/*
* 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"
+#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 int consume_whitespace(const char *buf)
-{
- return 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;
-
- *buf += 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)--;
- *buf += consume_whitespace(*buf);
-
- 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;
(*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:
return name;
}
-static AVFilterContext *create_filter(AVFilterGraph *ctx, int index,
- const char *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;
-
- AVFilter *filterdef;
+ AVFilter *filt;
char inst_name[30];
+ char tmp_args[256];
+ int ret;
- snprintf(inst_name, sizeof(inst_name), "Parsed filter %d", index);
+ snprintf(inst_name, sizeof(inst_name), "Parsed filter %d %s", index, filt_name);
- filterdef = avfilter_get_by_name(name);
+ filt = avfilter_get_by_name(filt_name);
- if(!filterdef) {
+ if (!filt) {
av_log(log_ctx, AV_LOG_ERROR,
- "no such filter: '%s'\n", name);
- return NULL;
+ "No such filter: '%s'\n", filt_name);
+ return AVERROR(EINVAL);
}
- filt = avfilter_open(filterdef, inst_name);
- if(!filt) {
+ ret = avfilter_open(filt_ctx, filt, inst_name);
+ if (!*filt_ctx) {
av_log(log_ctx, AV_LOG_ERROR,
- "error creating filter '%s'\n", name);
- return NULL;
+ "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(avfilter_graph_add_filter(ctx, filt) < 0)
- return NULL;
+ 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, 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", name, args);
- return NULL;
+ "Error initializing filter '%s' with args '%s'\n", filt_name, args);
+ return ret;
}
- return filt;
+ 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 = consume_string(buf);
+ char *name = av_get_token(buf, "=,;[\n");
+ int ret;
- if(**buf == '=') {
+ if (**buf == '=') {
(*buf)++;
- opts = consume_string(buf);
+ opts = av_get_token(buf, "[],;\n");
}
- return 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;
}
-static void free_inout(AVFilterInOut *head)
+AVFilterInOut *avfilter_inout_alloc(void)
{
- while(head) {
- AVFilterInOut *next = head->next;
- av_free(head);
- head = next;
+ return av_mallocz(sizeof(AVFilterInOut));
+}
+
+void avfilter_inout_free(AVFilterInOut **inout)
+{
+ while (*inout) {
+ AVFilterInOut *next = (*inout)->next;
+ av_freep(&(*inout)->name);
+ av_freep(inout);
+ *inout = next;
}
}
{
AVFilterInOut *ret;
- while(*links && strcmp((*links)->name, label))
+ while (*links && (!(*links)->name || strcmp((*links)->name, label)))
links = &((*links)->next);
ret = *links;
- if(ret)
+ if (ret) {
*links = ret->next;
+ ret->next = NULL;
+ }
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 void append_inout(AVFilterInOut **inouts, AVFilterInOut **element)
{
- int pad = 0;
+ while (*inouts && (*inouts)->next)
+ inouts = &((*inouts)->next);
+
+ if (!*inouts)
+ *inouts = *element;
+ else
+ (*inouts)->next = *element;
+ *element = NULL;
+}
- pad = filter->input_count;
- while(pad--) {
- AVFilterInOut *p = *currInputs;
- *currInputs = (*currInputs)->next;
- if(!p) {
- av_log(log_ctx, AV_LOG_ERROR,
- "Not enough inputs specified for the \"%s\" filter.\n",
- filter->filter->name);
- return -1;
- }
+static int link_filter_inouts(AVFilterContext *filt_ctx,
+ AVFilterInOut **curr_inputs,
+ AVFilterInOut **open_inputs, void *log_ctx)
+{
+ int pad, ret;
- if(p->filter) {
- if(link_filter(p->filter, p->pad_idx, filter, pad, log_ctx))
- return -1;
+ for (pad = 0; pad < filt_ctx->input_count; pad++) {
+ AVFilterInOut *p = *curr_inputs;
+
+ if (p) {
+ *curr_inputs = (*curr_inputs)->next;
+ p->next = NULL;
+ } else if (!(p = av_mallocz(sizeof(*p))))
+ return AVERROR(ENOMEM);
+
+ 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;
- p->next = *openLinks;
- *openLinks = p;
+ append_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->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;
}
-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)
{
+ AVFilterInOut *parsed_inputs = NULL;
int pad = 0;
- while(**buf == '[') {
+ while (**buf == '[') {
char *name = parse_link_name(buf, log_ctx);
- AVFilterInOut *link_to_add;
AVFilterInOut *match;
- 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_outputs list */
+ match = extract_inout(name, open_outputs);
- if(match) {
- /* A label of a open link. Make it one of the inputs of the next
- filter */
- if(match->type != LinkTypeOut) {
- av_log(log_ctx, AV_LOG_ERROR,
- "Label \"%s\" appears twice as input!\n", match->name);
- return -1;
- }
-
- link_to_add = match;
+ if (match) {
+ av_free(name);
} else {
/* Not in the list, so add it as an input */
- link_to_add = av_malloc(sizeof(AVFilterInOut));
-
- link_to_add->name = name;
- link_to_add->type = LinkTypeIn;
- link_to_add->filter = NULL;
- link_to_add->pad_idx = pad;
+ if (!(match = av_mallocz(sizeof(AVFilterInOut))))
+ return AVERROR(ENOMEM);
+ match->name = name;
+ match->pad_idx = pad;
}
- link_to_add->next = *currInputs;
- *currInputs = link_to_add;
- *buf += consume_whitespace(*buf);
+
+ append_inout(&parsed_inputs, &match);
+
+ *buf += strspn(*buf, WHITESPACES);
pad++;
}
+ append_inout(&parsed_inputs, curr_inputs);
+ *curr_inputs = parsed_inputs;
+
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 == '[') {
+ while (**buf == '[') {
char *name = parse_link_name(buf, log_ctx);
AVFilterInOut *match;
- AVFilterInOut *input = *currInputs;
- *currInputs = (*currInputs)->next;
-
- if(!name)
- return -1;
+ 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;
- /* First check if the label is not in the openLinks list */
- match = extract_inout(name, openLinks);
+ if (!name)
+ return AVERROR(EINVAL);
- if(match) {
- /* A label of a open link. Link it. */
- if(match->type != LinkTypeIn) {
- av_log(log_ctx, AV_LOG_ERROR,
- "Label \"%s\" appears twice as output!\n", match->name);
- return -1;
- }
+ /* First check if the label is not in the open_inputs list */
+ match = extract_inout(name, open_inputs);
- if(link_filter(input->filter, input->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(input);
} else {
- /* Not in the list, so add the first input as a openLink */
- input->next = *openLinks;
- input->type = LinkTypeOut;
+ /* Not in the list, so add the first input as a open_output */
input->name = name;
- *openLinks = input;
+ insert_inout(open_outputs, input);
}
- *buf += 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,
- AVFilterInOut *openLinks, AVClass *log_ctx)
+#if FF_API_GRAPH_AVCLASS
+#define log_ctx graph
+#else
+#define log_ctx NULL
+#endif
+
+static int parse_sws_flags(const char **buf, AVFilterGraph *graph)
+{
+ char *p = strchr(*buf, ';');
+
+ if (strncmp(*buf, "sws_flags=", 10))
+ return 0;
+
+ if (!p) {
+ 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)))
+ return AVERROR(ENOMEM);
+ av_strlcpy(graph->scale_sws_opts, *buf, p - *buf + 1);
+
+ *buf = p + 1;
+ return 0;
+}
+
+int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
+ AVFilterInOut **inputs,
+ AVFilterInOut **outputs)
{
- int index = 0;
+ int index = 0, ret;
char chr = 0;
- int pad = 0;
- AVFilterInOut *currInputs = NULL;
+ AVFilterInOut *curr_inputs = NULL, *open_inputs = NULL, *open_outputs = NULL;
+
+ filters += strspn(filters, WHITESPACES);
+
+ if ((ret = parse_sws_flags(&filters, graph)) < 0)
+ goto fail;
do {
AVFilterContext *filter;
- filters += consume_whitespace(filters);
-
- pad = parse_inputs(&filters, &currInputs, &openLinks, log_ctx);
+ filters += strspn(filters, WHITESPACES);
- if(pad < 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 && !currInputs && !index) {
- // First input can be ommitted if it is "[in]"
- const char *tmp = "[in]";
- pad = parse_inputs(&tmp, &currInputs, &openLinks, log_ctx);
- if(pad < 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;
- filters += consume_whitespace(filters);
+ filters += strspn(filters, WHITESPACES);
chr = *filters++;
- if(chr == ';' && currInputs) {
- av_log(log_ctx, AV_LOG_ERROR,
- "Could not find a output to link when parsing \"%s\"\n",
- filters - 1);
- goto fail;
- }
+ if (chr == ';' && curr_inputs)
+ append_inout(&open_outputs, &curr_inputs);
index++;
- } while(chr == ',' || chr == ';');
+ } while (chr == ',' || chr == ';');
- if(openLinks && !strcmp(openLinks->name, "out") && currInputs) {
- // Last output can be ommitted if it is "[out]"
- const char *tmp = "[out]";
- if(parse_outputs(&tmp, &currInputs, &openLinks, log_ctx) < 0)
- goto fail;
+ if (chr) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Unable to parse graph description substring: \"%s\"\n",
+ filters - 1);
+ ret = AVERROR(EINVAL);
+ goto fail;
}
+ append_inout(&open_outputs, &curr_inputs);
+
+ *inputs = open_inputs;
+ *outputs = open_outputs;
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);
+ avfilter_inout_free(&open_inputs);
+ avfilter_inout_free(&open_outputs);
+ avfilter_inout_free(&curr_inputs);
+
+ *inputs = NULL;
+ *outputs = NULL;
+
+ return ret;
+}
+#undef log_ctx
+
+int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
+ AVFilterInOut *open_inputs,
+ AVFilterInOut *open_outputs, void *log_ctx)
+{
+ int ret;
+ AVFilterInOut *cur, *match, *inputs = NULL, *outputs = NULL;
+
+ if ((ret = avfilter_graph_parse2(graph, filters, &inputs, &outputs)) < 0)
+ goto fail;
+
+ /* First input can be omitted if it is "[in]" */
+ if (inputs && !inputs->name)
+ inputs->name = av_strdup("in");
+ for (cur = inputs; cur; cur = cur->next) {
+ if (!cur->name) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Not enough inputs specified for the \"%s\" filter.\n",
+ cur->filter_ctx->filter->name);
+ ret = AVERROR(EINVAL);
+ goto fail;
+ }
+ if (!(match = extract_inout(cur->name, &open_outputs)))
+ continue;
+ ret = avfilter_link(match->filter_ctx, match->pad_idx,
+ cur->filter_ctx, cur->pad_idx);
+ avfilter_inout_free(&match);
+ if (ret < 0)
+ goto fail;
+ }
+
+ /* Last output can be omitted if it is "[out]" */
+ if (outputs && !outputs->name)
+ outputs->name = av_strdup("out");
+ for (cur = outputs; cur; cur = cur->next) {
+ if (!cur->name) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Invalid filterchain containing an unlabelled output pad: \"%s\"\n",
+ filters);
+ ret = AVERROR(EINVAL);
+ goto fail;
+ }
+ if (!(match = extract_inout(cur->name, &open_inputs)))
+ continue;
+ ret = avfilter_link(cur->filter_ctx, cur->pad_idx,
+ match->filter_ctx, match->pad_idx);
+ avfilter_inout_free(&match);
+ if (ret < 0)
+ goto fail;
+ }
+
+ fail:
+ if (ret < 0) {
+ for (; graph->filter_count > 0; graph->filter_count--)
+ avfilter_free(graph->filters[graph->filter_count - 1]);
+ av_freep(&graph->filters);
+ }
+ avfilter_inout_free(&inputs);
+ avfilter_inout_free(&outputs);
+ avfilter_inout_free(&open_inputs);
+ avfilter_inout_free(&open_outputs);
+ return ret;
}