1/*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19/**
20 * @file
21 * null video source
22 */
23
24#include "avfilter.h"
25
26typedef struct {
27    int w, h;
28} NullContext;
29
30static int init(AVFilterContext *ctx, const char *args, void *opaque)
31{
32    NullContext *priv = ctx->priv;
33
34    priv->w = 352;
35    priv->h = 288;
36
37    if (args)
38        sscanf(args, "%d:%d", &priv->w, &priv->h);
39
40    if (priv->w <= 0 || priv->h <= 0) {
41        av_log(ctx, AV_LOG_ERROR, "Non-positive size values are not acceptable.\n");
42        return -1;
43    }
44
45    return 0;
46}
47
48static int config_props(AVFilterLink *outlink)
49{
50    NullContext *priv = outlink->src->priv;
51
52    outlink->w = priv->w;
53    outlink->h = priv->h;
54
55    av_log(outlink->src, AV_LOG_INFO, "w:%d h:%d\n", priv->w, priv->h);
56
57    return 0;
58}
59
60static int request_frame(AVFilterLink *link)
61{
62    return -1;
63}
64
65AVFilter avfilter_vsrc_nullsrc = {
66    .name        = "nullsrc",
67    .description = "Null video source, never return images.",
68
69    .init       = init,
70    .priv_size = sizeof(NullContext),
71
72    .inputs    = (AVFilterPad[]) {{ .name = NULL}},
73
74    .outputs   = (AVFilterPad[]) {
75        {
76            .name            = "default",
77            .type            = AVMEDIA_TYPE_VIDEO,
78            .config_props    = config_props,
79            .request_frame   = request_frame,
80        },
81        { .name = NULL}
82    },
83};
84