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/*

 * 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.

 */

AVFilterChannelLayouts *ff_all_channel_layouts(void);

AVFilterFormats *ff_all_samplerates(void);

/**

 * Construct an AVFilterChannelLayouts coding for any channel layout, with

 * known or unknown disposition.

 */

AVFilterChannelLayouts *ff_all_channel_counts(void);

AVFilterChannelLayouts *avfilter_make_format64_list(const int64_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.

 */

void ff_set_common_channel_layouts(AVFilterContext *ctx,

                                   AVFilterChannelLayouts *layouts);

void 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.

 */

void ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);

int ff_add_channel_layout(AVFilterChannelLayouts **l, uint64_t channel_layout);

/**

 * Add *ref as a new reference to f.

 */

void 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);

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.

 */

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

 */

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

 */

int ff_add_format(AVFilterFormats **avff, int64_t fmt);

/**

 * Return a list of all formats supported by FFmpeg for the given media type.

 */

AVFilterFormats *ff_all_formats(enum AVMediaType type);

/**

 * Construct a formats list containing all planar sample formats.

 */

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|

 *  | |____| |    | |____|

 *  |________|    |________________________

 */

void 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 */