2 * encoder.h include file
4 * Copyright (c) 2000 Mark Taylor
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.
23 #ifndef LAME_ENCODER_H
24 #define LAME_ENCODER_H
26 /***********************************************************************
28 * encoder and decoder delays
30 ***********************************************************************/
33 * layer III enc->dec delay: 1056 (1057?) (observed)
34 * layer II enc->dec delay: 480 (481?) (observed)
36 * polyphase 256-16 (dec or enc) = 240
37 * mdct 256+32 (9*32) (dec or enc) = 288
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
46 * ENCDELAY The encoder delay.
48 * Minimum allowed is MDCTDELAY (see below)
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.
54 * set to 1160 to sync with FhG.
62 * make sure there is at least one complete frame after the
63 * last frame containing real data
65 * Using a value of 288 would be sufficient for a
66 * a very sophisticated decoder that can decode granule-by-granule instead
67 * of frame by frame. But lets not assume this, and assume the decoder
68 * will not decode frame N unless it also has data for frame N+1
71 /*#define POSTDELAY 288*/
72 #define POSTDELAY 1152
77 * delay of the MDCT used in mdct.c
78 * original ISO routines had a delay of 528!
79 * Takehiro's routines:
83 #define FFTOFFSET (224+MDCTDELAY)
86 * Most decoders, including the one we use, have a delay of 528 samples.
92 /* number of subbands */
95 /* parition bands bands */
98 /* number of critical bands/scale factor bands where masking is computed*/
102 /* total number of scalefactor bands encoded */
110 #define HBLKSIZE (BLKSIZE/2 + 1)
111 #define BLKSIZE_s 256
112 #define HBLKSIZE_s (BLKSIZE_s/2 + 1)
115 /* #define switch_pe 1800 */
123 * When we are in stereo mode, there are 4 possible methods to store these
124 * two channels. The stereo modes -m? are using a subset of them.
127 * -mj: MPG_MD_LR_LR and MPG_MD_MS_LR
132 #define MPG_MD_LR_LR 0
133 #define MPG_MD_LR_I 1
134 #define MPG_MD_MS_LR 2
135 #define MPG_MD_MS_I 3
141 int lame_encode_mp3_frame (
142 lame_global_flags* const gfp,
145 unsigned char* mp3buf,
148 #endif /* LAME_ENCODER_H */