| 1 | /* |
| 2 | * Copyright (c) 2012 Justin Ruggles |
| 3 | * |
| 4 | * This file is part of FFmpeg. |
| 5 | * |
| 6 | * FFmpeg 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 | * FFmpeg 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 FFmpeg; 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 | #define VORBIS_FLAG_HEADER 0x00000001 |
| 54 | #define VORBIS_FLAG_COMMENT 0x00000002 |
| 55 | |
| 56 | /** |
| 57 | * Get the duration for a Vorbis packet. |
| 58 | * |
| 59 | * avpriv_vorbis_parse_extradata() must have been successfully called prior to |
| 60 | * this in order for a correct duration to be returned. If @p flags is @c NULL, |
| 61 | * special frames are considered invalid. |
| 62 | * |
| 63 | * @param s Vorbis parser context |
| 64 | * @param buf buffer containing a Vorbis frame |
| 65 | * @param buf_size size of the buffer |
| 66 | * @param flags flags for special frames |
| 67 | */ |
| 68 | int avpriv_vorbis_parse_frame_flags(VorbisParseContext *s, const uint8_t *buf, |
| 69 | int buf_size, int *flags); |
| 70 | |
| 71 | /** |
| 72 | * Get the duration for a Vorbis packet. |
| 73 | * |
| 74 | * avpriv_vorbis_parse_extradata() must have been successfully called prior to |
| 75 | * this in order for a correct duration to be returned. |
| 76 | * |
| 77 | * @param s Vorbis parser context |
| 78 | * @param buf buffer containing a Vorbis frame |
| 79 | * @param buf_size size of the buffer |
| 80 | */ |
| 81 | int avpriv_vorbis_parse_frame(VorbisParseContext *s, const uint8_t *buf, |
| 82 | int buf_size); |
| 83 | |
| 84 | void avpriv_vorbis_parse_reset(VorbisParseContext *s); |
| 85 | |
| 86 | #endif /* AVCODEC_VORBIS_PARSER_H */ |