xref: /plan9/sys/src/games/mp3enc/encoder.h (revision 8f5875f3e9b20916b4c52ad4336922bc8653eb7b)
1 /*
2  *      encoder.h include file
3  *
4  *      Copyright (c) 2000 Mark Taylor
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 
23 #ifndef LAME_ENCODER_H
24 #define LAME_ENCODER_H
25 
26 /***********************************************************************
27 *
28 *  encoder and decoder delays
29 *
30 ***********************************************************************/
31 
32 /*
33  * layer III enc->dec delay:  1056 (1057?)   (observed)
34  * layer  II enc->dec delay:   480  (481?)   (observed)
35  *
36  * polyphase 256-16             (dec or enc)        = 240
37  * mdct      256+32  (9*32)     (dec or enc)        = 288
38  * total:    512+16
39  *
40  * My guess is that delay of polyphase filterbank is actualy 240.5
41  * (there are technical reasons for this, see postings in mp3encoder).
42  * So total Encode+Decode delay = ENCDELAY + 528 + 1
43  */
44 
45 /*
46  * ENCDELAY  The encoder delay.
47  *
48  * Minimum allowed is MDCTDELAY (see below)
49  *
50  * The first 96 samples will be attenuated, so using a value less than 96
51  * will result in corrupt data for the first 96-ENCDELAY samples.
52  *
53  * suggested: 576
54  * set to 1160 to sync with FhG.
55  */
56 
57 #define ENCDELAY      576
58 
59 /*
60  * delay of the MDCT used in mdct.c
61  * original ISO routines had a delay of 528!
62  * Takehiro's routines:
63  */
64 
65 #define MDCTDELAY     48
66 #define FFTOFFSET     (224+MDCTDELAY)
67 
68 /*
69  * Most decoders, including the one we use, have a delay of 528 samples.
70  */
71 
72 #define DECDELAY      528
73 
74 
75 /* number of subbands */
76 #define SBLIMIT       32
77 
78 /* parition bands bands */
79 #define CBANDS        64
80 
81 /* number of critical bands/scale factor bands where masking is computed*/
82 #define SBPSY_l       21
83 #define SBPSY_s       12
84 
85 /* total number of scalefactor bands encoded */
86 #define SBMAX_l       22
87 #define SBMAX_s       13
88 
89 
90 
91 /* FFT sizes */
92 #define BLKSIZE       1024
93 #define HBLKSIZE      (BLKSIZE/2 + 1)
94 #define BLKSIZE_s     256
95 #define HBLKSIZE_s    (BLKSIZE_s/2 + 1)
96 
97 
98 /* #define switch_pe        1800 */
99 #define NORM_TYPE     0
100 #define START_TYPE    1
101 #define SHORT_TYPE    2
102 #define STOP_TYPE     3
103 
104 /*
105  * Mode Extention:
106  * When we are in stereo mode, there are 4 possible methods to store these
107  * two channels. The stereo modes -m? are using a subset of them.
108  *
109  *  -ms: MPG_MD_LR_LR
110  *  -mj: MPG_MD_LR_LR and MPG_MD_MS_LR
111  *  -mf: MPG_MD_MS_LR
112  *  -mi: all
113  */
114 
115 #define MPG_MD_LR_LR  0
116 #define MPG_MD_LR_I   1
117 #define MPG_MD_MS_LR  2
118 #define MPG_MD_MS_I   3
119 
120 
121 #include "machine.h"
122 #include "lame.h"
123 
124 int  lame_encode_mp3_frame (
125         lame_global_flags*  const gfp,
126         sample_t*           inbuf_l,
127         sample_t*           inbuf_r,
128         unsigned char*      mp3buf,
129 	int                 mp3buf_size );
130 
131 #endif /* LAME_ENCODER_H */
132