| /* |
| * 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). |
| */ |
| struct AVFilterChannelLayouts { |
| AVChannelLayout *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 |
| }; |
| |
| /** |
| * 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) ((AVChannelLayout) { .order = AV_CHANNEL_ORDER_UNSPEC, .nb_channels = 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)->order == AV_CHANNEL_ORDER_UNSPEC) ? \ |
| (l)->nb_channels : 0) |
| |
| #define KNOWN(l) (!FF_LAYOUT2COUNT(l)) /* for readability */ |
| |
| /** |
| * 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 *ff_make_channel_layout_list(const AVChannelLayout *fmts); |
| |
| /** |
| * Construct an AVFilterFormats representing all possible color spaces. |
| * |
| * Note: This list does not include AVCOL_SPC_RESERVED. |
| */ |
| av_warn_unused_result |
| AVFilterFormats *ff_all_color_spaces(void); |
| |
| /** |
| * Construct an AVFilterFormats representing all possible color ranges. |
| */ |
| av_warn_unused_result |
| AVFilterFormats *ff_all_color_ranges(void); |
| |
| /** |
| * Helpers for query_formats() which set all free audio links to the same list |
| * of channel layouts/sample rates. If there are no links hooked to this list, |
| * the list is freed. |
| */ |
| av_warn_unused_result |
| int ff_set_common_channel_layouts(AVFilterContext *ctx, |
| AVFilterChannelLayouts *layouts); |
| /** |
| * Equivalent to ff_set_common_channel_layouts(ctx, ff_make_channel_layout_list(fmts)) |
| */ |
| av_warn_unused_result |
| int ff_set_common_channel_layouts_from_list(AVFilterContext *ctx, |
| const AVChannelLayout *fmts); |
| /** |
| * Equivalent to ff_set_common_channel_layouts(ctx, ff_all_channel_counts()) |
| */ |
| av_warn_unused_result |
| int ff_set_common_all_channel_counts(AVFilterContext *ctx); |
| |
| av_warn_unused_result |
| int ff_set_common_samplerates(AVFilterContext *ctx, |
| AVFilterFormats *samplerates); |
| /** |
| * Equivalent to ff_set_common_samplerates(ctx, ff_make_format_list(samplerates)) |
| */ |
| av_warn_unused_result |
| int ff_set_common_samplerates_from_list(AVFilterContext *ctx, |
| const int *samplerates); |
| /** |
| * Equivalent to ff_set_common_samplerates(ctx, ff_all_samplerates()) |
| */ |
| av_warn_unused_result |
| int ff_set_common_all_samplerates(AVFilterContext *ctx); |
| |
| av_warn_unused_result |
| int ff_set_common_color_spaces(AVFilterContext *ctx, |
| AVFilterFormats *color_spaces); |
| /** |
| * Equivalent to ff_set_common_color_spaces(ctx, ff_make_format_list(color_spaces)) |
| */ |
| av_warn_unused_result |
| int ff_set_common_color_spaces_from_list(AVFilterContext *ctx, |
| const int *color_spaces); |
| |
| /** |
| * Equivalent to ff_set_common_color_spaces(ctx, ff_all_color_spaces()) |
| */ |
| av_warn_unused_result |
| int ff_set_common_all_color_spaces(AVFilterContext *ctx); |
| |
| av_warn_unused_result |
| int ff_set_common_color_ranges(AVFilterContext *ctx, |
| AVFilterFormats *color_ranges); |
| /** |
| * Equivalent to ff_set_common_color_ranges(ctx, ff_make_format_list(color_ranges)) |
| */ |
| av_warn_unused_result |
| int ff_set_common_color_ranges_from_list(AVFilterContext *ctx, |
| const int *color_ranges); |
| |
| /** |
| * Equivalent to ff_set_common_color_ranges(ctx, ff_all_color_ranges()) |
| */ |
| av_warn_unused_result |
| int ff_set_common_all_color_ranges(AVFilterContext *ctx); |
| |
| /** |
| * 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); |
| |
| /** |
| * Equivalent to ff_set_common_formats(ctx, ff_make_format_list(fmts)) |
| */ |
| av_warn_unused_result |
| int ff_set_common_formats_from_list(AVFilterContext *ctx, const int *fmts); |
| |
| av_warn_unused_result |
| int ff_add_channel_layout(AVFilterChannelLayouts **l, |
| const AVChannelLayout *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); |
| |
| /** |
| * Sets all remaining unset filter lists for all inputs/outputs to their |
| * corresponding `ff_all_*()` lists. |
| */ |
| av_warn_unused_result |
| int ff_default_query_formats(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); |
| |
| /** |
| * Equivalent to ff_make_format_list({const int[]}{ fmt, -1 }) |
| */ |
| av_warn_unused_result |
| AVFilterFormats *ff_make_formats_list_singleton(int fmt); |
| |
| /** |
| * 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 pixel formats with certain |
| * properties |
| */ |
| av_warn_unused_result |
| AVFilterFormats *ff_formats_pixdesc_filter(unsigned want, unsigned rej); |
| |
| //* format is software, non-planar with sub-sampling |
| #define FF_PIX_FMT_FLAG_SW_FLAT_SUB (1 << 24) |
| |
| /** |
| * Construct a formats list containing all planar sample formats. |
| */ |
| av_warn_unused_result |
| AVFilterFormats *ff_planar_sample_fmts(void); |
| |
| /** |
| * 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); |
| |
| /** |
| * Check that fmts is a valid pixel formats list. |
| * |
| * In particular, check for duplicates. |
| */ |
| int ff_formats_check_pixel_formats(void *log, const AVFilterFormats *fmts); |
| |
| /** |
| * Check that fmts is a valid sample formats list. |
| * |
| * In particular, check for duplicates. |
| */ |
| int ff_formats_check_sample_formats(void *log, const AVFilterFormats *fmts); |
| |
| /** |
| * Check that fmts is a valid sample rates list. |
| * |
| * In particular, check for duplicates. |
| */ |
| int ff_formats_check_sample_rates(void *log, const AVFilterFormats *fmts); |
| |
| /** |
| * Check that fmts is a valid channel layouts list. |
| * |
| * In particular, check for duplicates. |
| */ |
| int ff_formats_check_channel_layouts(void *log, const AVFilterChannelLayouts *fmts); |
| |
| /** |
| * Check that fmts is a valid formats list for YUV colorspace metadata. |
| * |
| * In particular, check for duplicates. |
| */ |
| int ff_formats_check_color_spaces(void *log, const AVFilterFormats *fmts); |
| int ff_formats_check_color_ranges(void *log, const AVFilterFormats *fmts); |
| |
| typedef struct AVFilterFormatMerger { |
| unsigned offset; |
| int (*merge)(void *a, void *b); |
| int (*can_merge)(const void *a, const void *b); |
| } AVFilterFormatsMerger; |
| |
| /** |
| * Callbacks and properties to describe the steps of a format negotiation. |
| * |
| * The steps are: |
| * |
| * 1. query_formats(): call the callbacks on all filter to set lists of |
| * supported formats. |
| * When links on a filter must eventually have the same |
| * format, the lists of supported formats are the same |
| * object in memory. |
| * See: |
| * http://www.normalesup.org/~george/articles/format_negotiation_in_libavfilter/#12 |
| * |
| * |
| * 2. query_formats(): merge lists of supported formats or insert automatic |
| * conversion filters. |
| * Compute the intersection of the lists of supported |
| * formats on the ends of links. If it succeeds, replace |
| * both objects with the intersection everywhere they |
| * are referenced. |
| * If the intersection is empty, insert an automatic |
| * conversion filter. |
| * If several formats are negotiated at once (format, |
| * rate, layout), only merge if all three can be, since |
| * the conversion filter can convert all three at once. |
| * This process goes on as long as progress is made. |
| * See: |
| * http://www.normalesup.org/~george/articles/format_negotiation_in_libavfilter/#14 |
| * http://www.normalesup.org/~george/articles/format_negotiation_in_libavfilter/#29 |
| * |
| * 3. reduce_formats(): try to reduce format conversion within filters. |
| * For each link where there is only one supported |
| * formats on output, for each output of the connected |
| * filter, if the media type is the same and said |
| * format is supported, keep only this one. |
| * This process goes on as long as progress is made. |
| * Rationale: conversion filters will set a large list |
| * of supported formats on outputs but users will |
| * expect the output to be as close as possible as the |
| * input (examples: scale without changing the pixel |
| * format, resample without changint the layout). |
| * FIXME: this can probably be done by merging the |
| * input and output lists instead of re-implementing |
| * the logic. |
| * |
| * 4. swap_sample_fmts(): |
| * swap_samplerates(): |
| * swap_channel_layouts(): For each filter with an input with only one |
| * supported format, when outputs have several |
| * supported formats, put the best one with |
| * reference to the input at the beginning of the |
| * list, to prepare it for being picked up by |
| * pick_formats(). |
| * The best format is the one that is most |
| * similar to the input while not losing too much |
| * information. |
| * This process need to run only once. |
| * FIXME: reduce_formats() operates on all inputs |
| * with a single format, swap_*() operates on the |
| * first one only: check if the difference makes |
| * sense. |
| * TODO: the swapping done for one filter can |
| * override the swapping done for another filter |
| * connected to the same list of formats, maybe |
| * it would be better to compute a total score |
| * for all connected filters and use the score to |
| * pick the format instead of just swapping. |
| * TODO: make the similarity logic available as |
| * public functions in libavutil. |
| * |
| * 5. pick_formats(): Choose one format from the lists of supported formats, |
| * use it for the link and reduce the list to a single |
| * element to force other filters connected to the same |
| * list to use it. |
| * First process all links where there is a single format |
| * and the output links of all filters with an input, |
| * trying to preserve similarity between input and |
| * outputs. |
| * Repeat as long as process is made. |
| * Then do a final run for the remaining filters. |
| * FIXME: the similarity logic (the ref argument to |
| * pick_format()) added in FFmpeg duplicates and |
| * overrides the swapping logic added in libav. Better |
| * merge them into a score system. |
| */ |
| typedef struct AVFilterNegotiation { |
| unsigned nb_mergers; |
| const AVFilterFormatsMerger *mergers; |
| const char *conversion_filter; |
| unsigned conversion_opts_offset; |
| } AVFilterNegotiation; |
| |
| const AVFilterNegotiation *ff_filter_get_negotiation(AVFilterLink *link); |
| |
| #endif /* AVFILTER_FORMATS_H */ |