FFmpeg 5.1.4
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
30typedef struct AVComponentDescriptor {
31 /**
32 * Which of the 4 planes contains the component.
33 */
34 int plane;
35
36 /**
37 * Number of elements between 2 horizontally consecutive pixels.
38 * Elements are bits for bitstream formats, bytes otherwise.
39 */
40 int step;
41
42 /**
43 * Number of elements before the component of the first pixel.
44 * Elements are bits for bitstream formats, bytes otherwise.
45 */
46 int offset;
47
48 /**
49 * Number of least significant bits that must be shifted away
50 * to get the value.
51 */
52 int shift;
53
54 /**
55 * Number of bits in the component.
56 */
57 int depth;
59
60/**
61 * Descriptor that unambiguously describes how the bits of a pixel are
62 * stored in the up to 4 data planes of an image. It also stores the
63 * subsampling factors and number of components.
64 *
65 * @note This is separate of the colorspace (RGB, YCbCr, YPbPr, JPEG-style YUV
66 * and all the YUV variants) AVPixFmtDescriptor just stores how values
67 * are stored not what these values represent.
68 */
69typedef struct AVPixFmtDescriptor {
70 const char *name;
71 uint8_t nb_components; ///< The number of components each pixel has, (1-4)
72
73 /**
74 * Amount to shift the luma width right to find the chroma width.
75 * For YV12 this is 1 for example.
76 * chroma_width = AV_CEIL_RSHIFT(luma_width, log2_chroma_w)
77 * The note above is needed to ensure rounding up.
78 * This value only refers to the chroma components.
79 */
81
82 /**
83 * Amount to shift the luma height right to find the chroma height.
84 * For YV12 this is 1 for example.
85 * chroma_height= AV_CEIL_RSHIFT(luma_height, log2_chroma_h)
86 * The note above is needed to ensure rounding up.
87 * This value only refers to the chroma components.
88 */
90
91 /**
92 * Combination of AV_PIX_FMT_FLAG_... flags.
93 */
94 uint64_t flags;
95
96 /**
97 * Parameters that describe how pixels are packed.
98 * If the format has 1 or 2 components, then luma is 0.
99 * If the format has 3 or 4 components:
100 * if the RGB flag is set then 0 is red, 1 is green and 2 is blue;
101 * otherwise 0 is luma, 1 is chroma-U and 2 is chroma-V.
102 *
103 * If present, the Alpha channel is always the last component.
104 */
106
107 /**
108 * Alternative comma-separated names.
109 */
110 const char *alias;
112
113/**
114 * Pixel format is big-endian.
115 */
116#define AV_PIX_FMT_FLAG_BE (1 << 0)
117/**
118 * Pixel format has a palette in data[1], values are indexes in this palette.
119 */
120#define AV_PIX_FMT_FLAG_PAL (1 << 1)
121/**
122 * All values of a component are bit-wise packed end to end.
123 */
124#define AV_PIX_FMT_FLAG_BITSTREAM (1 << 2)
125/**
126 * Pixel format is an HW accelerated format.
127 */
128#define AV_PIX_FMT_FLAG_HWACCEL (1 << 3)
129/**
130 * At least one pixel component is not in the first data plane.
131 */
132#define AV_PIX_FMT_FLAG_PLANAR (1 << 4)
133/**
134 * The pixel format contains RGB-like data (as opposed to YUV/grayscale).
135 */
136#define AV_PIX_FMT_FLAG_RGB (1 << 5)
137
138/**
139 * The pixel format has an alpha channel. This is set on all formats that
140 * support alpha in some way, including AV_PIX_FMT_PAL8. The alpha is always
141 * straight, never pre-multiplied.
142 *
143 * If a codec or a filter does not support alpha, it should set all alpha to
144 * opaque, or use the equivalent pixel formats without alpha component, e.g.
145 * AV_PIX_FMT_RGB0 (or AV_PIX_FMT_RGB24 etc.) instead of AV_PIX_FMT_RGBA.
146 */
147#define AV_PIX_FMT_FLAG_ALPHA (1 << 7)
148
149/**
150 * The pixel format is following a Bayer pattern
151 */
152#define AV_PIX_FMT_FLAG_BAYER (1 << 8)
153
154/**
155 * The pixel format contains IEEE-754 floating point values. Precision (double,
156 * single, or half) should be determined by the pixel size (64, 32, or 16 bits).
157 */
158#define AV_PIX_FMT_FLAG_FLOAT (1 << 9)
159
160/**
161 * Return the number of bits per pixel used by the pixel format
162 * described by pixdesc. Note that this is not the same as the number
163 * of bits per sample.
164 *
165 * The returned number of bits refers to the number of bits actually
166 * used for storing the pixel information, that is padding bits are
167 * not counted.
168 */
170
171/**
172 * Return the number of bits per pixel for the pixel format
173 * described by pixdesc, including any padding or unused bits.
174 */
176
177/**
178 * @return a pixel format descriptor for provided pixel format or NULL if
179 * this pixel format is unknown.
180 */
182
183/**
184 * Iterate over all pixel format descriptors known to libavutil.
185 *
186 * @param prev previous descriptor. NULL to get the first descriptor.
187 *
188 * @return next descriptor or NULL after the last descriptor
189 */
191
192/**
193 * @return an AVPixelFormat id described by desc, or AV_PIX_FMT_NONE if desc
194 * is not a valid pointer to a pixel format descriptor.
195 */
197
198/**
199 * Utility function to access log2_chroma_w log2_chroma_h from
200 * the pixel format AVPixFmtDescriptor.
201 *
202 * @param[in] pix_fmt the pixel format
203 * @param[out] h_shift store log2_chroma_w (horizontal/width shift)
204 * @param[out] v_shift store log2_chroma_h (vertical/height shift)
205 *
206 * @return 0 on success, AVERROR(ENOSYS) on invalid or unknown pixel format
207 */
209 int *h_shift, int *v_shift);
210
211/**
212 * @return number of planes in pix_fmt, a negative AVERROR if pix_fmt is not a
213 * valid pixel format.
214 */
216
217/**
218 * @return the name for provided color range or NULL if unknown.
219 */
220const char *av_color_range_name(enum AVColorRange range);
221
222/**
223 * @return the AVColorRange value for name or an AVError if not found.
224 */
225int av_color_range_from_name(const char *name);
226
227/**
228 * @return the name for provided color primaries or NULL if unknown.
229 */
230const char *av_color_primaries_name(enum AVColorPrimaries primaries);
231
232/**
233 * @return the AVColorPrimaries value for name or an AVError if not found.
234 */
235int av_color_primaries_from_name(const char *name);
236
237/**
238 * @return the name for provided color transfer or NULL if unknown.
239 */
241
242/**
243 * @return the AVColorTransferCharacteristic value for name or an AVError if not found.
244 */
245int av_color_transfer_from_name(const char *name);
246
247/**
248 * @return the name for provided color space or NULL if unknown.
249 */
250const char *av_color_space_name(enum AVColorSpace space);
251
252/**
253 * @return the AVColorSpace value for name or an AVError if not found.
254 */
255int av_color_space_from_name(const char *name);
256
257/**
258 * @return the name for provided chroma location or NULL if unknown.
259 */
260const char *av_chroma_location_name(enum AVChromaLocation location);
261
262/**
263 * @return the AVChromaLocation value for name or an AVError if not found.
264 */
265int av_chroma_location_from_name(const char *name);
266
267/**
268 * Return the pixel format corresponding to name.
269 *
270 * If there is no pixel format with name name, then looks for a
271 * pixel format with the name corresponding to the native endian
272 * format of name.
273 * For example in a little-endian system, first looks for "gray16",
274 * then for "gray16le".
275 *
276 * Finally if no pixel format has been found, returns AV_PIX_FMT_NONE.
277 */
278enum AVPixelFormat av_get_pix_fmt(const char *name);
279
280/**
281 * Return the short name for a pixel format, NULL in case pix_fmt is
282 * unknown.
283 *
284 * @see av_get_pix_fmt(), av_get_pix_fmt_string()
285 */
287
288/**
289 * Print in buf the string corresponding to the pixel format with
290 * number pix_fmt, or a header if pix_fmt is negative.
291 *
292 * @param buf the buffer where to write the string
293 * @param buf_size the size of buf
294 * @param pix_fmt the number of the pixel format to print the
295 * corresponding info string, or a negative value to print the
296 * corresponding header.
297 */
298char *av_get_pix_fmt_string(char *buf, int buf_size,
300
301/**
302 * Read a line from an image, and write the values of the
303 * pixel format component c to dst.
304 *
305 * @param data the array containing the pointers to the planes of the image
306 * @param linesize the array containing the linesizes of the image
307 * @param desc the pixel format descriptor for the image
308 * @param x the horizontal coordinate of the first pixel to read
309 * @param y the vertical coordinate of the first pixel to read
310 * @param w the width of the line to read, that is the number of
311 * values to write to dst
312 * @param read_pal_component if not zero and the format is a paletted
313 * format writes the values corresponding to the palette
314 * component c in data[1] to dst, rather than the palette indexes in
315 * data[0]. The behavior is undefined if the format is not paletted.
316 * @param dst_element_size size of elements in dst array (2 or 4 byte)
317 */
318void av_read_image_line2(void *dst, const uint8_t *data[4],
319 const int linesize[4], const AVPixFmtDescriptor *desc,
320 int x, int y, int c, int w, int read_pal_component,
321 int dst_element_size);
322
323void av_read_image_line(uint16_t *dst, const uint8_t *data[4],
324 const int linesize[4], const AVPixFmtDescriptor *desc,
325 int x, int y, int c, int w, int read_pal_component);
326
327/**
328 * Write the values from src to the pixel format component c of an
329 * image line.
330 *
331 * @param src array containing the values to write
332 * @param data the array containing the pointers to the planes of the
333 * image to write into. It is supposed to be zeroed.
334 * @param linesize the array containing the linesizes of the image
335 * @param desc the pixel format descriptor for the image
336 * @param x the horizontal coordinate of the first pixel to write
337 * @param y the vertical coordinate of the first pixel to write
338 * @param w the width of the line to write, that is the number of
339 * values to write to the image line
340 * @param src_element_size size of elements in src array (2 or 4 byte)
341 */
342void av_write_image_line2(const void *src, uint8_t *data[4],
343 const int linesize[4], const AVPixFmtDescriptor *desc,
344 int x, int y, int c, int w, int src_element_size);
345
346void av_write_image_line(const uint16_t *src, uint8_t *data[4],
347 const int linesize[4], const AVPixFmtDescriptor *desc,
348 int x, int y, int c, int w);
349
350/**
351 * Utility function to swap the endianness of a pixel format.
352 *
353 * @param[in] pix_fmt the pixel format
354 *
355 * @return pixel format with swapped endianness if it exists,
356 * otherwise AV_PIX_FMT_NONE
357 */
359
360#define FF_LOSS_RESOLUTION 0x0001 /**< loss due to resolution change */
361#define FF_LOSS_DEPTH 0x0002 /**< loss due to color depth change */
362#define FF_LOSS_COLORSPACE 0x0004 /**< loss due to color space conversion */
363#define FF_LOSS_ALPHA 0x0008 /**< loss of alpha bits */
364#define FF_LOSS_COLORQUANT 0x0010 /**< loss due to color quantization */
365#define FF_LOSS_CHROMA 0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */
366
367/**
368 * Compute what kind of losses will occur when converting from one specific
369 * pixel format to another.
370 * When converting from one pixel format to another, information loss may occur.
371 * For example, when converting from RGB24 to GRAY, the color information will
372 * be lost. Similarly, other losses occur when converting from some formats to
373 * other formats. These losses can involve loss of chroma, but also loss of
374 * resolution, loss of color depth, loss due to the color space conversion, loss
375 * of the alpha bits or loss due to color quantization.
376 * av_get_fix_fmt_loss() informs you about the various types of losses
377 * which will occur when converting from one pixel format to another.
378 *
379 * @param[in] dst_pix_fmt destination pixel format
380 * @param[in] src_pix_fmt source pixel format
381 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
382 * @return Combination of flags informing you what kind of losses will occur
383 * (maximum loss for an invalid dst_pix_fmt).
384 */
386 enum AVPixelFormat src_pix_fmt,
387 int has_alpha);
388
389/**
390 * Compute what kind of losses will occur when converting from one specific
391 * pixel format to another.
392 * When converting from one pixel format to another, information loss may occur.
393 * For example, when converting from RGB24 to GRAY, the color information will
394 * be lost. Similarly, other losses occur when converting from some formats to
395 * other formats. These losses can involve loss of chroma, but also loss of
396 * resolution, loss of color depth, loss due to the color space conversion, loss
397 * of the alpha bits or loss due to color quantization.
398 * av_get_fix_fmt_loss() informs you about the various types of losses
399 * which will occur when converting from one pixel format to another.
400 *
401 * @param[in] dst_pix_fmt destination pixel format
402 * @param[in] src_pix_fmt source pixel format
403 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
404 * @return Combination of flags informing you what kind of losses will occur
405 * (maximum loss for an invalid dst_pix_fmt).
406 */
407enum AVPixelFormat av_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
408 enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
409
410#endif /* AVUTIL_PIXDESC_H */
Macro definitions for various function/variable attributes.
static enum AVPixelFormat pix_fmt
enum AVPixelFormat av_pix_fmt_desc_get_id(const AVPixFmtDescriptor *desc)
int av_color_space_from_name(const char *name)
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.
int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt)
int av_chroma_location_from_name(const char *name)
int av_color_transfer_from_name(const char *name)
const AVPixFmtDescriptor * av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)
Iterate over all pixel format descriptors known to libavutil.
const char * av_color_space_name(enum AVColorSpace space)
const char * av_color_range_name(enum AVColorRange range)
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.
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.
int av_get_bits_per_pixel(const AVPixFmtDescriptor *pixdesc)
Return the number of bits per pixel used by the pixel format described by pixdesc.
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.
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.
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.
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)
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 ...
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)
enum AVPixelFormat av_get_pix_fmt(const char *name)
Return the pixel format corresponding to name.
const char * av_chroma_location_name(enum AVChromaLocation location)
int av_color_range_from_name(const char *name)
const char * av_color_transfer_name(enum AVColorTransferCharacteristic transfer)
const char * av_color_primaries_name(enum AVColorPrimaries primaries)
int av_color_primaries_from_name(const char *name)
enum AVPixelFormat av_pix_fmt_swap_endianness(enum AVPixelFormat pix_fmt)
Utility function to swap the endianness of a pixel format.
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...
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
pixel format definitions
AVChromaLocation
Location of chroma samples.
Definition: pixfmt.h:618
AVColorRange
Visual content value range.
Definition: pixfmt.h:564
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
AVColorPrimaries
Chromaticity coordinates of the source primaries.
Definition: pixfmt.h:471
AVColorTransferCharacteristic
Color Transfer Characteristic.
Definition: pixfmt.h:496
AVColorSpace
YUV colorspace type.
Definition: pixfmt.h:525
int shift
Number of least significant bits that must be shifted away to get the value.
Definition: pixdesc.h:52
int offset
Number of elements before the component of the first pixel.
Definition: pixdesc.h:46
int plane
Which of the 4 planes contains the component.
Definition: pixdesc.h:34
int step
Number of elements between 2 horizontally consecutive pixels.
Definition: pixdesc.h:40
int depth
Number of bits in the component.
Definition: pixdesc.h:57
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:69
const char * name
Definition: pixdesc.h:70
AVComponentDescriptor comp[4]
Parameters that describe how pixels are packed.
Definition: pixdesc.h:105
uint8_t log2_chroma_w
Amount to shift the luma width right to find the chroma width.
Definition: pixdesc.h:80
uint64_t flags
Combination of AV_PIX_FMT_FLAG_... flags.
Definition: pixdesc.h:94
const char * alias
Alternative comma-separated names.
Definition: pixdesc.h:110
uint8_t log2_chroma_h
Amount to shift the luma height right to find the chroma height.
Definition: pixdesc.h:89
uint8_t nb_components
The number of components each pixel has, (1-4)
Definition: pixdesc.h:71