blob: 72cabdb92964c4f5047a547caa789f33ccdf9487
1 | /* |
2 | * Copyright (c) 2003 Rich Felker |
3 | * Copyright (c) 2012 Stefano Sabatini |
4 | * |
5 | * This file is part of FFmpeg. |
6 | * |
7 | * FFmpeg is free software; you can redistribute it and/or |
8 | * modify it under the terms of the GNU Lesser General Public |
9 | * License as published by the Free Software Foundation; either |
10 | * version 2.1 of the License, or (at your option) any later version. |
11 | * |
12 | * FFmpeg is distributed in the hope that it will be useful, |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
15 | * Lesser General Public License for more details. |
16 | * |
17 | * You should have received a copy of the GNU Lesser General Public |
18 | * License along with FFmpeg; if not, write to the Free Software |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
20 | */ |
21 | |
22 | /** |
23 | * @file |
24 | * field filter, based on libmpcodecs/vf_field.c by Rich Felker |
25 | */ |
26 | |
27 | #include "libavutil/opt.h" |
28 | #include "libavutil/pixdesc.h" |
29 | #include "avfilter.h" |
30 | #include "internal.h" |
31 | |
32 | enum FieldType { FIELD_TYPE_TOP = 0, FIELD_TYPE_BOTTOM }; |
33 | |
34 | typedef struct { |
35 | const AVClass *class; |
36 | int type; ///< FieldType |
37 | int nb_planes; ///< number of planes of the current format |
38 | } FieldContext; |
39 | |
40 | #define OFFSET(x) offsetof(FieldContext, x) |
41 | #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM |
42 | |
43 | static const AVOption field_options[] = { |
44 | {"type", "set field type (top or bottom)", OFFSET(type), AV_OPT_TYPE_INT, {.i64=FIELD_TYPE_TOP}, 0, 1, FLAGS, "field_type" }, |
45 | {"top", "select top field", 0, AV_OPT_TYPE_CONST, {.i64=FIELD_TYPE_TOP}, INT_MIN, INT_MAX, FLAGS, "field_type"}, |
46 | {"bottom", "select bottom field", 0, AV_OPT_TYPE_CONST, {.i64=FIELD_TYPE_BOTTOM}, INT_MIN, INT_MAX, FLAGS, "field_type"}, |
47 | {NULL} |
48 | }; |
49 | |
50 | AVFILTER_DEFINE_CLASS(field); |
51 | |
52 | static int config_props_output(AVFilterLink *outlink) |
53 | { |
54 | AVFilterContext *ctx = outlink->src; |
55 | FieldContext *field = ctx->priv; |
56 | AVFilterLink *inlink = ctx->inputs[0]; |
57 | |
58 | field->nb_planes = av_pix_fmt_count_planes(outlink->format); |
59 | |
60 | outlink->w = inlink->w; |
61 | outlink->h = (inlink->h + (field->type == FIELD_TYPE_TOP)) / 2; |
62 | |
63 | av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d type:%s -> w:%d h:%d\n", |
64 | inlink->w, inlink->h, field->type == FIELD_TYPE_BOTTOM ? "bottom" : "top", |
65 | outlink->w, outlink->h); |
66 | return 0; |
67 | } |
68 | |
69 | static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref) |
70 | { |
71 | FieldContext *field = inlink->dst->priv; |
72 | AVFilterLink *outlink = inlink->dst->outputs[0]; |
73 | int i; |
74 | |
75 | inpicref->height = outlink->h; |
76 | inpicref->interlaced_frame = 0; |
77 | |
78 | for (i = 0; i < field->nb_planes; i++) { |
79 | if (field->type == FIELD_TYPE_BOTTOM) |
80 | inpicref->data[i] = inpicref->data[i] + inpicref->linesize[i]; |
81 | inpicref->linesize[i] = 2 * inpicref->linesize[i]; |
82 | } |
83 | return ff_filter_frame(outlink, inpicref); |
84 | } |
85 | |
86 | static const AVFilterPad field_inputs[] = { |
87 | { |
88 | .name = "default", |
89 | .type = AVMEDIA_TYPE_VIDEO, |
90 | .filter_frame = filter_frame, |
91 | }, |
92 | { NULL } |
93 | }; |
94 | |
95 | static const AVFilterPad field_outputs[] = { |
96 | { |
97 | .name = "default", |
98 | .type = AVMEDIA_TYPE_VIDEO, |
99 | .config_props = config_props_output, |
100 | }, |
101 | { NULL } |
102 | }; |
103 | |
104 | AVFilter ff_vf_field = { |
105 | .name = "field", |
106 | .description = NULL_IF_CONFIG_SMALL("Extract a field from the input video."), |
107 | .priv_size = sizeof(FieldContext), |
108 | .inputs = field_inputs, |
109 | .outputs = field_outputs, |
110 | .priv_class = &field_class, |
111 | }; |
112 |