FFmpeg: libavcodec/twinvq.h Source File

FFmpeg
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 
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 /**
62  * Parameters and tables that are different for each frame type
63  */
64  struct TwinVQFrameMode {
65   uint8_t sub; ///< Number subblocks in each frame
66   const uint16_t *bark_tab;
67 
68  /** number of distinct bark scale envelope values */
69   uint8_t bark_env_size;
70 
71   const int16_t *bark_cb; ///< codebook for the bark scale envelope (BSE)
72   uint8_t bark_n_coef;///< number of BSE CB coefficients to read
73   uint8_t bark_n_bit; ///< number of bits of the BSE coefs
74 
75  //@{
76  /** main codebooks for spectrum data */
77   const int16_t *cb0;
78   const int16_t *cb1;
79  //@}
80 
81   uint8_t cb_len_read; ///< number of spectrum coefficients to read
82 };
83 
84  typedef struct TwinVQFrameData {
85   int window_type;
86   enum TwinVQFrameType ftype;
87 
88   uint8_t main_coeffs[1024];
89   uint8_t ppc_coeffs[TWINVQ_PPC_SHAPE_LEN_MAX];
90 
91   uint8_t gain_bits[TWINVQ_CHANNELS_MAX];
92   uint8_t sub_gain_bits[TWINVQ_CHANNELS_MAX * TWINVQ_SUBBLOCKS_MAX];
93 
94   uint8_t bark1[TWINVQ_CHANNELS_MAX][TWINVQ_SUBBLOCKS_MAX][TWINVQ_BARK_N_COEF_MAX];
95   uint8_t bark_use_hist[TWINVQ_CHANNELS_MAX][TWINVQ_SUBBLOCKS_MAX];
96 
97   uint8_t lpc_idx1[TWINVQ_CHANNELS_MAX];
98   uint8_t lpc_idx2[TWINVQ_CHANNELS_MAX][TWINVQ_LSP_SPLIT_MAX];
99   uint8_t lpc_hist_idx[TWINVQ_CHANNELS_MAX];
100 
101   int p_coef[TWINVQ_CHANNELS_MAX];
102   int g_coef[TWINVQ_CHANNELS_MAX];
103 } TwinVQFrameData;
104 
105 /**
106  * Parameters and tables that are different for every combination of
107  * bitrate/sample rate
108  */
109  typedef struct TwinVQModeTab {
110   struct TwinVQFrameMode fmode[3]; ///< frame type-dependant parameters
111 
112   uint16_t size; ///< frame size in samples
113   uint8_t n_lsp; ///< number of lsp coefficients
114   const float *lspcodebook;
115 
116  /* number of bits of the different LSP CB coefficients */
117   uint8_t lsp_bit0;
118   uint8_t lsp_bit1;
119   uint8_t lsp_bit2;
120 
121   uint8_t lsp_split; ///< number of CB entries for the LSP decoding
122   const int16_t *ppc_shape_cb; ///< PPC shape CB
123 
124  /** number of the bits for the PPC period value */
125   uint8_t ppc_period_bit;
126 
127   uint8_t ppc_shape_bit; ///< number of bits of the PPC shape CB coeffs
128   uint8_t ppc_shape_len; ///< size of PPC shape CB
129   uint8_t pgain_bit; ///< bits for PPC gain
130 
131  /** constant for peak period to peak width conversion */
132   uint16_t peak_per2wid;
133 } TwinVQModeTab;
134 
135  typedef struct TwinVQContext {
136   AVCodecContext *avctx;
137   AVFloatDSPContext fdsp;
138   FFTContext mdct_ctx[3];
139 
140   const TwinVQModeTab *mtab;
141 
142  // history
143   float lsp_hist[2][20]; ///< LSP coefficients of the last frame
144   float bark_hist[3][2][40]; ///< BSE coefficients of last frame
145 
146  // bitstream parameters
147   int16_t permut[4][4096];
148   uint8_t length[4][2]; ///< main codebook stride
149   uint8_t length_change[4];
150   uint8_t bits_main_spec[2][4][2]; ///< bits for the main codebook
151   int bits_main_spec_change[4];
152   int n_div[4];
153 
154   float *spectrum;
155   float *curr_frame; ///< non-interleaved output
156   float *prev_frame; ///< non-interleaved previous frame
157   int last_block_pos[2];
158   int discarded_packets;
159 
160   float *cos_tabs[3];
161 
162  // scratch buffers
163   float *tmp_buf;
164 
165   TwinVQFrameData bits;
166 
167   enum TwinVQCodec codec;
168 
169   int (*read_bitstream)(AVCodecContext *avctx, struct TwinVQContext *tctx,
170  const uint8_t *buf, int buf_size);
171   void (*dec_bark_env)(struct TwinVQContext *tctx, const uint8_t *in,
172  int use_hist, int ch, float *out, float gain,
173  enum TwinVQFrameType ftype);
174   void (*decode_ppc)(struct TwinVQContext *tctx, int period_coef, int g_coef,
175  const float *shape, float *speech);
176 } TwinVQContext;
177 
178 extern const enum TwinVQFrameType ff_twinvq_wtype_to_ftype_table[];
179 
180 /** @note not speed critical, hence not optimized */
181  static inline void twinvq_memset_float(float *buf, float val, int size)
182 {
183  while (size--)
184  *buf++ = val;
185 }
186 
187  static inline float twinvq_mulawinv(float y, float clip, float mu)
188 {
189  y = av_clipf(y / clip, -1, 1);
190  return clip * FFSIGN(y) * (exp(log(1 + mu) * fabs(y)) - 1) / mu;
191 }
192 
193 int ff_twinvq_decode_frame(AVCodecContext *avctx, void *data,
194  int *got_frame_ptr, AVPacket *avpkt);
195 av_cold int ff_twinvq_decode_close(AVCodecContext *avctx);
196 av_cold int ff_twinvq_decode_init(AVCodecContext *avctx);
197 
198 #endif /* AVCODEC_TWINVQ_DATA_H */
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