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/*
* Copyright (c) 2012 Justin Ruggles
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Vorbis audio parser
*
* Determines the duration for each packet.
*/
#ifndef AVCODEC_VORBIS_PARSER_H
#define AVCODEC_VORBIS_PARSER_H
#include "avcodec.h"
typedef struct VorbisParseContext {
AVCodecContext *avctx; ///< codec context
int extradata_parsed; ///< we have attempted to parse extradata
int valid_extradata; ///< extradata is valid, so we can calculate duration
int blocksize[2]; ///< short and long window sizes
int previous_blocksize; ///< previous window size
int mode_blocksize[64]; ///< window size mapping for each mode
int mode_count; ///< number of modes
int mode_mask; ///< bitmask used to get the mode in each packet
int prev_mask; ///< bitmask used to get the previous mode flag in each packet
} VorbisParseContext;
/**
* Initialize the Vorbis parser using headers in the extradata.
*
* @param avctx codec context
* @param s Vorbis parser context
*/
int avpriv_vorbis_parse_extradata(AVCodecContext *avctx, VorbisParseContext *s);
#define VORBIS_FLAG_HEADER 0x00000001
#define VORBIS_FLAG_COMMENT 0x00000002
/**
* Get the duration for a Vorbis packet.
*
* avpriv_vorbis_parse_extradata() must have been successfully called prior to
* this in order for a correct duration to be returned. If @p flags is @c NULL,
* special frames are considered invalid.
*
* @param s Vorbis parser context
* @param buf buffer containing a Vorbis frame
* @param buf_size size of the buffer
* @param flags flags for special frames
*/
int avpriv_vorbis_parse_frame_flags(VorbisParseContext *s, const uint8_t *buf,
int buf_size, int *flags);
/**
* Get the duration for a Vorbis packet.
*
* avpriv_vorbis_parse_extradata() must have been successfully called prior to
* this in order for a correct duration to be returned.
*
* @param s Vorbis parser context
* @param buf buffer containing a Vorbis frame
* @param buf_size size of the buffer
*/
int avpriv_vorbis_parse_frame(VorbisParseContext *s, const uint8_t *buf,
int buf_size);
void avpriv_vorbis_parse_reset(VorbisParseContext *s);
#endif /* AVCODEC_VORBIS_PARSER_H */
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