WIP: 16x16 idct/recon merge

This patch eliminates the intermediate diff buffer usage by
combining the short idct and the add residual into one function.
The encoder can use the same code as well.

Change-Id: Iea7976b22b1927d24b8004d2a3fddae7ecca3ba1

1 files changed, 3 insertions, 18 deletions

diff --git a/vp9/decoder/vp9_idct_blk.c b/vp9/decoder/vp9_idct_blk.c
index faaee7378..bc943fa85 100644
--- a/vp9/decoder/vp9_idct_blk.c
+++ b/vp9/decoder/vp9_idct_blk.c
@@ -105,10 +105,6 @@ void vp9_add_residual_8x8_c(const int16_t *diff, uint8_t *dest, int stride) {
   add_residual(diff, dest, stride, 8, 8);
 }
 
-void vp9_add_residual_16x16_c(const int16_t *diff, uint8_t *dest, int stride) {
-  add_residual(diff, dest, stride, 16, 16);
-}
-
 static void add_constant_residual(const int16_t diff, uint8_t *dest, int stride,
                                   int width, int height) {
   int r, c;
@@ -260,19 +256,14 @@ void vp9_iht_add_16x16_c(TX_TYPE tx_type, int16_t *input, uint8_t *dest,
   if (tx_type == DCT_DCT) {
     vp9_idct_add_16x16(input, dest, stride, eob);
   } else {
-    DECLARE_ALIGNED_ARRAY(16, int16_t, output, 256);
-
     if (eob > 0) {
-      vp9_short_iht16x16(input, output, 16, tx_type);
+      vp9_short_iht16x16_add(input, dest, stride, tx_type);
       vpx_memset(input, 0, 512);
-      vp9_add_residual_16x16(output, dest, stride);
     }
   }
 }
 
 void vp9_idct_add_16x16_c(int16_t *input, uint8_t *dest, int stride, int eob) {
-  DECLARE_ALIGNED_ARRAY(16, int16_t, output, 256);
-
   /* The calculation can be simplified if there are not many non-zero dct
    * coefficients. Use eobs to separate different cases. */
   if (eob) {
@@ -288,21 +279,15 @@ void vp9_idct_add_16x16_c(int16_t *input, uint8_t *dest, int stride, int eob) {
       vp9_add_constant_residual_16x16(out, dest, stride);
 #if !CONFIG_SCATTERSCAN
     } else if (eob <= 10) {
-      // the idct halves ( >> 1) the pitch
-      vp9_short_idct10_16x16(input, output, 32);
-
+      vp9_short_idct10_16x16_add(input, dest, stride);
       input[0] = input[1] = input[2] = input[3] = 0;
       input[16] = input[17] = input[18] = 0;
       input[32] = input[33] = 0;
       input[48] = 0;
-
-      vp9_add_residual_16x16(output, dest, stride);
 #endif
     } else {
-      // the idct halves ( >> 1) the pitch
-      vp9_short_idct16x16(input, output, 16 << 1);
+      vp9_short_idct16x16_add(input, dest, stride);
       vpx_memset(input, 0, 512);
-      vp9_add_residual_16x16(output, dest, stride);
     }
   }
 }