/*

  * Copyright (c) 2007 Bobby Bingham

  *
  * 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

  * video vertical flip filter
  */
 

 #include "libavutil/internal.h"

 #include "libavutil/opt.h"

 #include "libavutil/pixdesc.h"

 #include "avfilter.h"

 #include "internal.h"

 #include "video.h"

 typedef struct FlipContext {

     const AVClass *class;

     int vsub;   ///< vertical chroma subsampling
 } FlipContext;
 

 static const AVOption vflip_options[] = {
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(vflip);
 

 static int config_input(AVFilterLink *link)
 {
     FlipContext *flip = link->dst->priv;

     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);

     flip->vsub = desc->log2_chroma_h;

 
     return 0;
 }
 

 static AVFrame *get_video_buffer(AVFilterLink *link, int w, int h)

 {
     FlipContext *flip = link->dst->priv;

     AVFrame *frame;

     int i;
 

     frame = ff_get_video_buffer(link->dst->outputs[0], w, h);
     if (!frame)

         return NULL;
 

     for (i = 0; i < 4; i ++) {
         int vsub = i == 1 || i == 2 ? flip->vsub : 0;

         int height = AV_CEIL_RSHIFT(h, vsub);

         if (frame->data[i]) {

             frame->data[i] += (height - 1) * frame->linesize[i];

             frame->linesize[i] = -frame->linesize[i];

         }
     }
 

     return frame;

 }
 

 static int filter_frame(AVFilterLink *link, AVFrame *frame)

 {
     FlipContext *flip = link->dst->priv;
     int i;
 

     for (i = 0; i < 4; i ++) {
         int vsub = i == 1 || i == 2 ? flip->vsub : 0;

         int height = AV_CEIL_RSHIFT(link->h, vsub);

         if (frame->data[i]) {

             frame->data[i] += (height - 1) * frame->linesize[i];

             frame->linesize[i] = -frame->linesize[i];

         }
     }
 

     return ff_filter_frame(link->dst->outputs[0], frame);

 }

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

         .filter_frame     = filter_frame,

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

 AVFilter ff_vf_vflip = {

     .name        = "vflip",

     .description = NULL_IF_CONFIG_SMALL("Flip the input video vertically."),

     .priv_size   = sizeof(FlipContext),

     .priv_class  = &vflip_class,

     .inputs      = avfilter_vf_vflip_inputs,
     .outputs     = avfilter_vf_vflip_outputs,

     .flags       = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,

 };