The LPC analysis window and lag window are now in Q15.

3 files changed, 31 insertions, 37 deletions

diff --git a/libspeex/lpc.c b/libspeex/lpc.c
index 9224392..141fd9d 100644
--- a/libspeex/lpc.c
+++ b/libspeex/lpc.c
@@ -82,13 +82,6 @@ int          p
    spx_word16_t r;
    spx_word16_t error = ac[0];
 
-   if (ac[0] == 0)
-   {
-      for (i = 0; i < p; i++)
-         lpc[i] = 0;
-      return 0;
-   }
-
    for (i = 0; i < p; i++) {
 
       /* Sum up this iteration's reflection coefficient */
diff --git a/libspeex/nb_celp.c b/libspeex/nb_celp.c
index a36da69..b696ebb 100644
--- a/libspeex/nb_celp.c
+++ b/libspeex/nb_celp.c
@@ -468,16 +468,17 @@ int nb_encode(void *state, void *vin, SpeexBits *bits)
       ALLOC(autocorr, NB_ORDER+1, spx_word16_t);
       /* Window for analysis */
       for (i=0;i<NB_WINDOW_SIZE-NB_FRAME_SIZE;i++)
-         w_sig[i] = EXTRACT16(SHR32(MULT16_16(st->winBuf[i],st->window[i]),SIG_SHIFT));
+         w_sig[i] = MULT16_16_Q15(st->winBuf[i],st->window[i]);
       for (;i<NB_WINDOW_SIZE;i++)
-         w_sig[i] = EXTRACT16(SHR32(MULT16_16(in[i-NB_WINDOW_SIZE+NB_FRAME_SIZE],st->window[i]),SIG_SHIFT));
+         w_sig[i] = MULT16_16_Q15(in[i-NB_WINDOW_SIZE+NB_FRAME_SIZE],st->window[i]);
       /* Compute auto-correlation */
       _spx_autocorr(w_sig, autocorr, NB_ORDER+1, NB_WINDOW_SIZE);
       autocorr[0] = ADD16(autocorr[0],MULT16_16_Q15(autocorr[0],st->lpc_floor)); /* Noise floor in auto-correlation domain */
 
       /* Lag windowing: equivalent to filtering in the power-spectrum domain */
       for (i=0;i<NB_ORDER+1;i++)
-         autocorr[i] = MULT16_16_Q14(autocorr[i],st->lagWindow[i]);
+         autocorr[i] = MULT16_16_Q15(autocorr[i],st->lagWindow[i]);
+      autocorr[0] = ADD16(autocorr[0],1);
 
       /* Levinson-Durbin */
       _spx_lpc(lpc, autocorr, NB_ORDER);
diff --git a/libspeex/window.c b/libspeex/window.c
index ac042d4..fe5ee70 100644
--- a/libspeex/window.c
+++ b/libspeex/window.c
@@ -37,39 +37,39 @@
 
 #ifdef FIXED_POINT
 const spx_word16_t lag_window[11] = {
-   16384, 16337, 16199, 15970, 15656, 15260, 14790, 14254, 13659, 13015, 12330
+   32767, 32675, 32397, 31940, 31311, 30520, 29581, 28508, 27318, 26029, 24661
 };
 
 const spx_word16_t lpc_window[200] = {
-1310, 1313, 1321, 1333, 1352, 1375, 1403, 1436,
-1475, 1518, 1567, 1621, 1679, 1743, 1811, 1884,
-1962, 2044, 2132, 2224, 2320, 2421, 2526, 2636,
-2750, 2868, 2990, 3116, 3246, 3380, 3518, 3659,
-3804, 3952, 4104, 4259, 4417, 4578, 4742, 4909,
-5079, 5251, 5425, 5602, 5781, 5963, 6146, 6331,
-6518, 6706, 6896, 7087, 7280, 7473, 7668, 7863,
-8059, 8256, 8452, 8650, 8847, 9044, 9241, 9438,
-9635, 9831, 10026, 10220, 10414, 10606, 10797, 10987,
-11176, 11363, 11548, 11731, 11912, 12091, 12268, 12443,
-12615, 12785, 12952, 13116, 13277, 13435, 13590, 13742,
-13890, 14035, 14176, 14314, 14448, 14578, 14704, 14826,
-14944, 15058, 15168, 15273, 15374, 15470, 15562, 15649,
-15732, 15810, 15883, 15951, 16015, 16073, 16127, 16175,
-16219, 16257, 16291, 16319, 16342, 16360, 16373, 16381,
-16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
-16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
-16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
-16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
-16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
-16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
-16384, 16384, 16384, 16361, 16294, 16183, 16028, 15830,
-15588, 15304, 14979, 14613, 14207, 13763, 13282, 12766,
-12215, 11631, 11016, 10373, 9702, 9007, 8289, 7551,
-6797, 6028, 5251, 4470, 3695, 2943, 2248, 1696
+2621, 2627, 2642, 2668, 2704, 2750, 2807, 2874, 
+2951, 3038, 3135, 3242, 3359, 3486, 3623, 3769, 
+3925, 4090, 4264, 4448, 4641, 4843, 5053, 5272, 
+5500, 5736, 5981, 6233, 6493, 6761, 7036, 7319, 
+7609, 7905, 8209, 8519, 8835, 9157, 9485, 9819, 
+10158, 10502, 10852, 11206, 11564, 11926, 12293, 12663, 
+13037, 13414, 13793, 14176, 14561, 14948, 15337, 15727, 
+16119, 16512, 16906, 17300, 17695, 18089, 18484, 18877, 
+19270, 19662, 20053, 20442, 20829, 21214, 21596, 21976, 
+22353, 22726, 23096, 23463, 23826, 24184, 24538, 24887, 
+25231, 25570, 25904, 26232, 26555, 26871, 27181, 27484, 
+27781, 28070, 28353, 28628, 28896, 29157, 29409, 29653, 
+29889, 30117, 30336, 30547, 30749, 30941, 31125, 31300, 
+31465, 31621, 31767, 31903, 32030, 32147, 32254, 32352, 
+32439, 32516, 32582, 32639, 32685, 32722, 32747, 32763, 
+32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 
+32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 
+32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 
+32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 
+32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 
+32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 
+32767, 32767, 32767, 32723, 32590, 32368, 32058, 31661, 
+31177, 30610, 29959, 29227, 28416, 27528, 26566, 25532, 
+24430, 23263, 22034, 20747, 19406, 18015, 16579, 15104, 
+13594, 12058, 10503, 8941, 7391, 5887, 4498, 3392
 };
 #else
 const spx_word16_t lag_window[11] = {
-   1.00000, 0.99716, 0.98869, 0.97474, 0.95554, 0.93140, 0.90273, 0.86998, 0.83367, 0.79434, 0.75258
+   1.00000f, 0.99716f, 0.98869f, 0.97474f, 0.95554f, 0.93140f, 0.90273f, 0.86998f, 0.83367f, 0.79434f, 0.75258f
 };
 
 const spx_word16_t lpc_window[200] = {