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 module ffmpeg.libavutil.pixdesc;
22 
23 import ffmpeg.libavutil;
24 
25 extern (C) @nogc nothrow:
26 
27 struct AVComponentDescriptor
28 {
29     /**
30      * Which of the 4 planes contains the component.
31      */
32     int plane;
33 
34     /**
35      * Number of elements between 2 horizontally consecutive pixels.
36      * Elements are bits for bitstream formats, bytes otherwise.
37      */
38     int step;
39 
40     /**
41      * Number of elements before the component of the first pixel.
42      * Elements are bits for bitstream formats, bytes otherwise.
43      */
44     int offset;
45 
46     /**
47      * Number of least significant bits that must be shifted away
48      * to get the value.
49      */
50     int shift;
51 
52     /**
53      * Number of bits in the component.
54      */
55     int depth;
56 
57     /** deprecated, use step instead */
58     int step_minus1;
59 
60     /** deprecated, use depth instead */
61     int depth_minus1;
62 
63     /** deprecated, use offset instead */
64     int offset_plus1;
65 }
66 
67 /**
68  * Descriptor that unambiguously describes how the bits of a pixel are
69  * stored in the up to 4 data planes of an image. It also stores the
70  * subsampling factors and number of components.
71  *
72  * @note This is separate of the colorspace (RGB, YCbCr, YPbPr, JPEG-style YUV
73  *       and all the YUV variants) AVPixFmtDescriptor just stores how values
74  *       are stored not what these values represent.
75  */
76 struct AVPixFmtDescriptor
77 {
78     const(char)* name;
79     ubyte nb_components; ///< The number of components each pixel has, (1-4)
80 
81     /**
82      * Amount to shift the luma width right to find the chroma width.
83      * For YV12 this is 1 for example.
84      * chroma_width = AV_CEIL_RSHIFT(luma_width, log2_chroma_w)
85      * The note above is needed to ensure rounding up.
86      * This value only refers to the chroma components.
87      */
88     ubyte log2_chroma_w;
89 
90     /**
91      * Amount to shift the luma height right to find the chroma height.
92      * For YV12 this is 1 for example.
93      * chroma_height= AV_CEIL_RSHIFT(luma_height, log2_chroma_h)
94      * The note above is needed to ensure rounding up.
95      * This value only refers to the chroma components.
96      */
97     ubyte log2_chroma_h;
98 
99     /**
100      * Combination of AV_PIX_FMT_FLAG_... flags.
101      */
102     ulong flags;
103 
104     /**
105      * Parameters that describe how pixels are packed.
106      * If the format has 1 or 2 components, then luma is 0.
107      * If the format has 3 or 4 components:
108      *   if the RGB flag is set then 0 is red, 1 is green and 2 is blue;
109      *   otherwise 0 is luma, 1 is chroma-U and 2 is chroma-V.
110      *
111      * If present, the Alpha channel is always the last component.
112      */
113     AVComponentDescriptor[4] comp;
114 
115     /**
116      * Alternative comma-separated names.
117      */
118     const(char)* alias_;
119 }
120 
121 /**
122  * Pixel format is big-endian.
123  */
124 enum AV_PIX_FMT_FLAG_BE = 1 << 0;
125 /**
126  * Pixel format has a palette in data[1], values are indexes in this palette.
127  */
128 enum AV_PIX_FMT_FLAG_PAL = 1 << 1;
129 /**
130  * All values of a component are bit-wise packed end to end.
131  */
132 enum AV_PIX_FMT_FLAG_BITSTREAM = 1 << 2;
133 /**
134  * Pixel format is an HW accelerated format.
135  */
136 enum AV_PIX_FMT_FLAG_HWACCEL = 1 << 3;
137 /**
138  * At least one pixel component is not in the first data plane.
139  */
140 enum AV_PIX_FMT_FLAG_PLANAR = 1 << 4;
141 /**
142  * The pixel format contains RGB-like data (as opposed to YUV/grayscale).
143  */
144 enum AV_PIX_FMT_FLAG_RGB = 1 << 5;
145 
146 /**
147  * The pixel format is "pseudo-paletted". This means that it contains a
148  * fixed palette in the 2nd plane but the palette is fixed/constant for each
149  * PIX_FMT. This allows interpreting the data as if it was PAL8, which can
150  * in some cases be simpler. Or the data can be interpreted purely based on
151  * the pixel format without using the palette.
152  * An example of a pseudo-paletted format is AV_PIX_FMT_GRAY8
153  *
154  * @deprecated This flag is deprecated, and will be removed. When it is removed,
155  * the extra palette allocation in AVFrame.data[1] is removed as well. Only
156  * actual paletted formats (as indicated by AV_PIX_FMT_FLAG_PAL) will have a
157  * palette. Starting with FFmpeg versions which have this flag deprecated, the
158  * extra "pseudo" palette is already ignored, and API users are not required to
159  * allocate a palette for AV_PIX_FMT_FLAG_PSEUDOPAL formats (it was required
160  * before the deprecation, though).
161  */
162 enum AV_PIX_FMT_FLAG_PSEUDOPAL = 1 << 6;
163 
164 /**
165  * The pixel format has an alpha channel. This is set on all formats that
166  * support alpha in some way, including AV_PIX_FMT_PAL8. The alpha is always
167  * straight, never pre-multiplied.
168  *
169  * If a codec or a filter does not support alpha, it should set all alpha to
170  * opaque, or use the equivalent pixel formats without alpha component, e.g.
171  * AV_PIX_FMT_RGB0 (or AV_PIX_FMT_RGB24 etc.) instead of AV_PIX_FMT_RGBA.
172  */
173 enum AV_PIX_FMT_FLAG_ALPHA = 1 << 7;
174 
175 /**
176  * The pixel format is following a Bayer pattern
177  */
178 enum AV_PIX_FMT_FLAG_BAYER = 1 << 8;
179 
180 /**
181  * The pixel format contains IEEE-754 floating point values. Precision (double,
182  * single, or half) should be determined by the pixel size (64, 32, or 16 bits).
183  */
184 enum AV_PIX_FMT_FLAG_FLOAT = 1 << 9;
185 
186 /**
187  * Return the number of bits per pixel used by the pixel format
188  * described by pixdesc. Note that this is not the same as the number
189  * of bits per sample.
190  *
191  * The returned number of bits refers to the number of bits actually
192  * used for storing the pixel information, that is padding bits are
193  * not counted.
194  */
195 int av_get_bits_per_pixel (const(AVPixFmtDescriptor)* pixdesc);
196 
197 /**
198  * Return the number of bits per pixel for the pixel format
199  * described by pixdesc, including any padding or unused bits.
200  */
201 int av_get_padded_bits_per_pixel (const(AVPixFmtDescriptor)* pixdesc);
202 
203 /**
204  * @return a pixel format descriptor for provided pixel format or NULL if
205  * this pixel format is unknown.
206  */
207 const(AVPixFmtDescriptor)* av_pix_fmt_desc_get (AVPixelFormat pix_fmt);
208 
209 /**
210  * Iterate over all pixel format descriptors known to libavutil.
211  *
212  * @param prev previous descriptor. NULL to get the first descriptor.
213  *
214  * @return next descriptor or NULL after the last descriptor
215  */
216 const(AVPixFmtDescriptor)* av_pix_fmt_desc_next (const(AVPixFmtDescriptor)* prev);
217 
218 /**
219  * @return an AVPixelFormat id described by desc, or AV_PIX_FMT_NONE if desc
220  * is not a valid pointer to a pixel format descriptor.
221  */
222 AVPixelFormat av_pix_fmt_desc_get_id (const(AVPixFmtDescriptor)* desc);
223 
224 /**
225  * Utility function to access log2_chroma_w log2_chroma_h from
226  * the pixel format AVPixFmtDescriptor.
227  *
228  * @param[in]  pix_fmt the pixel format
229  * @param[out] h_shift store log2_chroma_w (horizontal/width shift)
230  * @param[out] v_shift store log2_chroma_h (vertical/height shift)
231  *
232  * @return 0 on success, AVERROR(ENOSYS) on invalid or unknown pixel format
233  */
234 int av_pix_fmt_get_chroma_sub_sample (
235     AVPixelFormat pix_fmt,
236     int* h_shift,
237     int* v_shift);
238 
239 /**
240  * @return number of planes in pix_fmt, a negative AVERROR if pix_fmt is not a
241  * valid pixel format.
242  */
243 int av_pix_fmt_count_planes (AVPixelFormat pix_fmt);
244 
245 /**
246  * @return the name for provided color range or NULL if unknown.
247  */
248 const(char)* av_color_range_name (AVColorRange range);
249 
250 /**
251  * @return the AVColorRange value for name or an AVError if not found.
252  */
253 int av_color_range_from_name (const(char)* name);
254 
255 /**
256  * @return the name for provided color primaries or NULL if unknown.
257  */
258 const(char)* av_color_primaries_name (AVColorPrimaries primaries);
259 
260 /**
261  * @return the AVColorPrimaries value for name or an AVError if not found.
262  */
263 int av_color_primaries_from_name (const(char)* name);
264 
265 /**
266  * @return the name for provided color transfer or NULL if unknown.
267  */
268 const(char)* av_color_transfer_name (AVColorTransferCharacteristic transfer);
269 
270 /**
271  * @return the AVColorTransferCharacteristic value for name or an AVError if not found.
272  */
273 int av_color_transfer_from_name (const(char)* name);
274 
275 /**
276  * @return the name for provided color space or NULL if unknown.
277  */
278 const(char)* av_color_space_name (AVColorSpace space);
279 
280 /**
281  * @return the AVColorSpace value for name or an AVError if not found.
282  */
283 int av_color_space_from_name (const(char)* name);
284 
285 /**
286  * @return the name for provided chroma location or NULL if unknown.
287  */
288 const(char)* av_chroma_location_name (AVChromaLocation location);
289 
290 /**
291  * @return the AVChromaLocation value for name or an AVError if not found.
292  */
293 int av_chroma_location_from_name (const(char)* name);
294 
295 /**
296  * Return the pixel format corresponding to name.
297  *
298  * If there is no pixel format with name name, then looks for a
299  * pixel format with the name corresponding to the native endian
300  * format of name.
301  * For example in a little-endian system, first looks for "gray16",
302  * then for "gray16le".
303  *
304  * Finally if no pixel format has been found, returns AV_PIX_FMT_NONE.
305  */
306 AVPixelFormat av_get_pix_fmt (const(char)* name);
307 
308 /**
309  * Return the short name for a pixel format, NULL in case pix_fmt is
310  * unknown.
311  *
312  * @see av_get_pix_fmt(), av_get_pix_fmt_string()
313  */
314 const(char)* av_get_pix_fmt_name (AVPixelFormat pix_fmt);
315 
316 /**
317  * Print in buf the string corresponding to the pixel format with
318  * number pix_fmt, or a header if pix_fmt is negative.
319  *
320  * @param buf the buffer where to write the string
321  * @param buf_size the size of buf
322  * @param pix_fmt the number of the pixel format to print the
323  * corresponding info string, or a negative value to print the
324  * corresponding header.
325  */
326 char* av_get_pix_fmt_string (char* buf, int buf_size, AVPixelFormat pix_fmt);
327 
328 /**
329  * Read a line from an image, and write the values of the
330  * pixel format component c to dst.
331  *
332  * @param data the array containing the pointers to the planes of the image
333  * @param linesize the array containing the linesizes of the image
334  * @param desc the pixel format descriptor for the image
335  * @param x the horizontal coordinate of the first pixel to read
336  * @param y the vertical coordinate of the first pixel to read
337  * @param w the width of the line to read, that is the number of
338  * values to write to dst
339  * @param read_pal_component if not zero and the format is a paletted
340  * format writes the values corresponding to the palette
341  * component c in data[1] to dst, rather than the palette indexes in
342  * data[0]. The behavior is undefined if the format is not paletted.
343  * @param dst_element_size size of elements in dst array (2 or 4 byte)
344  */
345 void av_read_image_line2 (
346     void* dst,
347     ref const(ubyte)*[4] data,
348     ref const(int)[4] linesize,
349     const(AVPixFmtDescriptor)* desc,
350     int x,
351     int y,
352     int c,
353     int w,
354     int read_pal_component,
355     int dst_element_size);
356 
357 void av_read_image_line (
358     ushort* dst,
359     ref const(ubyte)*[4] data,
360     ref const(int)[4] linesize,
361     const(AVPixFmtDescriptor)* desc,
362     int x,
363     int y,
364     int c,
365     int w,
366     int read_pal_component);
367 
368 /**
369  * Write the values from src to the pixel format component c of an
370  * image line.
371  *
372  * @param src array containing the values to write
373  * @param data the array containing the pointers to the planes of the
374  * image to write into. It is supposed to be zeroed.
375  * @param linesize the array containing the linesizes of the image
376  * @param desc the pixel format descriptor for the image
377  * @param x the horizontal coordinate of the first pixel to write
378  * @param y the vertical coordinate of the first pixel to write
379  * @param w the width of the line to write, that is the number of
380  * values to write to the image line
381  * @param src_element_size size of elements in src array (2 or 4 byte)
382  */
383 void av_write_image_line2 (
384     const(void)* src,
385     ref ubyte*[4] data,
386     ref const(int)[4] linesize,
387     const(AVPixFmtDescriptor)* desc,
388     int x,
389     int y,
390     int c,
391     int w,
392     int src_element_size);
393 
394 void av_write_image_line (
395     const(ushort)* src,
396     ref ubyte*[4] data,
397     ref const(int)[4] linesize,
398     const(AVPixFmtDescriptor)* desc,
399     int x,
400     int y,
401     int c,
402     int w);
403 
404 /**
405  * Utility function to swap the endianness of a pixel format.
406  *
407  * @param[in]  pix_fmt the pixel format
408  *
409  * @return pixel format with swapped endianness if it exists,
410  * otherwise AV_PIX_FMT_NONE
411  */
412 AVPixelFormat av_pix_fmt_swap_endianness (AVPixelFormat pix_fmt);
413 
414 enum FF_LOSS_RESOLUTION = 0x0001; /**< loss due to resolution change */
415 enum FF_LOSS_DEPTH = 0x0002; /**< loss due to color depth change */
416 enum FF_LOSS_COLORSPACE = 0x0004; /**< loss due to color space conversion */
417 enum FF_LOSS_ALPHA = 0x0008; /**< loss of alpha bits */
418 enum FF_LOSS_COLORQUANT = 0x0010; /**< loss due to color quantization */
419 enum FF_LOSS_CHROMA = 0x0020; /**< loss of chroma (e.g. RGB to gray conversion) */
420 
421 /**
422  * Compute what kind of losses will occur when converting from one specific
423  * pixel format to another.
424  * When converting from one pixel format to another, information loss may occur.
425  * For example, when converting from RGB24 to GRAY, the color information will
426  * be lost. Similarly, other losses occur when converting from some formats to
427  * other formats. These losses can involve loss of chroma, but also loss of
428  * resolution, loss of color depth, loss due to the color space conversion, loss
429  * of the alpha bits or loss due to color quantization.
430  * av_get_fix_fmt_loss() informs you about the various types of losses
431  * which will occur when converting from one pixel format to another.
432  *
433  * @param[in] dst_pix_fmt destination pixel format
434  * @param[in] src_pix_fmt source pixel format
435  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
436  * @return Combination of flags informing you what kind of losses will occur
437  * (maximum loss for an invalid dst_pix_fmt).
438  */
439 int av_get_pix_fmt_loss (
440     AVPixelFormat dst_pix_fmt,
441     AVPixelFormat src_pix_fmt,
442     int has_alpha);
443 
444 /**
445  * Compute what kind of losses will occur when converting from one specific
446  * pixel format to another.
447  * When converting from one pixel format to another, information loss may occur.
448  * For example, when converting from RGB24 to GRAY, the color information will
449  * be lost. Similarly, other losses occur when converting from some formats to
450  * other formats. These losses can involve loss of chroma, but also loss of
451  * resolution, loss of color depth, loss due to the color space conversion, loss
452  * of the alpha bits or loss due to color quantization.
453  * av_get_fix_fmt_loss() informs you about the various types of losses
454  * which will occur when converting from one pixel format to another.
455  *
456  * @param[in] dst_pix_fmt destination pixel format
457  * @param[in] src_pix_fmt source pixel format
458  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
459  * @return Combination of flags informing you what kind of losses will occur
460  * (maximum loss for an invalid dst_pix_fmt).
461  */
462 AVPixelFormat av_find_best_pix_fmt_of_2 (
463     AVPixelFormat dst_pix_fmt1,
464     AVPixelFormat dst_pix_fmt2,
465     AVPixelFormat src_pix_fmt,
466     int has_alpha,
467     int* loss_ptr);
468 
469 /* AVUTIL_PIXDESC_H */