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ra144.h
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1 /*
2  * Real Audio 1.0 (14.4K)
3  * Copyright (c) 2003 the ffmpeg project
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #ifndef AVCODEC_RA144_H
23 #define AVCODEC_RA144_H
24 
25 #include <stdint.h>
26 #include "lpc.h"
27 #include "audio_frame_queue.h"
28 
29 #define NBLOCKS 4 ///< number of subblocks within a block
30 #define BLOCKSIZE 40 ///< subblock size in 16-bit words
31 #define BUFFERSIZE 146 ///< the size of the adaptive codebook
32 #define FIXED_CB_SIZE 128 ///< size of fixed codebooks
33 #define FRAMESIZE 20 ///< size of encoded frame
34 #define LPC_ORDER 10 ///< order of LPC filter
35 
36 typedef struct RA144Context {
41 
42  unsigned int old_energy; ///< previous frame energy
43 
44  unsigned int lpc_tables[2][10];
45 
46  /** LPC coefficients: lpc_coef[0] is the coefficients of the current frame
47  * and lpc_coef[1] of the previous one. */
48  unsigned int *lpc_coef[2];
49 
50  unsigned int lpc_refl_rms[2];
51 
53 
54  /** The current subblock padded by the last 10 values of the previous one. */
55  int16_t curr_sblock[50];
56 
57  /** Adaptive codebook, its size is two units bigger to avoid a
58  * buffer overflow. */
59  uint16_t adapt_cb[146+2];
60 } RA144Context;
61 
62 void ff_copy_and_dup(int16_t *target, const int16_t *source, int offset);
63 int ff_eval_refl(int *refl, const int16_t *coefs, AVCodecContext *avctx);
64 void ff_eval_coefs(int *coefs, const int *refl);
65 void ff_int_to_int16(int16_t *out, const int *inp);
66 int ff_t_sqrt(unsigned int x);
67 unsigned int ff_rms(const int *data);
68 int ff_interp(RA144Context *ractx, int16_t *out, int a, int copyold,
69  int energy);
70 unsigned int ff_rescale_rms(unsigned int rms, unsigned int energy);
71 int ff_irms(const int16_t *data);
72 void ff_subblock_synthesis(RA144Context *ractx, const uint16_t *lpc_coefs,
73  int cba_idx, int cb1_idx, int cb2_idx,
74  int gval, int gain);
75 
76 extern const int16_t ff_gain_val_tab[256][3];
77 extern const uint8_t ff_gain_exp_tab[256];
78 extern const int8_t ff_cb1_vects[128][40];
79 extern const int8_t ff_cb2_vects[128][40];
80 extern const uint16_t ff_cb1_base[128];
81 extern const uint16_t ff_cb2_base[128];
82 extern const int16_t ff_energy_tab[32];
83 extern const int16_t * const ff_lpc_refl_cb[10];
84 
85 #endif /* AVCODEC_RA144_H */