/*
  * DCA parser
  * Copyright (C) 2004 Gildas Bazin
  * Copyright (C) 2004 Benjamin Zores
  * Copyright (C) 2006 Benjamin Larsson
  * Copyright (C) 2007 Konstantin Shishkov
  *
  * 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 libavcodec/dca_parser.c

  */
 
 #include "parser.h"
 #include "dca.h"
 
 typedef struct DCAParseContext {
     ParseContext pc;
     uint32_t lastmarker;

     int size;
     int framesize;

     int hd_pos;

 } DCAParseContext;
 
 #define IS_MARKER(state, i, buf, buf_size) \
  ((state == DCA_MARKER_14B_LE && (i < buf_size-2) && (buf[i+1] & 0xF0) == 0xF0 && buf[i+2] == 0x07) \
  || (state == DCA_MARKER_14B_BE && (i < buf_size-2) && buf[i+1] == 0x07 && (buf[i+2] & 0xF0) == 0xF0) \
  || state == DCA_MARKER_RAW_LE || state == DCA_MARKER_RAW_BE)
 
 /**
  * finds the end of the current frame in the bitstream.
  * @return the position of the first byte of the next frame, or -1
  */
 static int dca_find_frame_end(DCAParseContext * pc1, const uint8_t * buf,
                               int buf_size)
 {
     int start_found, i;
     uint32_t state;
     ParseContext *pc = &pc1->pc;
 
     start_found = pc->frame_start_found;
     state = pc->state;
 
     i = 0;
     if (!start_found) {
         for (i = 0; i < buf_size; i++) {
             state = (state << 8) | buf[i];
             if (IS_MARKER(state, i, buf, buf_size)) {
                 if (pc1->lastmarker && state == pc1->lastmarker) {
                     start_found = 1;
                     break;
                 } else if (!pc1->lastmarker) {
                     start_found = 1;
                     pc1->lastmarker = state;
                     break;
                 }
             }
         }
     }
     if (start_found) {
         for (; i < buf_size; i++) {

             pc1->size++;

             state = (state << 8) | buf[i];

             if (state == DCA_HD_MARKER && !pc1->hd_pos)
                 pc1->hd_pos = pc1->size;
             if (state == pc1->lastmarker && IS_MARKER(state, i, buf, buf_size)) {
                 if(pc1->framesize > pc1->size)
                     continue;
                 if(!pc1->framesize){
                     pc1->framesize = pc1->hd_pos ? pc1->hd_pos : pc1->size;
                 }

                 pc->frame_start_found = 0;
                 pc->state = -1;

                 pc1->size = 0;

                 return i - 3;
             }
         }
     }
     pc->frame_start_found = start_found;
     pc->state = state;
     return END_NOT_FOUND;
 }
 

 static av_cold int dca_parse_init(AVCodecParserContext * s)

 {
     DCAParseContext *pc1 = s->priv_data;
 
     pc1->lastmarker = 0;
     return 0;
 }
 
 static int dca_parse(AVCodecParserContext * s,
                      AVCodecContext * avctx,

                      const uint8_t ** poutbuf, int *poutbuf_size,

                      const uint8_t * buf, int buf_size)
 {
     DCAParseContext *pc1 = s->priv_data;
     ParseContext *pc = &pc1->pc;
     int next;
 
     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
         next = buf_size;
     } else {
         next = dca_find_frame_end(pc1, buf, buf_size);
 

         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {

             *poutbuf = NULL;
             *poutbuf_size = 0;
             return buf_size;
         }
     }

     *poutbuf = buf;

     *poutbuf_size = buf_size;
     return next;
 }
 
 AVCodecParser dca_parser = {
     {CODEC_ID_DTS},
     sizeof(DCAParseContext),
     dca_parse_init,
     dca_parse,
     ff_parse_close,
 };