shithub: opus

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First shot at automatically adjusting the "allocation trim" for stereo.

Also fixed a fixed-point breakage.

--- a/libcelt/celt.c

+++ b/libcelt/celt.c

@@ -364,7 +364,7 @@

       {0, -2, 0, -3,    2, 0, 1 -1},

 };

-celt_word32 l1_metric(const celt_norm *tmp, int N, int LM, int width)

+static celt_word32 l1_metric(const celt_norm *tmp, int N, int LM, int width)

 {

    int i, j;

    static const celt_word16 sqrtM_1[4] = {Q15ONE, QCONST16(0.70711f,15), QCONST16(0.5f,15), QCONST16(0.35355f,15)};

@@ -408,7 +408,7 @@

    if (nbCompressedBytes<15*C)

    {

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

-         tf_res[i] = 0;

+         tf_res[i] = isTransient;

       return 0;

    }

    if (nbCompressedBytes<40)

@@ -475,7 +475,7 @@

    tf_select = 0;

    cost0 = 0;

-   cost1 = lambda;

+   cost1 = isTransient ? 0 : lambda;

    /* Viterbi forward pass */

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

    {

@@ -550,6 +550,58 @@

       tf_res[i] = tf_select_table[LM][4*isTransient+2*tf_select+tf_res[i]];

 }

+static int alloc_trim_analysis(const CELTMode *m, const celt_norm *X,

+      const celt_word16 *bandLogE, int nbEBands, int LM, int C, int N0)

+{

+   int i;

+   int trim_index = 3;

+   if (C==2)

+   {

+      celt_word16 sum = 0; /* Q10 */

+      /* Compute inter-channel correlation for low frequencies */

+      for (i=0;i<8;i++)

+      {

+         int j;

+         celt_word32 partial = 0;

+         for (j=m->eBands[i]<<LM;j<m->eBands[i+1]<<LM;j++)

+            partial = MAC16_16(partial, X[j], X[N0+j]);

+         sum = ADD16(sum, EXTRACT16(SHR32(partial, 18)));

+      }

+      sum = MULT16_16_Q15(QCONST16(1.f/8, 15), sum);

+      /*printf ("%f\n", sum);*/

+      trim_index++;

+      if (sum > QCONST16(.9,10))

+         trim_index-=3;

+      else if (sum > QCONST16(.65,10))

+         trim_index-=2;

+      else if (sum > QCONST16(.45,10))

+         trim_index--;

+   }

+#if 0

+   float diff=0;

+   for (c=0;c<C;c++)

+   {

+      for (i=0;i<nbEBands-1;i++)

+      {

+         diff += bandLogE[i+c*nbEBands]*(i-.5*nbEBands);

+      }

+   }

+   diff /= C*(nbEBands-1);

+   /*printf("%f\n", diff);*/

+   if (diff > 4)

+      trim_index--;

+   if (diff > 8)

+      trim_index--;

+   /*if (diff < -10)

+      trim_index++;*/

+#endif

+   if (trim_index<0)

+      trim_index = 0;

+   if (trim_index>5)

+      trim_index = 5;

+   return trim_index;

+}

+

 #ifdef FIXED_POINT

 int celt_encode_with_ec(CELTEncoder * restrict st, const celt_int16 * pcm, celt_int16 * optional_resynthesis, int frame_size, unsigned char *compressed, int nbCompressedBytes, ec_enc *enc)

 {

@@ -738,14 +790,7 @@

       offsets[i] *= (6<<BITRES);

    }

    {

-      int trim_index = 3;

-

-      /*if (isTransient)

-         trim_index--;

-      if (has_fold==0)

-         trim_index--;

-      if (C==2)

-         trim_index--;*/

+      int trim_index = alloc_trim_analysis(st->mode, X, bandLogE, st->mode->nbEBands, LM, C, N);

       alloc_trim = trim_coef[trim_index];

       ec_encode_bin(enc, trim_cdf[trim_index], trim_cdf[trim_index+1], 7);

    }

--- a/libcelt/mdct.c

+++ b/libcelt/mdct.c

@@ -66,9 +66,10 @@

 void clt_mdct_init(mdct_lookup *l,int N, int maxshift)

 {

    int i;

-   int N4;

+   int N4, N2;

    kiss_twiddle_scalar *trig;

    l->n = N;

+   N2 = N>>1;

    N4 = N>>2;

    l->maxshift = maxshift;

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