/*
  * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
  *
  * 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
  * swap UV filter
  */
 

 #include "libavutil/pixdesc.h"

 #include "avfilter.h"

 #include "formats.h"

 #include "internal.h"

 #include "video.h"

 static void do_swap(AVFrame *frame)

 {

     FFSWAP(uint8_t*,     frame->data[1],     frame->data[2]);
     FFSWAP(int,          frame->linesize[1], frame->linesize[2]);
     FFSWAP(uint64_t,     frame->error[1],    frame->error[2]);
     FFSWAP(AVBufferRef*, frame->buf[1],      frame->buf[2]);
 }

 static AVFrame *get_video_buffer(AVFilterLink *link, int w, int h)
 {
     AVFrame *picref = ff_default_get_video_buffer(link, w, h);
     do_swap(picref);

     return picref;
 }
 

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

 {

     do_swap(inpicref);

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

 }
 

 static int is_planar_yuv(const AVPixFmtDescriptor *desc)
 {
     int i;
 

     if (desc->flags & ~(AV_PIX_FMT_FLAG_BE | AV_PIX_FMT_FLAG_PLANAR | AV_PIX_FMT_FLAG_ALPHA) ||

         desc->nb_components < 3 ||
         (desc->comp[1].depth_minus1 != desc->comp[2].depth_minus1))
         return 0;
     for (i = 0; i < desc->nb_components; i++) {
         if (desc->comp[i].offset_plus1 != 1 ||
             desc->comp[i].shift != 0 ||
             desc->comp[i].plane != i)
             return 0;
     }
 
     return 1;
 }
 

 static int query_formats(AVFilterContext *ctx)
 {

     AVFilterFormats *formats = NULL;
     int fmt;
 
     for (fmt = 0; fmt < AV_PIX_FMT_NB; fmt++) {
         const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
         if (is_planar_yuv(desc))
             ff_add_format(&formats, fmt);
     }
 
     ff_set_common_formats(ctx, formats);

     return 0;
 }
 

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

         .filter_frame     = filter_frame,

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

 AVFilter avfilter_vf_swapuv = {

     .name          = "swapuv",
     .description   = NULL_IF_CONFIG_SMALL("Swap U and V components."),

     .query_formats = query_formats,

     .inputs        = swapuv_inputs,
     .outputs       = swapuv_outputs,

 };