FFmpeg
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/frame.h"
34 #include "libavutil/log.h"
35 #include "libavutil/pixfmt.h"
36 #include "version_major.h"
37 #ifndef HAVE_AV_CONFIG_H
38 /* When included as part of the ffmpeg build, only include the major version
39  * to avoid unnecessary rebuilds. When included externally, keep including
40  * the full version information. */
41 #include "version.h"
42 #endif
43 
44 /**
45  * @defgroup libsws libswscale
46  * Color conversion and scaling library.
47  *
48  * @{
49  *
50  * Return the LIBSWSCALE_VERSION_INT constant.
51  */
52 unsigned swscale_version(void);
53 
54 /**
55  * Return the libswscale build-time configuration.
56  */
57 const char *swscale_configuration(void);
58 
59 /**
60  * Return the libswscale license.
61  */
62 const char *swscale_license(void);
63 
64 /* values for the flags, the stuff on the command line is different */
65 #define SWS_FAST_BILINEAR 1
66 #define SWS_BILINEAR 2
67 #define SWS_BICUBIC 4
68 #define SWS_X 8
69 #define SWS_POINT 0x10
70 #define SWS_AREA 0x20
71 #define SWS_BICUBLIN 0x40
72 #define SWS_GAUSS 0x80
73 #define SWS_SINC 0x100
74 #define SWS_LANCZOS 0x200
75 #define SWS_SPLINE 0x400
76 
77 #define SWS_SRC_V_CHR_DROP_MASK 0x30000
78 #define SWS_SRC_V_CHR_DROP_SHIFT 16
79 
80 #define SWS_PARAM_DEFAULT 123456
81 
82 #define SWS_PRINT_INFO 0x1000
83 
84 //the following 3 flags are not completely implemented
85 //internal chrominance subsampling info
86 #define SWS_FULL_CHR_H_INT 0x2000
87 //input subsampling info
88 #define SWS_FULL_CHR_H_INP 0x4000
89 #define SWS_DIRECT_BGR 0x8000
90 #define SWS_ACCURATE_RND 0x40000
91 #define SWS_BITEXACT 0x80000
92 #define SWS_ERROR_DIFFUSION 0x800000
93 
94 #define SWS_MAX_REDUCE_CUTOFF 0.002
95 
96 #define SWS_CS_ITU709 1
97 #define SWS_CS_FCC 4
98 #define SWS_CS_ITU601 5
99 #define SWS_CS_ITU624 5
100 #define SWS_CS_SMPTE170M 5
101 #define SWS_CS_SMPTE240M 7
102 #define SWS_CS_DEFAULT 5
103 #define SWS_CS_BT2020 9
104 
105 /**
106  * Return a pointer to yuv<->rgb coefficients for the given colorspace
107  * suitable for sws_setColorspaceDetails().
108  *
109  * @param colorspace One of the SWS_CS_* macros. If invalid,
110  * SWS_CS_DEFAULT is used.
111  */
112 const int *sws_getCoefficients(int colorspace);
113 
114 // when used for filters they must have an odd number of elements
115 // coeffs cannot be shared between vectors
116 typedef struct SwsVector {
117  double *coeff; ///< pointer to the list of coefficients
118  int length; ///< number of coefficients in the vector
119 } SwsVector;
120 
121 // vectors can be shared
122 typedef struct SwsFilter {
127 } SwsFilter;
128 
129 struct SwsContext;
130 
131 /**
132  * Return a positive value if pix_fmt is a supported input format, 0
133  * otherwise.
134  */
136 
137 /**
138  * Return a positive value if pix_fmt is a supported output format, 0
139  * otherwise.
140  */
142 
143 /**
144  * @param[in] pix_fmt the pixel format
145  * @return a positive value if an endianness conversion for pix_fmt is
146  * supported, 0 otherwise.
147  */
149 
150 /**
151  * Allocate an empty SwsContext. This must be filled and passed to
152  * sws_init_context(). For filling see AVOptions, options.c and
153  * sws_setColorspaceDetails().
154  */
155 struct SwsContext *sws_alloc_context(void);
156 
157 /**
158  * Initialize the swscaler context sws_context.
159  *
160  * @return zero or positive value on success, a negative value on
161  * error
162  */
164 int sws_init_context(struct SwsContext *sws_context, SwsFilter *srcFilter, SwsFilter *dstFilter);
165 
166 /**
167  * Free the swscaler context swsContext.
168  * If swsContext is NULL, then does nothing.
169  */
170 void sws_freeContext(struct SwsContext *swsContext);
171 
172 /**
173  * Allocate and return an SwsContext. You need it to perform
174  * scaling/conversion operations using sws_scale().
175  *
176  * @param srcW the width of the source image
177  * @param srcH the height of the source image
178  * @param srcFormat the source image format
179  * @param dstW the width of the destination image
180  * @param dstH the height of the destination image
181  * @param dstFormat the destination image format
182  * @param flags specify which algorithm and options to use for rescaling
183  * @param param extra parameters to tune the used scaler
184  * For SWS_BICUBIC param[0] and [1] tune the shape of the basis
185  * function, param[0] tunes f(1) and param[1] f´(1)
186  * For SWS_GAUSS param[0] tunes the exponent and thus cutoff
187  * frequency
188  * For SWS_LANCZOS param[0] tunes the width of the window function
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  */
193 struct SwsContext *sws_getContext(int srcW, int srcH, enum AVPixelFormat srcFormat,
194  int dstW, int dstH, enum AVPixelFormat dstFormat,
195  int flags, SwsFilter *srcFilter,
196  SwsFilter *dstFilter, const double *param);
197 
198 /**
199  * Scale the image slice in srcSlice and put the resulting scaled
200  * slice in the image in dst. A slice is a sequence of consecutive
201  * rows in an image.
202  *
203  * Slices have to be provided in sequential order, either in
204  * top-bottom or bottom-top order. If slices are provided in
205  * non-sequential order the behavior of the function is undefined.
206  *
207  * @param c the scaling context previously created with
208  * sws_getContext()
209  * @param srcSlice the array containing the pointers to the planes of
210  * the source slice
211  * @param srcStride the array containing the strides for each plane of
212  * the source image
213  * @param srcSliceY the position in the source image of the slice to
214  * process, that is the number (counted starting from
215  * zero) in the image of the first row of the slice
216  * @param srcSliceH the height of the source slice, that is the number
217  * of rows in the slice
218  * @param dst the array containing the pointers to the planes of
219  * the destination image
220  * @param dstStride the array containing the strides for each plane of
221  * the destination image
222  * @return the height of the output slice
223  */
224 int sws_scale(struct SwsContext *c, const uint8_t *const srcSlice[],
225  const int srcStride[], int srcSliceY, int srcSliceH,
226  uint8_t *const dst[], const int dstStride[]);
227 
228 /**
229  * Scale source data from src and write the output to dst.
230  *
231  * This is merely a convenience wrapper around
232  * - sws_frame_start()
233  * - sws_send_slice(0, src->height)
234  * - sws_receive_slice(0, dst->height)
235  * - sws_frame_end()
236  *
237  * @param c The scaling context
238  * @param dst The destination frame. See documentation for sws_frame_start() for
239  * more details.
240  * @param src The source frame.
241  *
242  * @return 0 on success, a negative AVERROR code on failure
243  */
244 int sws_scale_frame(struct SwsContext *c, AVFrame *dst, const AVFrame *src);
245 
246 /**
247  * Initialize the scaling process for a given pair of source/destination frames.
248  * Must be called before any calls to sws_send_slice() and sws_receive_slice().
249  *
250  * This function will retain references to src and dst, so they must both use
251  * refcounted buffers (if allocated by the caller, in case of dst).
252  *
253  * @param c The scaling context
254  * @param dst The destination frame.
255  *
256  * The data buffers may either be already allocated by the caller or
257  * left clear, in which case they will be allocated by the scaler.
258  * The latter may have performance advantages - e.g. in certain cases
259  * some output planes may be references to input planes, rather than
260  * copies.
261  *
262  * Output data will be written into this frame in successful
263  * sws_receive_slice() calls.
264  * @param src The source frame. The data buffers must be allocated, but the
265  * frame data does not have to be ready at this point. Data
266  * availability is then signalled by sws_send_slice().
267  * @return 0 on success, a negative AVERROR code on failure
268  *
269  * @see sws_frame_end()
270  */
271 int sws_frame_start(struct SwsContext *c, AVFrame *dst, const AVFrame *src);
272 
273 /**
274  * Finish the scaling process for a pair of source/destination frames previously
275  * submitted with sws_frame_start(). Must be called after all sws_send_slice()
276  * and sws_receive_slice() calls are done, before any new sws_frame_start()
277  * calls.
278  *
279  * @param c The scaling context
280  */
281 void sws_frame_end(struct SwsContext *c);
282 
283 /**
284  * Indicate that a horizontal slice of input data is available in the source
285  * frame previously provided to sws_frame_start(). The slices may be provided in
286  * any order, but may not overlap. For vertically subsampled pixel formats, the
287  * slices must be aligned according to subsampling.
288  *
289  * @param c The scaling context
290  * @param slice_start first row of the slice
291  * @param slice_height number of rows in the slice
292  *
293  * @return a non-negative number on success, a negative AVERROR code on failure.
294  */
295 int sws_send_slice(struct SwsContext *c, unsigned int slice_start,
296  unsigned int slice_height);
297 
298 /**
299  * Request a horizontal slice of the output data to be written into the frame
300  * previously provided to sws_frame_start().
301  *
302  * @param c The scaling context
303  * @param slice_start first row of the slice; must be a multiple of
304  * sws_receive_slice_alignment()
305  * @param slice_height number of rows in the slice; must be a multiple of
306  * sws_receive_slice_alignment(), except for the last slice
307  * (i.e. when slice_start+slice_height is equal to output
308  * frame height)
309  *
310  * @return a non-negative number if the data was successfully written into the output
311  * AVERROR(EAGAIN) if more input data needs to be provided before the
312  * output can be produced
313  * another negative AVERROR code on other kinds of scaling failure
314  */
315 int sws_receive_slice(struct SwsContext *c, unsigned int slice_start,
316  unsigned int slice_height);
317 
318 /**
319  * Get the alignment required for slices
320  *
321  * @param c The scaling context
322  * @return alignment required for output slices requested with sws_receive_slice().
323  * Slice offsets and sizes passed to sws_receive_slice() must be
324  * multiples of the value returned from this function.
325  */
326 unsigned int sws_receive_slice_alignment(const struct SwsContext *c);
327 
328 /**
329  * @param c the scaling context
330  * @param dstRange flag indicating the while-black range of the output (1=jpeg / 0=mpeg)
331  * @param srcRange flag indicating the while-black range of the input (1=jpeg / 0=mpeg)
332  * @param table the yuv2rgb coefficients describing the output yuv space, normally ff_yuv2rgb_coeffs[x]
333  * @param inv_table the yuv2rgb coefficients describing the input yuv space, normally ff_yuv2rgb_coeffs[x]
334  * @param brightness 16.16 fixed point brightness correction
335  * @param contrast 16.16 fixed point contrast correction
336  * @param saturation 16.16 fixed point saturation correction
337  *
338  * @return A negative error code on error, non negative otherwise.
339  * If `LIBSWSCALE_VERSION_MAJOR < 7`, returns -1 if not supported.
340  */
341 int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4],
342  int srcRange, const int table[4], int dstRange,
343  int brightness, int contrast, int saturation);
344 
345 /**
346  * @return A negative error code on error, non negative otherwise.
347  * If `LIBSWSCALE_VERSION_MAJOR < 7`, returns -1 if not supported.
348  */
349 int sws_getColorspaceDetails(struct SwsContext *c, int **inv_table,
350  int *srcRange, int **table, int *dstRange,
351  int *brightness, int *contrast, int *saturation);
352 
353 /**
354  * Allocate and return an uninitialized vector with length coefficients.
355  */
356 SwsVector *sws_allocVec(int length);
357 
358 /**
359  * Return a normalized Gaussian curve used to filter stuff
360  * quality = 3 is high quality, lower is lower quality.
361  */
362 SwsVector *sws_getGaussianVec(double variance, double quality);
363 
364 /**
365  * Scale all the coefficients of a by the scalar value.
366  */
367 void sws_scaleVec(SwsVector *a, double scalar);
368 
369 /**
370  * Scale all the coefficients of a so that their sum equals height.
371  */
373 
375 
376 SwsFilter *sws_getDefaultFilter(float lumaGBlur, float chromaGBlur,
377  float lumaSharpen, float chromaSharpen,
378  float chromaHShift, float chromaVShift,
379  int verbose);
380 void sws_freeFilter(SwsFilter *filter);
381 
382 /**
383  * Check if context can be reused, otherwise reallocate a new one.
384  *
385  * If context is NULL, just calls sws_getContext() to get a new
386  * context. Otherwise, checks if the parameters are the ones already
387  * saved in context. If that is the case, returns the current
388  * context. Otherwise, frees context and gets a new context with
389  * the new parameters.
390  *
391  * Be warned that srcFilter and dstFilter are not checked, they
392  * are assumed to remain the same.
393  */
394 struct SwsContext *sws_getCachedContext(struct SwsContext *context,
395  int srcW, int srcH, enum AVPixelFormat srcFormat,
396  int dstW, int dstH, enum AVPixelFormat dstFormat,
397  int flags, SwsFilter *srcFilter,
398  SwsFilter *dstFilter, const double *param);
399 
400 /**
401  * Convert an 8-bit paletted frame into a frame with a color depth of 32 bits.
402  *
403  * The output frame will have the same packed format as the palette.
404  *
405  * @param src source frame buffer
406  * @param dst destination frame buffer
407  * @param num_pixels number of pixels to convert
408  * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
409  */
410 void sws_convertPalette8ToPacked32(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
411 
412 /**
413  * Convert an 8-bit paletted frame into a frame with a color depth of 24 bits.
414  *
415  * With the palette format "ABCD", the destination frame ends up with the format "ABC".
416  *
417  * @param src source frame buffer
418  * @param dst destination frame buffer
419  * @param num_pixels number of pixels to convert
420  * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
421  */
422 void sws_convertPalette8ToPacked24(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
423 
424 /**
425  * Get the AVClass for swsContext. It can be used in combination with
426  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
427  *
428  * @see av_opt_find().
429  */
430 const AVClass *sws_get_class(void);
431 
432 /**
433  * @}
434  */
435 
436 #endif /* SWSCALE_SWSCALE_H */
#define av_warn_unused_result
Definition: attributes.h:62
Convenience header that includes libavutil's core.
static enum AVPixelFormat pix_fmt
Definition: demux_decode.c:41
static int height
Definition: demux_decode.c:40
reference-counted frame API
int sws_getColorspaceDetails(struct SwsContext *c, int **inv_table, int *srcRange, int **table, int *dstRange, int *brightness, int *contrast, int *saturation)
const AVClass * sws_get_class(void)
Get the AVClass for swsContext.
void sws_freeFilter(SwsFilter *filter)
int sws_send_slice(struct SwsContext *c, unsigned int slice_start, unsigned int slice_height)
Indicate that a horizontal slice of input data is available in the source frame previously provided t...
int sws_scale_frame(struct SwsContext *c, AVFrame *dst, const AVFrame *src)
Scale source data from src and write the output to dst.
av_warn_unused_result int sws_init_context(struct SwsContext *sws_context, SwsFilter *srcFilter, SwsFilter *dstFilter)
Initialize the swscaler context sws_context.
unsigned int sws_receive_slice_alignment(const struct SwsContext *c)
Get the alignment required for slices.
SwsVector * sws_getGaussianVec(double variance, double quality)
Return a normalized Gaussian curve used to filter stuff quality = 3 is high quality,...
void sws_convertPalette8ToPacked32(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette)
Convert an 8-bit paletted frame into a frame with a color depth of 32 bits.
void sws_convertPalette8ToPacked24(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette)
Convert an 8-bit paletted frame into a frame with a color depth of 24 bits.
void sws_frame_end(struct SwsContext *c)
Finish the scaling process for a pair of source/destination frames previously submitted with sws_fram...
int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4], int srcRange, const int table[4], int dstRange, int brightness, int contrast, int saturation)
void sws_freeVec(SwsVector *a)
int sws_isSupportedEndiannessConversion(enum AVPixelFormat pix_fmt)
int sws_isSupportedOutput(enum AVPixelFormat pix_fmt)
Return a positive value if pix_fmt is a supported output format, 0 otherwise.
SwsVector * sws_allocVec(int length)
Allocate and return an uninitialized vector with length coefficients.
int sws_receive_slice(struct SwsContext *c, unsigned int slice_start, unsigned int slice_height)
Request a horizontal slice of the output data to be written into the frame previously provided to sws...
const char * swscale_license(void)
Return the libswscale license.
const char * swscale_configuration(void)
Return the libswscale build-time configuration.
void sws_normalizeVec(SwsVector *a, double height)
Scale all the coefficients of a so that their sum equals height.
int sws_isSupportedInput(enum AVPixelFormat pix_fmt)
Return a positive value if pix_fmt is a supported input format, 0 otherwise.
SwsFilter * sws_getDefaultFilter(float lumaGBlur, float chromaGBlur, float lumaSharpen, float chromaSharpen, float chromaHShift, float chromaVShift, int verbose)
struct SwsContext * sws_alloc_context(void)
Allocate an empty SwsContext.
int sws_frame_start(struct SwsContext *c, AVFrame *dst, const AVFrame *src)
Initialize the scaling process for a given pair of source/destination frames.
const int * sws_getCoefficients(int colorspace)
Return a pointer to yuv<->rgb coefficients for the given colorspace suitable for sws_setColorspaceDet...
unsigned swscale_version(void)
void sws_freeContext(struct SwsContext *swsContext)
Free the swscaler context swsContext.
struct SwsContext * sws_getCachedContext(struct SwsContext *context, int srcW, int srcH, enum AVPixelFormat srcFormat, int dstW, int dstH, enum AVPixelFormat dstFormat, int flags, SwsFilter *srcFilter, SwsFilter *dstFilter, const double *param)
Check if context can be reused, otherwise reallocate a new one.
int sws_scale(struct SwsContext *c, const uint8_t *const srcSlice[], const int srcStride[], int srcSliceY, int srcSliceH, uint8_t *const dst[], const int dstStride[])
Scale the image slice in srcSlice and put the resulting scaled slice in the image in dst.
struct SwsContext * sws_getContext(int srcW, int srcH, enum AVPixelFormat srcFormat, int dstW, int dstH, enum AVPixelFormat dstFormat, int flags, SwsFilter *srcFilter, SwsFilter *dstFilter, const double *param)
Allocate and return an SwsContext.
void sws_scaleVec(SwsVector *a, double scalar)
Scale all the coefficients of a by the scalar value.
Libavutil version macros.
swscale version macros
pixel format definitions
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
Describe the class of an AVClass context structure.
Definition: log.h:66
This structure describes decoded (raw) audio or video data.
Definition: frame.h:330
SwsVector * chrV
Definition: swscale.h:126
SwsVector * lumH
Definition: swscale.h:123
SwsVector * lumV
Definition: swscale.h:124
SwsVector * chrH
Definition: swscale.h:125
double * coeff
pointer to the list of coefficients
Definition: swscale.h:117
int length
number of coefficients in the vector
Definition: swscale.h:118