ref: c7e0b76c06101766201f7b6ee1859306f5480914
dir: /libcelt/celt.c/
/* (C) 2007-2008 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
#define CELT_C
#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"
#include "stack_alloc.h"
static const celt_word16_t preemph = QCONST16(0.8f,15);
/** 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;
celt_sig_t *preemph_memE;
celt_sig_t *preemph_memD;
kiss_fftr_cfg fft;
celt_sig_t *in_mem;
celt_sig_t *mdct_overlap;
celt_sig_t *out_mem;
celt_word16_t *oldBandE;
};
CELTEncoder EXPORT *celt_encoder_create(const CELTMode *mode)
{
int N, B, C;
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;
ec_byte_writeinit(&st->buf);
ec_enc_init(&st->enc,&st->buf);
st->fft = pitch_state_alloc(MAX_PERIOD);
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));
st->oldBandE = (celt_word16_t*)celt_alloc(C*mode->nbEBands*sizeof(celt_word16_t));
st->preemph_memE = (celt_sig_t*)celt_alloc(C*sizeof(celt_sig_t));;
st->preemph_memD = (celt_sig_t*)celt_alloc(C*sizeof(celt_sig_t));;
return st;
}
void EXPORT 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);
pitch_state_free(st->fft);
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);
}
static inline celt_int16_t SIG2INT16(celt_sig_t x)
{
x = PSHR32(x, SIG_SHIFT);
if (x>32767)
x = 32767;
else if (x<-32767)
x = -32767;
#ifdef FIXED_POINT
return EXTRACT16(x);
#else
return (celt_int16_t)floor(.5+x);
#endif
}
/** Apply window and compute the MDCT for all sub-frames and all channels in a frame */
static celt_word32_t compute_mdcts(const mdct_lookup *lookup, const celt_word16_t *window, celt_sig_t *in, celt_sig_t *out, int N, int overlap, int B, int C)
{
int i, c, N4;
celt_word32_t E = 0;
VARDECL(celt_word32_t, x);
VARDECL(celt_word32_t, tmp);
SAVE_STACK;
N4 = (N-overlap)/2;
ALLOC(x, 2*N, celt_word32_t);
ALLOC(tmp, N, celt_word32_t);
for (c=0;c<C;c++)
{
for (i=0;i<B;i++)
{
int j;
for (j=0;j<2*N-2*N4;j++)
x[j+N4] = in[C*i*N+C*j+c];
for (j=0;j<overlap;j++)
{
x[j+N4] = MULT16_32_Q15(window[j],x[j+N4]);
x[2*N-j-N4-1] = MULT16_32_Q15(window[j],x[2*N-j-N4-1]);
}
for (j=0;j<N4;j++)
{
x[j] = 0;
x[2*N-j-1] = 0;
}
for (j=0;j<2*N;j++)
E += MULT16_16(EXTRACT16(SHR32(x[j],SIG_SHIFT+4)),EXTRACT16(SHR32(x[j],SIG_SHIFT+4)));
mdct_forward(lookup, x, tmp);
/* Interleaving the sub-frames */
for (j=0;j<N;j++)
out[C*B*j+C*i+c] = tmp[j];
}
}
RESTORE_STACK;
return E;
}
/** Compute the IMDCT and apply window for all sub-frames and all channels in a frame */
static void compute_inv_mdcts(const mdct_lookup *lookup, const celt_word16_t *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_word32_t, x);
VARDECL(celt_word32_t, tmp);
SAVE_STACK;
ALLOC(x, 2*N, celt_word32_t);
ALLOC(tmp, N, celt_word32_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(lookup, tmp, x);
/* The first and last part would need to be set to zero if we actually
wanted to use them. */
for (j=0;j<overlap;j++)
{
x[j+N4] = MULT16_32_Q15(window[j],x[j+N4]);
x[2*N-j-N4-1] = MULT16_32_Q15(window[j],x[2*N-j-N4-1]);
}
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];
}
}
RESTORE_STACK;
}
int EXPORT 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;
celt_word32_t 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(celt_ener_t, bandE);
VARDECL(celt_pgain_t, gains);
SAVE_STACK;
if (check_mode(st->mode) != CELT_OK)
return CELT_INVALID_MODE;
N = st->block_size;
B = st->nb_blocks;
C = st->mode->nbChannels;
N4 = (N-st->overlap)/2;
ALLOC(in, (B+1)*C*N-2*N4, celt_sig_t);
for (c=0;c<C;c++)
{
for (i=0;i<st->overlap;i++)
in[C*i+c] = st->in_mem[C*i+c];
for (i=0;i<B*N;i++)
{
celt_sig_t tmp = SHL32(EXTEND32(pcm[C*i+c]), SIG_SHIFT);
in[C*(i+st->overlap)+c] = SUB32(tmp, MULT16_32_Q15(preemph,st->preemph_memE[c]));
st->preemph_memE[c] = tmp;
}
for (i=0;i<st->overlap;i++)
st->in_mem[C*i+c] = in[C*(N*(B+1)-2*N4-st->overlap+i)+c];
}
/* Pitch analysis: we do it early to save on the peak stack space */
find_spectral_pitch(st->fft, &st->mode->psy, in, st->out_mem, st->mode->window, st->overlap, MAX_PERIOD, (B+1)*N-2*N4, C, &pitch_index);
ALLOC(freq, B*C*N, celt_sig_t); /**< Interleaved signal MDCTs */
/*for (i=0;i<(B+1)*C*N;i++) printf ("%f(%d) ", in[i], i); printf ("\n");*/
/* Compute MDCTs */
curr_power = compute_mdcts(&st->mode->mdct, st->mode->window, in, freq, N, st->overlap, 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]);
#endif
/* Deferred allocation after find_spectral_pitch() to reduce the peak memory usage */
ALLOC(X, B*C*N, celt_norm_t); /**< Interleaved normalised MDCTs */
ALLOC(P, B*C*N, celt_norm_t); /**< Interleaved normalised pitch MDCTs*/
ALLOC(bandE,st->mode->nbEBands*C, celt_ener_t);
ALLOC(gains,st->mode->nbPBands, celt_pgain_t);
/*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->mode->mdct, st->mode->window, st->out_mem+pitch_index*C, freq, N, st->overlap, 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 (MULT16_32_Q15(QCONST16(.1f, 15),curr_power) + SHR16(10000,8) < pitch_power)
{
/* Normalise the pitch vector as well (discard the energies) */
VARDECL(celt_ener_t, bandEp);
ALLOC(bandEp, st->mode->nbEBands*st->mode->nbChannels, celt_ener_t);
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);
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-2*N4));
} 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, 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];
/* Residual quantisation */
quant_bands(st->mode, X, P, NULL, 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->mode->mdct, st->mode->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++)
{
celt_sig_t tmp = ADD32(st->out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c],
MULT16_32_Q15(preemph,st->preemph_memD[c]));
st->preemph_memD[c] = tmp;
pcm[C*i*N+C*j+c] = SIG2INT16(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);
RESTORE_STACK;
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);
RESTORE_STACK;
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;
celt_sig_t *preemph_memD;
celt_sig_t *mdct_overlap;
celt_sig_t *out_mem;
celt_word16_t *oldBandE;
int last_pitch_index;
};
CELTDecoder EXPORT *celt_decoder_create(const CELTMode *mode)
{
int N, B, C;
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;
st->mdct_overlap = celt_alloc(N*C*sizeof(celt_sig_t));
st->out_mem = celt_alloc(MAX_PERIOD*C*sizeof(celt_sig_t));
st->oldBandE = (celt_word16_t*)celt_alloc(C*mode->nbEBands*sizeof(celt_word16_t));
st->preemph_memD = (celt_sig_t*)celt_alloc(C*sizeof(celt_sig_t));;
st->last_pitch_index = 0;
return st;
}
void EXPORT 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;
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);
SAVE_STACK;
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->mode->mdct, st->mode->window, st->out_mem+pitch_index*C, freq, N, st->overlap, 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->mode->mdct, st->mode->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++)
{
celt_sig_t tmp = ADD32(st->out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c],
MULT16_32_Q15(preemph,st->preemph_memD[c]));
st->preemph_memD[c] = tmp;
pcm[C*i*N+C*j+c] = SIG2INT16(tmp);
}
}
}
RESTORE_STACK;
}
int EXPORT celt_decode(CELTDecoder *st, unsigned char *data, int len, celt_int16_t *pcm)
{
int i, c, N, B, C, N4;
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(celt_ener_t, bandE);
VARDECL(celt_pgain_t, gains);
SAVE_STACK;
if (check_mode(st->mode) != CELT_OK)
return CELT_INVALID_MODE;
N = st->block_size;
B = st->nb_blocks;
C = st->mode->nbChannels;
N4 = (N-st->overlap)/2;
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, celt_ener_t);
ALLOC(gains, st->mode->nbPBands, celt_pgain_t);
if (check_mode(st->mode) != CELT_OK)
{
RESTORE_STACK;
return CELT_INVALID_MODE;
}
if (data == NULL)
{
celt_decode_lost(st, pcm);
RESTORE_STACK;
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-2*N4));
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->mode->mdct, st->mode->window, st->out_mem+pitch_index*C, freq, N, st->overlap, B, C);
{
VARDECL(celt_ener_t, bandEp);
ALLOC(bandEp, st->mode->nbEBands*C, celt_ener_t);
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, 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->mode->mdct, st->mode->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++)
{
celt_sig_t tmp = ADD32(st->out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c],
MULT16_32_Q15(preemph,st->preemph_memD[c]));
st->preemph_memD[c] = tmp;
pcm[C*i*N+C*j+c] = SIG2INT16(tmp);
}
}
}
{
unsigned int val = 0;
while (ec_dec_tell(&dec, 0) < len*8)
{
if (ec_dec_uint(&dec, 2) != val)
{
celt_warning("decode error");
RESTORE_STACK;
return CELT_CORRUPTED_DATA;
}
val = 1-val;
}
}
RESTORE_STACK;
return 0;
/*printf ("\n");*/
}