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
34 enum TwinVQCodec {
35 TWINVQ_CODEC_VQF,
36 TWINVQ_CODEC_METASOUND,
37 };
38
39 enum TwinVQFrameType {
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 */
66 struct TwinVQFrameMode {
67 uint8_t sub; ///< Number subblocks in each frame
68 const uint16_t *bark_tab;
69
70 /** number of distinct bark scale envelope values */
71 uint8_t bark_env_size;
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 {
87 int window_type;
88 enum TwinVQFrameType ftype;
89
90 uint8_t main_coeffs[1024];
91 uint8_t ppc_coeffs[TWINVQ_PPC_SHAPE_LEN_MAX];
92
93 uint8_t gain_bits[TWINVQ_CHANNELS_MAX];
94 uint8_t sub_gain_bits[TWINVQ_CHANNELS_MAX * TWINVQ_SUBBLOCKS_MAX];
95
96 uint8_t bark1[TWINVQ_CHANNELS_MAX][TWINVQ_SUBBLOCKS_MAX][TWINVQ_BARK_N_COEF_MAX];
97 uint8_t bark_use_hist[TWINVQ_CHANNELS_MAX][TWINVQ_SUBBLOCKS_MAX];
98
99 uint8_t lpc_idx1[TWINVQ_CHANNELS_MAX];
100 uint8_t lpc_idx2[TWINVQ_CHANNELS_MAX][TWINVQ_LSP_SPLIT_MAX];
101 uint8_t lpc_hist_idx[TWINVQ_CHANNELS_MAX];
102
103 int p_coef[TWINVQ_CHANNELS_MAX];
104 int g_coef[TWINVQ_CHANNELS_MAX];
105 } TwinVQFrameData;
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-dependent 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 */
119 uint8_t lsp_bit0;
120 uint8_t lsp_bit1;
121 uint8_t lsp_bit2;
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 */
127 uint8_t ppc_period_bit;
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 {
138 AVCodecContext *avctx;
139 AVFloatDSPContext *fdsp;
140 FFTContext mdct_ctx[3];
141
142 const TwinVQModeTab *mtab;
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
153 uint8_t length_change[4];
154 uint8_t bits_main_spec[2][4][2]; ///< bits for the main codebook
155 int bits_main_spec_change[4];
156 int n_div[4];
157
158 float *spectrum;
159 float *curr_frame; ///< non-interleaved output
160 float *prev_frame; ///< non-interleaved previous frame
161 int last_block_pos[2];
162 int discarded_packets;
163
164 float *cos_tabs[3];
165
166 // scratch buffers
167 float *tmp_buf;
168
169 int frame_size, frames_per_packet, cur_frame;
170 TwinVQFrameData bits[TWINVQ_MAX_FRAMES_PER_PACKET];
171
172 enum TwinVQCodec codec;
173
174 int (*read_bitstream)(AVCodecContext *avctx, struct TwinVQContext *tctx,
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
183 extern const enum TwinVQFrameType ff_twinvq_wtype_to_ftype_table[];
184
185 /** @note not speed critical, hence not optimized */
twinvq_memset_float(float * buf,float val,int size)186 static inline void twinvq_memset_float(float *buf, float val, int size)
187 {
188 while (size--)
189 *buf++ = val;
190 }
191
twinvq_mulawinv(float y,float clip,float mu)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
198 int ff_twinvq_decode_frame(AVCodecContext *avctx, void *data,
199 int *got_frame_ptr, AVPacket *avpkt);
200 int ff_twinvq_decode_close(AVCodecContext *avctx);
201 int ff_twinvq_decode_init(AVCodecContext *avctx);
202
203 #endif /* AVCODEC_TWINVQ_H */
204