/*
  * XBM 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 "avcodec.h"
 #include "internal.h"

 #include "mathops.h"

 
 static av_cold int xbm_decode_init(AVCodecContext *avctx)
 {
     avctx->coded_frame = avcodec_alloc_frame();
     if (!avctx->coded_frame)
         return AVERROR(ENOMEM);
 
     return 0;
 }
 
 static int convert(uint8_t x)
 {
     if (x >= 'a')
         x -= 87;
     else if (x >= 'A')
         x -= 55;
     else
         x -= '0';
     return x;
 }
 
 static int xbm_decode_frame(AVCodecContext *avctx, void *data,

                             int *got_frame, AVPacket *avpkt)

 {
     AVFrame *p = avctx->coded_frame;
     const uint8_t *end, *ptr = avpkt->data;
     uint8_t *dst;
     int ret, linesize, i, j;
 
     end = avpkt->data + avpkt->size;
     while (!avctx->width || !avctx->height) {
         char name[256];
         int number, len;
 
         ptr += strcspn(ptr, "#");

         if (sscanf(ptr, "#define %256s %u", name, &number) != 2) {
             av_log(avctx, AV_LOG_ERROR, "Unexpected preprocessor directive\n");

             return AVERROR_INVALIDDATA;

         }

 
         len = strlen(name);
         if ((len > 6) && !avctx->height && !memcmp(name + len - 7, "_height", 7)) {
                 avctx->height = number;
         } else if ((len > 5) && !avctx->width && !memcmp(name + len - 6, "_width", 6)) {
                 avctx->width = number;
         } else {

             av_log(avctx, AV_LOG_ERROR, "Unknown define '%s'\n", name);

             return AVERROR_INVALIDDATA;
         }
         ptr += strcspn(ptr, "\n\r") + 1;
     }
 

     avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;

 
     if (p->data[0])
         avctx->release_buffer(avctx, p);
 
     p->reference = 0;

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

         return ret;
 

     // goto start of image data
     ptr += strcspn(ptr, "{") + 1;
 

     linesize = (avctx->width + 7) / 8;
     for (i = 0; i < avctx->height; i++) {
         dst = p->data[0] + i * p->linesize[0];
         for (j = 0; j < linesize; j++) {
             uint8_t val;
 
             ptr += strcspn(ptr, "x") + 1;
             if (ptr < end && isxdigit(*ptr)) {
                 val = convert(*ptr);
                 ptr++;
                 if (isxdigit(*ptr))
                     val = (val << 4) + convert(*ptr);

                 *dst++ = ff_reverse[val];

             } else {

                 av_log(avctx, AV_LOG_ERROR, "Unexpected data at '%.8s'\n", ptr);

                 return AVERROR_INVALIDDATA;
             }
         }
     }
 
     p->key_frame = 1;
     p->pict_type = AV_PICTURE_TYPE_I;
 

     *got_frame       = 1;

     *(AVFrame *)data = *p;
 
     return avpkt->size;
 }
 
 static av_cold int xbm_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_xbm_decoder = {
     .name         = "xbm",
     .type         = AVMEDIA_TYPE_VIDEO,

     .id           = AV_CODEC_ID_XBM,

     .init         = xbm_decode_init,
     .close        = xbm_decode_close,
     .decode       = xbm_decode_frame,
     .capabilities = CODEC_CAP_DR1,
     .long_name    = NULL_IF_CONFIG_SMALL("XBM (X BitMap) image"),
 };