/*

  * 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.
  */

 int ff_set_common_channel_layouts(AVFilterContext *ctx,
                                   AVFilterChannelLayouts *layouts);
 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.
  */

 int 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.
  */

 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);
 

 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|
  *  | |____| |    | |____|
  *  |________|    |________________________
  */

 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 */