Use dynamic stack allocations in SILK decoder.

This allows the decoder to be compiled with
 NONTHREADSAFE_PSEUDOSTACK to move the memory for large buffers off
 the stack for devices where it is very limited.
This patch only attempts to do this for the decoder.
The encoder still requires more than 10 kB of stack.

1 files changed, 15 insertions, 12 deletions

diff --git a/silk/decode_frame.c b/silk/decode_frame.c
index 9db93d86..3e4a6e2b 100644
--- a/silk/decode_frame.c
+++ b/silk/decode_frame.c
@@ -30,6 +30,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #endif
 
 #include "main.h"
+#include "stack_alloc.h"
 #include "PLC.h"
 
 /****************/
@@ -44,12 +45,16 @@ opus_int silk_decode_frame(
     opus_int                    condCoding                      /* I    The type of conditional coding to use       */
 )
 {
-    silk_decoder_control sDecCtrl;
+    VARDECL( silk_decoder_control, psDecCtrl );
     opus_int         L, mv_len, ret = 0;
-    opus_int         pulses[ MAX_FRAME_LENGTH ];
+    VARDECL( opus_int, pulses );
+    SAVE_STACK;
 
     L = psDec->frame_length;
-    sDecCtrl.LTP_scale_Q14 = 0;
+    ALLOC( psDecCtrl, 1, silk_decoder_control );
+    ALLOC( pulses, (L + SHELL_CODEC_FRAME_LENGTH - 1) &
+                   ~(SHELL_CODEC_FRAME_LENGTH - 1), opus_int );
+    psDecCtrl->LTP_scale_Q14 = 0;
 
     /* Safety checks */
     silk_assert( L > 0 && L <= MAX_FRAME_LENGTH );
@@ -71,20 +76,17 @@ opus_int silk_decode_frame(
         /********************************************/
         /* Decode parameters and pulse signal       */
         /********************************************/
-        silk_decode_parameters( psDec, &sDecCtrl, condCoding );
-
-        /* Update length. Sampling frequency may have changed */
-        L = psDec->frame_length;
+        silk_decode_parameters( psDec, psDecCtrl, condCoding );
 
         /********************************************************/
         /* Run inverse NSQ                                      */
         /********************************************************/
-        silk_decode_core( psDec, &sDecCtrl, pOut, pulses );
+        silk_decode_core( psDec, psDecCtrl, pOut, pulses );
 
         /********************************************************/
         /* Update PLC state                                     */
         /********************************************************/
-        silk_PLC( psDec, &sDecCtrl, pOut, 0 );
+        silk_PLC( psDec, psDecCtrl, pOut, 0 );
 
         psDec->lossCnt = 0;
         psDec->prevSignalType = psDec->indices.signalType;
@@ -94,7 +96,7 @@ opus_int silk_decode_frame(
         psDec->first_frame_after_reset = 0;
     } else {
         /* Handle packet loss by extrapolation */
-        silk_PLC( psDec, &sDecCtrl, pOut, 1 );
+        silk_PLC( psDec, psDecCtrl, pOut, 1 );
     }
 
     /*************************/
@@ -113,13 +115,14 @@ opus_int silk_decode_frame(
     /************************************************/
     /* Comfort noise generation / estimation        */
     /************************************************/
-    silk_CNG( psDec, &sDecCtrl, pOut, L );
+    silk_CNG( psDec, psDecCtrl, pOut, L );
 
     /* Update some decoder state variables */
-    psDec->lagPrev = sDecCtrl.pitchL[ psDec->nb_subfr - 1 ];
+    psDec->lagPrev = psDecCtrl->pitchL[ psDec->nb_subfr - 1 ];
 
     /* Set output frame length */
     *pN = L;
 
+    RESTORE_STACK;
     return ret;
 }