/*
  * VC-1 and WMV3 parser
  * Copyright (c) 2006-2007 Konstantin Shishkov
  * Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer
  *
  * 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/vc1_parser.c

  * VC-1 and WMV3 parser
  */

 #include "parser.h"
 #include "vc1.h"
 
 /**
  * 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 vc1_find_frame_end(ParseContext *pc, const uint8_t *buf,
                                int buf_size) {
     int pic_found, i;
     uint32_t state;
 
     pic_found= pc->frame_start_found;
     state= pc->state;
 
     i=0;
     if(!pic_found){
         for(i=0; i<buf_size; i++){
             state= (state<<8) | buf[i];
             if(state == VC1_CODE_FRAME || state == VC1_CODE_FIELD){
                 i++;
                 pic_found=1;
                 break;
             }
         }
     }
 
     if(pic_found){
         /* EOF considered as end of frame */
         if (buf_size == 0)
             return 0;
         for(; i<buf_size; i++){
             state= (state<<8) | buf[i];
             if(IS_MARKER(state) && state != VC1_CODE_FIELD && state != VC1_CODE_SLICE){
                 pc->frame_start_found=0;
                 pc->state=-1;
                 return i-3;
             }
         }
     }
     pc->frame_start_found= pic_found;
     pc->state= state;
     return END_NOT_FOUND;
 }
 
 static int vc1_parse(AVCodecParserContext *s,
                            AVCodecContext *avctx,

                            const uint8_t **poutbuf, int *poutbuf_size,

                            const uint8_t *buf, int buf_size)
 {
     ParseContext *pc = s->priv_data;
     int next;
 
     if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
         next= buf_size;
     }else{
         next= vc1_find_frame_end(pc, 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;
 }
 
 static int vc1_split(AVCodecContext *avctx,
                            const uint8_t *buf, int buf_size)
 {
     int i;
     uint32_t state= -1;

     int charged=0;

 
     for(i=0; i<buf_size; i++){
         state= (state<<8) | buf[i];

         if(IS_MARKER(state)){
             if(state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT){
                 charged=1;
             }else if(charged){
                 return i-3;
             }
         }

     }
     return 0;
 }
 
 AVCodecParser vc1_parser = {
     { CODEC_ID_VC1 },
     sizeof(ParseContext1),
     NULL,
     vc1_parse,
     ff_parse1_close,
     vc1_split,
 };