libavcodec/vorbis_parser.h

   1 /*
   2  * Copyright (c) 2012 Justin Ruggles
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * Libav is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with Libav; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /**
  22  * @file
  23  * Vorbis audio parser
  24  *
  25  * Determines the duration for each packet.
  26  */
  27
  28 #ifndef AVCODEC_VORBIS_PARSER_H
  29 #define AVCODEC_VORBIS_PARSER_H
  30
  31 #include "avcodec.h"
  32
  33 typedef struct VorbisParseContext {
  34     AVCodecContext *avctx;      ///< codec context
  35     int extradata_parsed;       ///< we have attempted to parse extradata
  36     int valid_extradata;        ///< extradata is valid, so we can calculate duration
  37     int blocksize[2];           ///< short and long window sizes
  38     int previous_blocksize;     ///< previous window size
  39     int mode_blocksize[64];     ///< window size mapping for each mode
  40     int mode_count;             ///< number of modes
  41     int mode_mask;              ///< bitmask used to get the mode in each packet
  42     int prev_mask;              ///< bitmask used to get the previous mode flag in each packet
  43 } VorbisParseContext;
  44
  45 /**
  46  * Initialize the Vorbis parser using headers in the extradata.
  47  *
  48  * @param avctx codec context
  49  * @param s     Vorbis parser context
  50  */
  51 int avpriv_vorbis_parse_extradata(AVCodecContext *avctx, VorbisParseContext *s);
  52
  53 /**
  54  * Get the duration for a Vorbis packet.
  55  *
  56  * avpriv_vorbis_parse_extradata() must have been successfully called prior to
  57  * this in order for a correct duration to be returned.
  58  *
  59  * @param s        Vorbis parser context
  60  * @param buf      buffer containing a Vorbis frame
  61  * @param buf_size size of the buffer
  62  */
  63 int avpriv_vorbis_parse_frame(VorbisParseContext *s, const uint8_t *buf,
  64                               int buf_size);
  65
  66 void avpriv_vorbis_parse_reset(VorbisParseContext *s);
  67
  68 #endif /* AVCODEC_VORBIS_PARSER_H */