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1 | /* |
2 | * This file is part of FFmpeg. | |
3 | * | |
4 | * FFmpeg is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU Lesser General Public | |
6 | * License as published by the Free Software Foundation; either | |
7 | * version 2.1 of the License, or (at your option) any later version. | |
8 | * | |
9 | * FFmpeg is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * Lesser General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU Lesser General Public | |
15 | * License along with FFmpeg; if not, write to the Free Software | |
16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
17 | */ | |
18 | ||
19 | #ifndef AVFILTER_FORMATS_H | |
20 | #define AVFILTER_FORMATS_H | |
21 | ||
22 | #include "avfilter.h" | |
23 | ||
24 | /** | |
25 | * A list of supported formats for one end of a filter link. This is used | |
26 | * during the format negotiation process to try to pick the best format to | |
27 | * use to minimize the number of necessary conversions. Each filter gives a | |
28 | * list of the formats supported by each input and output pad. The list | |
29 | * given for each pad need not be distinct - they may be references to the | |
30 | * same list of formats, as is often the case when a filter supports multiple | |
31 | * formats, but will always output the same format as it is given in input. | |
32 | * | |
33 | * In this way, a list of possible input formats and a list of possible | |
34 | * output formats are associated with each link. When a set of formats is | |
35 | * negotiated over a link, the input and output lists are merged to form a | |
36 | * new list containing only the common elements of each list. In the case | |
37 | * that there were no common elements, a format conversion is necessary. | |
38 | * Otherwise, the lists are merged, and all other links which reference | |
39 | * either of the format lists involved in the merge are also affected. | |
40 | * | |
41 | * For example, consider the filter chain: | |
42 | * filter (a) --> (b) filter (b) --> (c) filter | |
43 | * | |
44 | * where the letters in parenthesis indicate a list of formats supported on | |
45 | * the input or output of the link. Suppose the lists are as follows: | |
46 | * (a) = {A, B} | |
47 | * (b) = {A, B, C} | |
48 | * (c) = {B, C} | |
49 | * | |
50 | * First, the first link's lists are merged, yielding: | |
51 | * filter (a) --> (a) filter (a) --> (c) filter | |
52 | * | |
53 | * Notice that format list (b) now refers to the same list as filter list (a). | |
54 | * Next, the lists for the second link are merged, yielding: | |
55 | * filter (a) --> (a) filter (a) --> (a) filter | |
56 | * | |
57 | * where (a) = {B}. | |
58 | * | |
59 | * Unfortunately, when the format lists at the two ends of a link are merged, | |
60 | * we must ensure that all links which reference either pre-merge format list | |
61 | * get updated as well. Therefore, we have the format list structure store a | |
62 | * pointer to each of the pointers to itself. | |
63 | */ | |
64 | struct AVFilterFormats { | |
65 | unsigned nb_formats; ///< number of formats | |
66 | int *formats; ///< list of media formats | |
67 | ||
68 | unsigned refcount; ///< number of references to this list | |
69 | struct AVFilterFormats ***refs; ///< references to this list | |
70 | }; | |
71 | ||
72 | /** | |
73 | * A list of supported channel layouts. | |
74 | * | |
75 | * The list works the same as AVFilterFormats, except for the following | |
76 | * differences: | |
77 | * - A list with all_layouts = 1 means all channel layouts with a known | |
78 | * disposition; nb_channel_layouts must then be 0. | |
79 | * - A list with all_counts = 1 means all channel counts, with a known or | |
80 | * unknown disposition; nb_channel_layouts must then be 0 and all_layouts 1. | |
81 | * - The list must not contain a layout with a known disposition and a | |
82 | * channel count with unknown disposition with the same number of channels | |
83 | * (e.g. AV_CH_LAYOUT_STEREO and FF_COUNT2LAYOUT(2). | |
84 | */ | |
85 | typedef struct AVFilterChannelLayouts { | |
86 | uint64_t *channel_layouts; ///< list of channel layouts | |
87 | int nb_channel_layouts; ///< number of channel layouts | |
88 | char all_layouts; ///< accept any known channel layout | |
89 | char all_counts; ///< accept any channel layout or count | |
90 | ||
91 | unsigned refcount; ///< number of references to this list | |
92 | struct AVFilterChannelLayouts ***refs; ///< references to this list | |
93 | } AVFilterChannelLayouts; | |
94 | ||
95 | /** | |
96 | * Encode a channel count as a channel layout. | |
97 | * FF_COUNT2LAYOUT(c) means any channel layout with c channels, with a known | |
98 | * or unknown disposition. | |
99 | * The result is only valid inside AVFilterChannelLayouts and immediately | |
100 | * related functions. | |
101 | */ | |
102 | #define FF_COUNT2LAYOUT(c) (0x8000000000000000ULL | (c)) | |
103 | ||
104 | /** | |
105 | * Decode a channel count encoded as a channel layout. | |
106 | * Return 0 if the channel layout was a real one. | |
107 | */ | |
108 | #define FF_LAYOUT2COUNT(l) (((l) & 0x8000000000000000ULL) ? \ | |
109 | (int)((l) & 0x7FFFFFFF) : 0) | |
110 | ||
111 | /** | |
112 | * Return a channel layouts/samplerates list which contains the intersection of | |
113 | * the layouts/samplerates of a and b. Also, all the references of a, all the | |
114 | * references of b, and a and b themselves will be deallocated. | |
115 | * | |
116 | * If a and b do not share any common elements, neither is modified, and NULL | |
117 | * is returned. | |
118 | */ | |
119 | AVFilterChannelLayouts *ff_merge_channel_layouts(AVFilterChannelLayouts *a, | |
120 | AVFilterChannelLayouts *b); | |
121 | AVFilterFormats *ff_merge_samplerates(AVFilterFormats *a, | |
122 | AVFilterFormats *b); | |
123 | ||
124 | /** | |
125 | * Construct an empty AVFilterChannelLayouts/AVFilterFormats struct -- | |
126 | * representing any channel layout (with known disposition)/sample rate. | |
127 | */ | |
128 | AVFilterChannelLayouts *ff_all_channel_layouts(void); | |
129 | AVFilterFormats *ff_all_samplerates(void); | |
130 | ||
131 | /** | |
132 | * Construct an AVFilterChannelLayouts coding for any channel layout, with | |
133 | * known or unknown disposition. | |
134 | */ | |
135 | AVFilterChannelLayouts *ff_all_channel_counts(void); | |
136 | ||
137 | AVFilterChannelLayouts *avfilter_make_format64_list(const int64_t *fmts); | |
138 | ||
139 | ||
140 | /** | |
141 | * A helper for query_formats() which sets all links to the same list of channel | |
142 | * layouts/sample rates. If there are no links hooked to this filter, the list | |
143 | * is freed. | |
144 | */ | |
145 | void ff_set_common_channel_layouts(AVFilterContext *ctx, | |
146 | AVFilterChannelLayouts *layouts); | |
147 | void ff_set_common_samplerates(AVFilterContext *ctx, | |
148 | AVFilterFormats *samplerates); | |
149 | ||
150 | /** | |
151 | * A helper for query_formats() which sets all links to the same list of | |
152 | * formats. If there are no links hooked to this filter, the list of formats is | |
153 | * freed. | |
154 | */ | |
155 | void ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats); | |
156 | ||
157 | int ff_add_channel_layout(AVFilterChannelLayouts **l, uint64_t channel_layout); | |
158 | ||
159 | /** | |
160 | * Add *ref as a new reference to f. | |
161 | */ | |
162 | void ff_channel_layouts_ref(AVFilterChannelLayouts *f, | |
163 | AVFilterChannelLayouts **ref); | |
164 | ||
165 | /** | |
166 | * Remove a reference to a channel layouts list. | |
167 | */ | |
168 | void ff_channel_layouts_unref(AVFilterChannelLayouts **ref); | |
169 | ||
170 | void ff_channel_layouts_changeref(AVFilterChannelLayouts **oldref, | |
171 | AVFilterChannelLayouts **newref); | |
172 | ||
173 | int ff_default_query_formats(AVFilterContext *ctx); | |
174 | ||
175 | /** | |
176 | * Set the formats list to all existing formats. | |
177 | * This function behaves like ff_default_query_formats(), except it also | |
178 | * accepts channel layouts with unknown disposition. It should only be used | |
179 | * with audio filters. | |
180 | */ | |
181 | int ff_query_formats_all(AVFilterContext *ctx); | |
182 | ||
183 | ||
184 | /** | |
185 | * Create a list of supported formats. This is intended for use in | |
186 | * AVFilter->query_formats(). | |
187 | * | |
188 | * @param fmts list of media formats, terminated by -1 | |
189 | * @return the format list, with no existing references | |
190 | */ | |
191 | AVFilterFormats *ff_make_format_list(const int *fmts); | |
192 | ||
193 | /** | |
194 | * Add fmt to the list of media formats contained in *avff. | |
195 | * If *avff is NULL the function allocates the filter formats struct | |
196 | * and puts its pointer in *avff. | |
197 | * | |
198 | * @return a non negative value in case of success, or a negative | |
199 | * value corresponding to an AVERROR code in case of error | |
200 | */ | |
201 | int ff_add_format(AVFilterFormats **avff, int64_t fmt); | |
202 | ||
203 | /** | |
204 | * Return a list of all formats supported by FFmpeg for the given media type. | |
205 | */ | |
206 | AVFilterFormats *ff_all_formats(enum AVMediaType type); | |
207 | ||
208 | /** | |
209 | * Construct a formats list containing all planar sample formats. | |
210 | */ | |
211 | AVFilterFormats *ff_planar_sample_fmts(void); | |
212 | ||
213 | /** | |
214 | * Return a format list which contains the intersection of the formats of | |
215 | * a and b. Also, all the references of a, all the references of b, and | |
216 | * a and b themselves will be deallocated. | |
217 | * | |
218 | * If a and b do not share any common formats, neither is modified, and NULL | |
219 | * is returned. | |
220 | */ | |
221 | AVFilterFormats *ff_merge_formats(AVFilterFormats *a, AVFilterFormats *b, | |
222 | enum AVMediaType type); | |
223 | ||
224 | /** | |
225 | * Add *ref as a new reference to formats. | |
226 | * That is the pointers will point like in the ascii art below: | |
227 | * ________ | |
228 | * |formats |<--------. | |
229 | * | ____ | ____|___________________ | |
230 | * | |refs| | | __|_ | |
231 | * | |* * | | | | | | AVFilterLink | |
232 | * | |* *--------->|*ref| | |
233 | * | |____| | | |____| | |
234 | * |________| |________________________ | |
235 | */ | |
236 | void ff_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref); | |
237 | ||
238 | /** | |
239 | * If *ref is non-NULL, remove *ref as a reference to the format list | |
240 | * it currently points to, deallocates that list if this was the last | |
241 | * reference, and sets *ref to NULL. | |
242 | * | |
243 | * Before After | |
244 | * ________ ________ NULL | |
245 | * |formats |<--------. |formats | ^ | |
246 | * | ____ | ____|________________ | ____ | ____|________________ | |
247 | * | |refs| | | __|_ | |refs| | | __|_ | |
248 | * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink | |
249 | * | |* *--------->|*ref| | |* | | | |*ref| | |
250 | * | |____| | | |____| | |____| | | |____| | |
251 | * |________| |_____________________ |________| |_____________________ | |
252 | */ | |
253 | void ff_formats_unref(AVFilterFormats **ref); | |
254 | ||
255 | /** | |
256 | * | |
257 | * Before After | |
258 | * ________ ________ | |
259 | * |formats |<---------. |formats |<---------. | |
260 | * | ____ | ___|___ | ____ | ___|___ | |
261 | * | |refs| | | | | | |refs| | | | | NULL | |
262 | * | |* *--------->|*oldref| | |* *--------->|*newref| ^ | |
263 | * | |* * | | |_______| | |* * | | |_______| ___|___ | |
264 | * | |____| | | |____| | | | | | |
265 | * |________| |________| |*oldref| | |
266 | * |_______| | |
267 | */ | |
268 | void ff_formats_changeref(AVFilterFormats **oldref, AVFilterFormats **newref); | |
269 | ||
270 | #endif /* AVFILTER_FORMATS_H */ |