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 33typedef 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 */ 51int 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 */ 68int 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 */ 81int avpriv_vorbis_parse_frame(VorbisParseContext *s, const uint8_t *buf, 82 int buf_size); 83 84void avpriv_vorbis_parse_reset(VorbisParseContext *s); 85 86#endif /* AVCODEC_VORBIS_PARSER_H */ 87