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
29
31 uint16_t
plane :2;
///< which of the 4 planes contains the component
32
33 /**
34 * Number of elements between 2 horizontally consecutive pixels minus 1.
35 * Elements are bits for bitstream formats, bytes otherwise.
36 */
38
39 /**
40 * Number of elements before the component of the first pixel plus 1.
41 * Elements are bits for bitstream formats, bytes otherwise.
42 */
44 uint16_t
shift :3;
///< number of least significant bits that must be shifted away to get the value
45 uint16_t
depth_minus1 :4;
///< number of bits in the component minus 1
47
48 /**
49 * Descriptor that unambiguously describes how the bits of a pixel are
50 * stored in the up to 4 data planes of an image. It also stores the
51 * subsampling factors and number of components.
52 *
53 * @note This is separate of the colorspace (RGB, YCbCr, YPbPr, JPEG-style YUV
54 * and all the YUV variants) AVPixFmtDescriptor just stores how values
55 * are stored not what these values represent.
56 */
60
61 /**
62 * Amount to shift the luma width right to find the chroma width.
63 * For YV12 this is 1 for example.
64 * chroma_width = -((-luma_width) >> log2_chroma_w)
65 * The note above is needed to ensure rounding up.
66 * This value only refers to the chroma components.
67 */
69
70 /**
71 * Amount to shift the luma height right to find the chroma height.
72 * For YV12 this is 1 for example.
73 * chroma_height= -((-luma_height) >> log2_chroma_h)
74 * The note above is needed to ensure rounding up.
75 * This value only refers to the chroma components.
76 */
79
80 /**
81 * Parameters that describe how pixels are packed.
82 * If the format has 2 or 4 components, then alpha is last.
83 * If the format has 1 or 2 components, then luma is 0.
84 * If the format has 3 or 4 components,
85 * if the RGB flag is set then 0 is red, 1 is green and 2 is blue;
86 * otherwise 0 is luma, 1 is chroma-U and 2 is chroma-V.
87 */
90
91 /**
92 * Pixel format is big-endian.
93 */
94 #define AV_PIX_FMT_FLAG_BE (1 << 0)
95 /**
96 * Pixel format has a palette in data[1], values are indexes in this palette.
97 */
98 #define AV_PIX_FMT_FLAG_PAL (1 << 1)
99 /**
100 * All values of a component are bit-wise packed end to end.
101 */
102 #define AV_PIX_FMT_FLAG_BITSTREAM (1 << 2)
103 /**
104 * Pixel format is an HW accelerated format.
105 */
106 #define AV_PIX_FMT_FLAG_HWACCEL (1 << 3)
107 /**
108 * At least one pixel component is not in the first data plane.
109 */
110 #define AV_PIX_FMT_FLAG_PLANAR (1 << 4)
111 /**
112 * The pixel format contains RGB-like data (as opposed to YUV/grayscale).
113 */
114 #define AV_PIX_FMT_FLAG_RGB (1 << 5)
115 /**
116 * The pixel format is "pseudo-paletted". This means that FFmpeg treats it as
117 * paletted internally, but the palette is generated by the decoder and is not
118 * stored in the file.
119 */
120 #define AV_PIX_FMT_FLAG_PSEUDOPAL (1 << 6)
121 /**
122 * The pixel format has an alpha channel.
123 */
124 #define AV_PIX_FMT_FLAG_ALPHA (1 << 7)
125
126 #if FF_API_PIX_FMT
127 /**
128 * @deprecated use the AV_PIX_FMT_FLAG_* flags
129 */
130 #define PIX_FMT_BE AV_PIX_FMT_FLAG_BE
131 #define PIX_FMT_PAL AV_PIX_FMT_FLAG_PAL
132 #define PIX_FMT_BITSTREAM AV_PIX_FMT_FLAG_BITSTREAM
133 #define PIX_FMT_HWACCEL AV_PIX_FMT_FLAG_HWACCEL
134 #define PIX_FMT_PLANAR AV_PIX_FMT_FLAG_PLANAR
135 #define PIX_FMT_RGB AV_PIX_FMT_FLAG_RGB
136 #define PIX_FMT_PSEUDOPAL AV_PIX_FMT_FLAG_PSEUDOPAL
137 #define PIX_FMT_ALPHA AV_PIX_FMT_FLAG_ALPHA
138 #endif
139
140 #if FF_API_PIX_FMT_DESC
141 /**
142 * The array of all the pixel format descriptors.
143 */
145 #endif
146
147 /**
148 * Read a line from an image, and write the values of the
149 * pixel format component c to dst.
150 *
151 * @param data the array containing the pointers to the planes of the image
152 * @param linesize the array containing the linesizes of the image
153 * @param desc the pixel format descriptor for the image
154 * @param x the horizontal coordinate of the first pixel to read
155 * @param y the vertical coordinate of the first pixel to read
156 * @param w the width of the line to read, that is the number of
157 * values to write to dst
158 * @param read_pal_component if not zero and the format is a paletted
159 * format writes the values corresponding to the palette
160 * component c in data[1] to dst, rather than the palette indexes in
161 * data[0]. The behavior is undefined if the format is not paletted.
162 */
165
166 /**
167 * Write the values from src to the pixel format component c of an
168 * image line.
169 *
170 * @param src array containing the values to write
171 * @param data the array containing the pointers to the planes of the
172 * image to write into. It is supposed to be zeroed.
173 * @param linesize the array containing the linesizes of the image
174 * @param desc the pixel format descriptor for the image
175 * @param x the horizontal coordinate of the first pixel to write
176 * @param y the vertical coordinate of the first pixel to write
177 * @param w the width of the line to write, that is the number of
178 * values to write to the image line
179 */
182
183 /**
184 * Return the pixel format corresponding to name.
185 *
186 * If there is no pixel format with name name, then looks for a
187 * pixel format with the name corresponding to the native endian
188 * format of name.
189 * For example in a little-endian system, first looks for "gray16",
190 * then for "gray16le".
191 *
192 * Finally if no pixel format has been found, returns AV_PIX_FMT_NONE.
193 */
195
196 /**
197 * Return the short name for a pixel format, NULL in case pix_fmt is
198 * unknown.
199 *
200 * @see av_get_pix_fmt(), av_get_pix_fmt_string()
201 */
203
204 /**
205 * Print in buf the string corresponding to the pixel format with
206 * number pix_fmt, or a header if pix_fmt is negative.
207 *
208 * @param buf the buffer where to write the string
209 * @param buf_size the size of buf
210 * @param pix_fmt the number of the pixel format to print the
211 * corresponding info string, or a negative value to print the
212 * corresponding header.
213 */
215
216 /**
217 * Return the number of bits per pixel used by the pixel format
218 * described by pixdesc. Note that this is not the same as the number
219 * of bits per sample.
220 *
221 * The returned number of bits refers to the number of bits actually
222 * used for storing the pixel information, that is padding bits are
223 * not counted.
224 */
226
227 /**
228 * Return the number of bits per pixel for the pixel format
229 * described by pixdesc, including any padding or unused bits.
230 */
232
233 /**
234 * @return a pixel format descriptor for provided pixel format or NULL if
235 * this pixel format is unknown.
236 */
238
239 /**
240 * Iterate over all pixel format descriptors known to libavutil.
241 *
242 * @param prev previous descriptor. NULL to get the first descriptor.
243 *
244 * @return next descriptor or NULL after the last descriptor
245 */
247
248 /**
249 * @return an AVPixelFormat id described by desc, or AV_PIX_FMT_NONE if desc
250 * is not a valid pointer to a pixel format descriptor.
251 */
253
254 /**
255 * Utility function to access log2_chroma_w log2_chroma_h from
256 * the pixel format AVPixFmtDescriptor.
257 *
258 * See avcodec_get_chroma_sub_sample() for a function that asserts a
259 * valid pixel format instead of returning an error code.
260 * Its recommanded that you use avcodec_get_chroma_sub_sample unless
261 * you do check the return code!
262 *
263 * @param[in] pix_fmt the pixel format
264 * @param[out] h_shift store log2_chroma_w
265 * @param[out] v_shift store log2_chroma_h
266 *
267 * @return 0 on success, AVERROR(ENOSYS) on invalid or unknown pixel format
268 */
270 int *h_shift, int *v_shift);
271
272 /**
273 * @return number of planes in pix_fmt, a negative AVERROR if pix_fmt is not a
274 * valid pixel format.
275 */
277
279
280 /**
281 * Utility function to swap the endianness of a pixel format.
282 *
283 * @param[in] pix_fmt the pixel format
284 *
285 * @return pixel format with swapped endianness if it exists,
286 * otherwise AV_PIX_FMT_NONE
287 */
289
290
291 #endif /* AVUTIL_PIXDESC_H */