/*
* filter graph parser
- * copyright (c) 2008 Vitor Sessak
- * copyright (c) 2007 Bobby Bingham
+ * Copyright (c) 2008 Vitor Sessak
+ * Copyright (c) 2007 Bobby Bingham
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <ctype.h>
#include <string.h>
+#include "libavutil/avstring.h"
#include "avfilter.h"
#include "avfiltergraph.h"
-static AVFilterContext *create_filter(AVFilterGraph *ctx, int index,
- const char *name, const char *args,
- AVClass *log_ctx)
-{
- AVFilterContext *filt;
-
- AVFilter *filterdef;
- char inst_name[30];
-
- snprintf(inst_name, sizeof(inst_name), "Parsed filter %d", index);
-
- if(!(filterdef = avfilter_get_by_name(name))) {
- av_log(log_ctx, AV_LOG_ERROR,
- "no such filter: '%s'\n", name);
- return NULL;
- }
-
- if(!(filt = avfilter_open(filterdef, inst_name))) {
- av_log(log_ctx, AV_LOG_ERROR,
- "error creating filter '%s'\n", name);
- return NULL;
- }
-
- if(avfilter_graph_add_filter(ctx, filt) < 0)
- return NULL;
-
- if(avfilter_init_filter(filt, args, NULL)) {
- av_log(log_ctx, AV_LOG_ERROR,
- "error initializing filter '%s' with args '%s'\n", name, args);
- return NULL;
- }
-
- return filt;
-}
+#define WHITESPACES " \n\t"
+/**
+ * Link two filters together.
+ *
+ * @see avfilter_link()
+ */
static int link_filter(AVFilterContext *src, int srcpad,
AVFilterContext *dst, int dstpad,
- AVClass *log_ctx)
+ void *log_ctx)
{
- if(avfilter_link(src, srcpad, dst, dstpad)) {
+ int ret;
+ if ((ret = avfilter_link(src, srcpad, dst, dstpad))) {
av_log(log_ctx, AV_LOG_ERROR,
- "cannot create the link %s:%d -> %s:%d\n",
+ "Cannot create the link %s:%d -> %s:%d\n",
src->filter->name, srcpad, dst->filter->name, dstpad);
- return -1;
+ return ret;
}
return 0;
}
-static void consume_whitespace(const char **buf)
-{
- *buf += strspn(*buf, " \n\t");
-}
-
-/**
- * Consumes a string from *buf.
- * @return a copy of the consumed string, which should be free'd after use
- */
-static char *consume_string(const char **buf)
-{
- char *out = av_malloc(strlen(*buf) + 1);
- char *ret = out;
-
- consume_whitespace(buf);
-
- do{
- char c = *(*buf)++;
- switch (c) {
- case '\\':
- *out++= *(*buf)++;
- break;
- case '\'':
- while(**buf && **buf != '\'')
- *out++= *(*buf)++;
- if(**buf) (*buf)++;
- break;
- case 0:
- case ']':
- case '[':
- case '=':
- case ',':
- case ';':
- case ' ':
- case '\n':
- *out++= 0;
- break;
- default:
- *out++= c;
- }
- } while(out[-1]);
-
- (*buf)--;
- consume_whitespace(buf);
-
- return ret;
-}
-
/**
- * Parse "[linkname]"
- * @arg name a pointer (that need to be free'd after use) to the name between
- * parenthesis
+ * Parse the name of a link, which has the format "[linkname]".
+ *
+ * @return a pointer (that need to be freed after use) to the name
+ * between parenthesis
*/
-static void parse_link_name(const char **buf, char **name, AVClass *log_ctx)
+static char *parse_link_name(const char **buf, void *log_ctx)
{
const char *start = *buf;
+ char *name;
(*buf)++;
- *name = consume_string(buf);
+ name = av_get_token(buf, "]");
- if(!*name[0]) {
+ if (!name[0]) {
av_log(log_ctx, AV_LOG_ERROR,
"Bad (empty?) label found in the following: \"%s\".\n", start);
goto fail;
}
- if(*(*buf)++ != ']') {
+ if (*(*buf)++ != ']') {
av_log(log_ctx, AV_LOG_ERROR,
"Mismatched '[' found in the following: \"%s\".\n", start);
fail:
- av_freep(name);
+ av_freep(&name);
}
+
+ return name;
}
+/**
+ * Create an instance of a filter, initialize and insert it in the
+ * filtergraph in *ctx.
+ *
+ * @param filt_ctx put here a filter context in case of successful creation and configuration, NULL otherwise.
+ * @param ctx the filtergraph context
+ * @param index an index which is supposed to be unique for each filter instance added to the filtergraph
+ * @param filt_name the name of the filter to create
+ * @param args the arguments provided to the filter during its initialization
+ * @param log_ctx the log context to use
+ * @return 0 in case of success, a negative AVERROR code otherwise
+ */
+static int create_filter(AVFilterContext **filt_ctx, AVFilterGraph *ctx, int index,
+ const char *filt_name, const char *args, void *log_ctx)
+{
+ AVFilter *filt;
+ char inst_name[30];
+ char tmp_args[256];
+ int ret;
+
+ snprintf(inst_name, sizeof(inst_name), "Parsed filter %d %s", index, filt_name);
+
+ filt = avfilter_get_by_name(filt_name);
+
+ if (!filt) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "No such filter: '%s'\n", filt_name);
+ return AVERROR(EINVAL);
+ }
+
+ ret = avfilter_open(filt_ctx, filt, inst_name);
+ if (!*filt_ctx) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Error creating filter '%s'\n", filt_name);
+ return ret;
+ }
+
+ if ((ret = avfilter_graph_add_filter(ctx, *filt_ctx)) < 0) {
+ avfilter_free(*filt_ctx);
+ return ret;
+ }
+
+ if (!strcmp(filt_name, "scale") && args && !strstr(args, "flags")) {
+ snprintf(tmp_args, sizeof(tmp_args), "%s:%s",
+ args, ctx->scale_sws_opts);
+ args = tmp_args;
+ }
+
+ if ((ret = avfilter_init_filter(*filt_ctx, args, NULL)) < 0) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Error initializing filter '%s' with args '%s'\n", filt_name, args);
+ return ret;
+ }
-enum LinkType {
- LinkTypeIn,
- LinkTypeOut,
-};
+ return 0;
+}
/**
- * A linked-list of the inputs/outputs of the filter chain.
+ * Parse a string of the form FILTER_NAME[=PARAMS], and create a
+ * corresponding filter instance which is added to graph with
+ * create_filter().
+ *
+ * @param filt_ctx Pointer that is set to the created and configured filter
+ * context on success, set to NULL on failure.
+ * @param filt_ctx put here a pointer to the created filter context on
+ * success, NULL otherwise
+ * @param buf pointer to the buffer to parse, *buf will be updated to
+ * point to the char next after the parsed string
+ * @param index an index which is assigned to the created filter
+ * instance, and which is supposed to be unique for each filter
+ * instance added to the filtergraph
+ * @return 0 in case of success, a negative AVERROR code otherwise
*/
-typedef struct AVFilterInOut {
- enum LinkType type;
- const char *name;
- AVFilterContext *filter;
- int pad_idx;
+static int parse_filter(AVFilterContext **filt_ctx, const char **buf, AVFilterGraph *graph,
+ int index, void *log_ctx)
+{
+ char *opts = NULL;
+ char *name = av_get_token(buf, "=,;[\n");
+ int ret;
- struct AVFilterInOut *next;
-} AVFilterInOut;
+ if (**buf == '=') {
+ (*buf)++;
+ opts = av_get_token(buf, "[],;\n");
+ }
+
+ ret = create_filter(filt_ctx, graph, index, name, opts, log_ctx);
+ av_free(name);
+ av_free(opts);
+ return ret;
+}
static void free_inout(AVFilterInOut *head)
{
while (head) {
AVFilterInOut *next = head->next;
+ av_free(head->name);
av_free(head);
head = next;
}
{
AVFilterInOut *ret;
+ while (*links && strcmp((*links)->name, label))
+ links = &((*links)->next);
- while(*links && strcmp((*links)->name, label))
- links= &((*links)->next);
-
- ret= *links;
+ ret = *links;
- if(ret)
- *links= ret->next;
+ if (ret)
+ *links = ret->next;
return ret;
}
+static void insert_inout(AVFilterInOut **inouts, AVFilterInOut *element)
+{
+ element->next = *inouts;
+ *inouts = element;
+}
-static int link_filter_inouts(AVFilterContext *filter,
- AVFilterInOut **currInputs,
- AVFilterInOut **openLinks, AVClass *log_ctx)
+static int link_filter_inouts(AVFilterContext *filt_ctx,
+ AVFilterInOut **curr_inputs,
+ AVFilterInOut **open_inputs, void *log_ctx)
{
- AVFilterInOut *p;
- int pad = 0;
+ int pad = filt_ctx->input_count, ret;
- pad = filter->input_count;
- while(pad--) {
- p = *currInputs;
- if(!p) {
+ while (pad--) {
+ AVFilterInOut *p = *curr_inputs;
+ if (!p) {
av_log(log_ctx, AV_LOG_ERROR,
"Not enough inputs specified for the \"%s\" filter.\n",
- filter->name);
- return -1;
+ filt_ctx->filter->name);
+ return AVERROR(EINVAL);
}
- if(p->filter) {
- if(link_filter(p->filter, p->pad_idx, filter, pad, log_ctx))
- return -1;
- *currInputs = (*currInputs)->next;
+ *curr_inputs = (*curr_inputs)->next;
+
+ if (p->filter_ctx) {
+ if ((ret = link_filter(p->filter_ctx, p->pad_idx, filt_ctx, pad, log_ctx)) < 0)
+ return ret;
+ av_free(p->name);
av_free(p);
} else {
- p = *currInputs;
- *currInputs = (*currInputs)->next;
- p->filter = filter;
+ p->filter_ctx = filt_ctx;
p->pad_idx = pad;
- p->next = *openLinks;
- *openLinks = p;
+ insert_inout(open_inputs, p);
}
}
-
- if(*currInputs) {
+ if (*curr_inputs) {
av_log(log_ctx, AV_LOG_ERROR,
"Too many inputs specified for the \"%s\" filter.\n",
- filter->name);
- return -1;
+ filt_ctx->filter->name);
+ return AVERROR(EINVAL);
}
- pad = filter->output_count;
- while(pad--) {
- AVFilterInOut *currlinkn = av_malloc(sizeof(AVFilterInOut));
- currlinkn->name = NULL;
- currlinkn->type = LinkTypeOut;
- currlinkn->filter = filter;
+ pad = filt_ctx->output_count;
+ while (pad--) {
+ AVFilterInOut *currlinkn = av_mallocz(sizeof(AVFilterInOut));
+ if (!currlinkn)
+ return AVERROR(ENOMEM);
+ currlinkn->filter_ctx = filt_ctx;
currlinkn->pad_idx = pad;
- currlinkn->next = *currInputs;
- *currInputs = currlinkn;
+ insert_inout(curr_inputs, currlinkn);
}
return 0;
}
-/**
- * Parse "filter=params"
- * @arg name a pointer (that need to be free'd after use) to the name of the
- * filter
- * @arg ars a pointer (that need to be free'd after use) to the args of the
- * filter
- */
-static AVFilterContext *parse_filter(const char **buf, AVFilterGraph *graph,
- int index, AVClass *log_ctx)
-{
- char *opts;
- char *name = consume_string(buf);
-
- if(**buf == '=') {
- (*buf)++;
- opts = consume_string(buf);
- } else {
- opts = NULL;
- }
-
- return create_filter(graph, index, name, opts, log_ctx);
-}
-
-static int parse_inputs(const char **buf, AVFilterInOut **currInputs,
- AVFilterInOut **openLinks, AVClass *log_ctx)
+static int parse_inputs(const char **buf, AVFilterInOut **curr_inputs,
+ AVFilterInOut **open_outputs, void *log_ctx)
{
int pad = 0;
- AVFilterInOut *p;
while (**buf == '[') {
- char *name;
-
- parse_link_name(buf, &name, log_ctx);
-
- if(!name)
- return -1;
+ char *name = parse_link_name(buf, log_ctx);
+ AVFilterInOut *match;
- /* First check if the label is not in the openLinks list */
- p = extract_inout(name, openLinks);
+ if (!name)
+ return AVERROR(EINVAL);
- /* Not in the list, so add it as an input */
- if(!p) {
- AVFilterInOut *currlinkn = av_malloc(sizeof(AVFilterInOut));
+ /* First check if the label is not in the open_outputs list */
+ match = extract_inout(name, open_outputs);
- currlinkn->name = name;
- currlinkn->type = LinkTypeIn;
- currlinkn->filter = NULL;
- currlinkn->pad_idx = pad;
- currlinkn->next = *currInputs;
- *currInputs = currlinkn;
+ if (match) {
+ av_free(name);
} else {
- /* A label of a open link. Make it one of the inputs of the next
- filter */
- AVFilterInOut *currlinkn = p;
- if (p->type != LinkTypeOut) {
- av_log(log_ctx, AV_LOG_ERROR,
- "Label \"%s\" appears twice as input!\n", p->name);
- return -1;
- }
- currlinkn->next = *currInputs;
- *currInputs = currlinkn;
+ /* Not in the list, so add it as an input */
+ if (!(match = av_mallocz(sizeof(AVFilterInOut))))
+ return AVERROR(ENOMEM);
+ match->name = name;
+ match->pad_idx = pad;
}
- consume_whitespace(buf);
+
+ insert_inout(curr_inputs, match);
+
+ *buf += strspn(*buf, WHITESPACES);
pad++;
}
return pad;
}
-static int parse_outputs(const char **buf, AVFilterInOut **currInputs,
- AVFilterInOut **openLinks, AVClass *log_ctx)
+static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs,
+ AVFilterInOut **open_inputs,
+ AVFilterInOut **open_outputs, void *log_ctx)
{
- int pad = 0;
+ int ret, pad = 0;
while (**buf == '[') {
- char *name;
+ char *name = parse_link_name(buf, log_ctx);
AVFilterInOut *match;
- parse_link_name(buf, &name, log_ctx);
+ AVFilterInOut *input = *curr_inputs;
+ if (!input) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "No output pad can be associated to link label '%s'.\n",
+ name);
+ return AVERROR(EINVAL);
+ }
+ *curr_inputs = (*curr_inputs)->next;
- if(!name)
- return -1;
+ if (!name)
+ return AVERROR(EINVAL);
- /* First check if the label is not in the openLinks list */
- match = extract_inout(name, openLinks);
+ /* First check if the label is not in the open_inputs list */
+ match = extract_inout(name, open_inputs);
- /* Not in the list, so add the first input as a openLink */
- if(!match) {
- AVFilterInOut *p = *currInputs;
- *currInputs = (*currInputs)->next;
- p->next = *openLinks;
- p->type = LinkTypeOut;
- p->name = name;
- *openLinks = p;
- } else {
- /* A label of a open link. Link it. */
- AVFilterInOut *p = *currInputs;
- if (match->type != LinkTypeIn) {
- av_log(log_ctx, AV_LOG_ERROR,
- "Label \"%s\" appears twice as output!\n", match->name);
- return -1;
- }
-
- *currInputs = (*currInputs)->next;
- if(link_filter(p->filter, p->pad_idx,
- match->filter, match->pad_idx, log_ctx) < 0)
- return -1;
+ if (match) {
+ if ((ret = link_filter(input->filter_ctx, input->pad_idx,
+ match->filter_ctx, match->pad_idx, log_ctx)) < 0)
+ return ret;
+ av_free(match->name);
+ av_free(name);
av_free(match);
- av_free(p);
+ av_free(input);
+ } else {
+ /* Not in the list, so add the first input as a open_output */
+ input->name = name;
+ insert_inout(open_outputs, input);
}
- consume_whitespace(buf);
+ *buf += strspn(*buf, WHITESPACES);
pad++;
}
return pad;
}
-/**
- * Parse a string describing a filter graph.
- */
-int avfilter_parse_graph(AVFilterGraph *graph, const char *filters,
- AVFilterContext *in, int inpad,
- AVFilterContext *out, int outpad,
- AVClass *log_ctx)
+int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
+ AVFilterInOut *open_inputs,
+ AVFilterInOut *open_outputs, void *log_ctx)
{
- int index = 0;
+ int index = 0, ret;
char chr = 0;
- int pad = 0;
- AVFilterInOut *currInputs=NULL;
- AVFilterInOut *openLinks = av_malloc(sizeof(AVFilterInOut));
-
- openLinks->name = "in";
- openLinks->filter = in;
- openLinks->type = LinkTypeOut;
- openLinks->pad_idx = inpad;
- openLinks->next = av_malloc(sizeof(AVFilterInOut));
-
- openLinks->next->name = "out";
- openLinks->next->filter = out;
- openLinks->next->type = LinkTypeIn;
- openLinks->next->pad_idx = outpad;
- openLinks->next->next = NULL;
+ AVFilterInOut *curr_inputs = NULL;
do {
AVFilterContext *filter;
- consume_whitespace(&filters);
-
- pad = parse_inputs(&filters, &currInputs, &openLinks, log_ctx);
+ const char *filterchain = filters;
+ filters += strspn(filters, WHITESPACES);
- if(pad < 0)
+ if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, log_ctx)) < 0)
goto fail;
- if(!(filter = parse_filter(&filters, graph, index, log_ctx)))
+ if ((ret = parse_filter(&filter, &filters, graph, index, log_ctx)) < 0)
goto fail;
- if(filter->input_count == 1 && !currInputs && !index) {
- // First input can be ommitted if it is "[in]"
+ if (filter->input_count == 1 && !curr_inputs && !index) {
+ /* First input can be omitted if it is "[in]" */
const char *tmp = "[in]";
- pad = parse_inputs(&tmp, &currInputs, &openLinks, log_ctx);
- if (pad < 0)
+ if ((ret = parse_inputs(&tmp, &curr_inputs, &open_outputs, log_ctx)) < 0)
goto fail;
}
- if(link_filter_inouts(filter, &currInputs, &openLinks, log_ctx) < 0)
+ if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, log_ctx)) < 0)
goto fail;
- pad = parse_outputs(&filters, &currInputs, &openLinks, log_ctx);
-
- if(pad < 0)
+ if ((ret = parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs,
+ log_ctx)) < 0)
goto fail;
- consume_whitespace(&filters);
+ filters += strspn(filters, WHITESPACES);
chr = *filters++;
- if (chr == ';' && currInputs) {
+ if (chr == ';' && curr_inputs) {
av_log(log_ctx, AV_LOG_ERROR,
- "Could not find a output to link when parsing \"%s\"\n",
- filters - 1);
+ "Invalid filterchain containing an unlabelled output pad: \"%s\"\n",
+ filterchain);
+ ret = AVERROR(EINVAL);
goto fail;
}
index++;
} while (chr == ',' || chr == ';');
- if(openLinks && !strcmp(openLinks->name, "out") && currInputs) {
- // Last output can be ommitted if it is "[out]"
+ if (chr) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Unable to parse graph description substring: \"%s\"\n",
+ filters - 1);
+ ret = AVERROR(EINVAL);
+ goto fail;
+ }
+
+ if (open_inputs && !strcmp(open_inputs->name, "out") && curr_inputs) {
+ /* Last output can be omitted if it is "[out]" */
const char *tmp = "[out]";
- if(parse_outputs(&tmp, &currInputs, &openLinks, log_ctx) < 0)
+ if ((ret = parse_outputs(&tmp, &curr_inputs, &open_inputs, &open_outputs,
+ log_ctx)) < 0)
goto fail;
}
return 0;
fail:
- avfilter_destroy_graph(graph);
- free_inout(openLinks);
- free_inout(currInputs);
- return -1;
+ for (; graph->filter_count > 0; graph->filter_count--)
+ avfilter_free(graph->filters[graph->filter_count - 1]);
+ av_freep(&graph->filters);
+ free_inout(open_inputs);
+ free_inout(open_outputs);
+ free_inout(curr_inputs);
+ return ret;
}