eden-emu/opus
18
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Saving ~1 kB by using chars for the alloc table

Browse source 
Also a bunch of comments
This commit is contained in:
Jean-Marc Valin 2010-05-15 23:47:09 -04:00
parent 72c97f5633
commit c1ca587d47
2 changed files with 17 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

19
libcelt/bands.c
View file

@ -424,6 +424,10 @@ int folding_decision(const CELTMode *m, celt_norm *X, celt_word16 *average, int
return *last_decision;
}
/* This function is responsible for encoding and decoding a band for both
the mono and stereo case. Even in the mono case, it can split the band
in two and transmit the energy difference with the two half-bands. It
can be called recursively so bands can end up being split in 8 parts. */
static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_norm *Y, int N, int b, int spread, celt_norm *lowband, int resynth, ec_enc *ec, celt_int32 *remaining_bits, int LM, celt_norm *lowband_out, const celt_ener *bandE)
{
int q;
@ -434,6 +438,7 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
split = stereo = Y != NULL;
/* If we need more than 32 bits, try splitting the band in two. */
if (!stereo && LM>0 && !fits_in32(N, get_pulses(bits2pulses(m, m->bits[LM][i], N, b))))
{
N >>= 1;
@ -485,6 +490,9 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
int fs=1, ft;
shift = 14-qb;
ft = ((1<<qb>>1)+1)*((1<<qb>>1)+1);
/* Entropy coding of the angle. We use a uniform pdf for the
first stereo split but a triangular one for the rest. */
if (encode)
itheta = (itheta+(1<<shift>>1))>>shift;
if (stereo || qb>9)
@ -534,6 +542,7 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
}
itheta <<= shift;
}
if (itheta == 0)
{
imid = 32767;
@ -549,7 +558,10 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
iside = bitexact_cos(16384-itheta);
delta = (N-1)*(log2_frac(iside,BITRES+2)-log2_frac(imid,BITRES+2))>>2;
}
#if 1
/* This is a special case for N=2 that only works for stereo and takes
advantage of the fact that mid and side are orthogonal to encode
the side with just one bit. */
if (N==2 && stereo)
{
int c, c2;
@ -588,6 +600,7 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
{
if (encode)
{
/* Here we only need to encode a sign for the side */
if (v[0]*w[1] - v[1]*w[0] > 0)
sign = 1;
else
@ -614,9 +627,8 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
y2[1] = v[1];
}
} else
#endif
{
/* "Normal" split code */
mbits = (b-qalloc/2-delta)/2;
if (mbits > b-qalloc)
mbits = b-qalloc;
@ -632,6 +644,7 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
}
} else {
/* This is the basis no-split case */
q = bits2pulses(m, m->bits[LM][i], N, b);
curr_bits = pulses2bits(m->bits[LM][i], N, q);
*remaining_bits -= curr_bits;

2
libcelt/modes.c
View file

@ -97,7 +97,7 @@ int BITALLOC_SIZE;
int *band_allocation;
#else
#define BITALLOC_SIZE 12
static const int band_allocation[BARK_BANDS*BITALLOC_SIZE] =
static const unsigned char band_allocation[BARK_BANDS*BITALLOC_SIZE] =
/* 0 100 200 300 400 510 630 770 920 1k 1.2 1.5 1.7 2k 2.3 2.7 3.1 3.7 4.4 5.3 6.4 7.7 9.5 12k 15k */
{ 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /*0*/
2, 2, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /*1*/