/*
  * Copyright (c) 2011  Justin Ruggles
  *
  * This file is part of Libav.
  *
  * Libav 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.
  *
  * Libav 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 Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file
  * ADX audio parser
  *

  * Splits packets into individual blocks.

  */
 
 #include "libavutil/intreadwrite.h"
 #include "parser.h"
 #include "adx.h"
 
 typedef struct ADXParseContext {
     ParseContext pc;
     int header_size;
     int block_size;

     int remaining;

 } ADXParseContext;
 
 static int adx_parse(AVCodecParserContext *s1,
                            AVCodecContext *avctx,
                            const uint8_t **poutbuf, int *poutbuf_size,
                            const uint8_t *buf, int buf_size)
 {
     ADXParseContext *s = s1->priv_data;
     ParseContext *pc = &s->pc;
     int next = END_NOT_FOUND;

     int i;
     uint64_t state = pc->state64;

     if (!s->header_size) {
         for (i = 0; i < buf_size; i++) {
             state = (state << 8) | buf[i];
             /* check for fixed fields in ADX header for possible match */
             if ((state & 0xFFFF0000FFFFFF00) == 0x8000000003120400ULL) {
                 int channels    = state & 0xFF;
                 int header_size = ((state >> 32) & 0xFFFF) + 4;
                 if (channels > 0 && header_size >= 8) {
                     s->header_size = header_size;
                     s->block_size  = BLOCK_SIZE * channels;
                     s->remaining   = i - 7 + s->header_size + s->block_size;
                     break;
                 }
             }

         }

         pc->state64 = state;

     }
 

     if (s->header_size) {
         if (!s->remaining)
             s->remaining = s->block_size;
         if (s->remaining <= buf_size) {
             next = s->remaining;
             s->remaining = 0;
         } else
             s->remaining -= buf_size;

     }
 
     if (ff_combine_frame(pc, next, &buf, &buf_size) < 0 || !buf_size) {
         *poutbuf      = NULL;
         *poutbuf_size = 0;
         return buf_size;
     }

 
     s1->duration = BLOCK_SAMPLES;
 

     *poutbuf = buf;
     *poutbuf_size = buf_size;
     return next;
 }
 
 AVCodecParser ff_adx_parser = {
     .codec_ids      = { CODEC_ID_ADPCM_ADX },
     .priv_data_size = sizeof(ADXParseContext),
     .parser_parse   = adx_parse,
     .parser_close   = ff_parse_close,
 };