/*
  * Copyright (c) 2012 Stefano Sabatini
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file
  * set field order
  */
 

 #include "libavutil/opt.h"

 #include "avfilter.h"

 #include "internal.h"

 #include "video.h"

 enum SetFieldMode {
     MODE_AUTO = -1,
     MODE_BFF,
     MODE_TFF,
     MODE_PROG,
 };
 

 typedef struct {

     const AVClass *class;

     enum SetFieldMode mode;

 } SetFieldContext;
 

 #define OFFSET(x) offsetof(SetFieldContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 static const AVOption setfield_options[] = {
     {"mode", "select interlace mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=MODE_AUTO}, -1, MODE_PROG, FLAGS, "mode"},
     {"auto", "keep the same input field",  0, AV_OPT_TYPE_CONST, {.i64=MODE_AUTO}, INT_MIN, INT_MAX, FLAGS, "mode"},
     {"bff",  "mark as bottom-field-first", 0, AV_OPT_TYPE_CONST, {.i64=MODE_BFF},  INT_MIN, INT_MAX, FLAGS, "mode"},
     {"tff",  "mark as top-field-first",    0, AV_OPT_TYPE_CONST, {.i64=MODE_TFF},  INT_MIN, INT_MAX, FLAGS, "mode"},
     {"prog", "mark as progressive",        0, AV_OPT_TYPE_CONST, {.i64=MODE_PROG}, INT_MIN, INT_MAX, FLAGS, "mode"},
     {NULL}
 };
 
 AVFILTER_DEFINE_CLASS(setfield);
 

 static int filter_frame(AVFilterLink *inlink, AVFrame *picref)

 {
     SetFieldContext *setfield = inlink->dst->priv;
 

     if (setfield->mode == MODE_PROG) {

         picref->interlaced_frame = 0;

     } else if (setfield->mode != MODE_AUTO) {

         picref->interlaced_frame = 1;
         picref->top_field_first = setfield->mode;

     }

     return ff_filter_frame(inlink->dst->outputs[0], picref);

 }
 

 static const AVFilterPad setfield_inputs[] = {
     {
         .name             = "default",
         .type             = AVMEDIA_TYPE_VIDEO,
         .get_video_buffer = ff_null_get_video_buffer,

         .filter_frame     = filter_frame,

     },
     { NULL }
 };
 
 static const AVFilterPad setfield_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter avfilter_vf_setfield = {
     .name      = "setfield",
     .description = NULL_IF_CONFIG_SMALL("Force field for the output video frame."),
     .priv_size = sizeof(SetFieldContext),

     .inputs    = setfield_inputs,
     .outputs   = setfield_outputs,

     .priv_class = &setfield_class,

 };