| /* |
| * 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 <string.h> |
| #include <stdio.h> |
| |
| #include "libavutil/avstring.h" |
| #include "libavutil/mem.h" |
| #include "avfilter.h" |
| |
| #define WHITESPACES " \n\t" |
| |
| /** |
| * Link two filters together. |
| * |
| * @see avfilter_link() |
| */ |
| static int link_filter(AVFilterContext *src, int srcpad, |
| AVFilterContext *dst, int dstpad, |
| 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", |
| src->filter->name, srcpad, dst->filter->name, dstpad); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * 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, void *log_ctx) |
| { |
| const char *start = *buf; |
| char *name; |
| (*buf)++; |
| |
| name = av_get_token(buf, "]"); |
| if (!name) |
| goto fail; |
| |
| 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; |
| } |
| |
| /** |
| * 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 = NULL; |
| int ret; |
| |
| snprintf(inst_name, sizeof(inst_name), "Parsed_%s_%d", filt_name, 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 AVERROR(EINVAL); |
| } |
| |
| *filt_ctx = avfilter_graph_alloc_filter(ctx, filt, inst_name); |
| if (!*filt_ctx) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "Error creating filter '%s'\n", filt_name); |
| return AVERROR(ENOMEM); |
| } |
| |
| if (!strcmp(filt_name, "scale") && (!args || !strstr(args, "flags")) && |
| ctx->scale_sws_opts) { |
| if (args) { |
| tmp_args = av_asprintf("%s:%s", |
| args, ctx->scale_sws_opts); |
| if (!tmp_args) |
| return AVERROR(ENOMEM); |
| args = tmp_args; |
| } else |
| args = ctx->scale_sws_opts; |
| } |
| |
| ret = avfilter_init_str(*filt_ctx, args); |
| if (ret < 0) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "Error initializing filter '%s'", filt_name); |
| if (args) |
| av_log(log_ctx, AV_LOG_ERROR, " with args '%s'", args); |
| av_log(log_ctx, AV_LOG_ERROR, "\n"); |
| avfilter_free(*filt_ctx); |
| *filt_ctx = NULL; |
| } |
| |
| av_free(tmp_args); |
| return ret; |
| } |
| |
| /** |
| * 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 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; |
| |
| 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; |
| } |
| |
| AVFilterInOut *avfilter_inout_alloc(void) |
| { |
| 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; |
| } |
| } |
| |
| static AVFilterInOut *extract_inout(const char *label, AVFilterInOut **links) |
| { |
| AVFilterInOut *ret; |
| |
| while (*links && (!(*links)->name || strcmp((*links)->name, label))) |
| links = &((*links)->next); |
| |
| ret = *links; |
| |
| if (ret) { |
| *links = ret->next; |
| ret->next = NULL; |
| } |
| |
| return ret; |
| } |
| |
| static void insert_inout(AVFilterInOut **inouts, AVFilterInOut *element) |
| { |
| element->next = *inouts; |
| *inouts = element; |
| } |
| |
| static void append_inout(AVFilterInOut **inouts, AVFilterInOut **element) |
| { |
| while (*inouts && (*inouts)->next) |
| inouts = &((*inouts)->next); |
| |
| if (!*inouts) |
| *inouts = *element; |
| else |
| (*inouts)->next = *element; |
| *element = NULL; |
| } |
| |
| static int link_filter_inouts(AVFilterContext *filt_ctx, |
| AVFilterInOut **curr_inputs, |
| AVFilterInOut **open_inputs, void *log_ctx) |
| { |
| int pad, ret; |
| |
| for (pad = 0; pad < filt_ctx->nb_inputs; 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) { |
| ret = link_filter(p->filter_ctx, p->pad_idx, filt_ctx, pad, log_ctx); |
| av_freep(&p->name); |
| av_freep(&p); |
| if (ret < 0) |
| return ret; |
| } else { |
| p->filter_ctx = filt_ctx; |
| p->pad_idx = pad; |
| append_inout(open_inputs, &p); |
| } |
| } |
| |
| if (*curr_inputs) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "Too many inputs specified for the \"%s\" filter.\n", |
| filt_ctx->filter->name); |
| return AVERROR(EINVAL); |
| } |
| |
| pad = filt_ctx->nb_outputs; |
| while (pad--) { |
| AVFilterInOut *currlinkn = av_mallocz(sizeof(AVFilterInOut)); |
| if (!currlinkn) |
| return AVERROR(ENOMEM); |
| currlinkn->filter_ctx = filt_ctx; |
| currlinkn->pad_idx = pad; |
| insert_inout(curr_inputs, currlinkn); |
| } |
| |
| return 0; |
| } |
| |
| 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 == '[') { |
| char *name = parse_link_name(buf, log_ctx); |
| AVFilterInOut *match; |
| |
| if (!name) |
| return AVERROR(EINVAL); |
| |
| /* 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 */ |
| if (!(match = av_mallocz(sizeof(AVFilterInOut)))) { |
| av_free(name); |
| return AVERROR(ENOMEM); |
| } |
| match->name = name; |
| match->pad_idx = pad; |
| } |
| |
| 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 **curr_inputs, |
| AVFilterInOut **open_inputs, |
| AVFilterInOut **open_outputs, void *log_ctx) |
| { |
| int ret, pad = 0; |
| |
| while (**buf == '[') { |
| char *name = parse_link_name(buf, log_ctx); |
| AVFilterInOut *match; |
| |
| AVFilterInOut *input = *curr_inputs; |
| |
| if (!name) |
| return AVERROR(EINVAL); |
| |
| if (!input) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "No output pad can be associated to link label '%s'.\n", name); |
| av_free(name); |
| return AVERROR(EINVAL); |
| } |
| *curr_inputs = (*curr_inputs)->next; |
| |
| /* First check if the label is not in the open_inputs list */ |
| match = extract_inout(name, open_inputs); |
| |
| if (match) { |
| if ((ret = link_filter(input->filter_ctx, input->pad_idx, |
| match->filter_ctx, match->pad_idx, log_ctx)) < 0) { |
| av_free(name); |
| return ret; |
| } |
| av_freep(&match->name); |
| av_freep(&name); |
| av_freep(&match); |
| av_freep(&input); |
| } else { |
| /* Not in the list, so add the first input as a open_output */ |
| input->name = name; |
| insert_inout(open_outputs, input); |
| } |
| *buf += strspn(*buf, WHITESPACES); |
| pad++; |
| } |
| |
| return pad; |
| } |
| |
| 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(graph, 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, ret = 0; |
| char chr = 0; |
| |
| 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 += strspn(filters, WHITESPACES); |
| |
| if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, graph)) < 0) |
| goto end; |
| if ((ret = parse_filter(&filter, &filters, graph, index, graph)) < 0) |
| goto end; |
| |
| |
| if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, graph)) < 0) |
| goto end; |
| |
| if ((ret = parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs, |
| graph)) < 0) |
| goto end; |
| |
| filters += strspn(filters, WHITESPACES); |
| chr = *filters++; |
| |
| if (chr == ';' && curr_inputs) |
| append_inout(&open_outputs, &curr_inputs); |
| index++; |
| } while (chr == ',' || chr == ';'); |
| |
| if (chr) { |
| av_log(graph, AV_LOG_ERROR, |
| "Unable to parse graph description substring: \"%s\"\n", |
| filters - 1); |
| ret = AVERROR(EINVAL); |
| goto end; |
| } |
| |
| append_inout(&open_outputs, &curr_inputs); |
| |
| |
| *inputs = open_inputs; |
| *outputs = open_outputs; |
| return 0; |
| |
| fail:end: |
| while (graph->nb_filters) |
| avfilter_free(graph->filters[0]); |
| 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; |
| } |
| |
| 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) { |
| while (graph->nb_filters) |
| avfilter_free(graph->filters[0]); |
| av_freep(&graph->filters); |
| } |
| avfilter_inout_free(&inputs); |
| avfilter_inout_free(&outputs); |
| avfilter_inout_free(&open_inputs); |
| avfilter_inout_free(&open_outputs); |
| return ret; |
| } |
| |
| int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters, |
| AVFilterInOut **open_inputs_ptr, AVFilterInOut **open_outputs_ptr, |
| void *log_ctx) |
| { |
| int index = 0, ret = 0; |
| char chr = 0; |
| |
| AVFilterInOut *curr_inputs = NULL; |
| 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) |
| goto end; |
| |
| do { |
| AVFilterContext *filter; |
| const char *filterchain = filters; |
| filters += strspn(filters, WHITESPACES); |
| |
| if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, log_ctx)) < 0) |
| goto end; |
| |
| if ((ret = parse_filter(&filter, &filters, graph, index, log_ctx)) < 0) |
| goto end; |
| |
| if (filter->nb_inputs == 1 && !curr_inputs && !index) { |
| /* First input pad, assume it is "[in]" if not specified */ |
| const char *tmp = "[in]"; |
| if ((ret = parse_inputs(&tmp, &curr_inputs, &open_outputs, log_ctx)) < 0) |
| goto end; |
| } |
| |
| if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, log_ctx)) < 0) |
| goto end; |
| |
| if ((ret = parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs, |
| log_ctx)) < 0) |
| goto end; |
| |
| filters += strspn(filters, WHITESPACES); |
| chr = *filters++; |
| |
| if (chr == ';' && curr_inputs) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "Invalid filterchain containing an unlabelled output pad: \"%s\"\n", |
| filterchain); |
| ret = AVERROR(EINVAL); |
| goto end; |
| } |
| index++; |
| } while (chr == ',' || chr == ';'); |
| |
| if (chr) { |
| av_log(log_ctx, AV_LOG_ERROR, |
| "Unable to parse graph description substring: \"%s\"\n", |
| filters - 1); |
| ret = AVERROR(EINVAL); |
| goto end; |
| } |
| |
| if (curr_inputs) { |
| /* Last output pad, assume it is "[out]" if not specified */ |
| const char *tmp = "[out]"; |
| if ((ret = parse_outputs(&tmp, &curr_inputs, &open_inputs, &open_outputs, |
| log_ctx)) < 0) |
| goto end; |
| } |
| |
| end: |
| /* clear open_in/outputs only if not passed as parameters */ |
| if (open_inputs_ptr) *open_inputs_ptr = open_inputs; |
| else avfilter_inout_free(&open_inputs); |
| if (open_outputs_ptr) *open_outputs_ptr = open_outputs; |
| else avfilter_inout_free(&open_outputs); |
| avfilter_inout_free(&curr_inputs); |
| |
| if (ret < 0) { |
| while (graph->nb_filters) |
| avfilter_free(graph->filters[0]); |
| av_freep(&graph->filters); |
| } |
| return ret; |
| } |
