blob: 870809b5a03e4b694450dbbf1b30c6298493f965
| 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 | av_warn_unused_result |
| 129 | AVFilterChannelLayouts *ff_all_channel_layouts(void); |
| 130 | |
| 131 | av_warn_unused_result |
| 132 | AVFilterFormats *ff_all_samplerates(void); |
| 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(void); |
| 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 | int ff_set_common_channel_layouts(AVFilterContext *ctx, |
| 155 | AVFilterChannelLayouts *layouts); |
| 156 | av_warn_unused_result |
| 157 | int 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 | int 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 | int 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 known channel layouts. This function behaves |
| 191 | * like ff_default_query_formats(), except it only accepts known channel |
| 192 | * layouts. It should only be used with audio filters. |
| 193 | */ |
| 194 | av_warn_unused_result |
| 195 | int ff_query_formats_all_layouts(AVFilterContext *ctx); |
| 196 | |
| 197 | /** |
| 198 | * Create a list of supported formats. This is intended for use in |
| 199 | * AVFilter->query_formats(). |
| 200 | * |
| 201 | * @param fmts list of media formats, terminated by -1 |
| 202 | * @return the format list, with no existing references |
| 203 | */ |
| 204 | av_warn_unused_result |
| 205 | AVFilterFormats *ff_make_format_list(const int *fmts); |
| 206 | |
| 207 | /** |
| 208 | * Add fmt to the list of media formats contained in *avff. |
| 209 | * If *avff is NULL the function allocates the filter formats struct |
| 210 | * and puts its pointer in *avff. |
| 211 | * |
| 212 | * @return a non negative value in case of success, or a negative |
| 213 | * value corresponding to an AVERROR code in case of error |
| 214 | */ |
| 215 | av_warn_unused_result |
| 216 | int ff_add_format(AVFilterFormats **avff, int64_t fmt); |
| 217 | |
| 218 | /** |
| 219 | * Return a list of all formats supported by FFmpeg for the given media type. |
| 220 | */ |
| 221 | av_warn_unused_result |
| 222 | AVFilterFormats *ff_all_formats(enum AVMediaType type); |
| 223 | |
| 224 | /** |
| 225 | * Construct a formats list containing all planar sample formats. |
| 226 | */ |
| 227 | av_warn_unused_result |
| 228 | AVFilterFormats *ff_planar_sample_fmts(void); |
| 229 | |
| 230 | /** |
| 231 | * Return a format list which contains the intersection of the formats of |
| 232 | * a and b. Also, all the references of a, all the references of b, and |
| 233 | * a and b themselves will be deallocated. |
| 234 | * |
| 235 | * If a and b do not share any common formats, neither is modified, and NULL |
| 236 | * is returned. |
| 237 | */ |
| 238 | AVFilterFormats *ff_merge_formats(AVFilterFormats *a, AVFilterFormats *b, |
| 239 | enum AVMediaType type); |
| 240 | |
| 241 | /** |
| 242 | * Add *ref as a new reference to formats. |
| 243 | * That is the pointers will point like in the ascii art below: |
| 244 | * ________ |
| 245 | * |formats |<--------. |
| 246 | * | ____ | ____|___________________ |
| 247 | * | |refs| | | __|_ |
| 248 | * | |* * | | | | | | AVFilterLink |
| 249 | * | |* *--------->|*ref| |
| 250 | * | |____| | | |____| |
| 251 | * |________| |________________________ |
| 252 | */ |
| 253 | av_warn_unused_result |
| 254 | int ff_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref); |
| 255 | |
| 256 | /** |
| 257 | * If *ref is non-NULL, remove *ref as a reference to the format list |
| 258 | * it currently points to, deallocates that list if this was the last |
| 259 | * reference, and sets *ref to NULL. |
| 260 | * |
| 261 | * Before After |
| 262 | * ________ ________ NULL |
| 263 | * |formats |<--------. |formats | ^ |
| 264 | * | ____ | ____|________________ | ____ | ____|________________ |
| 265 | * | |refs| | | __|_ | |refs| | | __|_ |
| 266 | * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink |
| 267 | * | |* *--------->|*ref| | |* | | | |*ref| |
| 268 | * | |____| | | |____| | |____| | | |____| |
| 269 | * |________| |_____________________ |________| |_____________________ |
| 270 | */ |
| 271 | void ff_formats_unref(AVFilterFormats **ref); |
| 272 | |
| 273 | /** |
| 274 | * Before After |
| 275 | * ________ ________ |
| 276 | * |formats |<---------. |formats |<---------. |
| 277 | * | ____ | ___|___ | ____ | ___|___ |
| 278 | * | |refs| | | | | | |refs| | | | | NULL |
| 279 | * | |* *--------->|*oldref| | |* *--------->|*newref| ^ |
| 280 | * | |* * | | |_______| | |* * | | |_______| ___|___ |
| 281 | * | |____| | | |____| | | | | |
| 282 | * |________| |________| |*oldref| |
| 283 | * |_______| |
| 284 | */ |
| 285 | void ff_formats_changeref(AVFilterFormats **oldref, AVFilterFormats **newref); |
| 286 | |
| 287 | #endif /* AVFILTER_FORMATS_H */ |
| 288 |