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
34enum TwinVQCodec {
35    TWINVQ_CODEC_VQF,
36    TWINVQ_CODEC_METASOUND,
37};
38
39enum 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 */
66struct 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
86typedef 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 */
111typedef 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 */
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
137typedef 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
183extern const enum TwinVQFrameType ff_twinvq_wtype_to_ftype_table[];
184
185/** @note not speed critical, hence not optimized */
186static inline void twinvq_memset_float(float *buf, float val, int size)
187{
188    while (size--)
189        *buf++ = val;
190}
191
192static 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
198int ff_twinvq_decode_frame(AVCodecContext *avctx, void *data,
199                           int *got_frame_ptr, AVPacket *avpkt);
200av_cold int ff_twinvq_decode_close(AVCodecContext *avctx);
201av_cold int ff_twinvq_decode_init(AVCodecContext *avctx);
202
203#endif /* AVCODEC_TWINVQ_DATA_H */
204