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 module ffmpeg.libavfilter.formats; 19 20 import std.stdint; 21 import ffmpeg.libavfilter.avfilter; 22 23 @nogc nothrow extern(C): 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 uint nb_formats; ///< number of formats 66 int *formats; ///< list of media formats 67 68 uint refcount; ///< number of references to this list 69 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 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 uint refcount; ///< number of references to this list 92 AVFilterChannelLayouts ***refs; ///< references to this list 93 } 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 template FF_COUNT2LAYOUT(int c) { enum FF_COUNT2LAYOUT = (0x8000000000000000 | (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 template FF_LAYOUT2COUNT(int l) { enum FF_LAYOUT2COUNT = (((l) & 0x8000000000000000) ? 109 ((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 // av_warn_unused_result 129 AVFilterChannelLayouts *ff_all_channel_layouts(); 130 131 // av_warn_unused_result 132 AVFilterFormats *ff_all_samplerates(); 133 134 /** 135 * Construct an AVFilterChannelLayouts coding for any channel layout, with 136 * known or unknown disposition. 137 */ 138 // av_warn_unused_result 139 AVFilterChannelLayouts *ff_all_channel_counts(); 140 141 // av_warn_unused_result 142 AVFilterChannelLayouts *avfilter_make_format64_list(const int64_t *fmts); 143 144 // av_warn_unused_result 145 AVFilterChannelLayouts *ff_make_formatu64_list(const uint64_t *fmts); 146 147 148 /** 149 * A helper for query_formats() which sets all links to the same list of channel 150 * layouts/sample rates. If there are no links hooked to this filter, the list 151 * is freed. 152 */ 153 // av_warn_unused_result 154 void ff_set_common_channel_layouts(AVFilterContext *ctx, 155 AVFilterChannelLayouts *layouts); 156 // av_warn_unused_result 157 void ff_set_common_samplerates(AVFilterContext *ctx, 158 AVFilterFormats *samplerates); 159 160 /** 161 * A helper for query_formats() which sets all links to the same list of 162 * formats. If there are no links hooked to this filter, the list of formats is 163 * freed. 164 */ 165 // av_warn_unused_result 166 void ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats); 167 168 // av_warn_unused_result 169 int ff_add_channel_layout(AVFilterChannelLayouts **l, uint64_t channel_layout); 170 171 /** 172 * Add *ref as a new reference to f. 173 */ 174 // av_warn_unused_result 175 void ff_channel_layouts_ref(AVFilterChannelLayouts *f, 176 AVFilterChannelLayouts **_ref); 177 178 /** 179 * Remove a reference to a channel layouts list. 180 */ 181 void ff_channel_layouts_unref(AVFilterChannelLayouts **_ref); 182 183 void ff_channel_layouts_changeref(AVFilterChannelLayouts **oldref, 184 AVFilterChannelLayouts **newref); 185 186 // av_warn_unused_result 187 int ff_default_query_formats(AVFilterContext *ctx); 188 189 /** 190 * Set the formats list to all existing formats. 191 * This function behaves like ff_default_query_formats(), except it also 192 * accepts channel layouts with unknown disposition. It should only be used 193 * with audio filters. 194 */ 195 // av_warn_unused_result 196 int ff_query_formats_all(AVFilterContext *ctx); 197 198 199 /** 200 * Create a list of supported formats. This is intended for use in 201 * AVFilter->query_formats(). 202 * 203 * @param fmts list of media formats, terminated by -1 204 * @return the format list, with no existing references 205 */ 206 // av_warn_unused_result 207 AVFilterFormats *ff_make_format_list(const int *fmts); 208 209 /** 210 * Add fmt to the list of media formats contained in *avff. 211 * If *avff is NULL the function allocates the filter formats struct 212 * and puts its pointer in *avff. 213 * 214 * @return a non negative value in case of success, or a negative 215 * value corresponding to an AVERROR code in case of error 216 */ 217 // av_warn_unused_result 218 int ff_add_format(AVFilterFormats **avff, int64_t fmt); 219 220 /** 221 * Return a list of all formats supported by FFmpeg for the given media type. 222 */ 223 // av_warn_unused_result 224 AVFilterFormats *ff_all_formats(ffmpeg.libavutil.avutil.AVMediaType type); 225 226 /** 227 * Construct a formats list containing all planar sample formats. 228 */ 229 // av_warn_unused_result 230 AVFilterFormats *ff_planar_sample_fmts(); 231 232 /** 233 * Return a format list which contains the intersection of the formats of 234 * a and b. Also, all the references of a, all the references of b, and 235 * a and b themselves will be deallocated. 236 * 237 * If a and b do not share any common formats, neither is modified, and NULL 238 * is returned. 239 */ 240 AVFilterFormats *ff_merge_formats(AVFilterFormats *a, AVFilterFormats *b, 241 ffmpeg.libavutil.avutil.AVMediaType type); 242 243 /** 244 * Add *ref as a new reference to formats. 245 * That is the pointers will point like in the ascii art below: 246 * ________ 247 * |formats |<--------. 248 * | ____ | ____|___________________ 249 * | |refs| | | __|_ 250 * | |* * | | | | | | AVFilterLink 251 * | |* *--------->|*ref| 252 * | |____| | | |____| 253 * |________| |________________________ 254 */ 255 // av_warn_unused_result 256 void ff_formats_ref(AVFilterFormats *formats, AVFilterFormats **_ref); 257 258 /** 259 * If *ref is non-NULL, remove *ref as a reference to the format list 260 * it currently points to, deallocates that list if this was the last 261 * reference, and sets *ref to NULL. 262 * 263 * Before After 264 * ________ ________ NULL 265 * |formats |<--------. |formats | ^ 266 * | ____ | ____|________________ | ____ | ____|________________ 267 * | |refs| | | __|_ | |refs| | | __|_ 268 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink 269 * | |* *--------->|*ref| | |* | | | |*ref| 270 * | |____| | | |____| | |____| | | |____| 271 * |________| |_____________________ |________| |_____________________ 272 */ 273 void ff_formats_unref(AVFilterFormats **_ref); 274 275 /** 276 * Before After 277 * ________ ________ 278 * |formats |<---------. |formats |<---------. 279 * | ____ | ___|___ | ____ | ___|___ 280 * | |refs| | | | | | |refs| | | | | NULL 281 * | |* *--------->|*oldref| | |* *--------->|*newref| ^ 282 * | |* * | | |_______| | |* * | | |_______| ___|___ 283 * | |____| | | |____| | | | | 284 * |________| |________| |*oldref| 285 * |_______| 286 */ 287 void ff_formats_changeref(AVFilterFormats **oldref, AVFilterFormats **newref); 288 289 //#endif /* AVFILTER_FORMATS_H */