| /* |
| * 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_result |
| AVFilterChannelLayouts *ff_all_channel_layouts(void); |
| |
| av_warn_unused_result |
| AVFilterFormats *ff_all_samplerates(void); |
| |
| /** |
| * Construct an AVFilterChannelLayouts coding for any channel layout, with |
| * known or unknown disposition. |
| */ |
| av_warn_unused_result |
| AVFilterChannelLayouts *ff_all_channel_counts(void); |
| |
| av_warn_unused_result |
| AVFilterChannelLayouts *avfilter_make_format64_list(const int64_t *fmts); |
| |
| av_warn_unused_result |
| AVFilterChannelLayouts *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_result |
| int ff_set_common_channel_layouts(AVFilterContext *ctx, |
| AVFilterChannelLayouts *layouts); |
| av_warn_unused_result |
| int 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_result |
| int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats); |
| |
| av_warn_unused_result |
| int ff_add_channel_layout(AVFilterChannelLayouts **l, uint64_t channel_layout); |
| |
| /** |
| * Add *ref as a new reference to f. |
| */ |
| av_warn_unused_result |
| int 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_result |
| int ff_default_query_formats(AVFilterContext *ctx); |
| |
| /** |
| * Set the formats list to all existing formats. |
| * This function behaves like ff_default_query_formats(), except it also |
| * accepts channel layouts with unknown disposition. It should only be used |
| * with audio filters. |
| */ |
| av_warn_unused_result |
| int ff_query_formats_all(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_result |
| AVFilterFormats *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_result |
| int 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_result |
| AVFilterFormats *ff_all_formats(enum AVMediaType type); |
| |
| /** |
| * Construct a formats list containing all planar sample formats. |
| */ |
| av_warn_unused_result |
| AVFilterFormats *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_result |
| int 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 */ |