/* * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVFILTER_FORMATS_H#define AVFILTER_FORMATS_H #include "avfilter.h" /** * A list of supported formats for one end of a filter link. This is used * during the format negotiation process to try to pick the best format to * use to minimize the number of necessary conversions. Each filter gives a * list of the formats supported by each input and output pad. The list * given for each pad need not be distinct - they may be references to the * same list of formats, as is often the case when a filter supports multiple * formats, but will always output the same format as it is given in input. * * In this way, a list of possible input formats and a list of possible * output formats are associated with each link. When a set of formats is * negotiated over a link, the input and output lists are merged to form a * new list containing only the common elements of each list. In the case * that there were no common elements, a format conversion is necessary. * Otherwise, the lists are merged, and all other links which reference * either of the format lists involved in the merge are also affected. * * For example, consider the filter chain: * filter (a) --> (b) filter (b) --> (c) filter * * where the letters in parenthesis indicate a list of formats supported on * the input or output of the link. Suppose the lists are as follows: * (a) = {A, B} * (b) = {A, B, C} * (c) = {B, C} * * First, the first link's lists are merged, yielding: * filter (a) --> (a) filter (a) --> (c) filter * * Notice that format list (b) now refers to the same list as filter list (a). * Next, the lists for the second link are merged, yielding: * filter (a) --> (a) filter (a) --> (a) filter * * where (a) = {B}. * * Unfortunately, when the format lists at the two ends of a link are merged, * we must ensure that all links which reference either pre-merge format list * get updated as well. Therefore, we have the format list structure store a * pointer to each of the pointers to itself. */struct AVFilterFormats {    unsigned nb_formats;        ///< number of formats    int *formats;               ///< list of media formats     unsigned refcount;          ///< number of references to this list    struct AVFilterFormats ***refs; ///< references to this list}; /** * A list of supported channel layouts. * * The list works the same as AVFilterFormats, except for the following * differences: * - A list with all_layouts = 1 means all channel layouts with a known *   disposition; nb_channel_layouts must then be 0. * - A list with all_counts = 1 means all channel counts, with a known or *   unknown disposition; nb_channel_layouts must then be 0 and all_layouts 1. * - The list must not contain a layout with a known disposition and a *   channel count with unknown disposition with the same number of channels *   (e.g. AV_CH_LAYOUT_STEREO and FF_COUNT2LAYOUT(2). */typedef struct AVFilterChannelLayouts {    uint64_t *channel_layouts;  ///< list of channel layouts    int    nb_channel_layouts;  ///< number of channel layouts    char all_layouts;           ///< accept any known channel layout    char all_counts;            ///< accept any channel layout or count     unsigned refcount;          ///< number of references to this list    struct AVFilterChannelLayouts ***refs; ///< references to this list} AVFilterChannelLayouts; /** * Encode a channel count as a channel layout. * FF_COUNT2LAYOUT(c) means any channel layout with c channels, with a known * or unknown disposition. * The result is only valid inside AVFilterChannelLayouts and immediately * related functions. */#define FF_COUNT2LAYOUT(c) (0x8000000000000000ULL | (c)) /** * Decode a channel count encoded as a channel layout. * Return 0 if the channel layout was a real one. */#define FF_LAYOUT2COUNT(l) (((l) & 0x8000000000000000ULL) ? \                           (int)((l) & 0x7FFFFFFF) : 0) /** * Return a channel layouts/samplerates list which contains the intersection of * the layouts/samplerates of a and b. Also, all the references of a, all the * references of b, and a and b themselves will be deallocated. * * If a and b do not share any common elements, neither is modified, and NULL * is returned. */AVFilterChannelLayouts *ff_merge_channel_layouts(AVFilterChannelLayouts *a,                                                 AVFilterChannelLayouts *b);AVFilterFormats *ff_merge_samplerates(AVFilterFormats *a,                                      AVFilterFormats *b); /** * Construct an empty AVFilterChannelLayouts/AVFilterFormats struct -- * representing any channel layout (with known disposition)/sample rate. */av_warn_unused_resultAVFilterChannelLayouts *ff_all_channel_layouts(void); av_warn_unused_resultAVFilterFormats *ff_all_samplerates(void); /** * Construct an AVFilterChannelLayouts coding for any channel layout, with * known or unknown disposition. */av_warn_unused_resultAVFilterChannelLayouts *ff_all_channel_counts(void); av_warn_unused_resultAVFilterChannelLayouts *avfilter_make_format64_list(const int64_t *fmts); av_warn_unused_resultAVFilterChannelLayouts *ff_make_formatu64_list(const uint64_t *fmts);  /** * A helper for query_formats() which sets all links to the same list of channel * layouts/sample rates. If there are no links hooked to this filter, the list * is freed. */av_warn_unused_resultint ff_set_common_channel_layouts(AVFilterContext *ctx,                                  AVFilterChannelLayouts *layouts);av_warn_unused_resultint ff_set_common_samplerates(AVFilterContext *ctx,                              AVFilterFormats *samplerates); /** * A helper for query_formats() which sets all links to the same list of * formats. If there are no links hooked to this filter, the list of formats is * freed. */av_warn_unused_resultint ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats); av_warn_unused_resultint ff_add_channel_layout(AVFilterChannelLayouts **l, uint64_t channel_layout); /** * Add *ref as a new reference to f. */av_warn_unused_resultint ff_channel_layouts_ref(AVFilterChannelLayouts *f,                           AVFilterChannelLayouts **ref); /** * Remove a reference to a channel layouts list. */void ff_channel_layouts_unref(AVFilterChannelLayouts **ref); void ff_channel_layouts_changeref(AVFilterChannelLayouts **oldref,                                  AVFilterChannelLayouts **newref); av_warn_unused_resultint ff_default_query_formats(AVFilterContext *ctx);  /** * Set the formats list to all known channel layouts. This function behaves * like ff_default_query_formats(), except it only accepts known channel * layouts. It should only be used with audio filters. */av_warn_unused_resultint ff_query_formats_all_layouts(AVFilterContext *ctx); /** * Create a list of supported formats. This is intended for use in * AVFilter->query_formats(). * * @param fmts list of media formats, terminated by -1 * @return the format list, with no existing references */av_warn_unused_resultAVFilterFormats *ff_make_format_list(const int *fmts); /** * Add fmt to the list of media formats contained in *avff. * If *avff is NULL the function allocates the filter formats struct * and puts its pointer in *avff. * * @return a non negative value in case of success, or a negative * value corresponding to an AVERROR code in case of error */av_warn_unused_resultint ff_add_format(AVFilterFormats **avff, int64_t fmt); /** * Return a list of all formats supported by FFmpeg for the given media type. */av_warn_unused_resultAVFilterFormats *ff_all_formats(enum AVMediaType type); /** * Construct a formats list containing all planar sample formats. */av_warn_unused_resultAVFilterFormats *ff_planar_sample_fmts(void); /** * Return a format list which contains the intersection of the formats of * a and b. Also, all the references of a, all the references of b, and * a and b themselves will be deallocated. * * If a and b do not share any common formats, neither is modified, and NULL * is returned. */AVFilterFormats *ff_merge_formats(AVFilterFormats *a, AVFilterFormats *b,                                  enum AVMediaType type); /** * Add *ref as a new reference to formats. * That is the pointers will point like in the ascii art below: *   ________ *  |formats |<--------. *  |  ____  |     ____|___________________ *  | |refs| |    |  __|_ *  | |* * | |    | |  | |  AVFilterLink *  | |* *--------->|*ref| *  | |____| |    | |____| *  |________|    |________________________ */av_warn_unused_resultint ff_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref); /** * If *ref is non-NULL, remove *ref as a reference to the format list * it currently points to, deallocates that list if this was the last * reference, and sets *ref to NULL. * *         Before                                 After *   ________                               ________         NULL *  |formats |<--------.                   |formats |         ^ *  |  ____  |     ____|________________   |  ____  |     ____|________________ *  | |refs| |    |  __|_                  | |refs| |    |  __|_ *  | |* * | |    | |  | |  AVFilterLink   | |* * | |    | |  | |  AVFilterLink *  | |* *--------->|*ref|                 | |*   | |    | |*ref| *  | |____| |    | |____|                 | |____| |    | |____| *  |________|    |_____________________   |________|    |_____________________ */void ff_formats_unref(AVFilterFormats **ref); /** *         Before                                 After *   ________                         ________ *  |formats |<---------.            |formats |<---------. *  |  ____  |       ___|___         |  ____  |       ___|___ *  | |refs| |      |   |   |        | |refs| |      |   |   |   NULL *  | |* *--------->|*oldref|        | |* *--------->|*newref|     ^ *  | |* * | |      |_______|        | |* * | |      |_______|  ___|___ *  | |____| |                       | |____| |                |   |   | *  |________|                       |________|                |*oldref| *                                                             |_______| */void ff_formats_changeref(AVFilterFormats **oldref, AVFilterFormats **newref); #endif /* AVFILTER_FORMATS_H */