Adding resampling support
We use the MDCT as low-pass filter.
This commit is contained in:
Jean-Marc Valin
parent
c97b258c62
commit
913a1742b9
2 changed files with 103 additions and 23 deletions
116
libcelt/celt.c
116
libcelt/celt.c
|
|
@ -63,6 +63,32 @@ static const unsigned char tapset_icdf[3]={2,1,0};
|
|||
#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 @@ struct CELTEncoder {
|
|||
|
||||
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 @@ int celt_encoder_get_size(const CELTMode *mode, int channels)
|
|||
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 @@ CELTEncoder *celt_encoder_create_custom(const CELTMode *mode, int channels, int
|
|||
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 @@ CELTEncoder *celt_encoder_init_custom(CELTEncoder *st, const CELTMode *mode, int
|
|||
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 @@ static void compute_inv_mdcts(const CELTMode *mode, int shortBlocks, celt_sig *X
|
|||
} 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 @@ static void deemphasis(celt_sig *in[], celt_word16 *pcm, int N, int _C, const ce
|
|||
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++;
|
||||
/* 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 @@ int celt_encode_with_ec_float(CELTEncoder * restrict st, const celt_sig * pcm, i
|
|||
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 @@ int celt_encode_with_ec_float(CELTEncoder * restrict st, const celt_sig * pcm, i
|
|||
|
||||
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 @@ int celt_encode_with_ec_float(CELTEncoder * restrict st, const celt_sig * pcm, i
|
|||
/* 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 @@ int celt_encode_with_ec_float(CELTEncoder * restrict st, const celt_sig * pcm, i
|
|||
} 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 @@ struct CELTDecoder {
|
|||
int overlap;
|
||||
int channels;
|
||||
|
||||
int downsample;
|
||||
int start, end;
|
||||
|
||||
/* Everything beyond this point gets cleared on a reset */
|
||||
|
|
@ -1685,12 +1752,12 @@ int celt_decoder_get_size(const CELTMode *mode, int channels)
|
|||
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 @@ CELTDecoder *celt_decoder_create_custom(const CELTMode *mode, int channels, int
|
|||
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 @@ CELTDecoder *celt_decoder_init_custom(CELTDecoder *st, const CELTMode *mode, int
|
|||
st->overlap = mode->overlap;
|
||||
st->channels = channels;
|
||||
|
||||
st->downsample = 1;
|
||||
st->start = 0;
|
||||
st->end = st->mode->effEBands;
|
||||
|
||||
|
|
@ -1955,7 +2031,7 @@ static void celt_decode_lost(CELTDecoder * restrict st, celt_word16 * restrict p
|
|||
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 @@ int celt_decode_with_ec_float(CELTDecoder * restrict st, const unsigned char *da
|
|||
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 @@ int celt_decode_with_ec_float(CELTDecoder * restrict st, const unsigned char *da
|
|||
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 @@ int celt_decode_with_ec_float(CELTDecoder * restrict st, const unsigned char *da
|
|||
}
|
||||
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))
|
||||
|
|
|
|||
|
|
@ -167,7 +167,7 @@ EXPORT int celt_encoder_get_size(const CELTMode *mode, int channels);
|
|||
@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(int channels, int *error);
|
|||
*/
|
||||
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 @@ EXPORT int celt_decoder_get_size(const CELTMode *mode, int channels);
|
|||
@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(int channels, int *error);
|
|||
*/
|
||||
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);
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue