2 * Copyright (c) 2013 Paul B Mahol
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #include "libavutil/pixdesc.h"
25 typedef struct SeparateFieldsContext {
28 } SeparateFieldsContext;
30 static int config_props_output(AVFilterLink *outlink)
32 AVFilterContext *ctx = outlink->src;
33 SeparateFieldsContext *s = ctx->priv;
34 AVFilterLink *inlink = ctx->inputs[0];
36 s->nb_planes = av_pix_fmt_count_planes(inlink->format);
39 av_log(ctx, AV_LOG_ERROR, "height must be even\n");
40 return AVERROR_INVALIDDATA;
43 outlink->time_base.num = inlink->time_base.num;
44 outlink->time_base.den = inlink->time_base.den * 2;
45 outlink->frame_rate.num = inlink->frame_rate.num * 2;
46 outlink->frame_rate.den = inlink->frame_rate.den;
47 outlink->w = inlink->w;
48 outlink->h = inlink->h / 2;
53 static void extract_field(AVFrame *frame, int nb_planes, int type)
57 for (i = 0; i < nb_planes; i++) {
59 frame->data[i] = frame->data[i] + frame->linesize[i];
60 frame->linesize[i] *= 2;
64 static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)
66 AVFilterContext *ctx = inlink->dst;
67 SeparateFieldsContext *s = ctx->priv;
68 AVFilterLink *outlink = ctx->outputs[0];
71 inpicref->height = outlink->h;
72 inpicref->interlaced_frame = 0;
77 AVFrame *second = s->second;
79 extract_field(second, s->nb_planes, second->top_field_first);
81 if (second->pts != AV_NOPTS_VALUE &&
82 inpicref->pts != AV_NOPTS_VALUE)
83 second->pts += inpicref->pts;
85 second->pts = AV_NOPTS_VALUE;
87 ret = ff_filter_frame(outlink, second);
91 s->second = av_frame_clone(inpicref);
93 return AVERROR(ENOMEM);
96 extract_field(inpicref, s->nb_planes, !inpicref->top_field_first);
98 if (inpicref->pts != AV_NOPTS_VALUE)
101 return ff_filter_frame(outlink, inpicref);
104 static int request_frame(AVFilterLink *outlink)
106 AVFilterContext *ctx = outlink->src;
107 SeparateFieldsContext *s = ctx->priv;
110 ret = ff_request_frame(ctx->inputs[0]);
111 if (ret == AVERROR_EOF && s->second) {
113 extract_field(s->second, s->nb_planes, s->second->top_field_first);
114 ret = ff_filter_frame(outlink, s->second);
121 static av_cold void uninit(AVFilterContext *ctx)
123 SeparateFieldsContext *s = ctx->priv;
125 av_frame_free(&s->second);
128 static const AVFilterPad separatefields_inputs[] = {
131 .type = AVMEDIA_TYPE_VIDEO,
132 .filter_frame = filter_frame,
137 static const AVFilterPad separatefields_outputs[] = {
140 .type = AVMEDIA_TYPE_VIDEO,
141 .config_props = config_props_output,
142 .request_frame = request_frame,
147 AVFilter ff_vf_separatefields = {
148 .name = "separatefields",
149 .description = NULL_IF_CONFIG_SMALL("Split input video frames into fields."),
150 .priv_size = sizeof(SeparateFieldsContext),
152 .inputs = separatefields_inputs,
153 .outputs = separatefields_outputs,