1/*
2 * filter graphs
3 * Copyright (c) 2008 Vitor Sessak
4 * Copyright (c) 2007 Bobby Bingham
5 *
6 * This file is part of Libav.
7 *
8 * Libav is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * Libav is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include <ctype.h>
24#include <string.h>
25
26#include "libavutil/avstring.h"
27#include "avfilter.h"
28#include "avfiltergraph.h"
29#include "internal.h"
30
31AVFilterGraph *avfilter_graph_alloc(void)
32{
33    return av_mallocz(sizeof(AVFilterGraph));
34}
35
36void avfilter_graph_free(AVFilterGraph **graph)
37{
38    if (!*graph)
39        return;
40    for (; (*graph)->filter_count > 0; (*graph)->filter_count--)
41        avfilter_free((*graph)->filters[(*graph)->filter_count - 1]);
42    av_freep(&(*graph)->scale_sws_opts);
43    av_freep(&(*graph)->filters);
44    av_freep(graph);
45}
46
47int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
48{
49    AVFilterContext **filters = av_realloc(graph->filters,
50                                           sizeof(AVFilterContext*) * (graph->filter_count+1));
51    if (!filters)
52        return AVERROR(ENOMEM);
53
54    graph->filters = filters;
55    graph->filters[graph->filter_count++] = filter;
56
57    return 0;
58}
59
60int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
61                                 const char *name, const char *args, void *opaque,
62                                 AVFilterGraph *graph_ctx)
63{
64    int ret;
65
66    if ((ret = avfilter_open(filt_ctx, filt, name)) < 0)
67        goto fail;
68    if ((ret = avfilter_init_filter(*filt_ctx, args, opaque)) < 0)
69        goto fail;
70    if ((ret = avfilter_graph_add_filter(graph_ctx, *filt_ctx)) < 0)
71        goto fail;
72    return 0;
73
74fail:
75    if (*filt_ctx)
76        avfilter_free(*filt_ctx);
77    *filt_ctx = NULL;
78    return ret;
79}
80
81int ff_avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
82{
83    AVFilterContext *filt;
84    int i, j;
85
86    for (i = 0; i < graph->filter_count; i++) {
87        filt = graph->filters[i];
88
89        for (j = 0; j < filt->input_count; j++) {
90            if (!filt->inputs[j] || !filt->inputs[j]->src) {
91                av_log(log_ctx, AV_LOG_ERROR,
92                       "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
93                       filt->input_pads[j].name, filt->name, filt->filter->name);
94                return AVERROR(EINVAL);
95            }
96        }
97
98        for (j = 0; j < filt->output_count; j++) {
99            if (!filt->outputs[j] || !filt->outputs[j]->dst) {
100                av_log(log_ctx, AV_LOG_ERROR,
101                       "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
102                       filt->output_pads[j].name, filt->name, filt->filter->name);
103                return AVERROR(EINVAL);
104            }
105        }
106    }
107
108    return 0;
109}
110
111int ff_avfilter_graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
112{
113    AVFilterContext *filt;
114    int i, ret;
115
116    for (i=0; i < graph->filter_count; i++) {
117        filt = graph->filters[i];
118
119        if (!filt->output_count) {
120            if ((ret = avfilter_config_links(filt)))
121                return ret;
122        }
123    }
124
125    return 0;
126}
127
128AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
129{
130    int i;
131
132    for (i = 0; i < graph->filter_count; i++)
133        if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
134            return graph->filters[i];
135
136    return NULL;
137}
138
139static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
140{
141    int i, j, ret;
142    int scaler_count = 0;
143    char inst_name[30];
144
145    /* ask all the sub-filters for their supported media formats */
146    for (i = 0; i < graph->filter_count; i++) {
147        if (graph->filters[i]->filter->query_formats)
148            graph->filters[i]->filter->query_formats(graph->filters[i]);
149        else
150            avfilter_default_query_formats(graph->filters[i]);
151    }
152
153    /* go through and merge as many format lists as possible */
154    for (i = 0; i < graph->filter_count; i++) {
155        AVFilterContext *filter = graph->filters[i];
156
157        for (j = 0; j < filter->input_count; j++) {
158            AVFilterLink *link = filter->inputs[j];
159            if (link && link->in_formats != link->out_formats) {
160                if (!avfilter_merge_formats(link->in_formats,
161                                            link->out_formats)) {
162                    AVFilterContext *scale;
163                    char scale_args[256];
164                    /* couldn't merge format lists. auto-insert scale filter */
165                    snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
166                             scaler_count++);
167                    av_strlcpy(scale_args, "0:0", sizeof(scale_args));
168                    if (graph->scale_sws_opts) {
169                        av_strlcat(scale_args, ":", sizeof(scale_args));
170                        av_strlcat(scale_args, graph->scale_sws_opts, sizeof(scale_args));
171                    }
172                    if ((ret = avfilter_graph_create_filter(&scale, avfilter_get_by_name("scale"),
173                                                            inst_name, scale_args, NULL, graph)) < 0)
174                        return ret;
175                    if ((ret = avfilter_insert_filter(link, scale, 0, 0)) < 0)
176                        return ret;
177
178                    scale->filter->query_formats(scale);
179                    if (((link = scale-> inputs[0]) &&
180                         !avfilter_merge_formats(link->in_formats, link->out_formats)) ||
181                        ((link = scale->outputs[0]) &&
182                         !avfilter_merge_formats(link->in_formats, link->out_formats))) {
183                        av_log(log_ctx, AV_LOG_ERROR,
184                               "Impossible to convert between the formats supported by the filter "
185                               "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
186                        return AVERROR(EINVAL);
187                    }
188                }
189            }
190        }
191    }
192
193    return 0;
194}
195
196static void pick_format(AVFilterLink *link)
197{
198    if (!link || !link->in_formats)
199        return;
200
201    link->in_formats->format_count = 1;
202    link->format = link->in_formats->formats[0];
203
204    avfilter_formats_unref(&link->in_formats);
205    avfilter_formats_unref(&link->out_formats);
206}
207
208static void pick_formats(AVFilterGraph *graph)
209{
210    int i, j;
211
212    for (i = 0; i < graph->filter_count; i++) {
213        AVFilterContext *filter = graph->filters[i];
214
215        for (j = 0; j < filter->input_count; j++)
216            pick_format(filter->inputs[j]);
217        for (j = 0; j < filter->output_count; j++)
218            pick_format(filter->outputs[j]);
219    }
220}
221
222int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
223{
224    int ret;
225
226    /* find supported formats from sub-filters, and merge along links */
227    if ((ret = query_formats(graph, log_ctx)) < 0)
228        return ret;
229
230    /* Once everything is merged, it's possible that we'll still have
231     * multiple valid media format choices. We pick the first one. */
232    pick_formats(graph);
233
234    return 0;
235}
236
237int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)
238{
239    int ret;
240
241    if ((ret = ff_avfilter_graph_check_validity(graphctx, log_ctx)))
242        return ret;
243    if ((ret = ff_avfilter_graph_config_formats(graphctx, log_ctx)))
244        return ret;
245    if ((ret = ff_avfilter_graph_config_links(graphctx, log_ctx)))
246        return ret;
247
248    return 0;
249}
250