/*
* 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 "graphparser.h"
+#include "libavutil/avstring.h"
#include "avfilter.h"
#include "avfiltergraph.h"
-#include "parseutils.h"
#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)
{
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 ret;
}
}
/**
- * Parse "[linkname]"
- * @param 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 char *parse_link_name(const char **buf, AVClass *log_ctx)
+static char *parse_link_name(const char **buf, void *log_ctx)
{
const char *start = *buf;
char *name;
return name;
}
-static AVFilterContext *create_filter(AVFilterGraph *ctx, int index,
- const char *filt_name, const char *args,
- AVClass *log_ctx)
+/**
+ * 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)
{
- AVFilterContext *filt_ctx;
-
AVFilter *filt;
char inst_name[30];
char tmp_args[256];
+ int ret;
- snprintf(inst_name, sizeof(inst_name), "Filter %d %s", index, filt_name);
+ 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 NULL;
+ "No such filter: '%s'\n", filt_name);
+ return AVERROR(EINVAL);
}
- filt_ctx = avfilter_open(filt, inst_name);
- if (!filt_ctx) {
+ 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 NULL;
+ "Error creating filter '%s'\n", filt_name);
+ return ret;
}
- if (avfilter_graph_add_filter(ctx, filt_ctx) < 0) {
- avfilter_destroy(filt_ctx);
- return NULL;
+ if ((ret = avfilter_graph_add_filter(ctx, *filt_ctx)) < 0) {
+ avfilter_free(*filt_ctx);
+ return ret;
}
- if (!strcmp(filt_name, "scale") && !strstr(args, "flags")) {
+ 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 (avfilter_init_filter(filt_ctx, args, NULL)) {
+ 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 NULL;
+ "Error initializing filter '%s' with args '%s'\n", filt_name, args);
+ return ret;
}
- return filt_ctx;
+ return 0;
}
/**
- * Parse "filter=params"
+ * 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
*/
-static AVFilterContext *parse_filter(const char **buf, AVFilterGraph *graph,
- int index, AVClass *log_ctx)
+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");
- AVFilterContext *ret;
+ int ret;
if (**buf == '=') {
(*buf)++;
opts = av_get_token(buf, "[],;\n");
}
- ret = create_filter(graph, index, name, opts, log_ctx);
+ ret = create_filter(filt_ctx, graph, index, name, opts, log_ctx);
av_free(name);
av_free(opts);
return ret;
*inouts = element;
}
-static int link_filter_inouts(AVFilterContext *filter,
+static int link_filter_inouts(AVFilterContext *filt_ctx,
AVFilterInOut **curr_inputs,
- AVFilterInOut **open_inputs, AVClass *log_ctx)
+ AVFilterInOut **open_inputs, void *log_ctx)
{
- int pad = filter->input_count;
+ int pad = filt_ctx->input_count, ret;
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->filter->name);
- return -1;
+ filt_ctx->filter->name);
+ return AVERROR(EINVAL);
}
*curr_inputs = (*curr_inputs)->next;
- if (p->filter) {
- if (link_filter(p->filter, p->pad_idx, filter, pad, log_ctx))
- return -1;
+ 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->filter = filter;
+ p->filter_ctx = filt_ctx;
p->pad_idx = pad;
insert_inout(open_inputs, p);
}
if (*curr_inputs) {
av_log(log_ctx, AV_LOG_ERROR,
"Too many inputs specified for the \"%s\" filter.\n",
- filter->filter->name);
- return -1;
+ filt_ctx->filter->name);
+ return AVERROR(EINVAL);
}
- pad = filter->output_count;
+ pad = filt_ctx->output_count;
while (pad--) {
AVFilterInOut *currlinkn = av_mallocz(sizeof(AVFilterInOut));
- currlinkn->filter = filter;
+ if (!currlinkn)
+ return AVERROR(ENOMEM);
+ currlinkn->filter_ctx = filt_ctx;
currlinkn->pad_idx = pad;
insert_inout(curr_inputs, currlinkn);
}
}
static int parse_inputs(const char **buf, AVFilterInOut **curr_inputs,
- AVFilterInOut **open_outputs, AVClass *log_ctx)
+ AVFilterInOut **open_outputs, void *log_ctx)
{
int pad = 0;
AVFilterInOut *match;
if (!name)
- return -1;
+ return AVERROR(EINVAL);
/* First check if the label is not in the open_outputs list */
match = extract_inout(name, open_outputs);
av_free(name);
} else {
/* Not in the list, so add it as an input */
- match = av_mallocz(sizeof(AVFilterInOut));
+ if (!(match = av_mallocz(sizeof(AVFilterInOut))))
+ return AVERROR(ENOMEM);
match->name = name;
match->pad_idx = pad;
}
static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs,
AVFilterInOut **open_inputs,
- AVFilterInOut **open_outputs, AVClass *log_ctx)
+ AVFilterInOut **open_outputs, void *log_ctx)
{
- int pad = 0;
+ int ret, pad = 0;
while (**buf == '[') {
char *name = parse_link_name(buf, log_ctx);
AVFilterInOut *match;
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;
+ return AVERROR(EINVAL);
/* First check if the label is not in the open_inputs list */
match = extract_inout(name, open_inputs);
if (match) {
- if (link_filter(input->filter, input->pad_idx,
- match->filter, match->pad_idx, log_ctx) < 0)
- return -1;
+ 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);
int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
AVFilterInOut *open_inputs,
- AVFilterInOut *open_outputs, AVClass *log_ctx)
+ AVFilterInOut *open_outputs, void *log_ctx)
{
- int index = 0;
+ int index = 0, ret;
char chr = 0;
AVFilterInOut *curr_inputs = NULL;
do {
AVFilterContext *filter;
+ const char *filterchain = filters;
filters += strspn(filters, WHITESPACES);
- if (parse_inputs(&filters, &curr_inputs, &open_outputs, log_ctx) < 0)
+ if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, log_ctx)) < 0)
goto fail;
- filter = parse_filter(&filters, graph, index, log_ctx);
-
- if (!filter)
+ if ((ret = parse_filter(&filter, &filters, graph, index, log_ctx)) < 0)
goto fail;
if (filter->input_count == 1 && !curr_inputs && !index) {
/* First input can be omitted if it is "[in]" */
const char *tmp = "[in]";
- if(parse_inputs(&tmp, &curr_inputs, &open_outputs, log_ctx) < 0)
+ if ((ret = parse_inputs(&tmp, &curr_inputs, &open_outputs, log_ctx)) < 0)
goto fail;
}
- if (link_filter_inouts(filter, &curr_inputs, &open_inputs, log_ctx) < 0)
+ if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, log_ctx)) < 0)
goto fail;
- if (parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs,
- log_ctx) < 0)
+ if ((ret = parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs,
+ log_ctx)) < 0)
goto fail;
filters += strspn(filters, WHITESPACES);
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++;
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, &curr_inputs, &open_inputs,
- &open_outputs, log_ctx) < 0)
+ if ((ret = parse_outputs(&tmp, &curr_inputs, &open_inputs, &open_outputs,
+ log_ctx)) < 0)
goto fail;
}
return 0;
fail:
- avfilter_graph_destroy(graph);
+ 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 -1;
+ return ret;
}