/*
  * BMP parser
  * 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
  */
 
 /**
  * @file
  * BMP parser
  */
 
 #include "libavutil/bswap.h"

 #include "libavutil/common.h"
 

 #include "parser.h"
 
 typedef struct BMPParseContext {
     ParseContext pc;
     uint32_t fsize;
     uint32_t remaining_size;
 } BMPParseContext;
 
 static int bmp_parse(AVCodecParserContext *s, AVCodecContext *avctx,
                      const uint8_t **poutbuf, int *poutbuf_size,
                      const uint8_t *buf, int buf_size)
 {
     BMPParseContext *bpc = s->priv_data;
     uint64_t state = bpc->pc.state64;
     int next = END_NOT_FOUND;
     int i = 0;
 
     *poutbuf_size = 0;
 

 restart:

     if (bpc->pc.frame_start_found <= 2+4+4) {

         for (; i < buf_size; i++) {
             state = (state << 8) | buf[i];

             if (bpc->pc.frame_start_found == 0) {
                 if ((state >> 48) == (('B' << 8) | 'M')) {
                     bpc->fsize = av_bswap32(state >> 16);

                     if (bpc->fsize > 17)
                         bpc->pc.frame_start_found = 1;

                 }
             } else if (bpc->pc.frame_start_found == 2+4+4) {
 //                 unsigned hsize = av_bswap32(state>>32);
                 unsigned ihsize = av_bswap32(state);
                 if (ihsize < 12 || ihsize > 200) {
                     bpc->pc.frame_start_found = 0;
                     continue;
                 }
                 bpc->pc.frame_start_found++;

                 bpc->remaining_size = bpc->fsize + i - 17;

 
                 if (bpc->pc.index + i > 17) {
                     next = i - 17;

                     state = 0;
                     break;

                 } else {
                     bpc->pc.state64 = 0;

                     goto restart;

                 }

             } else if (bpc->pc.frame_start_found)
                 bpc->pc.frame_start_found++;

         }
         bpc->pc.state64 = state;
     } else {
         if (bpc->remaining_size) {
             i = FFMIN(bpc->remaining_size, buf_size);
             bpc->remaining_size -= i;
             if (bpc->remaining_size)
                 goto flush;

 
             bpc->pc.frame_start_found = 0;
             goto restart;

         }
     }
 
 flush:
     if (ff_combine_frame(&bpc->pc, next, &buf, &buf_size) < 0)
         return buf_size;
 

     if (next != END_NOT_FOUND && next < 0)
         bpc->pc.frame_start_found = FFMAX(bpc->pc.frame_start_found - i - 1, 0);
     else
         bpc->pc.frame_start_found = 0;

 
     *poutbuf      = buf;
     *poutbuf_size = buf_size;
     return next;
 }
 
 AVCodecParser ff_bmp_parser = {

     .codec_ids      = { AV_CODEC_ID_BMP },

     .priv_data_size = sizeof(BMPParseContext),
     .parser_parse   = bmp_parse,
     .parser_close   = ff_parse_close,
 };