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Commit a5431bfb authored by Jean-Marc Valin's avatar Jean-Marc Valin
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Allowing reduced overlap MDCTs as an alternative 

to multiple MDCTs per frame. Not complete yet.
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libcelt/celt.c
+ 42
− 19
View file @ a5431bfb
......@@ -50,6 +50,7 @@ struct CELTEncoder {
int frame_size;
int block_size;
int nb_blocks;
int overlap;
int channels;
int Fs;
......@@ -75,7 +76,7 @@ struct CELTEncoder {
CELTEncoder *celt_encoder_new(const CELTMode *mode)
{
int i, N, B, C;
int i, N, B, C, N4;
N = mode->mdctSize;
B = mode->nbMdctBlocks;
C = mode->nbChannels;
......@@ -85,8 +86,10 @@ CELTEncoder *celt_encoder_new(const CELTMode *mode)
st->frame_size = B*N;
st->block_size = N;
st->nb_blocks = B;
st->overlap = mode->overlap;
st->Fs = 44100;
N4 = (N-st->overlap)/2;
ec_byte_writeinit(&st->buf);
ec_enc_init(&st->enc,&st->buf);
......@@ -97,9 +100,13 @@ CELTEncoder *celt_encoder_new(const CELTMode *mode)
st->in_mem = celt_alloc(N*C*sizeof(float));
st->mdct_overlap = celt_alloc(N*C*sizeof(float));
st->out_mem = celt_alloc(MAX_PERIOD*C*sizeof(float));
for (i=0;i<N;i++)
st->window[i] = st->window[2*N-i-1] = sin(.5*M_PI* sin(.5*M_PI*(i+.5)/N) * sin(.5*M_PI*(i+.5)/N));
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(mode->nbEBands*sizeof(float));
st->preemph = 0.8;
......@@ -220,31 +227,37 @@ static void compute_inv_mdcts(mdct_lookup *mdct_lookup, float *window, float *X,
int celt_encode(CELTEncoder *st, short *pcm)
{
int i, c, N, B, C;
int i, c, N, B, C, N4;
N = st->block_size;
B = st->nb_blocks;
C = st->mode->nbChannels;
float in[(B+1)*C*N];
float X[B*C*N]; /**< Interleaved signal MDCTs */
float P[B*C*N]; /**< Interleaved pitch MDCTs*/
float mask[B*C*N]; /**< Masking curve */
float bandE[st->mode->nbEBands];
float gains[st->mode->nbPBands];
int pitch_index;
N4 = (N-st->overlap)/2;
for (c=0;c<C;c++)
{
for (i=0;i<N;i++)
in[C*i+c] = st->in_mem[C*i+c];
for (;i<(B+1)*N;i++)
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-N)+c];
in[C*i+c] = tmp - st->preemph*st->preemph_memE[c];
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=0;i<N;i++)
st->in_mem[C*i+c] = in[C*(B*N+i)+c];
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 */
......@@ -375,7 +388,8 @@ struct CELTDecoder {
int frame_size;
int block_size;
int nb_blocks;
int overlap;
ec_byte_buffer buf;
ec_enc enc;
......@@ -395,7 +409,7 @@ struct CELTDecoder {
CELTDecoder *celt_decoder_new(const CELTMode *mode)
{
int i, N, B, C;
int i, N, B, C, N4;
N = mode->mdctSize;
B = mode->nbMdctBlocks;
C = mode->nbChannels;
......@@ -405,14 +419,23 @@ CELTDecoder *celt_decoder_new(const CELTMode *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(float));
st->out_mem = celt_alloc(MAX_PERIOD*C*sizeof(float));
for (i=0;i<N;i++)
st->window[i] = st->window[2*N-i-1] = sin(.5*M_PI* sin(.5*M_PI*(i+.5)/N) * sin(.5*M_PI*(i+.5)/N));
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(mode->nbEBands*sizeof(float));
......
libcelt/modes.c
+ 14
− 11
View file @ a5431bfb
......@@ -71,12 +71,15 @@ const int qpulses2s[NBANDS128] ={38,30,24,20,24,20, 18, 16, 14, 20,-20,-14, -8,
const int pbank1[PBANDS128+2] = {0, 4, 8, 12, 20, PITCH_END128, 128};
const int qbank3[NBANDS128+2] = {0, 4, 8, 12, 16, 24, 32, 40, 48, 56, 72, 88, 104, 126, 168, 232, 256};
#define NBANDS256 15
#define PBANDS256 5
#define PITCH_END256 72
const int pbank3[PBANDS128+2] = {0, 8, 16, 24, 40, PITCH_END256, 256};
const int qbank3[NBANDS256+2] = {0, 4, 8, 12, 16, 24, 32, 40, 48, 56, 72, 88, 104, 126, 168, 232, 256};
const int pbank3[PBANDS256+2] = {0, 8, 16, 24, 40, PITCH_END256, 256};
const CELTMode mode0 = {
256, /**< frameSize */
128, /**< overlap */
128, /**< mdctSize */
2, /**< nbMdctBlocks */
1, /**< channels */
......@@ -97,7 +100,7 @@ const CELTMode mode0 = {
/* Approx 38 kbps @ 44.1 kHz */
const CELTMode mode1 = {
256, /**< frameSize */
128, /**< overlap */
128, /**< mdctSize */
2, /**< nbMdctBlocks */
1, /**< channels */
......@@ -117,7 +120,7 @@ const CELTMode mode1 = {
/* Approx 58 kbps @ 44.1 kHz */
const CELTMode mode2 = {
256, /**< frameSize */
128, /**< overlap */
128, /**< mdctSize */
2, /**< nbMdctBlocks */
1, /**< channels */
......@@ -136,18 +139,18 @@ const CELTMode mode2 = {
};
const CELTMode mode3 = {
512, /**< frameSize */
128, /**< overlap */
256, /**< mdctSize */
2, /**< nbMdctBlocks */
1, /**< nbMdctBlocks */
1, /**< channels */
NBANDS128, /**< nbEBands */
PBANDS128, /**< nbPBands */
NBANDS256, /**< nbEBands */
PBANDS256, /**< nbPBands */
PITCH_END256,/**< pitchEnd */
qbank3, /**< eBands */
pbank3, /**< pBands*/
qpulses2, /**< nbPulses */
qpulses1, /**< nbPulses */
0.7, /**< ePredCoef */
means, /**< eMeans */
......@@ -156,7 +159,7 @@ const CELTMode mode3 = {
/* Stereo mode around 120 kbps */
const CELTMode mode4 = {
256, /**< frameSize */
128, /**< overlap */
128, /**< mdctSize */
2, /**< nbMdctBlocks */
2, /**< channels */
......
libcelt/modes.h
+ 1
− 1
View file @ a5431bfb
......@@ -35,7 +35,7 @@
#include "celt.h"
struct CELTMode {
int frameSize;
int overlap;
int mdctSize;
int nbMdctBlocks;
int nbChannels;
......
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