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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 #define SWS_ERROR_DIFFUSION 0x800000
86 
87 #if FF_API_SWS_CPU_CAPS
88 /**
89  * CPU caps are autodetected now, those flags
90  * are only provided for API compatibility.
91  */
92 #define SWS_CPU_CAPS_MMX 0x80000000
93 #define SWS_CPU_CAPS_MMXEXT 0x20000000
94 #define SWS_CPU_CAPS_MMX2 0x20000000
95 #define SWS_CPU_CAPS_3DNOW 0x40000000
96 #define SWS_CPU_CAPS_ALTIVEC 0x10000000
97 #define SWS_CPU_CAPS_BFIN 0x01000000
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 #if FF_API_SWS_GETCONTEXT
178 /**
179  * Allocate and return an SwsContext. You need it to perform
180  * scaling/conversion operations using sws_scale().
181  *
182  * @param srcW the width of the source image
183  * @param srcH the height of the source image
184  * @param srcFormat the source image format
185  * @param dstW the width of the destination image
186  * @param dstH the height of the destination image
187  * @param dstFormat the destination image format
188  * @param flags specify which algorithm and options to use for rescaling
189  * @return a pointer to an allocated context, or NULL in case of error
190  * @note this function is to be removed after a saner alternative is
191  * written
192  * @deprecated Use sws_getCachedContext() instead.
193  */
195  int dstW, int dstH, enum AVPixelFormat dstFormat,
196  int flags, SwsFilter *srcFilter,
197  SwsFilter *dstFilter, const double *param);
198 #endif
199 
200 /**
201  * Scale the image slice in srcSlice and put the resulting scaled
202  * slice in the image in dst. A slice is a sequence of consecutive
203  * rows in an image.
204  *
205  * Slices have to be provided in sequential order, either in
206  * top-bottom or bottom-top order. If slices are provided in
207  * non-sequential order the behavior of the function is undefined.
208  *
209  * @param c the scaling context previously created with
210  * sws_getContext()
211  * @param srcSlice the array containing the pointers to the planes of
212  * the source slice
213  * @param srcStride the array containing the strides for each plane of
214  * the source image
215  * @param srcSliceY the position in the source image of the slice to
216  * process, that is the number (counted starting from
217  * zero) in the image of the first row of the slice
218  * @param srcSliceH the height of the source slice, that is the number
219  * of rows in the slice
220  * @param dst the array containing the pointers to the planes of
221  * the destination image
222  * @param dstStride the array containing the strides for each plane of
223  * the destination image
224  * @return the height of the output slice
225  */
226 int sws_scale(struct SwsContext *c, const uint8_t *const srcSlice[],
227  const int srcStride[], int srcSliceY, int srcSliceH,
228  uint8_t *const dst[], const int dstStride[]);
229 
230 /**
231  * @param dstRange flag indicating the while-black range of the output (1=jpeg / 0=mpeg)
232  * @param srcRange flag indicating the while-black range of the input (1=jpeg / 0=mpeg)
233  * @param table the yuv2rgb coefficients describing the output yuv space, normally ff_yuv2rgb_coeffs[x]
234  * @param inv_table the yuv2rgb coefficients describing the input yuv space, normally ff_yuv2rgb_coeffs[x]
235  * @param brightness 16.16 fixed point brightness correction
236  * @param contrast 16.16 fixed point contrast correction
237  * @param saturation 16.16 fixed point saturation correction
238  * @return -1 if not supported
239  */
240 int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4],
241  int srcRange, const int table[4], int dstRange,
242  int brightness, int contrast, int saturation);
243 
244 /**
245  * @return -1 if not supported
246  */
247 int sws_getColorspaceDetails(struct SwsContext *c, int **inv_table,
248  int *srcRange, int **table, int *dstRange,
249  int *brightness, int *contrast, int *saturation);
250 
251 /**
252  * Allocate and return an uninitialized vector with length coefficients.
253  */
255 
256 /**
257  * Return a normalized Gaussian curve used to filter stuff
258  * quality = 3 is high quality, lower is lower quality.
259  */
260 SwsVector *sws_getGaussianVec(double variance, double quality);
261 
262 /**
263  * Allocate and return a vector with length coefficients, all
264  * with the same value c.
265  */
266 SwsVector *sws_getConstVec(double c, int length);
267 
268 /**
269  * Allocate and return a vector with just one coefficient, with
270  * value 1.0.
271  */
273 
274 /**
275  * Scale all the coefficients of a by the scalar value.
276  */
277 void sws_scaleVec(SwsVector *a, double scalar);
278 
279 /**
280  * Scale all the coefficients of a so that their sum equals height.
281  */
282 void sws_normalizeVec(SwsVector *a, double height);
284 void sws_addVec(SwsVector *a, SwsVector *b);
285 void sws_subVec(SwsVector *a, SwsVector *b);
286 void sws_shiftVec(SwsVector *a, int shift);
287 
288 /**
289  * Allocate and return a clone of the vector a, that is a vector
290  * with the same coefficients as a.
291  */
293 
294 /**
295  * Print with av_log() a textual representation of the vector a
296  * if log_level <= av_log_level.
297  */
298 void sws_printVec2(SwsVector *a, AVClass *log_ctx, int log_level);
299 
300 void sws_freeVec(SwsVector *a);
301 
302 SwsFilter *sws_getDefaultFilter(float lumaGBlur, float chromaGBlur,
303  float lumaSharpen, float chromaSharpen,
304  float chromaHShift, float chromaVShift,
305  int verbose);
307 
308 /**
309  * Check if context can be reused, otherwise reallocate a new one.
310  *
311  * If context is NULL, just calls sws_getContext() to get a new
312  * context. Otherwise, checks if the parameters are the ones already
313  * saved in context. If that is the case, returns the current
314  * context. Otherwise, frees context and gets a new context with
315  * the new parameters.
316  *
317  * Be warned that srcFilter and dstFilter are not checked, they
318  * are assumed to remain the same.
319  */
320 struct SwsContext *sws_getCachedContext(struct SwsContext *context,
321  int srcW, int srcH, enum AVPixelFormat srcFormat,
322  int dstW, int dstH, enum AVPixelFormat dstFormat,
323  int flags, SwsFilter *srcFilter,
324  SwsFilter *dstFilter, const double *param);
325 
326 /**
327  * Convert an 8-bit paletted frame into a frame with a color depth of 32 bits.
328  *
329  * The output frame will have the same packed format as the palette.
330  *
331  * @param src source frame buffer
332  * @param dst destination frame buffer
333  * @param num_pixels number of pixels to convert
334  * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
335  */
336 void sws_convertPalette8ToPacked32(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
337 
338 /**
339  * Convert an 8-bit paletted frame into a frame with a color depth of 24 bits.
340  *
341  * With the palette format "ABCD", the destination frame ends up with the format "ABC".
342  *
343  * @param src source frame buffer
344  * @param dst destination frame buffer
345  * @param num_pixels number of pixels to convert
346  * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
347  */
348 void sws_convertPalette8ToPacked24(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
349 
350 /**
351  * Get the AVClass for swsContext. It can be used in combination with
352  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
353  *
354  * @see av_opt_find().
355  */
356 const AVClass *sws_get_class(void);
357 
358 /**
359  * @}
360  */
361 
362 #endif /* SWSCALE_SWSCALE_H */