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New transient handling code that weights the MDCTs directly unless there's

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a really big amplitude change, in which case the original time-domain window
is used.
This commit is contained in:
Jean-Marc Valin 2009-05-29 22:14:20 -04:00
parent 2b73a27ece
commit aa9362564d
1 changed files with 103 additions and 10 deletions
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113
libcelt/celt.c
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@ -212,14 +212,12 @@ static int transient_analysis(celt_word32_t *in, int len, int C, int *transient_
if (ratio > 1000)
ratio = 1000;
ratio *= ratio;
if (ratio < 50)
*transient_shift = 0;
else if (ratio < 256)
*transient_shift = 1;
else if (ratio < 4096)
*transient_shift = 2;
else
if (ratio > 2048)
*transient_shift = 3;
else
*transient_shift = 0;
*transient_time = n;
RESTORE_STACK;
@ -466,6 +464,8 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig_t * pcm, celt_si
int transient_time;
int transient_shift;
const int C = CHANNELS(st->mode);
int mdct_weight_shift = 0;
int mdct_weight_pos=0;
SAVE_STACK;
if (check_mode(st->mode) != CELT_OK)
@ -545,6 +545,63 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig_t * pcm, celt_si
ALLOC(bandE,st->mode->nbEBands*C, celt_ener_t);
/* Compute MDCTs */
compute_mdcts(st->mode, shortBlocks, in, freq);
if (shortBlocks && !transient_shift)
{
celt_word32_t sum[4];
int m=0;
do {
sum[m] = 1;
celt_word32_t tmp=0;
for (i=m;i<N;i+=st->mode->nbShortMdcts)
tmp += ABS32(freq[i]);
sum[m++] = tmp;
} while (m<st->mode->nbShortMdcts);
m=0;
#ifdef FIXED_POINT
do {
if (SHR32(sum[m+1],3) > sum[m])
{
mdct_weight_shift=2;
mdct_weight_pos = m;
} else if (SHR32(sum[m+1],1) > sum[m] && mdct_weight_shift < 2)
{
mdct_weight_shift=1;
mdct_weight_pos = m;
}
m++;
} while (m<st->mode->nbShortMdcts-1);
for (i=1;i<N;i+=2)
freq[i] = SHR32(freq[i],mdct_weight_shift);
#else
do {
if (sum[m+1] > 8*sum[m])
{
mdct_weight_shift=2;
mdct_weight_pos = m;
} else if (sum[m+1] > 2*sum[m] && mdct_weight_shift < 2)
{
mdct_weight_shift=1;
mdct_weight_pos = m;
}
m++;
} while (m<st->mode->nbShortMdcts-1);
if (mdct_weight_shift)
{
for (m=mdct_weight_pos+1;m<st->mode->nbShortMdcts;m++)
for (i=m;i<N;i+=st->mode->nbShortMdcts)
freq[i] = (1./(1<<mdct_weight_shift))*freq[i];
}
#endif
/*printf ("%f\n", short_ratio);*/
/*if (short_ratio < 1)
short_ratio = 1;
short_ratio = 1<<(int)floor(.5+log2(short_ratio));
if (short_ratio>4)
short_ratio = 4;*/
}/* else if (transient_shift)
printf ("8\n");
else printf ("1\n");*/
compute_band_energies(st->mode, freq, bandE);
intra_ener = st->delayedIntra;
@ -647,9 +704,15 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig_t * pcm, celt_si
}
if (shortBlocks)
{
ec_enc_bits(&enc, transient_shift, 2);
if (transient_shift)
{
ec_enc_bits(&enc, transient_shift, 2);
ec_enc_uint(&enc, transient_time, N+st->overlap);
} else {
ec_enc_bits(&enc, mdct_weight_shift, 2);
if (mdct_weight_shift && st->mode->nbShortMdcts!=2)
ec_enc_uint(&enc, mdct_weight_pos, st->mode->nbShortMdcts-1);
}
}
#ifdef STDIN_TUNING2
@ -727,6 +790,17 @@ int celt_encode_float(CELTEncoder * restrict st, const celt_sig_t * pcm, celt_si
CELT_MOVE(st->out_mem, st->out_mem+C*N, C*(MAX_PERIOD+st->overlap-N));
if (mdct_weight_shift)
{
int m;
for (m=mdct_weight_pos+1;m<st->mode->nbShortMdcts;m++)
for (i=m;i<N;i+=st->mode->nbShortMdcts)
#ifdef FIXED_POINT
freq[i] = SHL32(freq[i], mdct_weight_shift);
#else
freq[i] = (1<<mdct_weight_shift)*freq[i];
#endif
}
compute_inv_mdcts(st->mode, shortBlocks, freq, transient_time, transient_shift, st->out_mem);
/* De-emphasis and put everything back at the right place in the synthesis history */
if (optional_synthesis != NULL) {
@ -1061,7 +1135,9 @@ int celt_decode_float(CELTDecoder * restrict st, const unsigned char *data, int
int intra_ener;
int transient_time;
int transient_shift;
int mdct_weight_shift=0;
const int C = CHANNELS(st->mode);
int mdct_weight_pos=0;
SAVE_STACK;
if (check_mode(st->mode) != CELT_OK)
@ -1099,10 +1175,16 @@ int celt_decode_float(CELTDecoder * restrict st, const unsigned char *data, int
if (shortBlocks)
{
transient_shift = ec_dec_bits(&dec, 2);
if (transient_shift)
if (transient_shift == 3)
{
transient_time = ec_dec_uint(&dec, N+st->mode->overlap);
else
} else {
mdct_weight_shift = transient_shift;
if (mdct_weight_shift && st->mode->nbShortMdcts>2)
mdct_weight_pos = ec_dec_uint(&dec, st->mode->nbShortMdcts-1);
transient_shift = 0;
transient_time = 0;
}
} else {
transient_time = -1;
transient_shift = 0;
@ -1166,6 +1248,17 @@ int celt_decode_float(CELTDecoder * restrict st, const unsigned char *data, int
CELT_MOVE(st->decode_mem, st->decode_mem+C*N, C*(DECODE_BUFFER_SIZE+st->overlap-N));
if (mdct_weight_shift)
{
int m;
for (m=mdct_weight_pos+1;m<st->mode->nbShortMdcts;m++)
for (i=m;i<N;i+=st->mode->nbShortMdcts)
#ifdef FIXED_POINT
freq[i] = SHL32(freq[i], mdct_weight_shift);
#else
freq[i] = (1<<mdct_weight_shift)*freq[i];
#endif
}
/* Compute inverse MDCTs */
compute_inv_mdcts(st->mode, shortBlocks, freq, transient_time, transient_shift, st->out_mem);