2 * Xing VBR tagging for LAME.
4 * Copyright (c) 1999 A.L. Faber
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.
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.
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.
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
34 * toc (table of contents) gives seek points
36 * the ith entry determines the seek point for
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
43 #define FRAMES_FLAG 0x0001
44 #define BYTES_FLAG 0x0002
45 #define TOC_FLAG 0x0004
46 #define VBR_SCALE_FLAG 0x0008
48 #define NUMTOCENTRIES 100
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;
57 /*structure to receive extracted header */
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 */
72 int GetVbrTag(VBRTAGDATA * pTagData, const unsigned char *buf);
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);