ref: 913a1742b960b8cb705132d1ebfcf0718bb994e7
parent: c97b258c628ae6bd0e8e6229a8f398c980dfae77
author: Jean-Marc Valin <[email protected]>
date: Sat Jan 29 05:00:20 EST 2011
Adding resampling support We use the MDCT as low-pass filter.
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -63,6 +63,32 @@
#define COMBFILTER_MAXPERIOD 1024
#define COMBFILTER_MINPERIOD 15
+static int resampling_factor(celt_int32 rate)
+{+ int ret;
+ switch (rate)
+ {+ case 48000:
+ ret = 1;
+ break;
+ case 24000:
+ ret = 2;
+ break;
+ case 16000:
+ ret = 3;
+ break;
+ case 12000:
+ ret = 4;
+ break;
+ case 8000:
+ ret = 6;
+ break;
+ default:
+ ret = 0;
+ }
+ return ret;
+}
+
/** Encoder state
@brief Encoder state
*/
@@ -73,6 +99,7 @@
int force_intra;
int complexity;
+ int upsample;
int start, end;
celt_int32 vbr_rate_norm; /* Target number of 8th bits per frame */
@@ -127,12 +154,13 @@
return size;
}
-CELTEncoder *celt_encoder_create(int channels, int *error)
+CELTEncoder *celt_encoder_create(int sampling_rate, int channels, int *error)
{CELTMode *mode = celt_mode_create(48000, 960, NULL);
- return celt_encoder_init(
+ CELTEncoder *st = celt_encoder_init(
(CELTEncoder *)celt_alloc(celt_encoder_get_size(mode, channels)),
- channels, error);
+ sampling_rate, channels, error);
+ return st;
}
CELTEncoder *celt_encoder_create_custom(const CELTMode *mode, int channels, int *error)
@@ -142,9 +170,17 @@
mode, channels, error);
}
-CELTEncoder *celt_encoder_init(CELTEncoder *st, int channels, int *error)
+CELTEncoder *celt_encoder_init(CELTEncoder *st, int sampling_rate, int channels, int *error)
{- return celt_encoder_init_custom(st, celt_mode_create(48000, 960, NULL), channels, error);
+ celt_encoder_init_custom(st, celt_mode_create(48000, 960, NULL), channels, error);
+ st->upsample = resampling_factor(sampling_rate);
+ if (st->upsample==0)
+ {+ if (error)
+ *error = CELT_BAD_ARG;
+ return NULL;
+ }
+ return st;
}
CELTEncoder *celt_encoder_init_custom(CELTEncoder *st, const CELTMode *mode, int channels, int *error)
@@ -169,6 +205,7 @@
st->overlap = mode->overlap;
st->channels = channels;
+ st->upsample = 1;
st->start = 0;
st->end = st->mode->effEBands;
st->constrained_vbr = 1;
@@ -385,10 +422,11 @@
} while (++c<C);
}
-static void deemphasis(celt_sig *in[], celt_word16 *pcm, int N, int _C, const celt_word16 *coef, celt_sig *mem)
+static void deemphasis(celt_sig *in[], celt_word16 *pcm, int N, int _C, int downsample, const celt_word16 *coef, celt_sig *mem)
{const int C = CHANNELS(_C);
int c;
+ int count=0;
c=0; do {int j;
celt_sig * restrict x;
@@ -402,9 +440,15 @@
m = MULT16_32_Q15(coef[0], tmp)
- MULT16_32_Q15(coef[1], *x);
tmp = SHL32(MULT16_32_Q15(coef[3], tmp), 2);
- *y = SCALEOUT(SIG2WORD16(tmp));
x++;
- y+=C;
+ /* Technically the store could be moved outside of the if because
+ the stores we don't want will just be overwritten */
+ if (++count==downsample)
+ {+ *y = SCALEOUT(SIG2WORD16(tmp));
+ y+=C;
+ count=0;
+ }
}
mem[c] = m;
} while (++c<C);
@@ -841,6 +885,7 @@
if (nbCompressedBytes<2 || pcm==NULL)
return CELT_BAD_ARG;
+ frame_size *= st->upsample;
for (LM=0;LM<4;LM++)
if (st->mode->shortMdctSize<<LM==frame_size)
break;
@@ -919,19 +964,29 @@
silence = 1;
c=0; do {+ int count = 0;
const celt_word16 * restrict pcmp = pcm+c;
celt_sig * restrict inp = in+c*(N+st->overlap)+st->overlap;
for (i=0;i<N;i++)
{+ celt_sig x, tmp;
+
+ x = SCALEIN(*pcmp);
+ if (++count==st->upsample)
+ {+ count=0;
+ pcmp+=C;
+ } else {+ x = 0;
+ }
/* Apply pre-emphasis */
- celt_sig tmp = MULT16_16(st->mode->preemph[2], SCALEIN(*pcmp));
+ tmp = MULT16_16(st->mode->preemph[2], x);
*inp = tmp + st->preemph_memE[c];
st->preemph_memE[c] = MULT16_32_Q15(st->mode->preemph[1], *inp)
- MULT16_32_Q15(st->mode->preemph[0], tmp);
silence = silence && *inp == 0;
inp++;
- pcmp+=C;
}
CELT_COPY(pre[c], prefilter_mem+c*COMBFILTER_MAXPERIOD, COMBFILTER_MAXPERIOD);
CELT_COPY(pre[c]+COMBFILTER_MAXPERIOD, in+c*(N+st->overlap)+st->overlap, N);
@@ -1082,6 +1137,17 @@
/* Compute MDCTs */
compute_mdcts(st->mode, shortBlocks, in, freq, C, LM);
+ if (st->upsample != 1)
+ {+ c=0; do
+ {+ int bound = N/st->upsample;
+ for (i=0;i<bound;i++)
+ freq[c*N+i] *= st->upsample;
+ for (;i<N;i++)
+ freq[c*N+i] = 0;
+ } while (++c<C);
+ }
ALLOC(X, C*N, celt_norm); /**< Interleaved normalised MDCTs */
compute_band_energies(st->mode, freq, bandE, effEnd, C, M);
@@ -1412,7 +1478,7 @@
} while (++c<C);
#endif /* ENABLE_POSTFILTER */
- deemphasis(out_mem, (celt_word16*)pcm, N, C, st->mode->preemph, st->preemph_memD);
+ deemphasis(out_mem, (celt_word16*)pcm, N, C, st->upsample, st->mode->preemph, st->preemph_memD);
st->prefilter_period_old = st->prefilter_period;
st->prefilter_gain_old = st->prefilter_gain;
st->prefilter_tapset_old = st->prefilter_tapset;
@@ -1651,6 +1717,7 @@
int overlap;
int channels;
+ int downsample;
int start, end;
/* Everything beyond this point gets cleared on a reset */
@@ -1685,12 +1752,12 @@
return size;
}
-CELTDecoder *celt_decoder_create(int channels, int *error)
+CELTDecoder *celt_decoder_create(int sampling_rate, int channels, int *error)
{const CELTMode *mode = celt_mode_create(48000, 960, NULL);
return celt_decoder_init(
(CELTDecoder *)celt_alloc(celt_decoder_get_size(mode, channels)),
- channels, error);
+ sampling_rate, channels, error);
}
CELTDecoder *celt_decoder_create_custom(const CELTMode *mode, int channels, int *error)
@@ -1700,9 +1767,17 @@
mode, channels, error);
}
-CELTDecoder *celt_decoder_init(CELTDecoder *st, int channels, int *error)
+CELTDecoder *celt_decoder_init(CELTDecoder *st, int sampling_rate, int channels, int *error)
{- return celt_decoder_init_custom(st, celt_mode_create(48000, 960, NULL), channels, error);
+ celt_decoder_init_custom(st, celt_mode_create(48000, 960, NULL), channels, error);
+ st->downsample = resampling_factor(sampling_rate);
+ if (st->downsample==0)
+ {+ if (error)
+ *error = CELT_BAD_ARG;
+ return NULL;
+ }
+ return st;
}
CELTDecoder *celt_decoder_init_custom(CELTDecoder *st, const CELTMode *mode, int channels, int *error)
@@ -1727,6 +1802,7 @@
st->overlap = mode->overlap;
st->channels = channels;
+ st->downsample = 1;
st->start = 0;
st->end = st->mode->effEBands;
@@ -1955,7 +2031,7 @@
out_mem[c][MAX_PERIOD+i] = e[i];
} while (++c<C);
- deemphasis(out_syn, pcm, N, C, st->mode->preemph, st->preemph_memD);
+ deemphasis(out_syn, pcm, N, C, st->downsample, st->mode->preemph, st->preemph_memD);
st->loss_count++;
@@ -2015,6 +2091,7 @@
if (pcm==NULL)
return CELT_BAD_ARG;
+ frame_size *= st->downsample;
for (LM=0;LM<4;LM++)
if (st->mode->shortMdctSize<<LM==frame_size)
break;
@@ -2220,10 +2297,13 @@
for (i=0;i<M*st->mode->eBands[st->start];i++)
freq[c*N+i] = 0;
while (++c<C);
- c=0; do
+ c=0; do {+ int bound = M*st->mode->eBands[effEnd];
+ if (st->downsample!=1)
+ bound = IMIN(bound, N/st->downsample);
for (i=M*st->mode->eBands[effEnd];i<N;i++)
freq[c*N+i] = 0;
- while (++c<C);
+ } while (++c<C);
out_syn[0] = out_mem[0]+MAX_PERIOD-N;
if (C==2)
@@ -2280,7 +2360,7 @@
}
st->rng = dec->rng;
- deemphasis(out_syn, pcm, N, C, st->mode->preemph, st->preemph_memD);
+ deemphasis(out_syn, pcm, N, C, st->downsample, st->mode->preemph, st->preemph_memD);
st->loss_count = 0;
RESTORE_STACK;
if (ec_dec_tell(dec,0) > 8*len || ec_dec_get_error(dec))
--- a/libcelt/celt.h
+++ b/libcelt/celt.h
@@ -167,7 +167,7 @@
@param error Returns an error code
@return Newly created encoder state.
*/
-EXPORT CELTEncoder *celt_encoder_create(int channels, int *error);
+EXPORT CELTEncoder *celt_encoder_create(int sampling_rate, int channels, int *error);
/** Creates a new encoder state. Each stream needs its own encoder
state (can't be shared across simultaneous streams).
@@ -180,7 +180,7 @@
*/
EXPORT CELTEncoder *celt_encoder_create_custom(const CELTMode *mode, int channels, int *error);
-EXPORT CELTEncoder *celt_encoder_init(CELTEncoder *st, int channels, int *error);
+EXPORT CELTEncoder *celt_encoder_init(CELTEncoder *st, int sampling_rate, int channels, int *error);
EXPORT CELTEncoder *celt_encoder_init_custom(CELTEncoder *st, const CELTMode *mode, int channels, int *error);
@@ -245,7 +245,7 @@
@param error Returns an error code
@return Newly created decoder state.
*/
-EXPORT CELTDecoder *celt_decoder_create(int channels, int *error);
+EXPORT CELTDecoder *celt_decoder_create(int sampling_rate, int channels, int *error);
/** Creates a new decoder state. Each stream needs its own decoder state (can't
be shared across simultaneous streams).
@@ -257,7 +257,7 @@
*/
EXPORT CELTDecoder *celt_decoder_create_custom(const CELTMode *mode, int channels, int *error);
-EXPORT CELTDecoder *celt_decoder_init(CELTDecoder *st, int channels, int *error);
+EXPORT CELTDecoder *celt_decoder_init(CELTDecoder *st, int sampling_rate, int channels, int *error);
EXPORT CELTDecoder *celt_decoder_init_custom(CELTDecoder *st, const CELTMode *mode, int channels, int *error);