yading@10: /*
yading@10:  * Copyright (c) 2013 Paul B Mahol
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: #include "libavutil/pixdesc.h"
yading@10: #include "avfilter.h"
yading@10: #include "internal.h"
yading@10: 
yading@10: typedef struct {
yading@10:     int nb_planes;
yading@10:     int64_t frame_count;
yading@10:     double ts_unit;
yading@10: } SeparateFieldsContext;
yading@10: 
yading@10: static int config_props_output(AVFilterLink *outlink)
yading@10: {
yading@10:     AVFilterContext *ctx = outlink->src;
yading@10:     SeparateFieldsContext *sf = ctx->priv;
yading@10:     AVFilterLink *inlink = ctx->inputs[0];
yading@10: 
yading@10:     sf->nb_planes = av_pix_fmt_count_planes(inlink->format);;
yading@10: 
yading@10:     if (inlink->h & 1) {
yading@10:         av_log(ctx, AV_LOG_ERROR, "height must be even\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     outlink->time_base.num = inlink->time_base.num;
yading@10:     outlink->time_base.den = inlink->time_base.den * 2;
yading@10:     outlink->frame_rate.num = inlink->frame_rate.num * 2;
yading@10:     outlink->frame_rate.den = inlink->frame_rate.den;
yading@10:     outlink->w = inlink->w;
yading@10:     outlink->h = inlink->h / 2;
yading@10:     sf->ts_unit = av_q2d(av_inv_q(av_mul_q(outlink->frame_rate, outlink->time_base)));
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)
yading@10: {
yading@10:     AVFilterContext *ctx = inlink->dst;
yading@10:     SeparateFieldsContext *sf = ctx->priv;
yading@10:     AVFilterLink *outlink = ctx->outputs[0];
yading@10:     AVFrame *second;
yading@10:     int i, ret;
yading@10: 
yading@10:     inpicref->height = outlink->h;
yading@10:     inpicref->interlaced_frame = 0;
yading@10: 
yading@10:     second = av_frame_clone(inpicref);
yading@10:     if (!second)
yading@10:         return AVERROR(ENOMEM);
yading@10: 
yading@10:     for (i = 0; i < sf->nb_planes; i++) {
yading@10:         if (!inpicref->top_field_first)
yading@10:             inpicref->data[i] = inpicref->data[i] + inpicref->linesize[i];
yading@10:         else
yading@10:             second->data[i] = second->data[i] + second->linesize[i];
yading@10:         inpicref->linesize[i] *= 2;
yading@10:         second->linesize[i]   *= 2;
yading@10:     }
yading@10: 
yading@10:     inpicref->pts = sf->frame_count++ * sf->ts_unit;
yading@10:     second->pts   = sf->frame_count++ * sf->ts_unit;
yading@10: 
yading@10:     ret = ff_filter_frame(outlink, inpicref);
yading@10:     if (ret < 0)
yading@10:         return ret;
yading@10:     return ff_filter_frame(outlink, second);
yading@10: }
yading@10: 
yading@10: static const AVFilterPad separatefields_inputs[] = {
yading@10:     {
yading@10:         .name             = "default",
yading@10:         .type             = AVMEDIA_TYPE_VIDEO,
yading@10:         .filter_frame     = filter_frame,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: static const AVFilterPad separatefields_outputs[] = {
yading@10:     {
yading@10:         .name          = "default",
yading@10:         .type          = AVMEDIA_TYPE_VIDEO,
yading@10:         .config_props  = config_props_output,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: AVFilter avfilter_vf_separatefields = {
yading@10:     .name          = "separatefields",
yading@10:     .description   = NULL_IF_CONFIG_SMALL("Split input video frames into fields."),
yading@10:     .priv_size     = sizeof(SeparateFieldsContext),
yading@10:     .inputs        = separatefields_inputs,
yading@10:     .outputs       = separatefields_outputs,
yading@10: };