ref: a5431bfb090b3b3d31744265a86a1d8684c1e34d
parent: 71c9bbff02edd1b8818b782ebf498bd67e183027
author: Jean-Marc Valin <[email protected]>
date: Thu Jan 3 15:53:01 EST 2008
Allowing reduced overlap MDCTs as an alternative to multiple MDCTs per frame. Not complete yet.
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -50,6 +50,7 @@
int frame_size;
int block_size;
int nb_blocks;
+ int overlap;
int channels;
int Fs;
@@ -75,7 +76,7 @@
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 @@
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 @@
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;
@@ -220,12 +227,12 @@
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 */
@@ -232,19 +239,25 @@
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 @@
int frame_size;
int block_size;
int nb_blocks;
-
+ int overlap;
+
ec_byte_buffer buf;
ec_enc enc;
@@ -395,7 +409,7 @@
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;
@@ -405,6 +419,9 @@
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);
@@ -411,8 +428,14 @@
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));
--- a/libcelt/modes.c
+++ b/libcelt/modes.c
@@ -71,12 +71,15 @@
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 @@
/* Approx 38 kbps @ 44.1 kHz */
const CELTMode mode1 = {- 256, /**< frameSize */
+ 128, /**< overlap */
128, /**< mdctSize */
2, /**< nbMdctBlocks */
1, /**< channels */
@@ -117,7 +120,7 @@
/* 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 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 @@
/* Stereo mode around 120 kbps */
const CELTMode mode4 = {- 256, /**< frameSize */
+ 128, /**< overlap */
128, /**< mdctSize */
2, /**< nbMdctBlocks */
2, /**< channels */
--- a/libcelt/modes.h
+++ b/libcelt/modes.h
@@ -35,7 +35,7 @@
#include "celt.h"
struct CELTMode {- int frameSize;
+ int overlap;
int mdctSize;
int nbMdctBlocks;
int nbChannels;