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ffmpeg/libavcodec/twinvq.c

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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
*/
#include "avcodec.h"
#include "get_bits.h"
#include "dsputil.h"
#include "fft.h"
#include "lsp.h"
#include <math.h>
#include <stdint.h>
#include "twinvq_data.h"
enum FrameType {
FT_SHORT = 0, ///< Short frame (divided in n sub-blocks)
FT_MEDIUM, ///< Medium frame (divided in m<n sub-blocks)
FT_LONG, ///< Long frame (single sub-block + PPC)
FT_PPC, ///< Periodic Peak Component (part of the long frame)
};
/**
* Parameters and tables that are different for each frame type
*/
struct FrameMode {
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
};
/**
* Parameters and tables that are different for every combination of
* bitrate/sample rate
*/
typedef struct {
struct FrameMode fmode[3]; ///< frame type-dependant 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;
} ModeTab;
static const ModeTab mode_08_08 = {
{
{ 8, bark_tab_s08_64, 10, tab.fcb08s , 1, 5, tab.cb0808s0, tab.cb0808s1, 18},
{ 2, bark_tab_m08_256, 20, tab.fcb08m , 2, 5, tab.cb0808m0, tab.cb0808m1, 16},
{ 1, bark_tab_l08_512, 30, tab.fcb08l , 3, 6, tab.cb0808l0, tab.cb0808l1, 17}
},
512 , 12, tab.lsp08, 1, 5, 3, 3, tab.shape08 , 8, 28, 20, 6, 40
};
static const ModeTab mode_11_08 = {
{
{ 8, bark_tab_s11_64, 10, tab.fcb11s , 1, 5, tab.cb1108s0, tab.cb1108s1, 29},
{ 2, bark_tab_m11_256, 20, tab.fcb11m , 2, 5, tab.cb1108m0, tab.cb1108m1, 24},
{ 1, bark_tab_l11_512, 30, tab.fcb11l , 3, 6, tab.cb1108l0, tab.cb1108l1, 27}
},
512 , 16, tab.lsp11, 1, 6, 4, 3, tab.shape11 , 9, 36, 30, 7, 90
};
static const ModeTab mode_11_10 = {
{
{ 8, bark_tab_s11_64, 10, tab.fcb11s , 1, 5, tab.cb1110s0, tab.cb1110s1, 21},
{ 2, bark_tab_m11_256, 20, tab.fcb11m , 2, 5, tab.cb1110m0, tab.cb1110m1, 18},
{ 1, bark_tab_l11_512, 30, tab.fcb11l , 3, 6, tab.cb1110l0, tab.cb1110l1, 20}
},
512 , 16, tab.lsp11, 1, 6, 4, 3, tab.shape11 , 9, 36, 30, 7, 90
};
static const ModeTab mode_16_16 = {
{
{ 8, bark_tab_s16_128, 10, tab.fcb16s , 1, 5, tab.cb1616s0, tab.cb1616s1, 16},
{ 2, bark_tab_m16_512, 20, tab.fcb16m , 2, 5, tab.cb1616m0, tab.cb1616m1, 15},
{ 1, bark_tab_l16_1024,30, tab.fcb16l , 3, 6, tab.cb1616l0, tab.cb1616l1, 16}
},
1024, 16, tab.lsp16, 1, 6, 4, 3, tab.shape16 , 9, 56, 60, 7, 180
};
static const ModeTab mode_22_20 = {
{
{ 8, bark_tab_s22_128, 10, tab.fcb22s_1, 1, 6, tab.cb2220s0, tab.cb2220s1, 18},
{ 2, bark_tab_m22_512, 20, tab.fcb22m_1, 2, 6, tab.cb2220m0, tab.cb2220m1, 17},
{ 1, bark_tab_l22_1024,32, tab.fcb22l_1, 4, 6, tab.cb2220l0, tab.cb2220l1, 18}
},
1024, 16, tab.lsp22_1, 1, 6, 4, 3, tab.shape22_1, 9, 56, 36, 7, 144
};
static const ModeTab mode_22_24 = {
{
{ 8, bark_tab_s22_128, 10, tab.fcb22s_1, 1, 6, tab.cb2224s0, tab.cb2224s1, 15},
{ 2, bark_tab_m22_512, 20, tab.fcb22m_1, 2, 6, tab.cb2224m0, tab.cb2224m1, 14},
{ 1, bark_tab_l22_1024,32, tab.fcb22l_1, 4, 6, tab.cb2224l0, tab.cb2224l1, 15}
},
1024, 16, tab.lsp22_1, 1, 6, 4, 3, tab.shape22_1, 9, 56, 36, 7, 144
};
static const ModeTab mode_22_32 = {
{
{ 4, bark_tab_s22_128, 10, tab.fcb22s_2, 1, 6, tab.cb2232s0, tab.cb2232s1, 11},
{ 2, bark_tab_m22_256, 20, tab.fcb22m_2, 2, 6, tab.cb2232m0, tab.cb2232m1, 11},
{ 1, bark_tab_l22_512, 32, tab.fcb22l_2, 4, 6, tab.cb2232l0, tab.cb2232l1, 12}
},
512 , 16, tab.lsp22_2, 1, 6, 4, 4, tab.shape22_2, 9, 56, 36, 7, 72
};
static const ModeTab mode_44_40 = {
{
{16, bark_tab_s44_128, 10, tab.fcb44s , 1, 6, tab.cb4440s0, tab.cb4440s1, 18},
{ 4, bark_tab_m44_512, 20, tab.fcb44m , 2, 6, tab.cb4440m0, tab.cb4440m1, 17},
{ 1, bark_tab_l44_2048,40, tab.fcb44l , 4, 6, tab.cb4440l0, tab.cb4440l1, 17}
},
2048, 20, tab.lsp44, 1, 6, 4, 4, tab.shape44 , 9, 84, 54, 7, 432
};
static const ModeTab mode_44_48 = {
{
{16, bark_tab_s44_128, 10, tab.fcb44s , 1, 6, tab.cb4448s0, tab.cb4448s1, 15},
{ 4, bark_tab_m44_512, 20, tab.fcb44m , 2, 6, tab.cb4448m0, tab.cb4448m1, 14},
{ 1, bark_tab_l44_2048,40, tab.fcb44l , 4, 6, tab.cb4448l0, tab.cb4448l1, 14}
},
2048, 20, tab.lsp44, 1, 6, 4, 4, tab.shape44 , 9, 84, 54, 7, 432
};
typedef struct TwinContext {
AVCodecContext *avctx;
DSPContext dsp;
FFTContext mdct_ctx[3];
const ModeTab *mtab;
// 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];
float *cos_tabs[3];
// scratch buffers
float *tmp_buf;
} TwinContext;
#define PPC_SHAPE_CB_SIZE 64
#define PPC_SHAPE_LEN_MAX 60
#define SUB_AMP_MAX 4500.0
#define MULAW_MU 100.0
#define GAIN_BITS 8
#define AMP_MAX 13000.0
#define SUB_GAIN_BITS 5
#define WINDOW_TYPE_BITS 4
#define PGAIN_MU 200
#define LSP_COEFS_MAX 20
#define LSP_SPLIT_MAX 4
#define CHANNELS_MAX 2
#define SUBBLOCKS_MAX 16
#define BARK_N_COEF_MAX 4
/** @note not speed critical, hence not optimized */
static void memset_float(float *buf, float val, int size)
{
while (size--)
*buf++ = val;
}
/**
* Evaluate a single LPC amplitude spectrum envelope coefficient from the line
* spectrum pairs.
*
* @param lsp a vector of the cosinus of the LSP values
* @param cos_val cos(PI*i/N) where i is the index of the LPC amplitude
* @param order the order of the LSP (and the size of the *lsp buffer). Must
* be a multiple of four.
* @return the LPC value
*
* @todo reuse code from vorbis_dec.c: vorbis_floor0_decode
*/
static float eval_lpc_spectrum(const float *lsp, float cos_val, int order)
{
int j;
float p = 0.5f;
float q = 0.5f;
float two_cos_w = 2.0f*cos_val;
for (j = 0; j + 1 < order; j += 2*2) {
// Unroll the loop once since order is a multiple of four
q *= lsp[j ] - two_cos_w;
p *= lsp[j+1] - two_cos_w;
q *= lsp[j+2] - two_cos_w;
p *= lsp[j+3] - two_cos_w;
}
p *= p * (2.0f - two_cos_w);
q *= q * (2.0f + two_cos_w);
return 0.5 / (p + q);
}
/**
* Evaluate the LPC amplitude spectrum envelope from the line spectrum pairs.
*/
static void eval_lpcenv(TwinContext *tctx, const float *cos_vals, float *lpc)
{
int i;
const ModeTab *mtab = tctx->mtab;
int size_s = mtab->size / mtab->fmode[FT_SHORT].sub;
for (i = 0; i < size_s/2; i++) {
float cos_i = tctx->cos_tabs[0][i];
lpc[i] = eval_lpc_spectrum(cos_vals, cos_i, mtab->n_lsp);
lpc[size_s-i-1] = eval_lpc_spectrum(cos_vals, -cos_i, mtab->n_lsp);
}
}
static void interpolate(float *out, float v1, float v2, int size)
{
int i;
float step = (v1 - v2)/(size + 1);
for (i = 0; i < size; i++) {
v2 += step;
out[i] = v2;
}
}
static inline float get_cos(int idx, int part, const float *cos_tab, int size)
{
return part ? -cos_tab[size - idx - 1] :
cos_tab[ idx ];
}
/**
* Evaluate the LPC amplitude spectrum envelope from the line spectrum pairs.
* Probably for speed reasons, the coefficients are evaluated as
* siiiibiiiisiiiibiiiisiiiibiiiisiiiibiiiis ...
* where s is an evaluated value, i is a value interpolated from the others
* and b might be either calculated or interpolated, depending on an
* unexplained condition.
*
* @param step the size of a block "siiiibiiii"
* @param in the cosinus of the LSP data
* @param part is 0 for 0...PI (positive cossinus values) and 1 for PI...2PI
(negative cossinus values)
* @param size the size of the whole output
*/
static inline void eval_lpcenv_or_interp(TwinContext *tctx,
enum FrameType ftype,
float *out, const float *in,
int size, int step, int part)
{
int i;
const ModeTab *mtab = tctx->mtab;
const float *cos_tab = tctx->cos_tabs[ftype];
// Fill the 's'
for (i = 0; i < size; i += step)
out[i] =
eval_lpc_spectrum(in,
get_cos(i, part, cos_tab, size),
mtab->n_lsp);
// Fill the 'iiiibiiii'
for (i = step; i <= size - 2*step; i += step) {
if (out[i + step] + out[i - step] > 1.95*out[i] ||
out[i + step] >= out[i - step]) {
interpolate(out + i - step + 1, out[i], out[i-step], step - 1);
} else {
out[i - step/2] =
eval_lpc_spectrum(in,
get_cos(i-step/2, part, cos_tab, size),
mtab->n_lsp);
interpolate(out + i - step + 1, out[i-step/2], out[i-step ], step/2 - 1);
interpolate(out + i - step/2 + 1, out[i ], out[i-step/2], step/2 - 1);
}
}
interpolate(out + size - 2*step + 1, out[size-step], out[size - 2*step], step - 1);
}
static void eval_lpcenv_2parts(TwinContext *tctx, enum FrameType ftype,
const float *buf, float *lpc,
int size, int step)
{
eval_lpcenv_or_interp(tctx, ftype, lpc , buf, size/2, step, 0);
eval_lpcenv_or_interp(tctx, ftype, lpc + size/2, buf, size/2, 2*step, 1);
interpolate(lpc+size/2-step+1, lpc[size/2], lpc[size/2-step], step);
memset_float(lpc + size - 2*step + 1, lpc[size - 2*step], 2*step - 1);
}
/**
* Inverse quantization. Read CB coefficients for cb1 and cb2 from the
* bitstream, sum the corresponding vectors and write the result to *out
* after permutation.
*/
static void dequant(TwinContext *tctx, GetBitContext *gb, float *out,
enum FrameType ftype,
const int16_t *cb0, const int16_t *cb1, int cb_len)
{
int pos = 0;
int i, j;
for (i = 0; i < tctx->n_div[ftype]; i++) {
int tmp0, tmp1;
int sign0 = 1;
int sign1 = 1;
const int16_t *tab0, *tab1;
int length = tctx->length[ftype][i >= tctx->length_change[ftype]];
int bitstream_second_part = (i >= tctx->bits_main_spec_change[ftype]);
int bits = tctx->bits_main_spec[0][ftype][bitstream_second_part];
if (bits == 7) {
if (get_bits1(gb))
sign0 = -1;
bits = 6;
}
tmp0 = get_bits(gb, bits);
bits = tctx->bits_main_spec[1][ftype][bitstream_second_part];
if (bits == 7) {
if (get_bits1(gb))
sign1 = -1;
bits = 6;
}
tmp1 = get_bits(gb, bits);
tab0 = cb0 + tmp0*cb_len;
tab1 = cb1 + tmp1*cb_len;
for (j = 0; j < length; j++)
out[tctx->permut[ftype][pos+j]] = sign0*tab0[j] + sign1*tab1[j];
pos += length;
}
}
static inline float 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;
}
/**
* Evaluate a*b/400 rounded to the nearest integer. When, for example,
* a*b == 200 and the nearest integer is ill-defined, use a table to emulate
* the following broken float-based implementation used by the binary decoder:
*
* \code
* static int very_broken_op(int a, int b)
* {
* static float test; // Ugh, force gcc to do the division first...
*
* test = a/400.;
* return b * test + 0.5;
* }
* \endcode
*
* @note if this function is replaced by just ROUNDED_DIV(a*b,400.), the stddev
* between the original file (before encoding with Yamaha encoder) and the
* decoded output increases, which leads one to believe that the encoder expects
* exactly this broken calculation.
*/
static int very_broken_op(int a, int b)
{
int x = a*b + 200;
int size;
const uint8_t *rtab;
if (x%400 || b%5)
return x/400;
x /= 400;
size = tabs[b/5].size;
rtab = tabs[b/5].tab;
return x - rtab[size*av_log2(2*(x - 1)/size)+(x - 1)%size];
}
/**
* Sum to data a periodic peak of a given period, width and shape.
*
* @param period the period of the peak divised by 400.0
*/
static void add_peak(int period, int width, const float *shape,
float ppc_gain, float *speech, int len)
{
int i, j;
const float *shape_end = shape + len;
int center;
// First peak centered around zero
for (i = 0; i < width/2; i++)
speech[i] += ppc_gain * *shape++;
for (i = 1; i < ROUNDED_DIV(len,width) ; i++) {
center = very_broken_op(period, i);
for (j = -width/2; j < (width+1)/2; j++)
speech[j+center] += ppc_gain * *shape++;
}
// For the last block, be careful not to go beyond the end of the buffer
center = very_broken_op(period, i);
for (j = -width/2; j < (width + 1)/2 && shape < shape_end; j++)
speech[j+center] += ppc_gain * *shape++;
}
static void decode_ppc(TwinContext *tctx, int period_coef, const float *shape,
float ppc_gain, float *speech)
{
const ModeTab *mtab = tctx->mtab;
int isampf = tctx->avctx->sample_rate/1000;
int ibps = tctx->avctx->bit_rate/(1000 * tctx->avctx->channels);
int min_period = ROUNDED_DIV( 40*2*mtab->size, isampf);
int max_period = ROUNDED_DIV(6*40*2*mtab->size, isampf);
int period_range = max_period - min_period;
// This is actually the period multiplied by 400. It is just linearly coded
// between its maximum and minimum value.
int period = min_period +
ROUNDED_DIV(period_coef*period_range, (1 << mtab->ppc_period_bit) - 1);
int width;
if (isampf == 22 && ibps == 32) {
// For some unknown reason, NTT decided to code this case differently...
width = ROUNDED_DIV((period + 800)* mtab->peak_per2wid, 400*mtab->size);
} else
width = (period )* mtab->peak_per2wid/(400*mtab->size);
add_peak(period, width, shape, ppc_gain, speech, mtab->ppc_shape_len);
}
static void dec_gain(TwinContext *tctx, GetBitContext *gb, enum FrameType ftype,
float *out)
{
const ModeTab *mtab = tctx->mtab;
int i, j;
int sub = mtab->fmode[ftype].sub;
float step = AMP_MAX / ((1 << GAIN_BITS) - 1);
float sub_step = SUB_AMP_MAX / ((1 << SUB_GAIN_BITS) - 1);
if (ftype == FT_LONG) {
for (i = 0; i < tctx->avctx->channels; i++)
out[i] = (1./(1<<13)) *
mulawinv(step * 0.5 + step * get_bits(gb, GAIN_BITS),
AMP_MAX, MULAW_MU);
} else {
for (i = 0; i < tctx->avctx->channels; i++) {
float val = (1./(1<<23)) *
mulawinv(step * 0.5 + step * get_bits(gb, GAIN_BITS),
AMP_MAX, MULAW_MU);
for (j = 0; j < sub; j++) {
out[i*sub + j] =
val*mulawinv(sub_step* 0.5 +
sub_step* get_bits(gb, SUB_GAIN_BITS),
SUB_AMP_MAX, MULAW_MU);
}
}
}
}
/**
* Rearrange the LSP coefficients so that they have a minimum distance of
* min_dist. This function does it exactly as described in section of 3.2.4
* of the G.729 specification (but interestingly is different from what the
* reference decoder actually does).
*/
static void rearrange_lsp(int order, float *lsp, float min_dist)
{
int i;
float min_dist2 = min_dist * 0.5;
for (i = 1; i < order; i++)
if (lsp[i] - lsp[i-1] < min_dist) {
float avg = (lsp[i] + lsp[i-1]) * 0.5;
lsp[i-1] = avg - min_dist2;
lsp[i ] = avg + min_dist2;
}
}
static void decode_lsp(TwinContext *tctx, int lpc_idx1, uint8_t *lpc_idx2,
int lpc_hist_idx, float *lsp, float *hist)
{
const ModeTab *mtab = tctx->mtab;
int i, j;
const float *cb = mtab->lspcodebook;
const float *cb2 = cb + (1 << mtab->lsp_bit1)*mtab->n_lsp;
const float *cb3 = cb2 + (1 << mtab->lsp_bit2)*mtab->n_lsp;
const int8_t funny_rounding[4] = {
-2,
mtab->lsp_split == 4 ? -2 : 1,
mtab->lsp_split == 4 ? -2 : 1,
0
};
j = 0;
for (i = 0; i < mtab->lsp_split; i++) {
int chunk_end = ((i + 1)*mtab->n_lsp + funny_rounding[i])/mtab->lsp_split;
for (; j < chunk_end; j++)
lsp[j] = cb [lpc_idx1 * mtab->n_lsp + j] +
cb2[lpc_idx2[i] * mtab->n_lsp + j];
}
rearrange_lsp(mtab->n_lsp, lsp, 0.0001);
for (i = 0; i < mtab->n_lsp; i++) {
float tmp1 = 1. - cb3[lpc_hist_idx*mtab->n_lsp + i];
float tmp2 = hist[i] * cb3[lpc_hist_idx*mtab->n_lsp + i];
hist[i] = lsp[i];
lsp[i] = lsp[i] * tmp1 + tmp2;
}
rearrange_lsp(mtab->n_lsp, lsp, 0.0001);
rearrange_lsp(mtab->n_lsp, lsp, 0.000095);
ff_sort_nearly_sorted_floats(lsp, mtab->n_lsp);
}
static void dec_lpc_spectrum_inv(TwinContext *tctx, float *lsp,
enum FrameType ftype, float *lpc)
{
int i;
int size = tctx->mtab->size / tctx->mtab->fmode[ftype].sub;
for (i = 0; i < tctx->mtab->n_lsp; i++)
lsp[i] = 2*cos(lsp[i]);
switch (ftype) {
case FT_LONG:
eval_lpcenv_2parts(tctx, ftype, lsp, lpc, size, 8);
break;
case FT_MEDIUM:
eval_lpcenv_2parts(tctx, ftype, lsp, lpc, size, 2);
break;
case FT_SHORT:
eval_lpcenv(tctx, lsp, lpc);
break;
}
}
static void imdct_and_window(TwinContext *tctx, enum FrameType ftype, int wtype,
float *in, float *prev, int ch)
{
const ModeTab *mtab = tctx->mtab;
int bsize = mtab->size / mtab->fmode[ftype].sub;
int size = mtab->size;
float *buf1 = tctx->tmp_buf;
int j;
int wsize; // Window size
float *out = tctx->curr_frame + 2*ch*mtab->size;
float *out2 = out;
float *prev_buf;
int first_wsize;
static const uint8_t wtype_to_wsize[] = {0, 0, 2, 2, 2, 1, 0, 1, 1};
int types_sizes[] = {
mtab->size / mtab->fmode[FT_LONG ].sub,
mtab->size / mtab->fmode[FT_MEDIUM].sub,
mtab->size / (2*mtab->fmode[FT_SHORT ].sub),
};
wsize = types_sizes[wtype_to_wsize[wtype]];
first_wsize = wsize;
prev_buf = prev + (size - bsize)/2;
for (j = 0; j < mtab->fmode[ftype].sub; j++) {
int sub_wtype = ftype == FT_MEDIUM ? 8 : wtype;
if (!j && wtype == 4)
sub_wtype = 4;
else if (j == mtab->fmode[ftype].sub-1 && wtype == 7)
sub_wtype = 7;
wsize = types_sizes[wtype_to_wsize[sub_wtype]];
ff_imdct_half(&tctx->mdct_ctx[ftype], buf1 + bsize*j, in + bsize*j);
tctx->dsp.vector_fmul_window(out2,
prev_buf + (bsize-wsize)/2,
buf1 + bsize*j,
ff_sine_windows[av_log2(wsize)],
0.0,
wsize/2);
out2 += wsize;
memcpy(out2, buf1 + bsize*j + wsize/2, (bsize - wsize/2)*sizeof(float));
out2 += ftype == FT_MEDIUM ? (bsize-wsize)/2 : bsize - wsize;
prev_buf = buf1 + bsize*j + bsize/2;
}
tctx->last_block_pos[ch] = (size + first_wsize)/2;
}
static void imdct_output(TwinContext *tctx, enum FrameType ftype, int wtype,
float *out)
{
const ModeTab *mtab = tctx->mtab;
float *prev_buf = tctx->prev_frame + tctx->last_block_pos[0];
int i, j;
for (i = 0; i < tctx->avctx->channels; i++) {
imdct_and_window(tctx, ftype, wtype,
tctx->spectrum + i*mtab->size,
prev_buf + 2*i*mtab->size,
i);
}
if (tctx->avctx->channels == 2) {
for (i = 0; i < mtab->size - tctx->last_block_pos[0]; i++) {
float f1 = prev_buf[ i];
float f2 = prev_buf[2*mtab->size + i];
out[2*i ] = f1 + f2;
out[2*i + 1] = f1 - f2;
}
for (j = 0; i < mtab->size; j++,i++) {
float f1 = tctx->curr_frame[ j];
float f2 = tctx->curr_frame[2*mtab->size + j];
out[2*i ] = f1 + f2;
out[2*i + 1] = f1 - f2;
}
} else {
memcpy(out, prev_buf,
(mtab->size - tctx->last_block_pos[0]) * sizeof(*out));
out += mtab->size - tctx->last_block_pos[0];
memcpy(out, tctx->curr_frame,
(tctx->last_block_pos[0]) * sizeof(*out));
}
}
static void dec_bark_env(TwinContext *tctx, const uint8_t *in, int use_hist,
int ch, float *out, float gain, enum FrameType ftype)
{
const ModeTab *mtab = tctx->mtab;
int i,j;
float *hist = tctx->bark_hist[ftype][ch];
float val = ((const float []) {0.4, 0.35, 0.28})[ftype];
int bark_n_coef = mtab->fmode[ftype].bark_n_coef;
int fw_cb_len = mtab->fmode[ftype].bark_env_size / bark_n_coef;
int idx = 0;
for (i = 0; i < fw_cb_len; i++)
for (j = 0; j < bark_n_coef; j++, idx++) {
float tmp2 =
mtab->fmode[ftype].bark_cb[fw_cb_len*in[j] + i] * (1./4096);
float st = use_hist ?
(1. - val) * tmp2 + val*hist[idx] + 1. : tmp2 + 1.;
hist[idx] = tmp2;
if (st < -1.) st = 1.;
memset_float(out, st * gain, mtab->fmode[ftype].bark_tab[idx]);
out += mtab->fmode[ftype].bark_tab[idx];
}
}
static void read_and_decode_spectrum(TwinContext *tctx, GetBitContext *gb,
float *out, enum FrameType ftype)
{
const ModeTab *mtab = tctx->mtab;
int channels = tctx->avctx->channels;
int sub = mtab->fmode[ftype].sub;
int block_size = mtab->size / sub;
float gain[CHANNELS_MAX*SUBBLOCKS_MAX];
float ppc_shape[PPC_SHAPE_LEN_MAX * CHANNELS_MAX * 4];
uint8_t bark1[CHANNELS_MAX][SUBBLOCKS_MAX][BARK_N_COEF_MAX];
uint8_t bark_use_hist[CHANNELS_MAX][SUBBLOCKS_MAX];
uint8_t lpc_idx1[CHANNELS_MAX];
uint8_t lpc_idx2[CHANNELS_MAX][LSP_SPLIT_MAX];
uint8_t lpc_hist_idx[CHANNELS_MAX];
int i, j, k;
dequant(tctx, gb, out, ftype,
mtab->fmode[ftype].cb0, mtab->fmode[ftype].cb1,
mtab->fmode[ftype].cb_len_read);
for (i = 0; i < channels; i++)
for (j = 0; j < sub; j++)
for (k = 0; k < mtab->fmode[ftype].bark_n_coef; k++)
bark1[i][j][k] =
get_bits(gb, mtab->fmode[ftype].bark_n_bit);
for (i = 0; i < channels; i++)
for (j = 0; j < sub; j++)
bark_use_hist[i][j] = get_bits1(gb);
dec_gain(tctx, gb, ftype, gain);
for (i = 0; i < channels; i++) {
lpc_hist_idx[i] = get_bits(gb, tctx->mtab->lsp_bit0);
lpc_idx1 [i] = get_bits(gb, tctx->mtab->lsp_bit1);
for (j = 0; j < tctx->mtab->lsp_split; j++)
lpc_idx2[i][j] = get_bits(gb, tctx->mtab->lsp_bit2);
}
if (ftype == FT_LONG) {
int cb_len_p = (tctx->n_div[3] + mtab->ppc_shape_len*channels - 1)/
tctx->n_div[3];
dequant(tctx, gb, ppc_shape, FT_PPC, mtab->ppc_shape_cb,
mtab->ppc_shape_cb + cb_len_p*PPC_SHAPE_CB_SIZE, cb_len_p);
}
for (i = 0; i < channels; i++) {
float *chunk = out + mtab->size * i;
float lsp[LSP_COEFS_MAX];
for (j = 0; j < sub; j++) {
dec_bark_env(tctx, bark1[i][j], bark_use_hist[i][j], i,
tctx->tmp_buf, gain[sub*i+j], ftype);
tctx->dsp.vector_fmul(chunk + block_size*j, tctx->tmp_buf,
block_size);
}
if (ftype == FT_LONG) {
float pgain_step = 25000. / ((1 << mtab->pgain_bit) - 1);
int p_coef = get_bits(gb, tctx->mtab->ppc_period_bit);
int g_coef = get_bits(gb, tctx->mtab->pgain_bit);
float v = 1./8192*
mulawinv(pgain_step*g_coef+ pgain_step/2, 25000., PGAIN_MU);
decode_ppc(tctx, p_coef, ppc_shape + i*mtab->ppc_shape_len, v,
chunk);
}
decode_lsp(tctx, lpc_idx1[i], lpc_idx2[i], lpc_hist_idx[i], lsp,
tctx->lsp_hist[i]);
dec_lpc_spectrum_inv(tctx, lsp, ftype, tctx->tmp_buf);
for (j = 0; j < mtab->fmode[ftype].sub; j++) {
tctx->dsp.vector_fmul(chunk, tctx->tmp_buf, block_size);
chunk += block_size;
}
}
}
static int twin_decode_frame(AVCodecContext * avctx, void *data,
int *data_size, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
TwinContext *tctx = avctx->priv_data;
GetBitContext gb;
const ModeTab *mtab = tctx->mtab;
float *out = data;
enum FrameType ftype;
int window_type;
static const enum FrameType wtype_to_ftype_table[] = {
FT_LONG, FT_LONG, FT_SHORT, FT_LONG,
FT_MEDIUM, FT_LONG, FT_LONG, FT_MEDIUM, FT_MEDIUM
};
if (buf_size*8 < avctx->bit_rate*mtab->size/avctx->sample_rate + 8) {
av_log(avctx, AV_LOG_ERROR,
"Frame too small (%d bytes). Truncated file?\n", buf_size);
*data_size = 0;
return buf_size;
}
init_get_bits(&gb, buf, buf_size * 8);
skip_bits(&gb, get_bits(&gb, 8));
window_type = get_bits(&gb, WINDOW_TYPE_BITS);
if (window_type > 8) {
av_log(avctx, AV_LOG_ERROR, "Invalid window type, broken sample?\n");
return -1;
}
ftype = wtype_to_ftype_table[window_type];
read_and_decode_spectrum(tctx, &gb, tctx->spectrum, ftype);
imdct_output(tctx, ftype, window_type, out);
FFSWAP(float*, tctx->curr_frame, tctx->prev_frame);
if (tctx->avctx->frame_number < 2) {
*data_size=0;
return buf_size;
}
*data_size = mtab->size*avctx->channels*4;
return buf_size;
}
/**
* Init IMDCT and windowing tables
*/
static av_cold void init_mdct_win(TwinContext *tctx)
{
int i,j;
const ModeTab *mtab = tctx->mtab;
int size_s = mtab->size / mtab->fmode[FT_SHORT].sub;
int size_m = mtab->size / mtab->fmode[FT_MEDIUM].sub;
int channels = tctx->avctx->channels;
float norm = channels == 1 ? 2. : 1.;
for (i = 0; i < 3; i++) {
int bsize = tctx->mtab->size/tctx->mtab->fmode[i].sub;
ff_mdct_init(&tctx->mdct_ctx[i], av_log2(bsize) + 1, 1,
-sqrt(norm/bsize) / (1<<15));
}
tctx->tmp_buf = av_malloc(mtab->size * sizeof(*tctx->tmp_buf));
tctx->spectrum = av_malloc(2*mtab->size*channels*sizeof(float));
tctx->curr_frame = av_malloc(2*mtab->size*channels*sizeof(float));
tctx->prev_frame = av_malloc(2*mtab->size*channels*sizeof(float));
for (i = 0; i < 3; i++) {
int m = 4*mtab->size/mtab->fmode[i].sub;
double freq = 2*M_PI/m;
tctx->cos_tabs[i] = av_malloc((m/4)*sizeof(*tctx->cos_tabs));
for (j = 0; j <= m/8; j++)
tctx->cos_tabs[i][j] = cos((2*j + 1)*freq);
for (j = 1; j < m/8; j++)
tctx->cos_tabs[i][m/4-j] = tctx->cos_tabs[i][j];
}
ff_init_ff_sine_windows(av_log2(size_m));
ff_init_ff_sine_windows(av_log2(size_s/2));
ff_init_ff_sine_windows(av_log2(mtab->size));
}
/**
* Interpret the data as if it were a num_blocks x line_len[0] matrix and for
* each line do a cyclic permutation, i.e.
* abcdefghijklm -> defghijklmabc
* where the amount to be shifted is evaluated depending on the column.
*/
static void permutate_in_line(int16_t *tab, int num_vect, int num_blocks,
int block_size,
const uint8_t line_len[2], int length_div,
enum FrameType ftype)
{
int i,j;
for (i = 0; i < line_len[0]; i++) {
int shift;
if (num_blocks == 1 ||
(ftype == FT_LONG && num_vect % num_blocks) ||
(ftype != FT_LONG && num_vect & 1 ) ||
i == line_len[1]) {
shift = 0;
} else if (ftype == FT_LONG) {
shift = i;
} else
shift = i*i;
for (j = 0; j < num_vect && (j+num_vect*i < block_size*num_blocks); j++)
tab[i*num_vect+j] = i*num_vect + (j + shift) % num_vect;
}
}
/**
* Interpret the input data as in the following table:
*
* \verbatim
*
* abcdefgh
* ijklmnop
* qrstuvw
* x123456
*
* \endverbatim
*
* and transpose it, giving the output
* aiqxbjr1cks2dlt3emu4fvn5gow6hp
*/
static void transpose_perm(int16_t *out, int16_t *in, int num_vect,
const uint8_t line_len[2], int length_div)
{
int i,j;
int cont= 0;
for (i = 0; i < num_vect; i++)
for (j = 0; j < line_len[i >= length_div]; j++)
out[cont++] = in[j*num_vect + i];
}
static void linear_perm(int16_t *out, int16_t *in, int n_blocks, int size)
{
int block_size = size/n_blocks;
int i;
for (i = 0; i < size; i++)
out[i] = block_size * (in[i] % n_blocks) + in[i] / n_blocks;
}
static av_cold void construct_perm_table(TwinContext *tctx,enum FrameType ftype)
{
int block_size;
const ModeTab *mtab = tctx->mtab;
int size = tctx->avctx->channels*mtab->fmode[ftype].sub;
int16_t *tmp_perm = (int16_t *) tctx->tmp_buf;
if (ftype == FT_PPC) {
size = tctx->avctx->channels;
block_size = mtab->ppc_shape_len;
} else
block_size = mtab->size / mtab->fmode[ftype].sub;
permutate_in_line(tmp_perm, tctx->n_div[ftype], size,
block_size, tctx->length[ftype],
tctx->length_change[ftype], ftype);
transpose_perm(tctx->permut[ftype], tmp_perm, tctx->n_div[ftype],
tctx->length[ftype], tctx->length_change[ftype]);
linear_perm(tctx->permut[ftype], tctx->permut[ftype], size,
size*block_size);
}
static av_cold void init_bitstream_params(TwinContext *tctx)
{
const ModeTab *mtab = tctx->mtab;
int n_ch = tctx->avctx->channels;
int total_fr_bits = tctx->avctx->bit_rate*mtab->size/
tctx->avctx->sample_rate;
int lsp_bits_per_block = n_ch*(mtab->lsp_bit0 + mtab->lsp_bit1 +
mtab->lsp_split*mtab->lsp_bit2);
int ppc_bits = n_ch*(mtab->pgain_bit + mtab->ppc_shape_bit +
mtab->ppc_period_bit);
int bsize_no_main_cb[3];
int bse_bits[3];
int i;
enum FrameType frametype;
for (i = 0; i < 3; i++)
// +1 for history usage switch
bse_bits[i] = n_ch *
(mtab->fmode[i].bark_n_coef * mtab->fmode[i].bark_n_bit + 1);
bsize_no_main_cb[2] = bse_bits[2] + lsp_bits_per_block + ppc_bits +
WINDOW_TYPE_BITS + n_ch*GAIN_BITS;
for (i = 0; i < 2; i++)
bsize_no_main_cb[i] =
lsp_bits_per_block + n_ch*GAIN_BITS + WINDOW_TYPE_BITS +
mtab->fmode[i].sub*(bse_bits[i] + n_ch*SUB_GAIN_BITS);
// The remaining bits are all used for the main spectrum coefficients
for (i = 0; i < 4; i++) {
int bit_size;
int vect_size;
int rounded_up, rounded_down, num_rounded_down, num_rounded_up;
if (i == 3) {
bit_size = n_ch * mtab->ppc_shape_bit;
vect_size = n_ch * mtab->ppc_shape_len;
} else {
bit_size = total_fr_bits - bsize_no_main_cb[i];
vect_size = n_ch * mtab->size;
}
tctx->n_div[i] = (bit_size + 13) / 14;
rounded_up = (bit_size + tctx->n_div[i] - 1)/tctx->n_div[i];
rounded_down = (bit_size )/tctx->n_div[i];
num_rounded_down = rounded_up * tctx->n_div[i] - bit_size;
num_rounded_up = tctx->n_div[i] - num_rounded_down;
tctx->bits_main_spec[0][i][0] = (rounded_up + 1)/2;
tctx->bits_main_spec[1][i][0] = (rounded_up )/2;
tctx->bits_main_spec[0][i][1] = (rounded_down + 1)/2;
tctx->bits_main_spec[1][i][1] = (rounded_down )/2;
tctx->bits_main_spec_change[i] = num_rounded_up;
rounded_up = (vect_size + tctx->n_div[i] - 1)/tctx->n_div[i];
rounded_down = (vect_size )/tctx->n_div[i];
num_rounded_down = rounded_up * tctx->n_div[i] - vect_size;
num_rounded_up = tctx->n_div[i] - num_rounded_down;
tctx->length[i][0] = rounded_up;
tctx->length[i][1] = rounded_down;
tctx->length_change[i] = num_rounded_up;
}
for (frametype = FT_SHORT; frametype <= FT_PPC; frametype++)
construct_perm_table(tctx, frametype);
}
static av_cold int twin_decode_init(AVCodecContext *avctx)
{
TwinContext *tctx = avctx->priv_data;
int isampf = avctx->sample_rate/1000;
int ibps = avctx->bit_rate/(1000 * avctx->channels);
tctx->avctx = avctx;
avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
if (avctx->channels > CHANNELS_MAX) {
av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels: %i\n",
avctx->channels);
return -1;
}
switch ((isampf << 8) + ibps) {
case (8 <<8) + 8: tctx->mtab = &mode_08_08; break;
case (11<<8) + 8: tctx->mtab = &mode_11_08; break;
case (11<<8) + 10: tctx->mtab = &mode_11_10; break;
case (16<<8) + 16: tctx->mtab = &mode_16_16; break;
case (22<<8) + 20: tctx->mtab = &mode_22_20; break;
case (22<<8) + 24: tctx->mtab = &mode_22_24; break;
case (22<<8) + 32: tctx->mtab = &mode_22_32; break;
case (44<<8) + 40: tctx->mtab = &mode_44_40; break;
case (44<<8) + 48: tctx->mtab = &mode_44_48; break;
default:
av_log(avctx, AV_LOG_ERROR, "This version does not support %d kHz - %d kbit/s/ch mode.\n", isampf, isampf);
return -1;
}
dsputil_init(&tctx->dsp, avctx);
init_mdct_win(tctx);
init_bitstream_params(tctx);
memset_float(tctx->bark_hist[0][0], 0.1, FF_ARRAY_ELEMS(tctx->bark_hist));
return 0;
}
static av_cold int twin_decode_close(AVCodecContext *avctx)
{
TwinContext *tctx = avctx->priv_data;
int i;
for (i = 0; i < 3; i++) {
ff_mdct_end(&tctx->mdct_ctx[i]);
av_free(tctx->cos_tabs[i]);
}
av_free(tctx->curr_frame);
av_free(tctx->spectrum);
av_free(tctx->prev_frame);
av_free(tctx->tmp_buf);
return 0;
}
AVCodec twinvq_decoder =
{
"twinvq",
AVMEDIA_TYPE_AUDIO,
CODEC_ID_TWINVQ,
sizeof(TwinContext),
twin_decode_init,
NULL,
twin_decode_close,
twin_decode_frame,
.long_name = NULL_IF_CONFIG_SMALL("VQF TwinVQ"),
};
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