/*
  * Copyright (c) 2007 Benoit Fouet
  * Copyright (c) 2010 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

  * horizontal flip filter
  */
 

 #include <string.h>
 

 #include "avfilter.h"

 #include "formats.h"

 #include "internal.h"

 #include "video.h"

 #include "libavutil/pixdesc.h"

 #include "libavutil/internal.h"

 #include "libavutil/intreadwrite.h"

 #include "libavutil/imgutils.h"

 
 typedef struct {
     int max_step[4];    ///< max pixel step for each plane, expressed as a number of bytes
     int hsub, vsub;     ///< chroma subsampling
 } FlipContext;
 
 static int query_formats(AVFilterContext *ctx)
 {

     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_RGB48BE,      AV_PIX_FMT_RGB48LE,
         AV_PIX_FMT_BGR48BE,      AV_PIX_FMT_BGR48LE,
         AV_PIX_FMT_ARGB,         AV_PIX_FMT_RGBA,
         AV_PIX_FMT_ABGR,         AV_PIX_FMT_BGRA,
         AV_PIX_FMT_RGB24,        AV_PIX_FMT_BGR24,
         AV_PIX_FMT_RGB565BE,     AV_PIX_FMT_RGB565LE,
         AV_PIX_FMT_RGB555BE,     AV_PIX_FMT_RGB555LE,

         AV_PIX_FMT_RGB444BE,     AV_PIX_FMT_RGB444LE,

         AV_PIX_FMT_BGR565BE,     AV_PIX_FMT_BGR565LE,
         AV_PIX_FMT_BGR555BE,     AV_PIX_FMT_BGR555LE,

         AV_PIX_FMT_BGR444BE,     AV_PIX_FMT_BGR444LE,

         AV_PIX_FMT_GRAY16BE,     AV_PIX_FMT_GRAY16LE,
         AV_PIX_FMT_YUV420P16LE,  AV_PIX_FMT_YUV420P16BE,
         AV_PIX_FMT_YUV422P16LE,  AV_PIX_FMT_YUV422P16BE,
         AV_PIX_FMT_YUV444P16LE,  AV_PIX_FMT_YUV444P16BE,
         AV_PIX_FMT_YUV444P,      AV_PIX_FMT_YUV422P,
         AV_PIX_FMT_YUV420P,      AV_PIX_FMT_YUV411P,
         AV_PIX_FMT_YUV410P,      AV_PIX_FMT_YUV440P,
         AV_PIX_FMT_YUVJ444P,     AV_PIX_FMT_YUVJ422P,
         AV_PIX_FMT_YUVJ420P,     AV_PIX_FMT_YUVJ440P,
         AV_PIX_FMT_YUVA420P,
         AV_PIX_FMT_RGB8,         AV_PIX_FMT_BGR8,
         AV_PIX_FMT_RGB4_BYTE,    AV_PIX_FMT_BGR4_BYTE,
         AV_PIX_FMT_PAL8,         AV_PIX_FMT_GRAY8,
         AV_PIX_FMT_NONE

     };
 

     ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));

     return 0;
 }
 
 static int config_props(AVFilterLink *inlink)
 {
     FlipContext *flip = inlink->dst->priv;

     const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);

     av_image_fill_max_pixsteps(flip->max_step, NULL, pix_desc);

     flip->hsub = pix_desc->log2_chroma_w;
     flip->vsub = pix_desc->log2_chroma_h;

 
     return 0;
 }
 

 static int filter_frame(AVFilterLink *inlink, AVFilterBufferRef *in)

 {

     AVFilterContext *ctx  = inlink->dst;
     FlipContext *flip     = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
     AVFilterBufferRef *out;
     uint8_t *inrow, *outrow;
     int i, j, plane, step, hsub, vsub;

     out = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
     if (!out) {
         avfilter_unref_bufferp(&in);
         return AVERROR(ENOMEM);
     }
     avfilter_copy_buffer_ref_props(out, in);

 
     /* copy palette if required */

     if (av_pix_fmt_desc_get(inlink->format)->flags & PIX_FMT_PAL)

         memcpy(out->data[1], in->data[1], AVPALETTE_SIZE);

     for (plane = 0; plane < 4 && in->data[plane]; plane++) {

         step = flip->max_step[plane];
         hsub = (plane == 1 || plane == 2) ? flip->hsub : 0;
         vsub = (plane == 1 || plane == 2) ? flip->vsub : 0;
 

         outrow = out->data[plane];
         inrow  = in ->data[plane] + ((inlink->w >> hsub) - 1) * step;
         for (i = 0; i < in->video->h >> vsub; i++) {

             switch (step) {
             case 1:
                 for (j = 0; j < (inlink->w >> hsub); j++)
                     outrow[j] = inrow[-j];
             break;
 
             case 2:
             {
                 uint16_t *outrow16 = (uint16_t *)outrow;
                 uint16_t * inrow16 = (uint16_t *) inrow;
                 for (j = 0; j < (inlink->w >> hsub); j++)
                     outrow16[j] = inrow16[-j];
             }
             break;
 
             case 3:
             {
                 uint8_t *in  =  inrow;
                 uint8_t *out = outrow;
                 for (j = 0; j < (inlink->w >> hsub); j++, out += 3, in -= 3) {
                     int32_t v = AV_RB24(in);
                     AV_WB24(out, v);
                 }
             }
             break;
 
             case 4:
             {
                 uint32_t *outrow32 = (uint32_t *)outrow;
                 uint32_t * inrow32 = (uint32_t *) inrow;
                 for (j = 0; j < (inlink->w >> hsub); j++)
                     outrow32[j] = inrow32[-j];
             }
             break;
 
             default:
                 for (j = 0; j < (inlink->w >> hsub); j++)
                     memcpy(outrow + j*step, inrow - j*step, step);
             }
 

             inrow  += in ->linesize[plane];
             outrow += out->linesize[plane];

         }
     }
 

     avfilter_unref_bufferp(&in);
     return ff_filter_frame(outlink, out);

 }
 

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

         .filter_frame = filter_frame,

         .config_props = config_props,
         .min_perms    = AV_PERM_READ,
     },
     { NULL }
 };
 
 static const AVFilterPad avfilter_vf_hflip_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter avfilter_vf_hflip = {
     .name      = "hflip",
     .description = NULL_IF_CONFIG_SMALL("Horizontally flip the input video."),
     .priv_size = sizeof(FlipContext),
     .query_formats = query_formats,
 

     .inputs    = avfilter_vf_hflip_inputs,
     .outputs   = avfilter_vf_hflip_outputs,

 };