libavcodec/ac3_parser.h

   1 /*
   2  * AC3 parser prototypes
   3  * Copyright (c) 2003 Fabrice Bellard.
   4  * Copyright (c) 2003 Michael Niedermayer.
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #ifndef FFMPEG_AC3_PARSER_H
  24 #define FFMPEG_AC3_PARSER_H
  25
  26 #include "ac3.h"
  27 #include "bitstream.h"
  28
  29 typedef enum {
  30     AC3_PARSE_ERROR_SYNC        = -1,
  31     AC3_PARSE_ERROR_BSID        = -2,
  32     AC3_PARSE_ERROR_SAMPLE_RATE = -3,
  33     AC3_PARSE_ERROR_FRAME_SIZE  = -4,
  34     AC3_PARSE_ERROR_FRAME_TYPE  = -5,
  35     AC3_PARSE_ERROR_CRC         = -6,
  36 } AC3ParseError;
  37
  38 /**
  39  * Parses AC-3 frame header.
  40  * Parses the header up to the lfeon element, which is the first 52 or 54 bits
  41  * depending on the audio coding mode.
  42  * @param gbc[in] BitContext containing the first 54 bits of the frame.
  43  * @param hdr[out] Pointer to struct where header info is written.
  44  * @return Returns 0 on success, -1 if there is a sync word mismatch,
  45  * -2 if the bsid (version) element is invalid, -3 if the fscod (sample rate)
  46  * element is invalid, or -4 if the frmsizecod (bit rate) element is invalid.
  47  */
  48 int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr);
  49
  50 /**
  51  * Parses AC-3 frame header and sets channel_map
  52  * Parses the header up to the lfeon (channel_map in E-AC-3)
  53  * element, which is the first 52, 54 or 104 bits depending
  54  * on the audio coding mode.
  55  * @param gbc[in] BitContext containing the first 54 bits of the frame.
  56  * @param hdr[out] Pointer to struct where header info is written.
  57  * @return value returned by ff_ac3_parse_header
  58  */
  59 int ff_ac3_parse_header_full(GetBitContext *gbc, AC3HeaderInfo *hdr);
  60
  61 #endif /* FFMPEG_AC3_PARSER_H */