| /* |
| * filter graph parser |
| * copyright (c) 2008 Vitor Sessak |
| * copyright (c) 2007 Bobby Bingham |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg 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, |
| * 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 |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include <ctype.h> |
| #include <string.h> |
| |
| #include "graphparser.h" |
| #include "avfilter.h" |
| #include "avfiltergraph.h" |
| |
| static int link_filter(AVFilterContext *src, int srcpad, |
| AVFilterContext *dst, int dstpad, |
| AVClass *log_ctx) |
| { |
| if(avfilter_link(src, srcpad, dst, dstpad)) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "cannot create the link %s:%d -> %s:%d\n", |
| src->filter->name, srcpad, dst->filter->name, dstpad); |
| return -1; |
| } |
| |
| 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 |
| */ |
| static char *parse_link_name(const char **buf, AVClass *log_ctx) |
| { |
| const char *start = *buf; |
| char *name; |
| (*buf)++; |
| |
| name = consume_string(buf); |
| |
| if(!name[0]) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "Bad (empty?) label found in the following: \"%s\".\n", start); |
| goto fail; |
| } |
| |
| if(*(*buf)++ != ']') { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "Mismatched '[' found in the following: \"%s\".\n", start); |
| fail: |
| av_freep(&name); |
| } |
| |
| return name; |
| } |
| |
| static AVFilterContext *create_filter(AVFilterGraph *ctx, int index, |
| const char *filt_name, const char *args, |
| AVClass *log_ctx) |
| { |
| AVFilterContext *filt_ctx; |
| |
| AVFilter *filt; |
| char inst_name[30]; |
| |
| snprintf(inst_name, sizeof(inst_name), "Parsed filter %d", index); |
| |
| 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; |
| } |
| |
| filt_ctx = avfilter_open(filt, inst_name); |
| if(!filt_ctx) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "error creating filter '%s'\n", filt_name); |
| return NULL; |
| } |
| |
| if(avfilter_graph_add_filter(ctx, filt_ctx) < 0) { |
| avfilter_destroy(filt_ctx); |
| return NULL; |
| } |
| |
| if(avfilter_init_filter(filt_ctx, args, NULL)) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "error initializing filter '%s' with args '%s'\n", filt_name, args); |
| return NULL; |
| } |
| |
| return filt_ctx; |
| } |
| |
| /** |
| * Parse "filter=params" |
| */ |
| static AVFilterContext *parse_filter(const char **buf, AVFilterGraph *graph, |
| int index, AVClass *log_ctx) |
| { |
| char *opts = NULL; |
| char *name = consume_string(buf); |
| AVFilterContext *ret; |
| |
| if(**buf == '=') { |
| (*buf)++; |
| opts = consume_string(buf); |
| } |
| |
| ret = create_filter(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; |
| } |
| } |
| |
| static AVFilterInOut *extract_inout(const char *label, AVFilterInOut **links) |
| { |
| AVFilterInOut *ret; |
| |
| while(*links && strcmp((*links)->name, label)) |
| links = &((*links)->next); |
| |
| ret = *links; |
| |
| 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 **curr_inputs, |
| AVFilterInOut **open_inputs, AVClass *log_ctx) |
| { |
| int pad = filter->input_count; |
| |
| 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; |
| } |
| |
| *curr_inputs = (*curr_inputs)->next; |
| |
| if(p->filter) { |
| if(link_filter(p->filter, p->pad_idx, filter, pad, log_ctx)) |
| return -1; |
| av_free(p->name); |
| av_free(p); |
| } else { |
| p->filter = filter; |
| 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; |
| } |
| |
| pad = filter->output_count; |
| while(pad--) { |
| AVFilterInOut *currlinkn = av_mallocz(sizeof(AVFilterInOut)); |
| currlinkn->filter = filter; |
| currlinkn->pad_idx = pad; |
| insert_inout(curr_inputs, currlinkn); |
| } |
| |
| return 0; |
| } |
| |
| static int parse_inputs(const char **buf, AVFilterInOut **curr_inputs, |
| AVFilterInOut **open_outputs, AVClass *log_ctx) |
| { |
| int pad = 0; |
| |
| while(**buf == '[') { |
| char *name = parse_link_name(buf, log_ctx); |
| AVFilterInOut *match; |
| |
| if(!name) |
| return -1; |
| |
| /* First check if the label is not in the open_outputs list */ |
| match = extract_inout(name, open_outputs); |
| |
| if(match) { |
| av_free(name); |
| } else { |
| /* Not in the list, so add it as an input */ |
| match = av_mallocz(sizeof(AVFilterInOut)); |
| match->name = name; |
| match->pad_idx = pad; |
| } |
| |
| insert_inout(curr_inputs, match); |
| |
| *buf += consume_whitespace(*buf); |
| pad++; |
| } |
| |
| return pad; |
| } |
| |
| static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs, |
| AVFilterInOut **open_inputs, |
| AVFilterInOut **open_outputs, AVClass *log_ctx) |
| { |
| int pad = 0; |
| |
| while(**buf == '[') { |
| char *name = parse_link_name(buf, log_ctx); |
| AVFilterInOut *match; |
| |
| AVFilterInOut *input = *curr_inputs; |
| *curr_inputs = (*curr_inputs)->next; |
| |
| if(!name) |
| return -1; |
| |
| /* 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; |
| 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 open_output */ |
| input->name = name; |
| insert_inout(open_outputs, input); |
| } |
| *buf += consume_whitespace(*buf); |
| pad++; |
| } |
| |
| return pad; |
| } |
| |
| int avfilter_graph_parse(AVFilterGraph *graph, const char *filters, |
| AVFilterInOut *open_inputs, |
| AVFilterInOut *open_outputs, AVClass *log_ctx) |
| { |
| int index = 0; |
| char chr = 0; |
| |
| AVFilterInOut *curr_inputs = NULL; |
| |
| do { |
| AVFilterContext *filter; |
| filters += consume_whitespace(filters); |
| |
| if(parse_inputs(&filters, &curr_inputs, &open_outputs, log_ctx) < 0) |
| goto fail; |
| |
| filter = parse_filter(&filters, graph, index, log_ctx); |
| |
| if(!filter) |
| 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) |
| goto fail; |
| } |
| |
| if(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) |
| goto fail; |
| |
| filters += consume_whitespace(filters); |
| chr = *filters++; |
| |
| if(chr == ';' && curr_inputs) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "Could not find a output to link when parsing \"%s\"\n", |
| filters - 1); |
| goto fail; |
| } |
| index++; |
| } while(chr == ',' || chr == ';'); |
| |
| if (chr) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "Unable to parse graph description substring: \"%s\"\n", |
| filters - 1); |
| 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) |
| goto fail; |
| } |
| |
| return 0; |
| |
| fail: |
| avfilter_graph_destroy(graph); |
| free_inout(open_inputs); |
| free_inout(open_outputs); |
| free_inout(curr_inputs); |
| return -1; |
| } |