/*
  * TAK parser
  * Copyright (c) 2012 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
  * TAK parser
  **/
 

 #define BITSTREAM_READER_LE

 #include "parser.h"

 #include "tak.h"

 
 typedef struct TAKParseContext {
     ParseContext  pc;
     TAKStreamInfo ti;

     int           index;

 } TAKParseContext;
 
 static int tak_parse(AVCodecParserContext *s, AVCodecContext *avctx,
                      const uint8_t **poutbuf, int *poutbuf_size,
                      const uint8_t *buf, int buf_size)
 {
     TAKParseContext *t = s->priv_data;

     ParseContext *pc   = &t->pc;
     int next           = END_NOT_FOUND;

     GetBitContext gb;
     int consumed = 0;

     int needed   = buf_size ? TAK_MAX_FRAME_HEADER_BYTES : 8;

     int ret;

 
     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
         TAKStreamInfo ti;

         if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
             return ret;

         if (!ff_tak_decode_frame_header(avctx, &gb, &ti, 127))

             s->duration = t->ti.last_frame_samples ? t->ti.last_frame_samples
                                                    : t->ti.frame_samples;

         *poutbuf      = buf;
         *poutbuf_size = buf_size;
         return buf_size;
     }
 
     while (buf_size || t->index + needed <= pc->index) {
         if (buf_size && t->index + TAK_MAX_FRAME_HEADER_BYTES > pc->index) {

             int tmp_buf_size       = FFMIN(TAK_MAX_FRAME_HEADER_BYTES,

                                            buf_size);

             const uint8_t *tmp_buf = buf;
 

             if (ff_combine_frame(pc, END_NOT_FOUND, &tmp_buf, &tmp_buf_size) != -1)
                 return AVERROR(ENOMEM);

             consumed += tmp_buf_size;
             buf      += tmp_buf_size;
             buf_size -= tmp_buf_size;
         }
 
         for (; t->index + needed <= pc->index; t->index++) {
             if (pc->buffer[ t->index     ] == 0xFF &&
                 pc->buffer[ t->index + 1 ] == 0xA0) {
                 TAKStreamInfo ti;
 

                 if ((ret = init_get_bits8(&gb, pc->buffer + t->index,
                                           pc->index - t->index)) < 0)
                     return ret;

                 if (!ff_tak_decode_frame_header(avctx, &gb,
                         pc->frame_start_found ? &ti : &t->ti, 127) &&
                     !ff_tak_check_crc(pc->buffer + t->index,
                                       get_bits_count(&gb) / 8)) {
                     if (!pc->frame_start_found) {
                         pc->frame_start_found = 1;

                         s->duration           = t->ti.last_frame_samples ?
                                                 t->ti.last_frame_samples :
                                                 t->ti.frame_samples;

                         s->key_frame          = !!(t->ti.flags & TAK_FRAME_FLAG_HAS_INFO);

                     } else {
                         pc->frame_start_found = 0;

                         next                  = t->index - pc->index;
                         t->index              = 0;

                         goto found;
                     }
                 }
             }
         }
     }
 found:
 
     if (consumed && !buf_size && next == END_NOT_FOUND ||
         ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
         *poutbuf      = NULL;
         *poutbuf_size = 0;
         return buf_size + consumed;
     }
 
     if (next != END_NOT_FOUND) {

         next        += consumed;

         pc->overread = FFMAX(0, -next);
     }
 
     *poutbuf      = buf;
     *poutbuf_size = buf_size;
     return next;
 }
 
 AVCodecParser ff_tak_parser = {
     .codec_ids      = { AV_CODEC_ID_TAK },
     .priv_data_size = sizeof(TAKParseContext),
     .parser_parse   = tak_parse,
     .parser_close   = ff_parse_close,
 };