0,0 → 1,270 |
/* |
* 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); |
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#endif /* AVFILTER_FORMATS_H */ |