updated libfaad

CVS patchset: 3560
CVS date: 2002/12/16 18:59:50

1 files changed, 34 insertions, 4 deletions

diff --git a/src/libfaad/is.c b/src/libfaad/is.c
index f64c41859..8a4d50b5c 100644
--- a/src/libfaad/is.c
+++ b/src/libfaad/is.c
@@ -16,20 +16,37 @@
 ** along with this program; if not, write to the Free Software 
 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 **
-** $Id: is.c,v 1.1 2002/07/14 23:43:01 miguelfreitas Exp $
+** $Id: is.c,v 1.2 2002/12/16 19:00:26 miguelfreitas Exp $
 **/
 
 #include "common.h"
+#include "structs.h"
 
 #include "syntax.h"
 #include "is.h"
 
+#ifdef FIXED_POINT
+static real_t pow05_table[] = {
+    COEF_CONST(1.68179283050743), /* 0.5^(-3/4) */
+    COEF_CONST(1.41421356237310), /* 0.5^(-2/4) */
+    COEF_CONST(1.18920711500272), /* 0.5^(-1/4) */
+    COEF_CONST(1.0),              /* 0.5^( 0/4) */
+    COEF_CONST(0.84089641525371), /* 0.5^(+1/4) */
+    COEF_CONST(0.70710678118655), /* 0.5^(+2/4) */
+    COEF_CONST(0.59460355750136)  /* 0.5^(+3/4) */
+};
+#endif
+
 void is_decode(ic_stream *ics, ic_stream *icsr, real_t *l_spec, real_t *r_spec,
                uint16_t frame_len)
 {
     uint8_t g, sfb, b;
     uint16_t i, k;
+#ifndef FIXED_POINT
     real_t scale;
+#else
+    int32_t exp, frac;
+#endif
 
     uint16_t nshort = frame_len/8;
     uint8_t group = 0;
@@ -50,16 +67,29 @@ void is_decode(ic_stream *ics, ic_stream *icsr, real_t *l_spec, real_t *r_spec,
                     ics->pred.prediction_used[sfb] = 0;
                     icsr->pred.prediction_used[sfb] = 0;
 
-                    scale = MUL(is_intensity(icsr, g, sfb),
-                        MUL(invert_intensity(ics, g, sfb),
-                        (real_t)exp(LN05 * (0.25*icsr->scale_factors[g][sfb]))));
+#ifndef FIXED_POINT
+                    scale = (real_t)pow(0.5, (0.25*icsr->scale_factors[g][sfb]));
+#else
+                    exp = icsr->scale_factors[g][sfb] / 4;
+                    frac = icsr->scale_factors[g][sfb] % 4;
+#endif
 
                     /* Scale from left to right channel,
                        do not touch left channel */
                     for (i = icsr->swb_offset[sfb]; i < icsr->swb_offset[sfb+1]; i++)
                     {
                         k = (group*nshort)+i;
+#ifndef FIXED_POINT
                         r_spec[k] = MUL(l_spec[k], scale);
+#else
+                        if (exp < 0)
+                            r_spec[k] = l_spec[k] << -exp;
+                        else
+                            r_spec[k] = l_spec[k] >> exp;
+                        r_spec[k] = MUL_R_C(r_spec[k], pow05_table[frac + 3]);
+#endif
+                        if (is_intensity(icsr, g, sfb) != invert_intensity(ics, g, sfb))
+                            r_spec[k] = -r_spec[k];
                     }
                 }
             }