1 /* 2 * Xing VBR tagging for LAME. 3 * 4 * Copyright (c) 1999 A.L. Faber 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Library General Public 8 * License as published by the Free Software Foundation; either 9 * version 2 of the License, or (at your option) any later version. 10 * 11 * This library 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 * Library General Public License for more details. 15 * 16 * You should have received a copy of the GNU Library General Public 17 * License along with this library; if not, write to the 18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 19 * Boston, MA 02111-1307, USA. 20 */ 21 22 #ifndef LAME_VRBTAG_H 23 #define LAME_VRBTAG_H 24 25 26 /* ----------------------------------------------------------- 27 * A Vbr header may be present in the ancillary 28 * data field of the first frame of an mp3 bitstream 29 * The Vbr header (optionally) contains 30 * frames total number of audio frames in the bitstream 31 * bytes total number of bytes in the bitstream 32 * toc table of contents 33 34 * toc (table of contents) gives seek points 35 * for random access 36 * the ith entry determines the seek point for 37 * i-percent duration 38 * seek point in bytes = (toc[i]/256.0) * total_bitstream_bytes 39 * e.g. half duration seek point = (toc[50]/256.0) * total_bitstream_bytes 40 */ 41 42 43 #define FRAMES_FLAG 0x0001 44 #define BYTES_FLAG 0x0002 45 #define TOC_FLAG 0x0004 46 #define VBR_SCALE_FLAG 0x0008 47 48 #define NUMTOCENTRIES 100 49 50 #ifndef lame_internal_flags_defined 51 #define lame_internal_flags_defined 52 struct lame_internal_flags; 53 typedef struct lame_internal_flags lame_internal_flags; 54 #endif 55 56 57 /*structure to receive extracted header */ 58 /* toc may be NULL*/ 59 typedef struct { 60 int h_id; /* from MPEG header, 0=MPEG2, 1=MPEG1 */ 61 int samprate; /* determined from MPEG header */ 62 int flags; /* from Vbr header data */ 63 int frames; /* total bit stream frames from Vbr header data */ 64 int bytes; /* total bit stream bytes from Vbr header data */ 65 int vbr_scale; /* encoded vbr scale from Vbr header data */ 66 unsigned char toc[NUMTOCENTRIES]; /* may be NULL if toc not desired */ 67 int headersize; /* size of VBR header, in bytes */ 68 int enc_delay; /* encoder delay */ 69 int enc_padding; /* encoder paddign added at end of stream */ 70 } VBRTAGDATA; 71 72 int GetVbrTag(VBRTAGDATA * pTagData, const unsigned char *buf); 73 74 int InitVbrTag(lame_global_flags * gfp); 75 int PutVbrTag(lame_global_flags const *gfp, FILE * fid); 76 void AddVbrFrame(lame_internal_flags * gfc); 77 void UpdateMusicCRC(uint16_t * crc, const unsigned char *buffer, int size); 78 79 #endif 80