Sync to upstream libopus

Sync to commit bb4b6885a139644cf3ac14e7deda9f633ec2d93c

This brings in a bunch of optimizations to decode speed
and memory usage. Allocations are switched from using
the pseudostack to using the real stack. Enabled hacks
to reduce stack usage.

This should fix crashes on sansa clip, although some
files will not play due to failing allocations in the
codec buffer.

Speeds up decoding of the following test files:

                 H300 (cf)   C200 (arm7tdmi)  ipod classic (arm9e)
16 kbps (silk)   14.28 MHz   4.00 MHz         2.61 MHz
64 kbps (celt)   4.09 MHz    8.08 MHz         6.24 MHz
128 kbps (celt)  1.93 MHz    8.83 MHz         6.53 MHz

Change-Id: I851733a8a5824b61feb363a173091bc7e6629b58

1 files changed, 15 insertions, 6 deletions

diff --git a/lib/rbcodec/codecs/libopus/silk/CNG.c b/lib/rbcodec/codecs/libopus/silk/CNG.c
index 8481d95dbe..bb30a7ccf2 100644
--- a/lib/rbcodec/codecs/libopus/silk/CNG.c
+++ b/lib/rbcodec/codecs/libopus/silk/CNG.c
@@ -34,7 +34,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 /* Generates excitation for CNG LPC synthesis */
 static OPUS_INLINE void silk_CNG_exc(
-    opus_int32                       residual_Q10[],     /* O    CNG residual signal Q10                     */
+    opus_int32                       exc_Q10[],          /* O    CNG excitation signal Q10                   */
     opus_int32                       exc_buf_Q14[],      /* I    Random samples buffer Q10                   */
     opus_int32                       Gain_Q16,           /* I    Gain to apply                               */
     opus_int                         length,             /* I    Length                                      */
@@ -55,7 +55,7 @@ static OPUS_INLINE void silk_CNG_exc(
         idx = (opus_int)( silk_RSHIFT( seed, 24 ) & exc_mask );
         silk_assert( idx >= 0 );
         silk_assert( idx <= CNG_BUF_MASK_MAX );
-        residual_Q10[ i ] = (opus_int16)silk_SAT16( silk_SMULWW( exc_buf_Q14[ idx ], Gain_Q16 >> 4 ) );
+        exc_Q10[ i ] = (opus_int16)silk_SAT16( silk_SMULWW( exc_buf_Q14[ idx ], Gain_Q16 >> 4 ) );
     }
     *rand_seed = seed;
 }
@@ -85,7 +85,7 @@ void silk_CNG(
 )
 {
     opus_int   i, subfr;
-    opus_int32 sum_Q6, max_Gain_Q16;
+    opus_int32 sum_Q6, max_Gain_Q16, gain_Q16;
     opus_int16 A_Q12[ MAX_LPC_ORDER ];
     silk_CNG_struct *psCNG = &psDec->sCNG;
     SAVE_STACK;
@@ -125,11 +125,20 @@ void silk_CNG(
     /* Add CNG when packet is lost or during DTX */
     if( psDec->lossCnt ) {
         VARDECL( opus_int32, CNG_sig_Q10 );
-
         ALLOC( CNG_sig_Q10, length + MAX_LPC_ORDER, opus_int32 );
 
         /* Generate CNG excitation */
-        silk_CNG_exc( CNG_sig_Q10 + MAX_LPC_ORDER, psCNG->CNG_exc_buf_Q14, psCNG->CNG_smth_Gain_Q16, length, &psCNG->rand_seed );
+                gain_Q16 = silk_SMULWW( psDec->sPLC.randScale_Q14, psDec->sPLC.prevGain_Q16[1] );
+                if( gain_Q16 >= (1 << 21) || psCNG->CNG_smth_Gain_Q16 > (1 << 23) ) {
+                        gain_Q16 = silk_SMULTT( gain_Q16, gain_Q16 );
+                        gain_Q16 = silk_SUB_LSHIFT32(silk_SMULTT( psCNG->CNG_smth_Gain_Q16, psCNG->CNG_smth_Gain_Q16 ), gain_Q16, 5 );
+                        gain_Q16 = silk_LSHIFT32( silk_SQRT_APPROX( gain_Q16 ), 16 );
+                } else {
+                        gain_Q16 = silk_SMULWW( gain_Q16, gain_Q16 );
+                        gain_Q16 = silk_SUB_LSHIFT32(silk_SMULWW( psCNG->CNG_smth_Gain_Q16, psCNG->CNG_smth_Gain_Q16 ), gain_Q16, 5 );
+                        gain_Q16 = silk_LSHIFT32( silk_SQRT_APPROX( gain_Q16 ), 8 );
+                }
+        silk_CNG_exc( CNG_sig_Q10 + MAX_LPC_ORDER, psCNG->CNG_exc_buf_Q14, gain_Q16, length, &psCNG->rand_seed );
 
         /* Convert CNG NLSF to filter representation */
         silk_NLSF2A( A_Q12, psCNG->CNG_smth_NLSF_Q15, psDec->LPC_order );
@@ -162,7 +171,7 @@ void silk_CNG(
             /* Update states */
             CNG_sig_Q10[ MAX_LPC_ORDER + i ] = silk_ADD_LSHIFT( CNG_sig_Q10[ MAX_LPC_ORDER + i ], sum_Q6, 4 );
 
-            frame[ i ] = silk_ADD_SAT16( frame[ i ], silk_RSHIFT_ROUND( sum_Q6, 6 ) );
+            frame[ i ] = silk_ADD_SAT16( frame[ i ], silk_RSHIFT_ROUND( CNG_sig_Q10[ MAX_LPC_ORDER + i ], 10 ) );
         }
         silk_memcpy( psCNG->CNG_synth_state, &CNG_sig_Q10[ length ], MAX_LPC_ORDER * sizeof( opus_int32 ) );
     } else {