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/*
* TwinVQ decoder
* Copyright (c) 2009 Vitor Sessak
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_TWINVQ_H
#define AVCODEC_TWINVQ_H
#include <math.h>
#include <stdint.h>
#include "libavutil/common.h"
#include "libavutil/float_dsp.h"
#include "avcodec.h"
#include "fft.h"
enum TwinVQCodec {
TWINVQ_CODEC_VQF,
TWINVQ_CODEC_METASOUND,
};
enum TwinVQFrameType {
TWINVQ_FT_SHORT = 0, ///< Short frame (divided in n sub-blocks)
TWINVQ_FT_MEDIUM, ///< Medium frame (divided in m<n sub-blocks)
TWINVQ_FT_LONG, ///< Long frame (single sub-block + PPC)
TWINVQ_FT_PPC, ///< Periodic Peak Component (part of the long frame)
};
#define TWINVQ_PPC_SHAPE_CB_SIZE 64
#define TWINVQ_PPC_SHAPE_LEN_MAX 60
#define TWINVQ_SUB_AMP_MAX 4500.0
#define TWINVQ_MULAW_MU 100.0
#define TWINVQ_GAIN_BITS 8
#define TWINVQ_AMP_MAX 13000.0
#define TWINVQ_SUB_GAIN_BITS 5
#define TWINVQ_WINDOW_TYPE_BITS 4
#define TWINVQ_PGAIN_MU 200
#define TWINVQ_LSP_COEFS_MAX 20
#define TWINVQ_LSP_SPLIT_MAX 4
#define TWINVQ_CHANNELS_MAX 2
#define TWINVQ_SUBBLOCKS_MAX 16
#define TWINVQ_BARK_N_COEF_MAX 4
#define TWINVQ_MAX_FRAMES_PER_PACKET 2
/**
* Parameters and tables that are different for each frame type
*/
struct TwinVQFrameMode {
uint8_t sub; ///< Number subblocks in each frame
const uint16_t *bark_tab;
/** number of distinct bark scale envelope values */
uint8_t bark_env_size;
const int16_t *bark_cb; ///< codebook for the bark scale envelope (BSE)
uint8_t bark_n_coef;///< number of BSE CB coefficients to read
uint8_t bark_n_bit; ///< number of bits of the BSE coefs
//@{
/** main codebooks for spectrum data */
const int16_t *cb0;
const int16_t *cb1;
//@}
uint8_t cb_len_read; ///< number of spectrum coefficients to read
};
typedef struct TwinVQFrameData {
int window_type;
enum TwinVQFrameType ftype;
uint8_t main_coeffs[1024];
uint8_t ppc_coeffs[TWINVQ_PPC_SHAPE_LEN_MAX];
uint8_t gain_bits[TWINVQ_CHANNELS_MAX];
uint8_t sub_gain_bits[TWINVQ_CHANNELS_MAX * TWINVQ_SUBBLOCKS_MAX];
uint8_t bark1[TWINVQ_CHANNELS_MAX][TWINVQ_SUBBLOCKS_MAX][TWINVQ_BARK_N_COEF_MAX];
uint8_t bark_use_hist[TWINVQ_CHANNELS_MAX][TWINVQ_SUBBLOCKS_MAX];
uint8_t lpc_idx1[TWINVQ_CHANNELS_MAX];
uint8_t lpc_idx2[TWINVQ_CHANNELS_MAX][TWINVQ_LSP_SPLIT_MAX];
uint8_t lpc_hist_idx[TWINVQ_CHANNELS_MAX];
int p_coef[TWINVQ_CHANNELS_MAX];
int g_coef[TWINVQ_CHANNELS_MAX];
} TwinVQFrameData;
/**
* Parameters and tables that are different for every combination of
* bitrate/sample rate
*/
typedef struct TwinVQModeTab {
struct TwinVQFrameMode fmode[3]; ///< frame type-dependent parameters
uint16_t size; ///< frame size in samples
uint8_t n_lsp; ///< number of lsp coefficients
const float *lspcodebook;
/* number of bits of the different LSP CB coefficients */
uint8_t lsp_bit0;
uint8_t lsp_bit1;
uint8_t lsp_bit2;
uint8_t lsp_split; ///< number of CB entries for the LSP decoding
const int16_t *ppc_shape_cb; ///< PPC shape CB
/** number of the bits for the PPC period value */
uint8_t ppc_period_bit;
uint8_t ppc_shape_bit; ///< number of bits of the PPC shape CB coeffs
uint8_t ppc_shape_len; ///< size of PPC shape CB
uint8_t pgain_bit; ///< bits for PPC gain
/** constant for peak period to peak width conversion */
uint16_t peak_per2wid;
} TwinVQModeTab;
typedef struct TwinVQContext {
AVCodecContext *avctx;
AVFloatDSPContext *fdsp;
FFTContext mdct_ctx[3];
const TwinVQModeTab *mtab;
int is_6kbps;
// history
float lsp_hist[2][20]; ///< LSP coefficients of the last frame
float bark_hist[3][2][40]; ///< BSE coefficients of last frame
// bitstream parameters
int16_t permut[4][4096];
uint8_t length[4][2]; ///< main codebook stride
uint8_t length_change[4];
uint8_t bits_main_spec[2][4][2]; ///< bits for the main codebook
int bits_main_spec_change[4];
int n_div[4];
float *spectrum;
float *curr_frame; ///< non-interleaved output
float *prev_frame; ///< non-interleaved previous frame
int last_block_pos[2];
int discarded_packets;
float *cos_tabs[3];
// scratch buffers
float *tmp_buf;
int frame_size, frames_per_packet, cur_frame;
TwinVQFrameData bits[TWINVQ_MAX_FRAMES_PER_PACKET];
enum TwinVQCodec codec;
int (*read_bitstream)(AVCodecContext *avctx, struct TwinVQContext *tctx,
const uint8_t *buf, int buf_size);
void (*dec_bark_env)(struct TwinVQContext *tctx, const uint8_t *in,
int use_hist, int ch, float *out, float gain,
enum TwinVQFrameType ftype);
void (*decode_ppc)(struct TwinVQContext *tctx, int period_coef, int g_coef,
const float *shape, float *speech);
} TwinVQContext;
extern const enum TwinVQFrameType ff_twinvq_wtype_to_ftype_table[];
/** @note not speed critical, hence not optimized */
static inline void twinvq_memset_float(float *buf, float val, int size)
{
while (size--)
*buf++ = val;
}
static inline float twinvq_mulawinv(float y, float clip, float mu)
{
y = av_clipf(y / clip, -1, 1);
return clip * FFSIGN(y) * (exp(log(1 + mu) * fabs(y)) - 1) / mu;
}
int ff_twinvq_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt);
int ff_twinvq_decode_close(AVCodecContext *avctx);
/** Requires the caller to call ff_twinvq_decode_close() upon failure. */
int ff_twinvq_decode_init(AVCodecContext *avctx);
#endif /* AVCODEC_TWINVQ_H */
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