/*
  * XWD image format
  *
  * Copyright (c) 2012 Paul B Mahol
  *

  * 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
  */
 
 #include "libavutil/imgutils.h"
 #include "avcodec.h"
 #include "bytestream.h"

 #include "internal.h"

 #include "xwd.h"
 
 static av_cold int xwd_decode_init(AVCodecContext *avctx)
 {
     avctx->coded_frame = avcodec_alloc_frame();
     if (!avctx->coded_frame)
         return AVERROR(ENOMEM);
 
     return 0;
 }
 
 static int xwd_decode_frame(AVCodecContext *avctx, void *data,

                             int *got_frame, AVPacket *avpkt)

 {
     AVFrame *p = avctx->coded_frame;
     const uint8_t *buf = avpkt->data;
     int i, ret, buf_size = avpkt->size;
     uint32_t version, header_size, vclass, ncolors;
     uint32_t xoffset, be, bpp, lsize, rsize;
     uint32_t pixformat, pixdepth, bunit, bitorder, bpad;
     uint32_t rgb[3];
     uint8_t *ptr;

     GetByteContext gb;

 
     if (buf_size < XWD_HEADER_SIZE)
         return AVERROR_INVALIDDATA;
 

     bytestream2_init(&gb, buf, buf_size);
     header_size = bytestream2_get_be32u(&gb);

     version = bytestream2_get_be32u(&gb);

     if (version != XWD_VERSION) {
         av_log(avctx, AV_LOG_ERROR, "unsupported version\n");
         return AVERROR_INVALIDDATA;
     }
 

     if (buf_size < header_size || header_size < XWD_HEADER_SIZE) {

         av_log(avctx, AV_LOG_ERROR, "invalid header size\n");
         return AVERROR_INVALIDDATA;
     }
 

     pixformat     = bytestream2_get_be32u(&gb);
     pixdepth      = bytestream2_get_be32u(&gb);
     avctx->width  = bytestream2_get_be32u(&gb);
     avctx->height = bytestream2_get_be32u(&gb);
     xoffset       = bytestream2_get_be32u(&gb);
     be            = bytestream2_get_be32u(&gb);
     bunit         = bytestream2_get_be32u(&gb);
     bitorder      = bytestream2_get_be32u(&gb);
     bpad          = bytestream2_get_be32u(&gb);
     bpp           = bytestream2_get_be32u(&gb);
     lsize         = bytestream2_get_be32u(&gb);
     vclass        = bytestream2_get_be32u(&gb);
     rgb[0]        = bytestream2_get_be32u(&gb);
     rgb[1]        = bytestream2_get_be32u(&gb);
     rgb[2]        = bytestream2_get_be32u(&gb);
     bytestream2_skipu(&gb, 8);
     ncolors       = bytestream2_get_be32u(&gb);
     bytestream2_skipu(&gb, header_size - (XWD_HEADER_SIZE - 20));

 
     av_log(avctx, AV_LOG_DEBUG, "pixformat %d, pixdepth %d, bunit %d, bitorder %d, bpad %d\n",
            pixformat, pixdepth, bunit, bitorder, bpad);
     av_log(avctx, AV_LOG_DEBUG, "vclass %d, ncolors %d, bpp %d, be %d, lsize %d, xoffset %d\n",
            vclass, ncolors, bpp, be, lsize, xoffset);
     av_log(avctx, AV_LOG_DEBUG, "red %0x, green %0x, blue %0x\n", rgb[0], rgb[1], rgb[2]);
 
     if (pixformat > XWD_Z_PIXMAP) {
         av_log(avctx, AV_LOG_ERROR, "invalid pixmap format\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (pixdepth == 0 || pixdepth > 32) {
         av_log(avctx, AV_LOG_ERROR, "invalid pixmap depth\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (xoffset) {
         av_log_ask_for_sample(avctx, "unsupported xoffset %d\n", xoffset);
         return AVERROR_PATCHWELCOME;
     }
 
     if (be > 1) {
         av_log(avctx, AV_LOG_ERROR, "invalid byte order\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (bitorder > 1) {
         av_log(avctx, AV_LOG_ERROR, "invalid bitmap bit order\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (bunit != 8 && bunit != 16 && bunit != 32) {
         av_log(avctx, AV_LOG_ERROR, "invalid bitmap unit\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (bpad != 8 && bpad != 16 && bpad != 32) {
         av_log(avctx, AV_LOG_ERROR, "invalid bitmap scan-line pad\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (bpp == 0 || bpp > 32) {
         av_log(avctx, AV_LOG_ERROR, "invalid bits per pixel\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (ncolors > 256) {
         av_log(avctx, AV_LOG_ERROR, "invalid number of entries in colormap\n");
         return AVERROR_INVALIDDATA;
     }
 
     if ((ret = av_image_check_size(avctx->width, avctx->height, 0, NULL)) < 0)
         return ret;
 
     rsize = FFALIGN(avctx->width * bpp, bpad) / 8;
     if (lsize < rsize) {
         av_log(avctx, AV_LOG_ERROR, "invalid bytes per scan-line\n");
         return AVERROR_INVALIDDATA;
     }
 

     if (bytestream2_get_bytes_left(&gb) < ncolors * XWD_CMAP_SIZE + avctx->height * lsize) {

         av_log(avctx, AV_LOG_ERROR, "input buffer too small\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (pixformat != XWD_Z_PIXMAP) {
         av_log(avctx, AV_LOG_ERROR, "pixmap format %d unsupported\n", pixformat);
         return AVERROR_PATCHWELCOME;
     }
 

     avctx->pix_fmt = AV_PIX_FMT_NONE;

     switch (vclass) {
     case XWD_STATIC_GRAY:
     case XWD_GRAY_SCALE:

         if (bpp != 1 && bpp != 8)

             return AVERROR_INVALIDDATA;

         if (pixdepth == 1) {

             avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;

         } else if (pixdepth == 8) {

             avctx->pix_fmt = AV_PIX_FMT_GRAY8;

         }

         break;
     case XWD_STATIC_COLOR:
     case XWD_PSEUDO_COLOR:
         if (bpp == 8)

             avctx->pix_fmt = AV_PIX_FMT_PAL8;

         break;
     case XWD_TRUE_COLOR:
     case XWD_DIRECT_COLOR:
         if (bpp != 16 && bpp != 24 && bpp != 32)
             return AVERROR_INVALIDDATA;
         if (bpp == 16 && pixdepth == 15) {
             if (rgb[0] == 0x7C00 && rgb[1] == 0x3E0 && rgb[2] == 0x1F)

                 avctx->pix_fmt = be ? AV_PIX_FMT_RGB555BE : AV_PIX_FMT_RGB555LE;

             else if (rgb[0] == 0x1F && rgb[1] == 0x3E0 && rgb[2] == 0x7C00)

                 avctx->pix_fmt = be ? AV_PIX_FMT_BGR555BE : AV_PIX_FMT_BGR555LE;

         } else if (bpp == 16 && pixdepth == 16) {
             if (rgb[0] == 0xF800 && rgb[1] == 0x7E0 && rgb[2] == 0x1F)

                 avctx->pix_fmt = be ? AV_PIX_FMT_RGB565BE : AV_PIX_FMT_RGB565LE;

             else if (rgb[0] == 0x1F && rgb[1] == 0x7E0 && rgb[2] == 0xF800)

                 avctx->pix_fmt = be ? AV_PIX_FMT_BGR565BE : AV_PIX_FMT_BGR565LE;

         } else if (bpp == 24) {
             if (rgb[0] == 0xFF0000 && rgb[1] == 0xFF00 && rgb[2] == 0xFF)

                 avctx->pix_fmt = be ? AV_PIX_FMT_RGB24 : AV_PIX_FMT_BGR24;

             else if (rgb[0] == 0xFF && rgb[1] == 0xFF00 && rgb[2] == 0xFF0000)

                 avctx->pix_fmt = be ? AV_PIX_FMT_BGR24 : AV_PIX_FMT_RGB24;

         } else if (bpp == 32) {
             if (rgb[0] == 0xFF0000 && rgb[1] == 0xFF00 && rgb[2] == 0xFF)

                 avctx->pix_fmt = be ? AV_PIX_FMT_ARGB : AV_PIX_FMT_BGRA;

             else if (rgb[0] == 0xFF && rgb[1] == 0xFF00 && rgb[2] == 0xFF0000)

                 avctx->pix_fmt = be ? AV_PIX_FMT_ABGR : AV_PIX_FMT_RGBA;

         }

         bytestream2_skipu(&gb, ncolors * XWD_CMAP_SIZE);

         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "invalid visual class\n");
         return AVERROR_INVALIDDATA;
     }
 

     if (avctx->pix_fmt == AV_PIX_FMT_NONE) {

         av_log_ask_for_sample(avctx, "unknown file: bpp %d, pixdepth %d, vclass %d\n", bpp, pixdepth, vclass);
         return AVERROR_PATCHWELCOME;
     }
 
     if (p->data[0])
         avctx->release_buffer(avctx, p);
 
     p->reference = 0;

     if ((ret = ff_get_buffer(avctx, p)) < 0) {

         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
         return ret;
     }
 
     p->key_frame = 1;
     p->pict_type = AV_PICTURE_TYPE_I;
 

     if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {

         uint32_t *dst = (uint32_t *)p->data[1];
         uint8_t red, green, blue;
 
         for (i = 0; i < ncolors; i++) {
 

             bytestream2_skipu(&gb, 4); // skip colormap entry number
             red    = bytestream2_get_byteu(&gb);
             bytestream2_skipu(&gb, 1);
             green  = bytestream2_get_byteu(&gb);
             bytestream2_skipu(&gb, 1);
             blue   = bytestream2_get_byteu(&gb);
             bytestream2_skipu(&gb, 3); // skip bitmask flag and padding

 
             dst[i] = red << 16 | green << 8 | blue;
         }
     }
 
     ptr = p->data[0];
     for (i = 0; i < avctx->height; i++) {

         bytestream2_get_bufferu(&gb, ptr, rsize);
         bytestream2_skipu(&gb, lsize - rsize);

         ptr += p->linesize[0];
     }
 

     *got_frame       = 1;

     *(AVFrame *)data = *p;
 
     return buf_size;
 }
 
 static av_cold int xwd_decode_close(AVCodecContext *avctx)
 {
     if (avctx->coded_frame->data[0])
         avctx->release_buffer(avctx, avctx->coded_frame);
 
     av_freep(&avctx->coded_frame);
 
     return 0;
 }
 
 AVCodec ff_xwd_decoder = {
     .name           = "xwd",
     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_XWD,

     .init           = xwd_decode_init,
     .close          = xwd_decode_close,
     .decode         = xwd_decode_frame,
     .capabilities   = CODEC_CAP_DR1,
     .long_name      = NULL_IF_CONFIG_SMALL("XWD (X Window Dump) image"),
 };