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Diffstat (limited to 'libavfilter/avfilter.h')
| -rw-r--r-- | libavfilter/avfilter.h | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h index c2ec7a4b5f..8879235d3e 100644 --- a/libavfilter/avfilter.h +++ b/libavfilter/avfilter.h @@ -1119,6 +1119,294 @@ int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters, AVFilterInOut **outputs); /** + * Parameters of a filter's input or output pad. + * + * Created as a child of AVFilterParams by avfilter_graph_segment_parse(). + * Freed in avfilter_graph_segment_free(). + */ +typedef struct AVFilterPadParams { + /** + * An av_malloc()'ed string containing the pad label. + * + * May be av_free()'d and set to NULL by the caller, in which case this pad + * will be treated as unlabeled for linking. + * May also be replaced by another av_malloc()'ed string. + */ + char *label; +} AVFilterPadParams; + +/** + * Parameters describing a filter to be created in a filtergraph. + * + * Created as a child of AVFilterGraphSegment by avfilter_graph_segment_parse(). + * Freed in avfilter_graph_segment_free(). + */ +typedef struct AVFilterParams { + /** + * The filter context. + * + * Created by avfilter_graph_segment_create_filters() based on + * AVFilterParams.filter_name and instance_name. + * + * Callers may also create the filter context manually, then they should + * av_free() filter_name and set it to NULL. Such AVFilterParams instances + * are then skipped by avfilter_graph_segment_create_filters(). + */ + AVFilterContext *filter; + + /** + * Name of the AVFilter to be used. + * + * An av_malloc()'ed string, set by avfilter_graph_segment_parse(). Will be + * passed to avfilter_get_by_name() by + * avfilter_graph_segment_create_filters(). + * + * Callers may av_free() this string and replace it with another one or + * NULL. If the caller creates the filter instance manually, this string + * MUST be set to NULL. + * + * When both AVFilterParams.filter an AVFilterParams.filter_name are NULL, + * this AVFilterParams instance is skipped by avfilter_graph_segment_*() + * functions. + */ + char *filter_name; + /** + * Name to be used for this filter instance. + * + * An av_malloc()'ed string, may be set by avfilter_graph_segment_parse() or + * left NULL. The caller may av_free() this string and replace with another + * one or NULL. + * + * Will be used by avfilter_graph_segment_create_filters() - passed as the + * third argument to avfilter_graph_alloc_filter(), then freed and set to + * NULL. + */ + char *instance_name; + + /** + * Options to be apllied to the filter. + * + * Filled by avfilter_graph_segment_parse(). Afterwards may be freely + * modified by the caller. + * + * Will be applied to the filter by avfilter_graph_segment_apply_opts() + * with an equivalent of av_opt_set_dict2(filter, &opts, * AV_OPT_SEARCH_CHILDREN), + * i.e. any unapplied options will be left in this dictionary. + */ + AVDictionary *opts; + + AVFilterPadParams **inputs; + unsigned nb_inputs; + + AVFilterPadParams **outputs; + unsigned nb_outputs; +} AVFilterParams; + +/** + * A filterchain is a list of filter specifications. + * + * Created as a child of AVFilterGraphSegment by avfilter_graph_segment_parse(). + * Freed in avfilter_graph_segment_free(). + */ +typedef struct AVFilterChain { + AVFilterParams **filters; + size_t nb_filters; +} AVFilterChain; + +/** + * A parsed representation of a filtergraph segment. + * + * A filtergraph segment is conceptually a list of filterchains, with some + * supplementary information (e.g. format conversion flags). + * + * Created by avfilter_graph_segment_parse(). Must be freed with + * avfilter_graph_segment_free(). + */ +typedef struct AVFilterGraphSegment { + /** + * The filtergraph this segment is associated with. + * Set by avfilter_graph_segment_parse(). + */ + AVFilterGraph *graph; + + /** + * A list of filter chain contained in this segment.. + * Set in avfilter_graph_segment_parse(). + */ + AVFilterChain **chains; + size_t nb_chains; + + /** + * A string containing a colon-separated list of key=value options applied + * to all scale filters in this segment. + * + * May be set by avfilter_graph_segment_parse(). + * The caller may free this string with av_free() and replace it with a + * different av_malloc()'ed string. + */ + char *scale_sws_opts; +} AVFilterGraphSegment; + +/** + * Parse a textual filtergraph description into an intermediate form. + * + * This intermediate representation is intended to be modified by the caller as + * described in the documentation of AVFilterGraphSegment and its children, and + * then applied to the graph either manually or with other + * avfilter_graph_segment_*() functions. See the documentation for + * avfilter_graph_segment_apply() for the canonical way to apply + * AVFilterGraphSegment. + * + * @param graph Filter graph the parsed segment is associated with. Will only be + * used for logging and similar auxiliary purposes. The graph will + * not be actually modified by this function - the parsing results + * are instead stored in seg for further processing. + * @param graph_str a string describing the filtergraph segment + * @param flags reserved for future use, caller must set to 0 for now + * @param seg A pointer to the newly-created AVFilterGraphSegment is written + * here on success. The graph segment is owned by the caller and must + * be freed with avfilter_graph_segment_free() before graph itself is + * freed. + * + * @return a non-negative number on success, a negative error code on failure + */ +int avfilter_graph_segment_parse(AVFilterGraph *graph, const char *graph_str, + int flags, AVFilterGraphSegment **seg); + +/** + * Create filters specified in a graph segment. + * + * Walk through the creation-pending AVFilterParams in the segment and create + * new filter instances for them. + * Creation-pending params are those where AVFilterParams.filter_name is + * non-NULL (and hence AVFilterParams.filter is NULL). All other AVFilterParams + * instances are ignored. + * + * For any filter created by this function, the corresponding + * AVFilterParams.filter is set to the newly-created filter context, + * AVFilterParams.filter_name and AVFilterParams.instance_name are freed and set + * to NULL. + * + * @param seg the filtergraph segment to process + * @param flags reserved for future use, caller must set to 0 for now + * + * @return + * - a non-negative number if all creation-pending filters were successfully + * created + * - AVERROR_FILTER_NOT_FOUND if some filter's name did not correspond to a + * known filter + * - another negative error code on other failures + * + * @note Calling this function multiple times is safe, as it is idempotent. + */ +int avfilter_graph_segment_create_filters(AVFilterGraphSegment *seg, int flags); + +/** + * Apply parsed options to filter instances in a graph segment. + * + * Walk through all filter instances in the graph segment that have option + * dictionaries associated with them and apply those options with + * av_opt_set_dict2(..., AV_OPT_SEARCH_CHILDREN). AVFilterParams.opts is + * replaced by the dictionary output by av_opt_set_dict2(), which should be + * empty (NULL) if all options were successfully applied. + * + * If any options could not be found, this function will continue processing all + * other filters and finally return AVERROR_OPTION_NOT_FOUND (unless another + * error happens). The calling program may then deal with unapplied options as + * it wishes. + * + * Any creation-pending filters (see avfilter_graph_segment_create_filters()) + * present in the segment will cause this function to fail. AVFilterParams with + * no associated filter context are simply skipped. + * + * @param seg the filtergraph segment to process + * @param flags reserved for future use, caller must set to 0 for now + * + * @return + * - a non-negative number if all options were successfully applied + * - AVERROR_OPTION_NOT_FOUND if some options were not found in a filter + * - another negative error code on other failures + * + * @note Calling this function multiple times is safe, as it is idempotent. + */ +int avfilter_graph_segment_apply_opts(AVFilterGraphSegment *seg, int flags); + +/** + * Initialize all filter instances in a graph segment. + * + * Walk through all filter instances in the graph segment and call + * avfilter_init_dict(..., NULL) on those that have not been initialized yet. + * + * Any creation-pending filters (see avfilter_graph_segment_create_filters()) + * present in the segment will cause this function to fail. AVFilterParams with + * no associated filter context are simply skipped. + * + * @param seg the filtergraph segment to process + * @param flags reserved for future use, caller must set to 0 for now + * + * @return + * - a non-negative number if all filter instances were successfully initialized + * - a negative error code on other failures + * + * @note Calling this function multiple times is safe, as it is idempotent. + */ +int avfilter_graph_segment_init(AVFilterGraphSegment *seg, int flags); + +/** + * Link filters in a graph segment. + * + * Walk through all filter instances in the graph segment and call + * avfilter_init_dict(..., NULL) on those that have not been initialized yet. + * + * Any creation-pending filters (see avfilter_graph_segment_create_filters()) + * present in the segment will cause this function to fail. AVFilterParams with + * no associated filter context are simply skipped. + * + * @param seg the filtergraph segment to process + * @param flags reserved for future use, caller must set to 0 for now + * @param[out] inputs a linked list of all free (unlinked) inputs of the + * filters in this graph segment will be returned here. It + * is to be freed by the caller using avfilter_inout_free(). + * @param[out] outputs a linked list of all free (unlinked) outputs of the + * filters in this graph segment will be returned here. It + * is to be freed by the caller using avfilter_inout_free(). + * + * @return + * - a non-negative number if all filter instances were successfully initialized + * - a negative error code on other failures + * + * @note Calling this function multiple times is safe, as it is idempotent. + */ +int avfilter_graph_segment_link(AVFilterGraphSegment *seg, int flags, + AVFilterInOut **inputs, + AVFilterInOut **outputs); + +/** + * Apply all filter/link descriptions from a graph segment to the associated filtergraph. + * + * This functions is currently equivalent to calling the following in sequence: + * - avfilter_graph_segment_create_filters() + * - avfilter_graph_segment_apply_opts() + * - avfilter_graph_segment_init() + * - avfilter_graph_segment_link() + */ +int avfilter_graph_segment_apply(AVFilterGraphSegment *seg, int flags, + AVFilterInOut **inputs, + AVFilterInOut **outputs); + +/** + * Free the provided AVFilterGraphSegment and everything associated with it. + * + * @param seg double pointer to the AVFilterGraphSegment to be freed. NULL will + * be written to this pointer on exit from this function. + * + * @note + * The filter contexts (AVFilterParams.filter) are owned by AVFilterGraph rather + * than AVFilterGraphSegment, so they are not freed. + */ +void avfilter_graph_segment_free(AVFilterGraphSegment **seg); + +/** * Send a command to one or more filter instances. * * @param graph the filter graph |