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twinvq.h
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1 /*
2  * TwinVQ decoder
3  * Copyright (c) 2009 Vitor Sessak
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_TWINVQ_H
23 #define AVCODEC_TWINVQ_H
24 
25 #include <math.h>
26 #include <stdint.h>
27 
28 #include "libavutil/common.h"
29 #include "libavutil/float_dsp.h"
30 #include "avcodec.h"
31 #include "fft.h"
32 #include "internal.h"
33 
37 };
38 
40  TWINVQ_FT_SHORT = 0, ///< Short frame (divided in n sub-blocks)
41  TWINVQ_FT_MEDIUM, ///< Medium frame (divided in m<n sub-blocks)
42  TWINVQ_FT_LONG, ///< Long frame (single sub-block + PPC)
43  TWINVQ_FT_PPC, ///< Periodic Peak Component (part of the long frame)
44 };
45 
46 #define TWINVQ_PPC_SHAPE_CB_SIZE 64
47 #define TWINVQ_PPC_SHAPE_LEN_MAX 60
48 #define TWINVQ_SUB_AMP_MAX 4500.0
49 #define TWINVQ_MULAW_MU 100.0
50 #define TWINVQ_GAIN_BITS 8
51 #define TWINVQ_AMP_MAX 13000.0
52 #define TWINVQ_SUB_GAIN_BITS 5
53 #define TWINVQ_WINDOW_TYPE_BITS 4
54 #define TWINVQ_PGAIN_MU 200
55 #define TWINVQ_LSP_COEFS_MAX 20
56 #define TWINVQ_LSP_SPLIT_MAX 4
57 #define TWINVQ_CHANNELS_MAX 2
58 #define TWINVQ_SUBBLOCKS_MAX 16
59 #define TWINVQ_BARK_N_COEF_MAX 4
60 
61 #define TWINVQ_MAX_FRAMES_PER_PACKET 2
62 
63 /**
64  * Parameters and tables that are different for each frame type
65  */
67  uint8_t sub; ///< Number subblocks in each frame
68  const uint16_t *bark_tab;
69 
70  /** number of distinct bark scale envelope values */
72 
73  const int16_t *bark_cb; ///< codebook for the bark scale envelope (BSE)
74  uint8_t bark_n_coef;///< number of BSE CB coefficients to read
75  uint8_t bark_n_bit; ///< number of bits of the BSE coefs
76 
77  //@{
78  /** main codebooks for spectrum data */
79  const int16_t *cb0;
80  const int16_t *cb1;
81  //@}
82 
83  uint8_t cb_len_read; ///< number of spectrum coefficients to read
84 };
85 
86 typedef struct TwinVQFrameData {
89 
92 
95 
98 
102 
106 
107 /**
108  * Parameters and tables that are different for every combination of
109  * bitrate/sample rate
110  */
111 typedef struct TwinVQModeTab {
112  struct TwinVQFrameMode fmode[3]; ///< frame type-dependant parameters
113 
114  uint16_t size; ///< frame size in samples
115  uint8_t n_lsp; ///< number of lsp coefficients
116  const float *lspcodebook;
117 
118  /* number of bits of the different LSP CB coefficients */
122 
123  uint8_t lsp_split; ///< number of CB entries for the LSP decoding
124  const int16_t *ppc_shape_cb; ///< PPC shape CB
125 
126  /** number of the bits for the PPC period value */
128 
129  uint8_t ppc_shape_bit; ///< number of bits of the PPC shape CB coeffs
130  uint8_t ppc_shape_len; ///< size of PPC shape CB
131  uint8_t pgain_bit; ///< bits for PPC gain
132 
133  /** constant for peak period to peak width conversion */
134  uint16_t peak_per2wid;
135 } TwinVQModeTab;
136 
137 typedef struct TwinVQContext {
141 
143 
144  int is_6kbps;
145 
146  // history
147  float lsp_hist[2][20]; ///< LSP coefficients of the last frame
148  float bark_hist[3][2][40]; ///< BSE coefficients of last frame
149 
150  // bitstream parameters
151  int16_t permut[4][4096];
152  uint8_t length[4][2]; ///< main codebook stride
154  uint8_t bits_main_spec[2][4][2]; ///< bits for the main codebook
156  int n_div[4];
157 
158  float *spectrum;
159  float *curr_frame; ///< non-interleaved output
160  float *prev_frame; ///< non-interleaved previous frame
163 
164  float *cos_tabs[3];
165 
166  // scratch buffers
167  float *tmp_buf;
168 
171 
173 
175  const uint8_t *buf, int buf_size);
176  void (*dec_bark_env)(struct TwinVQContext *tctx, const uint8_t *in,
177  int use_hist, int ch, float *out, float gain,
178  enum TwinVQFrameType ftype);
179  void (*decode_ppc)(struct TwinVQContext *tctx, int period_coef, int g_coef,
180  const float *shape, float *speech);
181 } TwinVQContext;
182 
184 
185 /** @note not speed critical, hence not optimized */
186 static inline void twinvq_memset_float(float *buf, float val, int size)
187 {
188  while (size--)
189  *buf++ = val;
190 }
191 
192 static inline float twinvq_mulawinv(float y, float clip, float mu)
193 {
194  y = av_clipf(y / clip, -1, 1);
195  return clip * FFSIGN(y) * (exp(log(1 + mu) * fabs(y)) - 1) / mu;
196 }
197 
199  int *got_frame_ptr, AVPacket *avpkt);
202 
203 #endif /* AVCODEC_TWINVQ_DATA_H */