From 0dec778663568e38b595c1cd2ee555784925b60d Mon Sep 17 00:00:00 2001 From: Jean-Marc Valin Date: Thu, 15 Sep 2022 14:38:13 -0400 Subject: More general Laplace encoder --- celt/entdec.c | 21 ++++++++++++ celt/entdec.h | 10 ++++++ celt/entenc.c | 11 +++++++ celt/entenc.h | 9 +++++ celt/laplace.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 153 insertions(+) diff --git a/celt/entdec.c b/celt/entdec.c index 0b3433ed..027aa24b 100644 --- a/celt/entdec.c +++ b/celt/entdec.c @@ -195,6 +195,27 @@ int ec_dec_icdf(ec_dec *_this,const unsigned char *_icdf,unsigned _ftb){ return ret; } +int ec_dec_icdf16(ec_dec *_this,const opus_uint16 *_icdf,unsigned _ftb){ + opus_uint32 r; + opus_uint32 d; + opus_uint32 s; + opus_uint32 t; + int ret; + s=_this->rng; + d=_this->val; + r=s>>_ftb; + ret=-1; + do{ + t=s; + s=IMUL32(r,_icdf[++ret]); + } + while(dval=d-s; + _this->rng=t-s; + ec_dec_normalize(_this); + return ret; +} + opus_uint32 ec_dec_uint(ec_dec *_this,opus_uint32 _ft){ unsigned ft; unsigned s; diff --git a/celt/entdec.h b/celt/entdec.h index 025fc187..c81f26fd 100644 --- a/celt/entdec.h +++ b/celt/entdec.h @@ -81,6 +81,16 @@ int ec_dec_bit_logp(ec_dec *_this,unsigned _logp); Return: The decoded symbol s.*/ int ec_dec_icdf(ec_dec *_this,const unsigned char *_icdf,unsigned _ftb); +/*Decodes a symbol given an "inverse" CDF table. + No call to ec_dec_update() is necessary after this call. + _icdf: The "inverse" CDF, such that symbol s falls in the range + [s>0?ft-_icdf[s-1]:0,ft-_icdf[s]), where ft=1<<_ftb. + The values must be monotonically non-increasing, and the last value + must be 0. + _ftb: The number of bits of precision in the cumulative distribution. + Return: The decoded symbol s.*/ +int ec_dec_icdf16(ec_dec *_this,const opus_uint16 *_icdf,unsigned _ftb); + /*Extracts a raw unsigned integer with a non-power-of-2 range from the stream. The bits must have been encoded with ec_enc_uint(). No call to ec_dec_update() is necessary after this call. diff --git a/celt/entenc.c b/celt/entenc.c index f1750d25..69c6f835 100644 --- a/celt/entenc.c +++ b/celt/entenc.c @@ -172,6 +172,17 @@ void ec_enc_icdf(ec_enc *_this,int _s,const unsigned char *_icdf,unsigned _ftb){ ec_enc_normalize(_this); } +void ec_enc_icdf16(ec_enc *_this,int _s,const opus_uint16 *_icdf,unsigned _ftb){ + opus_uint32 r; + r=_this->rng>>_ftb; + if(_s>0){ + _this->val+=_this->rng-IMUL32(r,_icdf[_s-1]); + _this->rng=IMUL32(r,_icdf[_s-1]-_icdf[_s]); + } + else _this->rng-=IMUL32(r,_icdf[_s]); + ec_enc_normalize(_this); +} + void ec_enc_uint(ec_enc *_this,opus_uint32 _fl,opus_uint32 _ft){ unsigned ft; unsigned fl; diff --git a/celt/entenc.h b/celt/entenc.h index f502eaf6..010874bb 100644 --- a/celt/entenc.h +++ b/celt/entenc.h @@ -64,6 +64,15 @@ void ec_enc_bit_logp(ec_enc *_this,int _val,unsigned _logp); _ftb: The number of bits of precision in the cumulative distribution.*/ void ec_enc_icdf(ec_enc *_this,int _s,const unsigned char *_icdf,unsigned _ftb); +/*Encodes a symbol given an "inverse" CDF table. + _s: The index of the symbol to encode. + _icdf: The "inverse" CDF, such that symbol _s falls in the range + [_s>0?ft-_icdf[_s-1]:0,ft-_icdf[_s]), where ft=1<<_ftb. + The values must be monotonically non-increasing, and the last value + must be 0. + _ftb: The number of bits of precision in the cumulative distribution.*/ +void ec_enc_icdf16(ec_enc *_this,int _s,const opus_uint16 *_icdf,unsigned _ftb); + /*Encodes a raw unsigned integer in the stream. _fl: The integer to encode. _ft: The number of integers that can be encoded (one more than the max). diff --git a/celt/laplace.c b/celt/laplace.c index a7bca874..3c45c3eb 100644 --- a/celt/laplace.c +++ b/celt/laplace.c @@ -132,3 +132,105 @@ int ec_laplace_decode(ec_dec *dec, unsigned fs, int decay) ec_dec_update(dec, fl, IMIN(fl+fs,32768), 32768); return val; } + + +void ec_laplace_encode_p0(ec_enc *enc, int value, opus_uint16 p0, opus_uint16 decay) +{ + int s; + opus_uint16 sign_icdf[3]; + sign_icdf[0] = 32768-p0; + sign_icdf[1] = sign_icdf[0]/2; + sign_icdf[2] = 0; + s = value == 0 ? 0 : (value > 0 ? 1 : 2); + ec_enc_icdf16(enc, s, sign_icdf, 15); + value = abs(value); + if (value) + { + int i; + opus_uint16 icdf[8]; + icdf[0] = decay; + for (i=1;i<7;i++) + { + icdf[i] = IMAX(7-i, (icdf[i-1] * (opus_int32)decay) >> 15); + } + icdf[7] = 0; + value--; + do { + ec_enc_icdf16(enc, IMIN(value, 7), icdf, 15); + value -= 7; + } while (value >= 0); + } +} + +int ec_laplace_decode_p0(ec_dec *dec, opus_uint16 p0, opus_uint16 decay) +{ + int s; + int value; + opus_uint16 sign_icdf[3]; + sign_icdf[0] = 32768-p0; + sign_icdf[1] = sign_icdf[0]/2; + sign_icdf[2] = 0; + s = ec_dec_icdf16(dec, sign_icdf, 15); + if (s==2) s = -1; + if (s != 0) + { + int i; + int v; + opus_uint16 icdf[8]; + icdf[0] = decay; + for (i=1;i<7;i++) + { + icdf[i] = IMAX(7-i, (icdf[i-1] * (opus_int32)decay) >> 15); + } + icdf[7] = 0; + value = 1; + do { + v = ec_dec_icdf16(dec, icdf, 15); + value += v; + } while (v == 7); + return s*value; + } else return 0; +} + +#if 0 + +#include +#define NB_VALS 10 +#define DATA_SIZE 10000 +int main() { + ec_enc enc; + ec_dec dec; + unsigned char *ptr; + int i; + int decay, p0; + int val[NB_VALS] = {6, 7, 8, 9, 10, 11, 12, 13, 14, 15}; + /*for (i=0;i