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VBR tuning: increases transient and dynalloc boost

This only increases the average rate by about 1.5 kb/s, but it
restores the high quality of transients from 1.0. Also it
ensures that dynalloc can never starve other bands when used
aggressively.

--- a/celt/celt.c

+++ b/celt/celt.c

@@ -411,7 +411,7 @@

       }

    }

    /* *tf_estimate = 1 + MIN16(1, sqrt(MAX16(0, tf_max-30))/20); */

-   *tf_estimate = QCONST16(1.f, 14) + celt_sqrt(MAX16(0, SHL32(MULT16_16(QCONST16(0.0025f,14),IMIN(420,tf_max)),14)-QCONST32(0.075f,28)));

+   *tf_estimate = QCONST16(1.f, 14) + celt_sqrt(MAX16(0, SHL32(MULT16_16(QCONST16(0.0069,14),IMIN(163,tf_max)),14)-QCONST32(0.139,28)));

    RESTORE_STACK;

 #ifdef FUZZING

@@ -1641,7 +1641,7 @@

      /* Compensates for the average tonality boost */

      target -= MULT16_16_Q15(QCONST16(0.13f,15),coded_bins<<BITRES);

      /* Limits starving of other bands when using dynalloc */

-     target += IMAX(0,tot_boost-100)/2;

+     target += tot_boost;

      /* Compensates for the average transient boost */

      target = MULT16_32_Q15(QCONST16(0.96f,15),target);