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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 #include "audiodsp.h"
29 
30 #define NBLOCKS 4 ///< number of subblocks within a block
31 #define BLOCKSIZE 40 ///< subblock size in 16-bit words
32 #define BUFFERSIZE 146 ///< the size of the adaptive codebook
33 #define FIXED_CB_SIZE 128 ///< size of fixed codebooks
34 #define FRAME_SIZE 20 ///< size of encoded frame
35 #define LPC_ORDER 10 ///< order of LPC filter
36 
37 typedef struct RA144Context {
43 
44  unsigned int old_energy; ///< previous frame energy
45 
46  unsigned int lpc_tables[2][10];
47 
48  /** LPC coefficients: lpc_coef[0] is the coefficients of the current frame
49  * and lpc_coef[1] of the previous one. */
50  unsigned int *lpc_coef[2];
51 
52  unsigned int lpc_refl_rms[2];
53 
55 
56  /** The current subblock padded by the last 10 values of the previous one. */
57  int16_t curr_sblock[50];
58 
59  /** Adaptive codebook, its size is two units bigger to avoid a
60  * buffer overflow. */
61  int16_t adapt_cb[146+2];
62 
64 } RA144Context;
65 
66 void ff_copy_and_dup(int16_t *target, const int16_t *source, int offset);
67 int ff_eval_refl(int *refl, const int16_t *coefs, AVCodecContext *avctx);
68 void ff_eval_coefs(int *coefs, const int *refl);
69 void ff_int_to_int16(int16_t *out, const int *inp);
70 int ff_t_sqrt(unsigned int x);
71 unsigned int ff_rms(const int *data);
72 int ff_interp(RA144Context *ractx, int16_t *out, int a, int copyold,
73  int energy);
74 unsigned int ff_rescale_rms(unsigned int rms, unsigned int energy);
75 int ff_irms(AudioDSPContext *adsp, const int16_t *data/*align 16*/);
76 void ff_subblock_synthesis(RA144Context *ractx, const int16_t *lpc_coefs,
77  int cba_idx, int cb1_idx, int cb2_idx,
78  int gval, int gain);
79 
80 extern const int16_t ff_gain_val_tab[256][3];
81 extern const uint8_t ff_gain_exp_tab[256];
82 extern const int8_t ff_cb1_vects[128][40];
83 extern const int8_t ff_cb2_vects[128][40];
84 extern const uint16_t ff_cb1_base[128];
85 extern const uint16_t ff_cb2_base[128];
86 extern const int16_t ff_energy_tab[32];
87 extern const int16_t * const ff_lpc_refl_cb[10];
88 
89 #endif /* AVCODEC_RA144_H */