shithub: opus

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Fixed a bunch of fixed-point overflows on insanely hot signals by changing
the time-domain representation from Q14 to Q12 (Q29 to Q27 using the
standard convention).

--- a/configure.ac

+++ b/configure.ac

@@ -6,7 +6,7 @@

 CELT_MAJOR_VERSION=0

 CELT_MINOR_VERSION=4

-CELT_MICRO_VERSION=0

+CELT_MICRO_VERSION=1

 CELT_EXTRA_VERSION=

 CELT_VERSION=$CELT_MAJOR_VERSION.$CELT_MINOR_VERSION.$CELT_MICRO_VERSION$CELT_EXTRA_VERSION

--- a/libcelt/arch.h

+++ b/libcelt/arch.h

@@ -71,9 +71,7 @@

 #define Q15ONE 32767

 #define Q30ONE 1073741823

-#define SIG_SCALING 16384.f

-#define SIG_SCALING_1 (1.f/16384.f)

-#define SIG_SHIFT 14

+#define SIG_SHIFT 12

 #define NORM_SCALING 16384

 #define NORM_SCALING_1 (1.f/16384.f)

@@ -135,8 +133,6 @@

 #define Q15ONE 1.0f

 #define Q30ONE 1.0f

-#define SIG_SCALING  1.f

-#define SIG_SCALING_1 1.f

 #define NORM_SCALING 1.f

 #define NORM_SCALING_1 1.f

 #define ENER_SCALING 1.f

--- a/libcelt/bands.c

+++ b/libcelt/bands.c

@@ -175,9 +175,9 @@

       for (i=0;i<m->nbEBands;i++)

       {

          int j;

-         celt_word32_t g = MULT16_32_Q13(sqrtC_1[C-1],bank[i*C+c]);

+         celt_word32_t g = MULT16_32_Q15(sqrtC_1[C-1],bank[i*C+c]);

          j=eBands[i]; do {

-            freq[j*C+c] = MULT16_32_Q15(X[j*C+c], g);

+            freq[j*C+c] = SHL32(MULT16_32_Q15(X[j*C+c], g),2);

          } while (++j<eBands[i+1]);

       }

    }

--- a/libcelt/celt.c

+++ b/libcelt/celt.c

@@ -182,11 +182,11 @@

    SAVE_STACK;

    ALLOC(begin, len, celt_word32_t);

    for (i=0;i<len;i++)

-      begin[i] = EXTEND32(ABS16(SHR32(in[C*i],SIG_SHIFT)));

+      begin[i] = ABS32(SHR32(in[C*i],SIG_SHIFT));

    for (c=1;c<C;c++)

    {

       for (i=0;i<len;i++)

-         begin[i] = MAX32(begin[i], EXTEND32(ABS16(SHR32(in[C*i+c],SIG_SHIFT))));

+         begin[i] = MAX32(begin[i], ABS32(SHR32(in[C*i+c],SIG_SHIFT)));

    }

    for (i=1;i<len;i++)

       begin[i] = MAX32(begin[i-1],begin[i]);

@@ -412,7 +412,7 @@

       {

          /* Apply pre-emphasis */

          celt_sig_t tmp = SCALEIN(SHL32(EXTEND32(*pcmp), SIG_SHIFT));

-         *inp = SUB32(tmp, SHR32(MULT16_16(preemph,st->preemph_memE[c]),1));

+         *inp = SUB32(tmp, SHR32(MULT16_16(preemph,st->preemph_memE[c]),3));

          st->preemph_memE[c] = SCALEIN(*pcmp);

          inp += C;

          pcmp += C;

--- a/libcelt/mathops.h

+++ b/libcelt/mathops.h

@@ -246,7 +246,7 @@

    celt_word16_t frac;

    integer = SHR16(x,11);

    if (integer>14)

-      return 0x7fffffff;

+      return 0x7f000000;

    else if (integer < -15)

       return 0;

    frac = SHL16(x-SHL16(integer,11),3);

--- a/libcelt/quant_bands.c

+++ b/libcelt/quant_bands.c

@@ -52,10 +52,12 @@

 static inline celt_ener_t dB2Amp(celt_ener_t dB)

 {

    celt_ener_t amp;

+   if (dB>24659)

+      dB=24659;

    amp = PSHR32(celt_exp2(MULT16_16_Q14(21771,dB)),2)-QCONST16(.3f, 14);

    if (amp < 0)

       amp = 0;

-   return amp;

+   return PSHR32(amp,2);

 }

 #define DBofTWO 24661

@@ -62,7 +64,7 @@

 static inline celt_word16_t amp2dB(celt_ener_t amp)

 {

    /* equivalent to return 6.0207*log2(.3+amp) */

-   return ROUND16(MULT16_16(24661,celt_log2(ADD32(QCONST32(.3f,14),amp))),12);

+   return ROUND16(MULT16_16(24661,celt_log2(ADD32(QCONST32(.3f,14),SHL32(amp,2)))),12);

    /* return DB_SCALING*20*log10(.3+ENER_SCALING_1*amp); */

 }

 #else