text: /*
   * AAC ADTS header decoding prototypes and structures
   * Copyright (c) 2003 Fabrice Bellard
   * Copyright (c) 2003 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
   */
  
  #ifndef AVCODEC_ADTS_HEADER_H
  #define AVCODEC_ADTS_HEADER_H
  
  #include "get_bits.h"
  
  typedef struct AACADTSHeaderInfo {
      uint32_t sample_rate;
      uint32_t samples;
      uint32_t bit_rate;
      uint8_t  crc_absent;
      uint8_t  object_type;
      uint8_t  sampling_index;
      uint8_t  chan_config;
      uint8_t  num_aac_frames;
      uint32_t frame_length;
  } AACADTSHeaderInfo;
  
  /**
   * Parse the ADTS frame header to the end of the variable header, which is
   * the first 54 bits.
   * @param[in]  gbc BitContext containing the first 54 bits of the frame.
   * @param[out] hdr Pointer to struct where header info is written.
   * @return Returns 0 on success, -1 if there is a sync word mismatch,
   * -2 if the version element is invalid, -3 if the sample rate
   * element is invalid, or -4 if the bit rate element is invalid.
   */
  int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr);
  
  /**
   * Parse the ADTS frame header contained in the buffer, which is
   * the first 54 bits.
   * @param[in]  buf  Pointer to buffer containing the first 54 bits of the frame.
   * @param[in]  size Size of buffer containing the first 54 bits of the frame.
   * @param[out] phdr Pointer to pointer to struct AACADTSHeaderInfo for which
   * memory is allocated and header info is written into it. After using the header
   * information, the allocated memory must be freed by using av_free.
   * @return Returns 0 on success, -1 if there is a sync word mismatch,
   * -2 if the version element is invalid, -3 if the sample rate
   * element is invalid, or -4 if the bit rate element is invalid.
   */
  int avpriv_adts_header_parse(AACADTSHeaderInfo **phdr, const uint8_t *buf, size_t size);
  
  #endif /* AVCODEC_ADTS_HEADER_H */
  