ref: c5d00a066ea782c2c32eb3ff3e15f87d23b82c60
parent: 9d069846eeee8517c2cb97cd6e8e81cb4e34424c
author: Jean-Marc Valin <[email protected]>
date: Wed May 26 07:27:32 EDT 2010
Bunch of fixes for frames of 2.5 ms.
--- a/libcelt/bands.c
+++ b/libcelt/bands.c
@@ -490,6 +490,33 @@
split = stereo = Y != NULL;
+ /* Special case for one sample */
+ if (N==1)
+ {+ if (b>=1<<BITRES && *remaining_bits>=1<<BITRES)
+ {+ int sign;
+ if (encode)
+ {+ sign = X[0]<0;
+ ec_enc_bits(ec, sign, 1);
+ } else {+ sign = ec_dec_bits((ec_dec*)ec, 1);
+ }
+ if (resynth)
+ X[0] = sign ? -NORM_SCALING : NORM_SCALING;
+ *remaining_bits -= 1<<BITRES;
+ b--;
+ } else if (resynth) {+ X[0] = NORM_SCALING;
+ }
+ if (stereo)
+ quant_band(encode, m, i, Y, NULL, N, b, spread, NULL, resynth, ec,
+ remaining_bits, LM, NULL, NULL, level);
+ return;
+ }
+
+ /* Band recombining to increase frequency resolution */
if (!stereo && spread > 1 && level == 0 && tf_change>0)
{while (spread>1 && tf_change>0)
@@ -507,6 +534,7 @@
N_B0 = N_B;
}
+ /* Increasing the time resolution */
if (!stereo && spread>1 && level==0)
{while ((N_B&1) == 0 && tf_change<0 && spread <= (1<<LM))
@@ -532,7 +560,7 @@
}
/* If we need more than 32 bits, try splitting the band in two. */
- if (!stereo && LM != -1 && b > 32<<BITRES)
+ if (!stereo && LM != -1 && b > 32<<BITRES && N>2)
{if (LM>0 || (N&1)==0)
{@@ -547,52 +575,50 @@
if (split)
{int qb;
- int itheta;
+ int itheta=0;
int mbits, sbits, delta;
int qalloc;
celt_word16 mid, side;
- if (N>1)
- {- qb = (b-2*(N-1)*(QTHETA_OFFSET-m->logN[i]-(LM<<BITRES)))/(2*(N-1)<<BITRES);
- if (qb > (b>>(BITRES+1))-1)
- qb = (b>>(BITRES+1))-1;
- } else {- /* For N==1, allocate two bits for the signs and the rest goes to qb */
- qb = b-(2<<BITRES);
- }
+ int offset, N2;
+ offset = m->logN[i]+(LM<<BITRES)-QTHETA_OFFSET;
+ N2 = 2*N-1;
+ if (stereo && N>2)
+ N2--;
+ qb = (b+N2*offset)/(N2<<BITRES);
+ if (qb > (b>>(BITRES+1))-1)
+ qb = (b>>(BITRES+1))-1;
+
if (qb<0)
qb = 0;
if (qb>14)
qb = 14;
- if (encode)
- {- if (stereo)
- stereo_band_mix(m, X, Y, bandE, qb==0, i, 1, N);
-
- mid = renormalise_vector(X, Q15ONE, N, 1);
- side = renormalise_vector(Y, Q15ONE, N, 1);
-
- /* 0.63662 = 2/pi */
-#ifdef FIXED_POINT
- itheta = MULT16_16_Q15(QCONST16(0.63662f,15),celt_atan2p(side, mid));
-#else
- itheta = floor(.5f+16384*0.63662f*atan2(side,mid));
-#endif
- }
-
qalloc = 0;
- if (qb==0)
+ if (qb!=0)
{- itheta=0;
- } else {int shift;
shift = 14-qb;
- /* Entropy coding of the angle. We use a uniform pdf for the
- first stereo split but a triangular one for the rest. */
if (encode)
+ {+ if (stereo)
+ stereo_band_mix(m, X, Y, bandE, qb==0, i, 1, N);
+
+ mid = renormalise_vector(X, Q15ONE, N, 1);
+ side = renormalise_vector(Y, Q15ONE, N, 1);
+
+ /* 0.63662 = 2/pi */
+ #ifdef FIXED_POINT
+ itheta = MULT16_16_Q15(QCONST16(0.63662f,15),celt_atan2p(side, mid));
+ #else
+ itheta = floor(.5f+16384*0.63662f*atan2(side,mid));
+ #endif
+
itheta = (itheta+(1<<shift>>1))>>shift;
+ }
+
+ /* Entropy coding of the angle. We use a uniform pdf for the
+ first stereo split but a triangular one for the rest. */
if (stereo || qb>9 || spread>1)
{if (encode)
--- a/libcelt/modes.c
+++ b/libcelt/modes.c
@@ -339,7 +339,7 @@
} else if (frame_size >= 320 && (frame_size%8)==0)
{mode->nbShortMdcts = 4;
- } else if (frame_size >= 120 && (frame_size%4)==0)
+ } else if (frame_size >= 160 && (frame_size%4)==0)
{mode->nbShortMdcts = 2;
} else
--- a/libcelt/rate.c
+++ b/libcelt/rate.c
@@ -171,6 +171,8 @@
ebits[j] = (2*offset+d)/(2*d);
fine_priority[j] = ebits[j]*d >= offset;
+ if (N==1)
+ ebits[j] = (bits[j]/C >> BITRES)-1;
/* Make sure not to bust */
if (C*ebits[j] > (bits[j]>>BITRES))
ebits[j] = bits[j]/C >> BITRES;