* [FFmpeg-devel] [RFC PATCH 3/3] lavfi: add a new filtergraph parsing API
2023-01-17 17:04 [FFmpeg-devel] [RFC PATCH 1/3] lavfi/avfilter: export process_options() Anton Khirnov
2023-01-17 17:04 ` [FFmpeg-devel] [RFC PATCH 2/3] lavfi/avfilter: track whether a filter has been initialized Anton Khirnov
@ 2023-01-17 17:05 ` Anton Khirnov
1 sibling, 0 replies; 3+ messages in thread
From: Anton Khirnov @ 2023-01-17 17:05 UTC (permalink / raw)
To: ffmpeg-devel
Callers currently have two ways of adding filters to a graph - they can
either
- create, initialize, and link them manually
- use one of the avfilter_graph_parse*() functions, which take a
(typically end-user-written) string, split it into individual filter
definitions+options, then create filters, apply options, initialize
filters, and finally link them - all based on information from this
string.
A major problem with the second approach is that it performs many
actions as a single atomic unit, leaving the caller no space to
intervene in between. Such intervention would be useful e.g. to
- modify filter options;
- supply hardware device contexts;
both of which typically must be done before the filter is initialized.
Callers who need such intervention are then forced to invent their own
filtergraph parsing, which is clearly suboptimal.
This commit aims to address this problem by adding a new modular
filtergraph parsing API. It adds a new avfilter_graph_segment_parse()
function to parse a string filtergraph description into an intermediate
tree-like representation (AVFilterGraphSegment and its children).
This intermediate form may then be applied step by step using further
new avfilter_graph_segment*() functions, with user intervention possible
between each step.
---
Barely tested and not used by anything yet - sending for comments on
overall design.
My intent is to use this API in ffmpeg.c to allow
- special option syntax to load option values from files
- supplying hw device contexts before filter initialization, which would
allow avoiding ugly workarounds like
be13812a23a8b49e1382004d42b5ddb0d6b64782
---
libavfilter/avfilter.h | 236 +++++++++++++++
libavfilter/graphparser.c | 603 +++++++++++++++++++++++++++++++++++++-
2 files changed, 832 insertions(+), 7 deletions(-)
diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
index c2ec7a4b5f..a6134de759 100644
--- a/libavfilter/avfilter.h
+++ b/libavfilter/avfilter.h
@@ -1118,6 +1118,242 @@ int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
AVFilterInOut **inputs,
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 freed 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;
+
+typedef struct AVFilterParams {
+ AVFilterContext *filter;
+
+ char *filter_name;
+ char *instance_name;
+
+ 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.
+ */
+ AVDictionary *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.
*
diff --git a/libavfilter/graphparser.c b/libavfilter/graphparser.c
index 0759c39014..07f56cabab 100644
--- a/libavfilter/graphparser.c
+++ b/libavfilter/graphparser.c
@@ -24,10 +24,12 @@
#include <stdio.h>
#include "libavutil/avstring.h"
+#include "libavutil/dict.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "avfilter.h"
+#include "internal.h"
#define WHITESPACES " \n\t\r"
@@ -386,7 +388,7 @@ static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs,
return pad;
}
-static int parse_sws_flags(const char **buf, AVFilterGraph *graph)
+static int parse_sws_flags(const char **buf, char **dst, void *log_ctx)
{
char *p = strchr(*buf, ';');
@@ -394,16 +396,16 @@ static int parse_sws_flags(const char **buf, AVFilterGraph *graph)
return 0;
if (!p) {
- av_log(graph, AV_LOG_ERROR, "sws_flags not terminated with ';'.\n");
+ av_log(log_ctx, AV_LOG_ERROR, "sws_flags not terminated with ';'.\n");
return AVERROR(EINVAL);
}
*buf += 4; // keep the 'flags=' part
- av_freep(&graph->scale_sws_opts);
- if (!(graph->scale_sws_opts = av_mallocz(p - *buf + 1)))
+ av_freep(dst);
+ if (!(*dst = av_mallocz(p - *buf + 1)))
return AVERROR(ENOMEM);
- av_strlcpy(graph->scale_sws_opts, *buf, p - *buf + 1);
+ av_strlcpy(*dst, *buf, p - *buf + 1);
*buf = p + 1;
return 0;
@@ -420,7 +422,7 @@ int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
filters += strspn(filters, WHITESPACES);
- if ((ret = parse_sws_flags(&filters, graph)) < 0)
+ if ((ret = parse_sws_flags(&filters, &graph->scale_sws_opts, graph)) < 0)
goto end;
do {
@@ -551,7 +553,7 @@ int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters,
AVFilterInOut *open_inputs = open_inputs_ptr ? *open_inputs_ptr : NULL;
AVFilterInOut *open_outputs = open_outputs_ptr ? *open_outputs_ptr : NULL;
- if ((ret = parse_sws_flags(&filters, graph)) < 0)
+ if ((ret = parse_sws_flags(&filters, &graph->scale_sws_opts, graph)) < 0)
goto end;
do {
@@ -623,3 +625,590 @@ end:
}
return ret;
}
+
+static void pad_params_free(AVFilterPadParams **pfpp)
+{
+ AVFilterPadParams *fpp = *pfpp;
+
+ if (!fpp)
+ return;
+
+ av_freep(&fpp->label);
+
+ av_freep(pfpp);
+}
+
+static void filter_params_free(AVFilterParams **pp)
+{
+ AVFilterParams *p = *pp;
+
+ if (!p)
+ return;
+
+ for (unsigned i = 0; i < p->nb_inputs; i++)
+ pad_params_free(&p->inputs[i]);
+ av_freep(&p->inputs);
+
+ for (unsigned i = 0; i < p->nb_outputs; i++)
+ pad_params_free(&p->outputs[i]);
+ av_freep(&p->outputs);
+
+ av_dict_free(&p->opts);
+
+ av_freep(&p->filter_name);
+ av_freep(&p->instance_name);
+
+ av_freep(pp);
+}
+
+static void chain_free(AVFilterChain **pch)
+{
+ AVFilterChain *ch = *pch;
+
+ if (!ch)
+ return;
+
+ for (size_t i = 0; i < ch->nb_filters; i++)
+ filter_params_free(&ch->filters[i]);
+ av_freep(&ch->filters);
+
+ av_freep(pch);
+}
+
+void avfilter_graph_segment_free(AVFilterGraphSegment **pseg)
+{
+ AVFilterGraphSegment *seg = *pseg;
+
+ if (!seg)
+ return;
+
+ for (size_t i = 0; i < seg->nb_chains; i++)
+ chain_free(&seg->chains[i]);
+ av_freep(&seg->chains);
+
+ av_freep(&seg->scale_sws_opts);
+
+ av_freep(pseg);
+}
+
+static int linklabels_parse(void *logctx, const char **linklabels,
+ AVFilterPadParams ***res, unsigned *nb_res)
+{
+ AVFilterPadParams **pp = NULL;
+ unsigned nb = 0;
+ int ret;
+
+ while (**linklabels == '[') {
+ char *label;
+ AVFilterPadParams *par, **tmp;
+
+ label = parse_link_name(linklabels, logctx);
+ if (!label) {
+ ret = AVERROR(EINVAL);
+ goto fail;
+ }
+
+ par = av_mallocz(sizeof(*par));
+ if (!par) {
+ av_freep(&label);
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ par->label = label;
+
+ tmp = av_realloc_array(pp, nb + 1, sizeof(*pp));
+ if (!tmp) {
+ pad_params_free(&par);
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ pp = tmp;
+ pp[nb++] = par;
+
+ *linklabels += strspn(*linklabels, WHITESPACES);
+ }
+
+ *res = pp;
+ *nb_res = nb;
+
+ return 0;
+fail:
+ for (unsigned i = 0; i < nb; i++)
+ pad_params_free(&pp[i]);
+ av_freep(&pp);
+ return ret;
+}
+
+static int filter_parse(void *logctx, const char **filter,
+ AVFilterParams **pp)
+{
+ AVFilterParams *p;
+ char *inst_name;
+ int ret;
+
+ p = av_mallocz(sizeof(*p));
+ if (!p)
+ return AVERROR(ENOMEM);
+
+ ret = linklabels_parse(logctx, filter, &p->inputs, &p->nb_inputs);
+ if (ret < 0)
+ goto fail;
+
+ p->filter_name = av_get_token(filter, "=,;[");
+ if (!p->filter_name) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ inst_name = strchr(p->filter_name, '@');
+ if (inst_name) {
+ *inst_name++ = 0;
+ p->instance_name = av_strdup(inst_name);
+ if (!p->instance_name) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+ }
+
+ if (**filter == '=') {
+ const AVFilter *f = avfilter_get_by_name(p->filter_name);
+ char *opts;
+
+ (*filter)++;
+
+ opts = av_get_token(filter, "[],;");
+ if (!opts) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ ret = ff_filter_opt_parse(logctx, f ? f->priv_class : NULL,
+ &p->opts, opts);
+ av_freep(&opts);
+ if (ret < 0)
+ goto fail;
+ }
+
+ ret = linklabels_parse(logctx, filter, &p->outputs, &p->nb_outputs);
+ if (ret < 0)
+ goto fail;
+
+ *filter += strspn(*filter, WHITESPACES);
+
+ *pp = p;
+ return 0;
+fail:
+ av_log(logctx, AV_LOG_ERROR,
+ "Error parsing a filter description around: %s\n", *filter);
+ filter_params_free(&p);
+ return ret;
+}
+
+static int chain_parse(void *logctx, const char **pchain,
+ AVFilterChain **pch)
+{
+ const char *chain = *pchain;
+ AVFilterChain *ch;
+ int ret;
+
+ *pch = NULL;
+
+ ch = av_mallocz(sizeof(*ch));
+ if (!ch)
+ return AVERROR(ENOMEM);
+
+ while (*chain) {
+ AVFilterParams *p, **tmp;
+ char chr;
+
+ ret = filter_parse(logctx, &chain, &p);
+ if (ret < 0)
+ goto fail;
+
+ tmp = av_realloc_array(ch->filters, ch->nb_filters + 1, sizeof(*ch->filters));
+ if (!tmp) {
+ filter_params_free(&p);
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ ch->filters = tmp;
+ ch->filters[ch->nb_filters++] = p;
+
+ // a filter ends with one of: , ; end-of-string
+ chr = *chain;
+ if (chr && chr != ',' && chr != ';') {
+ av_log(logctx, AV_LOG_ERROR,
+ "Trailing garbage after a filter: %s\n", chain);
+ ret = AVERROR(EINVAL);
+ goto fail;
+ }
+
+ if (chr) {
+ chain++;
+ chain += strspn(chain, WHITESPACES);
+
+ if (chr == ';')
+ break;
+ }
+ }
+
+ *pchain = chain;
+ *pch = ch;
+
+ return 0;
+fail:
+ av_log(logctx, AV_LOG_ERROR,
+ "Error parsing filterchain '%s' around: %s\n", *pchain, chain);
+ chain_free(&ch);
+ return ret;
+}
+
+int avfilter_graph_segment_parse(AVFilterGraph *graph, const char *graph_str,
+ int flags, AVFilterGraphSegment **pseg)
+{
+ AVFilterGraphSegment *seg;
+ char *scale_sws_opts;
+ int ret;
+
+ *pseg = NULL;
+
+ seg = av_mallocz(sizeof(*seg));
+ if (!seg)
+ return AVERROR(ENOMEM);
+
+ seg->graph = graph;
+
+ graph_str += strspn(graph_str, WHITESPACES);
+
+ ret = parse_sws_flags(&graph_str, &scale_sws_opts, &graph);
+ if (ret < 0)
+ goto fail;
+
+ ret = av_dict_parse_string(&seg->scale_sws_opts, scale_sws_opts, "=", ":", 0);
+ av_freep(&scale_sws_opts);
+ if (ret < 0)
+ goto fail;
+
+ graph_str += strspn(graph_str, WHITESPACES);
+
+ while (*graph_str) {
+ AVFilterChain *ch, **tmp;
+
+ ret = chain_parse(graph, &graph_str, &ch);
+ if (ret < 0)
+ goto fail;
+
+ tmp = av_realloc_array(seg->chains, seg->nb_chains + 1, sizeof(*seg->chains));
+ if (!tmp) {
+ chain_free(&ch);
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ seg->chains = tmp;
+ seg->chains[seg->nb_chains++] = ch;
+
+ graph_str += strspn(graph_str, WHITESPACES);
+ }
+
+ *pseg = seg;
+
+ return 0;
+fail:
+ avfilter_graph_segment_free(&seg);
+ return ret;
+}
+
+int avfilter_graph_segment_create_filters(AVFilterGraphSegment *seg, int flags)
+{
+ size_t idx = 0;
+
+ for (size_t i = 0; i < seg->nb_chains; i++) {
+ AVFilterChain *ch = seg->chains[i];
+
+ for (size_t j = 0; j < ch->nb_filters; j++) {
+ AVFilterParams *p = ch->filters[j];
+ const AVFilter *f = avfilter_get_by_name(p->filter_name);
+ char inst_name[30], *name = p->instance_name ? p->instance_name :
+ inst_name;
+
+ // skip already processed filters
+ if (p->filter || !p->filter_name)
+ continue;
+
+ if (!f) {
+ av_log(seg->graph, AV_LOG_ERROR,
+ "No such filter: '%s'\n", p->filter_name);
+ return AVERROR_FILTER_NOT_FOUND;
+ }
+
+ if (!p->instance_name)
+ snprintf(inst_name, sizeof(inst_name), "Parsed_%s_%zu", f->name, idx);
+
+ p->filter = avfilter_graph_alloc_filter(seg->graph, f, name);
+ if (!p->filter)
+ return AVERROR(ENOMEM);
+
+ if (!strcmp(f->name, "scale") && seg->scale_sws_opts) {
+ int ret = av_opt_set_dict2(p->filter, &seg->scale_sws_opts, AV_OPT_SEARCH_CHILDREN);
+ if (ret < 0) {
+ avfilter_free(p->filter);
+ p->filter = NULL;
+ return ret;
+ }
+ }
+
+ av_freep(&p->filter_name);
+ av_freep(&p->instance_name);
+
+ idx++;
+ }
+ }
+
+ return 0;
+}
+
+int avfilter_graph_segment_apply_opts(AVFilterGraphSegment *seg, int flags)
+{
+ int leftover_opts = 0;
+
+ for (size_t i = 0; i < seg->nb_chains; i++) {
+ AVFilterChain *ch = seg->chains[i];
+
+ for (size_t j = 0; j < ch->nb_filters; j++) {
+ AVFilterParams *p = ch->filters[j];
+ int ret;
+
+ if (p->filter_name) {
+ av_log(seg->graph, AV_LOG_ERROR,
+ "A creation-pending filter present "
+ "in the segment. All filters must be created or cleared "
+ "before calling avfilter_graph_segment_apply_opts().\n");
+ return AVERROR(EINVAL);
+ }
+ if (!p->filter || !p->opts)
+ continue;
+
+ ret = av_opt_set_dict2(p->filter, &p->opts, AV_OPT_SEARCH_CHILDREN);
+ if (ret < 0)
+ return ret;
+
+ if (av_dict_count(p->opts))
+ leftover_opts = 1;
+ }
+ }
+
+ return leftover_opts ? AVERROR_OPTION_NOT_FOUND : 0;
+}
+
+int avfilter_graph_segment_init(AVFilterGraphSegment *seg, int flags)
+{
+ for (size_t i = 0; i < seg->nb_chains; i++) {
+ AVFilterChain *ch = seg->chains[i];
+
+ for (size_t j = 0; j < ch->nb_filters; j++) {
+ AVFilterParams *p = ch->filters[j];
+ int ret;
+
+ if (p->filter_name) {
+ av_log(seg->graph, AV_LOG_ERROR,
+ "A creation-pending filter present "
+ "in the segment. All filters must be created or cleared "
+ "before calling avfilter_graph_segment_init().\n");
+ return AVERROR(EINVAL);
+ }
+ if (!p->filter || p->filter->internal->initialized)
+ continue;
+
+ ret = avfilter_init_dict(p->filter, NULL);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static unsigned
+find_linklabel(AVFilterGraphSegment *seg, const char *label,
+ int output, size_t idx_chain, size_t idx_filter,
+ AVFilterParams **pp)
+{
+ for (; idx_chain < seg->nb_chains; idx_chain++) {
+ AVFilterChain *ch = seg->chains[idx_chain];
+
+ for (; idx_filter < ch->nb_filters; idx_filter++) {
+ AVFilterParams *p = ch->filters[idx_filter];
+ AVFilterPadParams **io = output ? p->outputs : p->inputs;
+ unsigned nb_io = output ? p->nb_outputs : p->nb_inputs;
+
+ if (!p->filter)
+ continue;
+
+ for (unsigned i = 0; i < nb_io; i++)
+ if (io[i]->label && !strcmp(io[i]->label, label)) {
+ *pp = p;
+ return i;
+ }
+ }
+
+ idx_filter = 0;
+ }
+
+ *pp = NULL;
+ return 0;
+}
+
+int avfilter_graph_segment_link(AVFilterGraphSegment *seg, int flags,
+ AVFilterInOut **inputs,
+ AVFilterInOut **outputs)
+{
+ *inputs = NULL;
+ *outputs = NULL;
+
+ for (size_t idx_chain = 0; idx_chain < seg->nb_chains; idx_chain++) {
+ AVFilterChain *ch = seg->chains[idx_chain];
+
+ for (size_t idx_filter = 0; idx_filter < ch->nb_filters; idx_filter++) {
+ AVFilterParams *p = ch->filters[idx_filter];
+ int ret;
+
+ if (p->filter_name) {
+ av_log(seg->graph, AV_LOG_ERROR,
+ "A creation-pending filter present "
+ "in the segment. All filters must be created or cleared "
+ "before calling avfilter_graph_segment_init().\n");
+ return AVERROR(EINVAL);
+ }
+ if (!p->filter)
+ continue;
+
+ if (p->filter->nb_inputs < p->nb_inputs) {
+ av_log(seg->graph, AV_LOG_ERROR,
+ "More input link labels specified for filter '%s' than "
+ "it has inputs: %u > %d\n", p->filter->filter->name,
+ p->nb_inputs, p->filter->nb_inputs);
+ return AVERROR(EINVAL);
+ }
+ for (unsigned in = 0; in < p->filter->nb_inputs; in++) {
+ AVFilterInOut *io;
+
+ // skip already linked inputs
+ if (p->filter->inputs[in])
+ continue;
+
+ // handle explicit labels
+ if (in < p->nb_inputs && p->inputs[in]->label) {
+ AVFilterParams *po = NULL;
+ unsigned idx = find_linklabel(seg, p->inputs[in]->label, 1,
+ idx_chain, idx_filter, &po);
+
+ if (po) {
+ ret = avfilter_link(po->filter, idx, p->filter, in);
+ if (ret < 0)
+ return ret;
+
+ continue;
+ }
+ }
+
+ io = av_mallocz(sizeof(*io));
+ if (!io)
+ return AVERROR(ENOMEM);
+
+ io->filter_ctx = p->filter;
+ io->pad_idx = in;
+ append_inout(inputs, &io);
+ }
+
+ if (p->filter->nb_outputs < p->nb_outputs) {
+ av_log(seg->graph, AV_LOG_ERROR,
+ "More output link labels specified for filter '%s' than "
+ "it has outputs: %u > %d\n", p->filter->filter->name,
+ p->nb_outputs, p->filter->nb_outputs);
+ return AVERROR(EINVAL);
+ }
+ for (unsigned out = 0; out < p->filter->nb_outputs; out++) {
+ AVFilterInOut *io;
+
+ // skip already linked outputs
+ if (p->filter->outputs[out])
+ continue;
+
+ // handle explicit labels
+ if (out < p->nb_outputs && p->outputs[out]->label) {
+ AVFilterParams *po = NULL;
+ unsigned idx = find_linklabel(seg, p->outputs[out]->label, 0,
+ idx_chain, idx_filter, &po);
+
+ if (po) {
+ ret = avfilter_link(p->filter, out, po->filter, idx);
+ if (ret < 0)
+ return ret;
+
+ continue;
+ }
+ }
+
+ {
+ // find next non-disabled filter in the chain
+ // try linking unlabelled outputs to it
+ AVFilterParams *p_next = NULL;
+ for (size_t i = idx_filter + 1; i < ch->nb_filters; i++)
+ if (ch->filters[i]->filter) {
+ p_next = ch->filters[i];
+ break;
+ }
+
+ if (p_next) {
+ for (unsigned in = 0; in < p_next->filter->nb_inputs; in++) {
+ if (!p_next->filter->inputs[in] &&
+ (in > p_next->nb_inputs || !p_next->inputs[in]->label)) {
+ ret = avfilter_link(p->filter, out, p_next->filter, in);
+ if (ret < 0)
+ return ret;
+ }
+ }
+ }
+ }
+
+ io = av_mallocz(sizeof(*io));
+ if (!io)
+ return AVERROR(ENOMEM);
+
+ io->filter_ctx = p->filter;
+ io->pad_idx = out;
+ append_inout(outputs, &io);
+ }
+ }
+ }
+ return 0;
+}
+
+int avfilter_graph_segment_apply(AVFilterGraphSegment *seg, int flags,
+ AVFilterInOut **inputs,
+ AVFilterInOut **outputs)
+{
+ int ret;
+
+ ret = avfilter_graph_segment_create_filters(seg, 0);
+ if (ret < 0)
+ return ret;
+
+ ret = avfilter_graph_segment_apply_opts(seg, 0);
+ if (ret < 0)
+ return ret;
+
+ ret = avfilter_graph_segment_init(seg, 0);
+ if (ret < 0)
+ return ret;
+
+ ret = avfilter_graph_segment_link(seg, 0, inputs, outputs);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
--
2.35.1
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