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 } AC3ParseError; 36 37 /** 38 * Parses AC-3 frame header. 39 * Parses the header up to the lfeon element, which is the first 52 or 54 bits 40 * depending on the audio coding mode. 41 * @param gbc[in] BitContext containing the first 54 bits of the frame. 42 * @param hdr[out] Pointer to struct where header info is written. 43 * @return Returns 0 on success, -1 if there is a sync word mismatch, 44 * -2 if the bsid (version) element is invalid, -3 if the fscod (sample rate) 45 * element is invalid, or -4 if the frmsizecod (bit rate) element is invalid. 46 */ 47 int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr); 48 49 /** 50 * Parses AC-3 frame header and sets channel_map 51 * Parses the header up to the lfeon (channel_map in E-AC-3) 52 * element, which is the first 52, 54 or 104 bits depending 53 * on the audio coding mode. 54 * @param gbc[in] BitContext containing the first 54 bits of the frame. 55 * @param hdr[out] Pointer to struct where header info is written. 56 * @return value returned by ff_ac3_parse_header 57 */ 58 int ff_ac3_parse_header_full(GetBitContext *gbc, AC3HeaderInfo *hdr); 59 60 #endif /* FFMPEG_AC3_PARSER_H */ 61