ref: e8b6830f538e41a5a0db076bd183db43e3b99b3e
dir: /libcelt/celt.c/
/* (C) 2007 Jean-Marc Valin, CSIRO
*/
/*
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of the Xiph.org Foundation nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "os_support.h"
#include "mdct.h"
#include <math.h>
#include "celt.h"
#include "pitch.h"
#include "kiss_fftr.h"
#include "bands.h"
#include "modes.h"
#include "entcode.h"
#include "quant_pitch.h"
#include "quant_bands.h"
#include "psy.h"
#include "rate.h"
#define MAX_PERIOD 1024
#ifndef M_PI
#define M_PI 3.14159263
#endif
/** Encoder state
@brief Encoder state
*/
struct CELTEncoder {
const CELTMode *mode; /**< Mode used by the encoder */
int frame_size;
int block_size;
int nb_blocks;
int overlap;
int channels;
ec_byte_buffer buf;
ec_enc enc;
float preemph;
float *preemph_memE;
float *preemph_memD;
mdct_lookup mdct_lookup;
kiss_fftr_cfg fft;
struct PsyDecay psy;
float *window;
celt_sig_t *in_mem;
celt_sig_t *mdct_overlap;
celt_sig_t *out_mem;
float *oldBandE;
};
CELTEncoder *celt_encoder_create(const CELTMode *mode)
{
int i, N, B, C, N4;
CELTEncoder *st;
if (check_mode(mode) != CELT_OK)
return NULL;
N = mode->mdctSize;
B = mode->nbMdctBlocks;
C = mode->nbChannels;
st = celt_alloc(sizeof(CELTEncoder));
st->mode = mode;
st->frame_size = B*N;
st->block_size = N;
st->nb_blocks = B;
st->overlap = mode->overlap;
N4 = (N-st->overlap)/2;
ec_byte_writeinit(&st->buf);
ec_enc_init(&st->enc,&st->buf);
mdct_init(&st->mdct_lookup, 2*N);
st->fft = kiss_fftr_alloc(MAX_PERIOD*C, 0, 0);
psydecay_init(&st->psy, MAX_PERIOD*C/2, st->mode->Fs);
st->window = celt_alloc(2*N*sizeof(float));
st->in_mem = celt_alloc(N*C*sizeof(celt_sig_t));
st->mdct_overlap = celt_alloc(N*C*sizeof(celt_sig_t));
st->out_mem = celt_alloc(MAX_PERIOD*C*sizeof(celt_sig_t));
for (i=0;i<2*N;i++)
st->window[i] = 0;
for (i=0;i<st->overlap;i++)
st->window[N4+i] = st->window[2*N-N4-i-1]
= sin(.5*M_PI* sin(.5*M_PI*(i+.5)/st->overlap) * sin(.5*M_PI*(i+.5)/st->overlap));
for (i=0;i<2*N4;i++)
st->window[N-N4+i] = 1;
st->oldBandE = celt_alloc(C*mode->nbEBands*sizeof(float));
st->preemph = 0.8;
st->preemph_memE = celt_alloc(C*sizeof(float));;
st->preemph_memD = celt_alloc(C*sizeof(float));;
return st;
}
void celt_encoder_destroy(CELTEncoder *st)
{
if (st == NULL)
{
celt_warning("NULL passed to celt_encoder_destroy");
return;
}
if (check_mode(st->mode) != CELT_OK)
return;
ec_byte_writeclear(&st->buf);
mdct_clear(&st->mdct_lookup);
kiss_fft_free(st->fft);
psydecay_clear(&st->psy);
celt_free(st->window);
celt_free(st->in_mem);
celt_free(st->mdct_overlap);
celt_free(st->out_mem);
celt_free(st->oldBandE);
celt_free(st->preemph_memE);
celt_free(st->preemph_memD);
celt_free(st);
}
/** Apply window and compute the MDCT for all sub-frames and all channels in a frame */
static float compute_mdcts(mdct_lookup *mdct_lookup, float *window, celt_sig_t *in, celt_sig_t *out, int N, int B, int C)
{
int i, c;
float E = 1e-15;
VARDECL(celt_sig_t *x);
VARDECL(celt_sig_t *tmp);
ALLOC(x, 2*N, celt_sig_t);
ALLOC(tmp, N, celt_sig_t);
for (c=0;c<C;c++)
{
for (i=0;i<B;i++)
{
int j;
for (j=0;j<2*N;j++)
{
x[j] = window[j]*in[C*i*N+C*j+c];
E += x[j]*x[j];
}
mdct_forward(mdct_lookup, x, tmp);
/* Interleaving the sub-frames */
for (j=0;j<N;j++)
out[C*B*j+C*i+c] = tmp[j];
}
}
return E;
}
/** Compute the IMDCT and apply window for all sub-frames and all channels in a frame */
static void compute_inv_mdcts(mdct_lookup *mdct_lookup, float *window, celt_sig_t *X, celt_sig_t *out_mem, celt_sig_t *mdct_overlap, int N, int overlap, int B, int C)
{
int i, c, N4;
VARDECL(celt_sig_t *x);
VARDECL(celt_sig_t *tmp);
ALLOC(x, 2*N, celt_sig_t);
ALLOC(tmp, N, celt_sig_t);
N4 = (N-overlap)/2;
for (c=0;c<C;c++)
{
for (i=0;i<B;i++)
{
int j;
/* De-interleaving the sub-frames */
for (j=0;j<N;j++)
tmp[j] = X[C*B*j+C*i+c];
mdct_backward(mdct_lookup, tmp, x);
for (j=0;j<2*N;j++)
x[j] = window[j]*x[j];
for (j=0;j<overlap;j++)
out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c] = 2*(x[N4+j]+mdct_overlap[C*j+c]);
for (j=0;j<2*N4;j++)
out_mem[C*(MAX_PERIOD+(i-B)*N)+C*(j+overlap)+c] = 2*x[j+N4+overlap];
for (j=0;j<overlap;j++)
mdct_overlap[C*j+c] = x[N+N4+j];
}
}
}
int celt_encode(CELTEncoder *st, celt_int16_t *pcm, unsigned char *compressed, int nbCompressedBytes)
{
int i, c, N, B, C, N4;
int has_pitch;
int pitch_index;
float curr_power, pitch_power;
VARDECL(celt_sig_t *in);
VARDECL(celt_sig_t *freq);
VARDECL(celt_norm_t *X);
VARDECL(celt_norm_t *P);
VARDECL(float *mask);
VARDECL(float *bandE);
VARDECL(float *gains);
if (check_mode(st->mode) != CELT_OK)
return CELT_INVALID_MODE;
N = st->block_size;
B = st->nb_blocks;
C = st->mode->nbChannels;
ALLOC(in, (B+1)*C*N, celt_sig_t);
ALLOC(freq, B*C*N, celt_sig_t); /**< Interleaved signal MDCTs */
ALLOC(X, B*C*N, celt_norm_t); /**< Interleaved normalised MDCTs */
ALLOC(P, B*C*N, celt_norm_t); /**< Interleaved normalised pitch MDCTs*/
ALLOC(mask, B*C*N, float); /**< Masking curve */
ALLOC(bandE,st->mode->nbEBands*C, float);
ALLOC(gains,st->mode->nbPBands, float);
N4 = (N-st->overlap)/2;
for (c=0;c<C;c++)
{
for (i=0;i<N4;i++)
in[C*i+c] = 0;
for (i=0;i<st->overlap;i++)
in[C*(i+N4)+c] = st->in_mem[C*i+c];
for (i=0;i<B*N;i++)
{
float tmp = pcm[C*i+c];
in[C*(i+st->overlap+N4)+c] = tmp - st->preemph*st->preemph_memE[c];
st->preemph_memE[c] = tmp;
}
for (i=N*(B+1)-N4;i<N*(B+1);i++)
in[C*i+c] = 0;
for (i=0;i<st->overlap;i++)
st->in_mem[C*i+c] = in[C*(N*(B+1)-N4-st->overlap+i)+c];
}
/*for (i=0;i<(B+1)*C*N;i++) printf ("%f(%d) ", in[i], i); printf ("\n");*/
/* Compute MDCTs */
curr_power = compute_mdcts(&st->mdct_lookup, st->window, in, freq, N, B, C);
#if 0 /* Mask disabled until it can be made to do something useful */
compute_mdct_masking(X, mask, B*C*N, st->Fs);
/* Invert and stretch the mask to length of X
For some reason, I get better results by using the sqrt instead,
although there's no valid reason to. Must investigate further */
for (i=0;i<B*C*N;i++)
mask[i] = 1/(.1+mask[i]);
#else
for (i=0;i<B*C*N;i++)
mask[i] = 1;
#endif
/* Pitch analysis */
for (c=0;c<C;c++)
{
for (i=0;i<N;i++)
{
in[C*i+c] *= st->window[i];
in[C*(B*N+i)+c] *= st->window[N+i];
}
}
find_spectral_pitch(st->fft, &st->psy, in, st->out_mem, MAX_PERIOD, (B+1)*N, C, &pitch_index);
/*printf ("%f %f\n", curr_power, pitch_power);*/
/*int j;
for (j=0;j<B*N;j++)
printf ("%f ", X[j]);
for (j=0;j<B*N;j++)
printf ("%f ", P[j]);
printf ("\n");*/
/* Band normalisation */
compute_band_energies(st->mode, freq, bandE);
normalise_bands(st->mode, freq, X, bandE);
/*for (i=0;i<st->mode->nbEBands;i++)printf("%f ", bandE[i]);printf("\n");*/
/*for (i=0;i<N*B*C;i++)printf("%f ", X[i]);printf("\n");*/
/* Compute MDCTs of the pitch part */
pitch_power = compute_mdcts(&st->mdct_lookup, st->window, st->out_mem+pitch_index*C, freq, N, B, C);
quant_energy(st->mode, bandE, st->oldBandE, nbCompressedBytes*8/3, &st->enc);
if (C==2)
{
stereo_mix(st->mode, X, bandE, 1);
}
/* Check if we can safely use the pitch (i.e. effective gain isn't too high) */
if (curr_power + 1e5f < 10.f*pitch_power)
{
/* Normalise the pitch vector as well (discard the energies) */
VARDECL(float *bandEp);
ALLOC(bandEp, st->mode->nbEBands*st->mode->nbChannels, float);
compute_band_energies(st->mode, freq, bandEp);
normalise_bands(st->mode, freq, P, bandEp);
if (C==2)
stereo_mix(st->mode, P, bandE, 1);
/* Simulates intensity stereo */
/*for (i=30;i<N*B;i++)
X[i*C+1] = P[i*C+1] = 0;*/
/* Pitch prediction */
compute_pitch_gain(st->mode, X, P, gains, bandE);
has_pitch = quant_pitch(gains, st->mode->nbPBands, &st->enc);
if (has_pitch)
ec_enc_uint(&st->enc, pitch_index, MAX_PERIOD-(B+1)*N);
} else {
/* No pitch, so we just pretend we found a gain of zero */
for (i=0;i<st->mode->nbPBands;i++)
gains[i] = 0;
ec_enc_uint(&st->enc, 0, 128);
for (i=0;i<B*C*N;i++)
P[i] = 0;
}
pitch_quant_bands(st->mode, X, P, gains);
/*for (i=0;i<B*N;i++) printf("%f ",P[i]);printf("\n");*/
/* Compute residual that we're going to encode */
for (i=0;i<B*C*N;i++)
X[i] -= P[i];
/*float sum=0;
for (i=0;i<B*N;i++)
sum += X[i]*X[i];
printf ("%f\n", sum);*/
/* Residual quantisation */
quant_bands(st->mode, X, P, mask, nbCompressedBytes*8, &st->enc);
if (C==2)
{
stereo_mix(st->mode, X, bandE, -1);
renormalise_bands(st->mode, X);
}
/* Synthesis */
denormalise_bands(st->mode, X, freq, bandE);
CELT_MOVE(st->out_mem, st->out_mem+C*B*N, C*(MAX_PERIOD-B*N));
compute_inv_mdcts(&st->mdct_lookup, st->window, freq, st->out_mem, st->mdct_overlap, N, st->overlap, B, C);
/* De-emphasis and put everything back at the right place in the synthesis history */
for (c=0;c<C;c++)
{
for (i=0;i<B;i++)
{
int j;
for (j=0;j<N;j++)
{
float tmp = st->out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c] + st->preemph*st->preemph_memD[c];
st->preemph_memD[c] = tmp;
if (tmp > 32767) tmp = 32767;
if (tmp < -32767) tmp = -32767;
pcm[C*i*N+C*j+c] = (short)floor(.5+tmp);
}
}
}
if (ec_enc_tell(&st->enc, 0) < nbCompressedBytes*8 - 7)
celt_warning_int ("many unused bits: ", nbCompressedBytes*8-ec_enc_tell(&st->enc, 0));
/*printf ("%d\n", ec_enc_tell(&st->enc, 0)-8*nbCompressedBytes);*/
/* Finishing the stream with a 0101... pattern so that the decoder can check is everything's right */
{
int val = 0;
while (ec_enc_tell(&st->enc, 0) < nbCompressedBytes*8)
{
ec_enc_uint(&st->enc, val, 2);
val = 1-val;
}
}
ec_enc_done(&st->enc);
{
unsigned char *data;
int nbBytes = ec_byte_bytes(&st->buf);
if (nbBytes > nbCompressedBytes)
{
celt_warning_int ("got too many bytes:", nbBytes);
return CELT_INTERNAL_ERROR;
}
/*printf ("%d\n", *nbBytes);*/
data = ec_byte_get_buffer(&st->buf);
for (i=0;i<nbBytes;i++)
compressed[i] = data[i];
for (;i<nbCompressedBytes;i++)
compressed[i] = 0;
}
/* Reset the packing for the next encoding */
ec_byte_reset(&st->buf);
ec_enc_init(&st->enc,&st->buf);
return nbCompressedBytes;
}
/****************************************************************************/
/* */
/* DECODER */
/* */
/****************************************************************************/
/** Decoder state
@brief Decoder state
*/
struct CELTDecoder {
const CELTMode *mode;
int frame_size;
int block_size;
int nb_blocks;
int overlap;
ec_byte_buffer buf;
ec_enc enc;
float preemph;
float *preemph_memD;
mdct_lookup mdct_lookup;
float *window;
celt_sig_t *mdct_overlap;
celt_sig_t *out_mem;
float *oldBandE;
int last_pitch_index;
};
CELTDecoder *celt_decoder_create(const CELTMode *mode)
{
int i, N, B, C, N4;
CELTDecoder *st;
if (check_mode(mode) != CELT_OK)
return NULL;
N = mode->mdctSize;
B = mode->nbMdctBlocks;
C = mode->nbChannels;
st = celt_alloc(sizeof(CELTDecoder));
st->mode = mode;
st->frame_size = B*N;
st->block_size = N;
st->nb_blocks = B;
st->overlap = mode->overlap;
N4 = (N-st->overlap)/2;
mdct_init(&st->mdct_lookup, 2*N);
st->window = celt_alloc(2*N*sizeof(float));
st->mdct_overlap = celt_alloc(N*C*sizeof(celt_sig_t));
st->out_mem = celt_alloc(MAX_PERIOD*C*sizeof(celt_sig_t));
for (i=0;i<2*N;i++)
st->window[i] = 0;
for (i=0;i<st->overlap;i++)
st->window[N4+i] = st->window[2*N-N4-i-1]
= sin(.5*M_PI* sin(.5*M_PI*(i+.5)/st->overlap) * sin(.5*M_PI*(i+.5)/st->overlap));
for (i=0;i<2*N4;i++)
st->window[N-N4+i] = 1;
st->oldBandE = celt_alloc(C*mode->nbEBands*sizeof(float));
st->preemph = 0.8;
st->preemph_memD = celt_alloc(C*sizeof(float));;
st->last_pitch_index = 0;
return st;
}
void celt_decoder_destroy(CELTDecoder *st)
{
if (st == NULL)
{
celt_warning("NULL passed to celt_encoder_destroy");
return;
}
if (check_mode(st->mode) != CELT_OK)
return;
mdct_clear(&st->mdct_lookup);
celt_free(st->window);
celt_free(st->mdct_overlap);
celt_free(st->out_mem);
celt_free(st->oldBandE);
celt_free(st->preemph_memD);
celt_free(st);
}
/** Handles lost packets by just copying past data with the same offset as the last
pitch period */
static void celt_decode_lost(CELTDecoder *st, short *pcm)
{
int i, c, N, B, C;
int pitch_index;
VARDECL(celt_sig_t *freq);
N = st->block_size;
B = st->nb_blocks;
C = st->mode->nbChannels;
ALLOC(freq,C*B*N, celt_sig_t); /**< Interleaved signal MDCTs */
pitch_index = st->last_pitch_index;
/* Use the pitch MDCT as the "guessed" signal */
compute_mdcts(&st->mdct_lookup, st->window, st->out_mem+pitch_index*C, freq, N, B, C);
CELT_MOVE(st->out_mem, st->out_mem+C*B*N, C*(MAX_PERIOD-B*N));
/* Compute inverse MDCTs */
compute_inv_mdcts(&st->mdct_lookup, st->window, freq, st->out_mem, st->mdct_overlap, N, st->overlap, B, C);
for (c=0;c<C;c++)
{
for (i=0;i<B;i++)
{
int j;
for (j=0;j<N;j++)
{
float tmp = st->out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c] + st->preemph*st->preemph_memD[c];
st->preemph_memD[c] = tmp;
if (tmp > 32767) tmp = 32767;
if (tmp < -32767) tmp = -32767;
pcm[C*i*N+C*j+c] = (short)floor(.5+tmp);
}
}
}
}
int celt_decode(CELTDecoder *st, unsigned char *data, int len, celt_int16_t *pcm)
{
int i, c, N, B, C;
int has_pitch;
int pitch_index;
ec_dec dec;
ec_byte_buffer buf;
VARDECL(celt_sig_t *freq);
VARDECL(celt_norm_t *X);
VARDECL(celt_norm_t *P);
VARDECL(float *bandE);
VARDECL(float *gains);
if (check_mode(st->mode) != CELT_OK)
return CELT_INVALID_MODE;
N = st->block_size;
B = st->nb_blocks;
C = st->mode->nbChannels;
ALLOC(freq, C*B*N, celt_sig_t); /**< Interleaved signal MDCTs */
ALLOC(X, C*B*N, celt_norm_t); /**< Interleaved normalised MDCTs */
ALLOC(P, C*B*N, celt_norm_t); /**< Interleaved normalised pitch MDCTs*/
ALLOC(bandE, st->mode->nbEBands*C, float);
ALLOC(gains, st->mode->nbPBands, float);
if (check_mode(st->mode) != CELT_OK)
return CELT_INVALID_MODE;
if (data == NULL)
{
celt_decode_lost(st, pcm);
return 0;
}
ec_byte_readinit(&buf,data,len);
ec_dec_init(&dec,&buf);
/* Get band energies */
unquant_energy(st->mode, bandE, st->oldBandE, len*8/3, &dec);
/* Get the pitch gains */
has_pitch = unquant_pitch(gains, st->mode->nbPBands, &dec);
/* Get the pitch index */
if (has_pitch)
{
pitch_index = ec_dec_uint(&dec, MAX_PERIOD-(B+1)*N);
st->last_pitch_index = pitch_index;
} else {
/* FIXME: We could be more intelligent here and just not compute the MDCT */
pitch_index = 0;
}
/* Pitch MDCT */
compute_mdcts(&st->mdct_lookup, st->window, st->out_mem+pitch_index*C, freq, N, B, C);
{
VARDECL(float *bandEp);
ALLOC(bandEp, st->mode->nbEBands*C, float);
compute_band_energies(st->mode, freq, bandEp);
normalise_bands(st->mode, freq, P, bandEp);
}
if (C==2)
stereo_mix(st->mode, P, bandE, 1);
/* Apply pitch gains */
pitch_quant_bands(st->mode, X, P, gains);
/* Decode fixed codebook and merge with pitch */
unquant_bands(st->mode, X, P, len*8, &dec);
if (C==2)
{
stereo_mix(st->mode, X, bandE, -1);
renormalise_bands(st->mode, X);
}
/* Synthesis */
denormalise_bands(st->mode, X, freq, bandE);
CELT_MOVE(st->out_mem, st->out_mem+C*B*N, C*(MAX_PERIOD-B*N));
/* Compute inverse MDCTs */
compute_inv_mdcts(&st->mdct_lookup, st->window, freq, st->out_mem, st->mdct_overlap, N, st->overlap, B, C);
for (c=0;c<C;c++)
{
for (i=0;i<B;i++)
{
int j;
for (j=0;j<N;j++)
{
float tmp = st->out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c] + st->preemph*st->preemph_memD[c];
st->preemph_memD[c] = tmp;
if (tmp > 32767) tmp = 32767;
if (tmp < -32767) tmp = -32767;
pcm[C*i*N+C*j+c] = (short)floor(.5+tmp);
}
}
}
{
int val = 0;
while (ec_dec_tell(&dec, 0) < len*8)
{
if (ec_dec_uint(&dec, 2) != val)
{
celt_warning("decode error");
return CELT_CORRUPTED_DATA;
}
val = 1-val;
}
}
return 0;
/*printf ("\n");*/
}