FFmpeg
pixdesc.h
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1 /*
2  * pixel format descriptor
3  * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #ifndef AVUTIL_PIXDESC_H
23 #define AVUTIL_PIXDESC_H
24 
25 #include <inttypes.h>
26 
27 #include "attributes.h"
28 #include "pixfmt.h"
29 #include "version.h"
30 
31 typedef struct AVComponentDescriptor {
32  /**
33  * Which of the 4 planes contains the component.
34  */
35  int plane;
36 
37  /**
38  * Number of elements between 2 horizontally consecutive pixels.
39  * Elements are bits for bitstream formats, bytes otherwise.
40  */
41  int step;
42 
43  /**
44  * Number of elements before the component of the first pixel.
45  * Elements are bits for bitstream formats, bytes otherwise.
46  */
47  int offset;
48 
49  /**
50  * Number of least significant bits that must be shifted away
51  * to get the value.
52  */
53  int shift;
54 
55  /**
56  * Number of bits in the component.
57  */
58  int depth;
59 
60 #if FF_API_PLUS1_MINUS1
61  /** deprecated, use step instead */
63 
64  /** deprecated, use depth instead */
66 
67  /** deprecated, use offset instead */
69 #endif
71 
72 /**
73  * Descriptor that unambiguously describes how the bits of a pixel are
74  * stored in the up to 4 data planes of an image. It also stores the
75  * subsampling factors and number of components.
76  *
77  * @note This is separate of the colorspace (RGB, YCbCr, YPbPr, JPEG-style YUV
78  * and all the YUV variants) AVPixFmtDescriptor just stores how values
79  * are stored not what these values represent.
80  */
81 typedef struct AVPixFmtDescriptor {
82  const char *name;
83  uint8_t nb_components; ///< The number of components each pixel has, (1-4)
84 
85  /**
86  * Amount to shift the luma width right to find the chroma width.
87  * For YV12 this is 1 for example.
88  * chroma_width = AV_CEIL_RSHIFT(luma_width, log2_chroma_w)
89  * The note above is needed to ensure rounding up.
90  * This value only refers to the chroma components.
91  */
93 
94  /**
95  * Amount to shift the luma height right to find the chroma height.
96  * For YV12 this is 1 for example.
97  * chroma_height= AV_CEIL_RSHIFT(luma_height, log2_chroma_h)
98  * The note above is needed to ensure rounding up.
99  * This value only refers to the chroma components.
100  */
102 
103  /**
104  * Combination of AV_PIX_FMT_FLAG_... flags.
105  */
106  uint64_t flags;
107 
108  /**
109  * Parameters that describe how pixels are packed.
110  * If the format has 1 or 2 components, then luma is 0.
111  * If the format has 3 or 4 components:
112  * if the RGB flag is set then 0 is red, 1 is green and 2 is blue;
113  * otherwise 0 is luma, 1 is chroma-U and 2 is chroma-V.
114  *
115  * If present, the Alpha channel is always the last component.
116  */
118 
119  /**
120  * Alternative comma-separated names.
121  */
122  const char *alias;
124 
125 /**
126  * Pixel format is big-endian.
127  */
128 #define AV_PIX_FMT_FLAG_BE (1 << 0)
129 /**
130  * Pixel format has a palette in data[1], values are indexes in this palette.
131  */
132 #define AV_PIX_FMT_FLAG_PAL (1 << 1)
133 /**
134  * All values of a component are bit-wise packed end to end.
135  */
136 #define AV_PIX_FMT_FLAG_BITSTREAM (1 << 2)
137 /**
138  * Pixel format is an HW accelerated format.
139  */
140 #define AV_PIX_FMT_FLAG_HWACCEL (1 << 3)
141 /**
142  * At least one pixel component is not in the first data plane.
143  */
144 #define AV_PIX_FMT_FLAG_PLANAR (1 << 4)
145 /**
146  * The pixel format contains RGB-like data (as opposed to YUV/grayscale).
147  */
148 #define AV_PIX_FMT_FLAG_RGB (1 << 5)
149 
150 /**
151  * The pixel format is "pseudo-paletted". This means that it contains a
152  * fixed palette in the 2nd plane but the palette is fixed/constant for each
153  * PIX_FMT. This allows interpreting the data as if it was PAL8, which can
154  * in some cases be simpler. Or the data can be interpreted purely based on
155  * the pixel format without using the palette.
156  * An example of a pseudo-paletted format is AV_PIX_FMT_GRAY8
157  *
158  * @deprecated This flag is deprecated, and will be removed. When it is removed,
159  * the extra palette allocation in AVFrame.data[1] is removed as well. Only
160  * actual paletted formats (as indicated by AV_PIX_FMT_FLAG_PAL) will have a
161  * palette. Starting with FFmpeg versions which have this flag deprecated, the
162  * extra "pseudo" palette is already ignored, and API users are not required to
163  * allocate a palette for AV_PIX_FMT_FLAG_PSEUDOPAL formats (it was required
164  * before the deprecation, though).
165  */
166 #define AV_PIX_FMT_FLAG_PSEUDOPAL (1 << 6)
167 
168 /**
169  * The pixel format has an alpha channel. This is set on all formats that
170  * support alpha in some way, including AV_PIX_FMT_PAL8. The alpha is always
171  * straight, never pre-multiplied.
172  *
173  * If a codec or a filter does not support alpha, it should set all alpha to
174  * opaque, or use the equivalent pixel formats without alpha component, e.g.
175  * AV_PIX_FMT_RGB0 (or AV_PIX_FMT_RGB24 etc.) instead of AV_PIX_FMT_RGBA.
176  */
177 #define AV_PIX_FMT_FLAG_ALPHA (1 << 7)
178 
179 /**
180  * The pixel format is following a Bayer pattern
181  */
182 #define AV_PIX_FMT_FLAG_BAYER (1 << 8)
183 
184 /**
185  * The pixel format contains IEEE-754 floating point values. Precision (double,
186  * single, or half) should be determined by the pixel size (64, 32, or 16 bits).
187  */
188 #define AV_PIX_FMT_FLAG_FLOAT (1 << 9)
189 
190 /**
191  * Return the number of bits per pixel used by the pixel format
192  * described by pixdesc. Note that this is not the same as the number
193  * of bits per sample.
194  *
195  * The returned number of bits refers to the number of bits actually
196  * used for storing the pixel information, that is padding bits are
197  * not counted.
198  */
199 int av_get_bits_per_pixel(const AVPixFmtDescriptor *pixdesc);
200 
201 /**
202  * Return the number of bits per pixel for the pixel format
203  * described by pixdesc, including any padding or unused bits.
204  */
206 
207 /**
208  * @return a pixel format descriptor for provided pixel format or NULL if
209  * this pixel format is unknown.
210  */
212 
213 /**
214  * Iterate over all pixel format descriptors known to libavutil.
215  *
216  * @param prev previous descriptor. NULL to get the first descriptor.
217  *
218  * @return next descriptor or NULL after the last descriptor
219  */
221 
222 /**
223  * @return an AVPixelFormat id described by desc, or AV_PIX_FMT_NONE if desc
224  * is not a valid pointer to a pixel format descriptor.
225  */
227 
228 /**
229  * Utility function to access log2_chroma_w log2_chroma_h from
230  * the pixel format AVPixFmtDescriptor.
231  *
232  * @param[in] pix_fmt the pixel format
233  * @param[out] h_shift store log2_chroma_w (horizontal/width shift)
234  * @param[out] v_shift store log2_chroma_h (vertical/height shift)
235  *
236  * @return 0 on success, AVERROR(ENOSYS) on invalid or unknown pixel format
237  */
239  int *h_shift, int *v_shift);
240 
241 /**
242  * @return number of planes in pix_fmt, a negative AVERROR if pix_fmt is not a
243  * valid pixel format.
244  */
246 
247 /**
248  * @return the name for provided color range or NULL if unknown.
249  */
250 const char *av_color_range_name(enum AVColorRange range);
251 
252 /**
253  * @return the AVColorRange value for name or an AVError if not found.
254  */
255 int av_color_range_from_name(const char *name);
256 
257 /**
258  * @return the name for provided color primaries or NULL if unknown.
259  */
260 const char *av_color_primaries_name(enum AVColorPrimaries primaries);
261 
262 /**
263  * @return the AVColorPrimaries value for name or an AVError if not found.
264  */
265 int av_color_primaries_from_name(const char *name);
266 
267 /**
268  * @return the name for provided color transfer or NULL if unknown.
269  */
270 const char *av_color_transfer_name(enum AVColorTransferCharacteristic transfer);
271 
272 /**
273  * @return the AVColorTransferCharacteristic value for name or an AVError if not found.
274  */
275 int av_color_transfer_from_name(const char *name);
276 
277 /**
278  * @return the name for provided color space or NULL if unknown.
279  */
280 const char *av_color_space_name(enum AVColorSpace space);
281 
282 /**
283  * @return the AVColorSpace value for name or an AVError if not found.
284  */
285 int av_color_space_from_name(const char *name);
286 
287 /**
288  * @return the name for provided chroma location or NULL if unknown.
289  */
290 const char *av_chroma_location_name(enum AVChromaLocation location);
291 
292 /**
293  * @return the AVChromaLocation value for name or an AVError if not found.
294  */
295 int av_chroma_location_from_name(const char *name);
296 
297 /**
298  * Return the pixel format corresponding to name.
299  *
300  * If there is no pixel format with name name, then looks for a
301  * pixel format with the name corresponding to the native endian
302  * format of name.
303  * For example in a little-endian system, first looks for "gray16",
304  * then for "gray16le".
305  *
306  * Finally if no pixel format has been found, returns AV_PIX_FMT_NONE.
307  */
308 enum AVPixelFormat av_get_pix_fmt(const char *name);
309 
310 /**
311  * Return the short name for a pixel format, NULL in case pix_fmt is
312  * unknown.
313  *
314  * @see av_get_pix_fmt(), av_get_pix_fmt_string()
315  */
316 const char *av_get_pix_fmt_name(enum AVPixelFormat pix_fmt);
317 
318 /**
319  * Print in buf the string corresponding to the pixel format with
320  * number pix_fmt, or a header if pix_fmt is negative.
321  *
322  * @param buf the buffer where to write the string
323  * @param buf_size the size of buf
324  * @param pix_fmt the number of the pixel format to print the
325  * corresponding info string, or a negative value to print the
326  * corresponding header.
327  */
328 char *av_get_pix_fmt_string(char *buf, int buf_size,
329  enum AVPixelFormat pix_fmt);
330 
331 /**
332  * Read a line from an image, and write the values of the
333  * pixel format component c to dst.
334  *
335  * @param data the array containing the pointers to the planes of the image
336  * @param linesize the array containing the linesizes of the image
337  * @param desc the pixel format descriptor for the image
338  * @param x the horizontal coordinate of the first pixel to read
339  * @param y the vertical coordinate of the first pixel to read
340  * @param w the width of the line to read, that is the number of
341  * values to write to dst
342  * @param read_pal_component if not zero and the format is a paletted
343  * format writes the values corresponding to the palette
344  * component c in data[1] to dst, rather than the palette indexes in
345  * data[0]. The behavior is undefined if the format is not paletted.
346  * @param dst_element_size size of elements in dst array (2 or 4 byte)
347  */
348 void av_read_image_line2(void *dst, const uint8_t *data[4],
349  const int linesize[4], const AVPixFmtDescriptor *desc,
350  int x, int y, int c, int w, int read_pal_component,
351  int dst_element_size);
352 
353 void av_read_image_line(uint16_t *dst, const uint8_t *data[4],
354  const int linesize[4], const AVPixFmtDescriptor *desc,
355  int x, int y, int c, int w, int read_pal_component);
356 
357 /**
358  * Write the values from src to the pixel format component c of an
359  * image line.
360  *
361  * @param src array containing the values to write
362  * @param data the array containing the pointers to the planes of the
363  * image to write into. It is supposed to be zeroed.
364  * @param linesize the array containing the linesizes of the image
365  * @param desc the pixel format descriptor for the image
366  * @param x the horizontal coordinate of the first pixel to write
367  * @param y the vertical coordinate of the first pixel to write
368  * @param w the width of the line to write, that is the number of
369  * values to write to the image line
370  * @param src_element_size size of elements in src array (2 or 4 byte)
371  */
372 void av_write_image_line2(const void *src, uint8_t *data[4],
373  const int linesize[4], const AVPixFmtDescriptor *desc,
374  int x, int y, int c, int w, int src_element_size);
375 
376 void av_write_image_line(const uint16_t *src, uint8_t *data[4],
377  const int linesize[4], const AVPixFmtDescriptor *desc,
378  int x, int y, int c, int w);
379 
380 /**
381  * Utility function to swap the endianness of a pixel format.
382  *
383  * @param[in] pix_fmt the pixel format
384  *
385  * @return pixel format with swapped endianness if it exists,
386  * otherwise AV_PIX_FMT_NONE
387  */
389 
390 #define FF_LOSS_RESOLUTION 0x0001 /**< loss due to resolution change */
391 #define FF_LOSS_DEPTH 0x0002 /**< loss due to color depth change */
392 #define FF_LOSS_COLORSPACE 0x0004 /**< loss due to color space conversion */
393 #define FF_LOSS_ALPHA 0x0008 /**< loss of alpha bits */
394 #define FF_LOSS_COLORQUANT 0x0010 /**< loss due to color quantization */
395 #define FF_LOSS_CHROMA 0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */
396 
397 /**
398  * Compute what kind of losses will occur when converting from one specific
399  * pixel format to another.
400  * When converting from one pixel format to another, information loss may occur.
401  * For example, when converting from RGB24 to GRAY, the color information will
402  * be lost. Similarly, other losses occur when converting from some formats to
403  * other formats. These losses can involve loss of chroma, but also loss of
404  * resolution, loss of color depth, loss due to the color space conversion, loss
405  * of the alpha bits or loss due to color quantization.
406  * av_get_fix_fmt_loss() informs you about the various types of losses
407  * which will occur when converting from one pixel format to another.
408  *
409  * @param[in] dst_pix_fmt destination pixel format
410  * @param[in] src_pix_fmt source pixel format
411  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
412  * @return Combination of flags informing you what kind of losses will occur
413  * (maximum loss for an invalid dst_pix_fmt).
414  */
415 int av_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt,
416  enum AVPixelFormat src_pix_fmt,
417  int has_alpha);
418 
419 /**
420  * Compute what kind of losses will occur when converting from one specific
421  * pixel format to another.
422  * When converting from one pixel format to another, information loss may occur.
423  * For example, when converting from RGB24 to GRAY, the color information will
424  * be lost. Similarly, other losses occur when converting from some formats to
425  * other formats. These losses can involve loss of chroma, but also loss of
426  * resolution, loss of color depth, loss due to the color space conversion, loss
427  * of the alpha bits or loss due to color quantization.
428  * av_get_fix_fmt_loss() informs you about the various types of losses
429  * which will occur when converting from one pixel format to another.
430  *
431  * @param[in] dst_pix_fmt destination pixel format
432  * @param[in] src_pix_fmt source pixel format
433  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
434  * @return Combination of flags informing you what kind of losses will occur
435  * (maximum loss for an invalid dst_pix_fmt).
436  */
437 enum AVPixelFormat av_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
438  enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
439 
440 #endif /* AVUTIL_PIXDESC_H */
attribute_deprecated int offset_plus1
deprecated, use offset instead
Definition: pixdesc.h:68
int plane
Which of the 4 planes contains the component.
Definition: pixdesc.h:35
static enum AVPixelFormat pix_fmt
const char * alias
Alternative comma-separated names.
Definition: pixdesc.h:122
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
void av_read_image_line(uint16_t *dst, const uint8_t *data[4], const int linesize[4], const AVPixFmtDescriptor *desc, int x, int y, int c, int w, int read_pal_component)
Definition: pixdesc.c:90
const char * desc
Definition: nvenc.c:68
const char * av_color_transfer_name(enum AVColorTransferCharacteristic transfer)
Definition: pixdesc.c:2867
#define src
Definition: vp8dsp.c:254
uint8_t log2_chroma_w
Amount to shift the luma width right to find the chroma width.
Definition: pixdesc.h:92
AVColorTransferCharacteristic
Color Transfer Characteristic.
Definition: pixfmt.h:464
Macro definitions for various function/variable attributes.
int av_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt, int has_alpha)
Compute what kind of losses will occur when converting from one specific pixel format to another...
Definition: pixdesc.c:2776
enum AVPixelFormat av_pix_fmt_swap_endianness(enum AVPixelFormat pix_fmt)
Utility function to swap the endianness of a pixel format.
Definition: pixdesc.c:2594
int av_get_bits_per_pixel(const AVPixFmtDescriptor *pixdesc)
Return the number of bits per pixel used by the pixel format described by pixdesc.
Definition: pixdesc.c:2450
void av_write_image_line(const uint16_t *src, uint8_t *data[4], const int linesize[4], const AVPixFmtDescriptor *desc, int x, int y, int c, int w)
Definition: pixdesc.c:162
uint8_t
AVColorSpace
YUV colorspace type.
Definition: pixfmt.h:493
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
int av_chroma_location_from_name(const char *name)
Definition: pixdesc.c:2921
int av_color_transfer_from_name(const char *name)
Definition: pixdesc.c:2873
int av_color_range_from_name(const char *name)
Definition: pixdesc.c:2830
AVColorRange
MPEG vs JPEG YUV range.
Definition: pixfmt.h:516
AVColorPrimaries
Chromaticity coordinates of the source primaries.
Definition: pixfmt.h:440
const char * name
Definition: pixdesc.h:82
int av_pix_fmt_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift)
Utility function to access log2_chroma_w log2_chroma_h from the pixel format AVPixFmtDescriptor.
Definition: pixdesc.c:2526
uint8_t log2_chroma_h
Amount to shift the luma height right to find the chroma height.
Definition: pixdesc.h:101
const char * av_color_range_name(enum AVColorRange range)
Definition: pixdesc.c:2824
const char * av_color_primaries_name(enum AVColorPrimaries primaries)
Definition: pixdesc.c:2843
Libavutil version macros.
uint64_t flags
Combination of AV_PIX_FMT_FLAG_...
Definition: pixdesc.h:106
uint8_t nb_components
The number of components each pixel has, (1-4)
Definition: pixdesc.h:83
const AVPixFmtDescriptor * av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)
Iterate over all pixel format descriptors known to libavutil.
Definition: pixdesc.c:2505
const char * av_color_space_name(enum AVColorSpace space)
Definition: pixdesc.c:2891
uint8_t w
Definition: llviddspenc.c:38
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2498
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated space
Definition: undefined.txt:3
int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2538
char * av_get_pix_fmt_string(char *buf, int buf_size, enum AVPixelFormat pix_fmt)
Print in buf the string corresponding to the pixel format with number pix_fmt, or a header if pix_fmt...
Definition: pixdesc.c:2483
static void comp(unsigned char *dst, ptrdiff_t dst_stride, unsigned char *src, ptrdiff_t src_stride, int add)
Definition: eamad.c:83
attribute_deprecated int step_minus1
deprecated, use step instead
Definition: pixdesc.h:62
enum AVPixelFormat av_pix_fmt_desc_get_id(const AVPixFmtDescriptor *desc)
Definition: pixdesc.c:2517
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:81
void * buf
Definition: avisynth_c.h:690
const char * av_chroma_location_name(enum AVChromaLocation location)
Definition: pixdesc.c:2915
int shift
Number of least significant bits that must be shifted away to get the value.
Definition: pixdesc.h:53
int offset
Number of elements before the component of the first pixel.
Definition: pixdesc.h:47
#define attribute_deprecated
Definition: attributes.h:94
int av_color_primaries_from_name(const char *name)
Definition: pixdesc.c:2849
int av_color_space_from_name(const char *name)
Definition: pixdesc.c:2897
attribute_deprecated int depth_minus1
deprecated, use depth instead
Definition: pixdesc.h:65
void av_write_image_line2(const void *src, uint8_t *data[4], const int linesize[4], const AVPixFmtDescriptor *desc, int x, int y, int c, int w, int src_element_size)
Write the values from src to the pixel format component c of an image line.
Definition: pixdesc.c:101
pixel format definitions
void av_read_image_line2(void *dst, const uint8_t *data[4], const int linesize[4], const AVPixFmtDescriptor *desc, int x, int y, int c, int w, int read_pal_component, int dst_element_size)
Read a line from an image, and write the values of the pixel format component c to dst...
Definition: pixdesc.c:34
const char * av_get_pix_fmt_name(enum AVPixelFormat pix_fmt)
Return the short name for a pixel format, NULL in case pix_fmt is unknown.
Definition: pixdesc.c:2414
int av_get_padded_bits_per_pixel(const AVPixFmtDescriptor *pixdesc)
Return the number of bits per pixel for the pixel format described by pixdesc, including any padding ...
Definition: pixdesc.c:2463
AVChromaLocation
Location of chroma samples.
Definition: pixfmt.h:538
int depth
Number of bits in the component.
Definition: pixdesc.h:58
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
enum AVPixelFormat av_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2, enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr)
Compute what kind of losses will occur when converting from one specific pixel format to another...
Definition: pixdesc.c:2787
enum AVPixelFormat av_get_pix_fmt(const char *name)
Return the pixel format corresponding to name.
Definition: pixdesc.c:2426
int step
Number of elements between 2 horizontally consecutive pixels.
Definition: pixdesc.h:41
const char * name
Definition: opengl_enc.c:103