/*
  * Copyright (c) 2012 Justin Ruggles
  *

  * 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
  * Vorbis audio parser
  *
  * Determines the duration for each packet.
  */
 
 #ifndef AVCODEC_VORBIS_PARSER_H
 #define AVCODEC_VORBIS_PARSER_H
 
 #include "avcodec.h"
 
 typedef struct VorbisParseContext {
     AVCodecContext *avctx;      ///< codec context
     int extradata_parsed;       ///< we have attempted to parse extradata
     int valid_extradata;        ///< extradata is valid, so we can calculate duration
     int blocksize[2];           ///< short and long window sizes
     int previous_blocksize;     ///< previous window size
     int mode_blocksize[64];     ///< window size mapping for each mode
     int mode_count;             ///< number of modes
     int mode_mask;              ///< bitmask used to get the mode in each packet
     int prev_mask;              ///< bitmask used to get the previous mode flag in each packet
 } VorbisParseContext;
 
 /**
  * Initialize the Vorbis parser using headers in the extradata.
  *
  * @param avctx codec context
  * @param s     Vorbis parser context
  */
 int avpriv_vorbis_parse_extradata(AVCodecContext *avctx, VorbisParseContext *s);
 

 #define VORBIS_FLAG_HEADER  0x00000001
 #define VORBIS_FLAG_COMMENT 0x00000002
 
 /**
  * Get the duration for a Vorbis packet.
  *
  * avpriv_vorbis_parse_extradata() must have been successfully called prior to
  * this in order for a correct duration to be returned. If @p flags is @c NULL,
  * special frames are considered invalid.
  *
  * @param s        Vorbis parser context
  * @param buf      buffer containing a Vorbis frame
  * @param buf_size size of the buffer
  * @param flags    flags for special frames
  */
 int avpriv_vorbis_parse_frame_flags(VorbisParseContext *s, const uint8_t *buf,
                                     int buf_size, int *flags);
 

 /**
  * Get the duration for a Vorbis packet.
  *
  * avpriv_vorbis_parse_extradata() must have been successfully called prior to
  * this in order for a correct duration to be returned.
  *
  * @param s        Vorbis parser context
  * @param buf      buffer containing a Vorbis frame
  * @param buf_size size of the buffer
  */
 int avpriv_vorbis_parse_frame(VorbisParseContext *s, const uint8_t *buf,
                               int buf_size);
 
 void avpriv_vorbis_parse_reset(VorbisParseContext *s);
 
 #endif /* AVCODEC_VORBIS_PARSER_H */