param table the yuv2rgb coefficients describing the output yuv space, normally ff_yuv2rgb_coeffs[x]
231  * @param inv_table the yuv2rgb coefficients describing the input yuv space, normally ff_yuv2rgb_coeffs[x]
232  * @param brightness 16.16 fixed point brightness correction
233  * @param contrast 16.16 fixed point contrast correction
234  * @param saturation 16.16 fixed point saturation correction
235  * @return -1 if not supported
236  */
237 int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4],
238  int srcRange, const int table[4], int dstRange,
239  int brightness, int contrast, int saturation);
240 
241 /**
242  * @return -1 if not supported
243  */
244 int sws_getColorspaceDetails(struct SwsContext *c, int **inv_table,
245  int *srcRange, int **table, int *dstRange,
246  int *brightness, int *contrast, int *saturation);
247 
248 /**
249  * Allocate and return an uninitialized vector with length coefficients.
250  */
252 
253 /**
254  * Return a normalized Gaussian curve used to filter stuff
255  * quality = 3 is high quality, lower is lower quality.
256  */
257 SwsVector *sws_getGaussianVec(double variance, double quality);
258 
259 /**
260  * Allocate and return a vector with length coefficients, all
261  * with the same value c.
262  */
263 SwsVector *sws_getConstVec(double c, int length);
264 
265 /**
266  * Allocate and return a vector with just one coefficient, with
267  * value 1.0.
268  */
270 
271 /**
272  * Scale all the coefficients of a by the scalar value.
273  */
274 void sws_scaleVec(SwsVector *a, double scalar);
275 
276 /**
277  * Scale all the coefficients of a so that their sum equals height.
278  */
279 void sws_normalizeVec(SwsVector *a, double height);
281 void sws_addVec(SwsVector *a, SwsVector *b);
282 void sws_subVec(SwsVector *a, SwsVector *b);
283 void sws_shiftVec(SwsVector *a, int shift);
284 
285 /**
286  * Allocate and return a clone of the vector a, that is a vector
287  * with the same coefficients as a.
288  */
290 
291 /**
292  * Print with av_log() a textual representation of the vector a
293  * if log_level <= av_log_level.
294  */
295 void sws_printVec2(SwsVector *a, AVClass *log_ctx, int log_level);
296 
297 void sws_freeVec(SwsVector *a);
298 
299 SwsFilter *sws_getDefaultFilter(float lumaGBlur, float chromaGBlur,
300  float lumaSharpen, float chromaSharpen,
301  float chromaHShift, float chromaVShift,
302  int verbose);
304 
305 /**
306  * Check if context can be reused, otherwise reallocate a new one.
307  *
308  * If context is NULL, just calls sws_getContext() to get a new
309  * context. Otherwise, checks if the parameters are the ones already
310  * saved in context. If that is the case, returns the current
311  * context. Otherwise, frees context and gets a new context with
312  * the new parameters.
313  *
314  * Be warned that srcFilter and dstFilter are not checked, they
315  * are assumed to remain the same.
316  */
317 struct SwsContext *sws_getCachedContext(struct SwsContext *context,
318  int srcW, int srcH, enum AVPixelFormat srcFormat,
319  int dstW, int dstH, enum AVPixelFormat dstFormat,
320  int flags, SwsFilter *srcFilter,
321  SwsFilter *dstFilter, const double *param);
322 
323 /**
324  * Convert an 8-bit paletted frame into a frame with a color depth of 32 bits.
325  *
326  * The output frame will have the same packed format as the palette.
327  *
328  * @param src source frame buffer
329  * @param dst destination frame buffer
330  * @param num_pixels number of pixels to convert
331  * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
332  */
333 void sws_convertPalette8ToPacked32(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
334 
335 /**
336  * Convert an 8-bit paletted frame into a frame with a color depth of 24 bits.
337  *
338  * With the palette format "ABCD", the destination frame ends up with the format "ABC".
339  *
340  * @param src source frame buffer
341  * @param dst destination frame buffer
342  * @param num_pixels number of pixels to convert
343  * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
344  */
345 void sws_convertPalette8ToPacked24(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
346 
347 /**
348  * Get the AVClass for swsContext. It can be used in combination with
349  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
350  *
351  * @see av_opt_find().
352  */
353 const AVClass *sws_get_class(void);
354 
355 /**
356  * @}
357  */
358 
359 #endif /* SWSCALE_SWSCALE_H */