shithub: libvpx

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Simplifying get_delta_q function.

Change-Id: I3a1e9cc5c3ed5be01ff75a84a6c82ec02c75af9c

--- a/vp9/decoder/vp9_decodframe.c

+++ b/vp9/decoder/vp9_decodframe.c

@@ -901,22 +901,18 @@

 #endif

 }

+static int get_delta_q(vp9_reader *r, int *dq) {

+  const int old_value = *dq;

-static int get_delta_q(vp9_reader *bc, int prev, int *q_update) {

-  int ret_val = 0;

-

-  if (vp9_read_bit(bc)) {

-    ret_val = vp9_read_literal(bc, 4);

-

-    if (vp9_read_bit(bc))

-      ret_val = -ret_val;

+  if (vp9_read_bit(r)) {  // Update bit

+    int value = vp9_read_literal(r, 4);

+    if (vp9_read_bit(r))  // Sign bit

+      value = -value;

+    *dq = value;

   }

   // Trigger a quantizer update if the delta-q value has changed

-  if (ret_val != prev)

-    *q_update = 1;

-

-  return ret_val;

+  return old_value != *dq;

 }

 #ifdef PACKET_TESTING

@@ -1716,9 +1712,9 @@

     pc->base_qindex = vp9_read_literal(&header_bc, QINDEX_BITS);

     // AC 1st order Q = default

-    pc->y1dc_delta_q = get_delta_q(&header_bc, pc->y1dc_delta_q, &q_update);

-    pc->uvdc_delta_q = get_delta_q(&header_bc, pc->uvdc_delta_q, &q_update);

-    pc->uvac_delta_q = get_delta_q(&header_bc, pc->uvac_delta_q, &q_update);

+    q_update = get_delta_q(&header_bc, &pc->y1dc_delta_q) |

+               get_delta_q(&header_bc, &pc->uvdc_delta_q) |

+               get_delta_q(&header_bc, &pc->uvac_delta_q);

     if (q_update)

       vp9_init_de_quantizer(pbi);