[rc]: add init qp estimation

if outside doesn't set init qp value, mpp will estimate one init qp
according to resolution and bitrate.

Change-Id: If5415f6a3bfa3f2981ffd4eb044614bf9b035d2f
Signed-off-by: Jung Zhao <jung.zhao@rock-chips.com>

osal/mpp_common.cpp

@@ -55,3 +55,54 @@ RK_S32 mpp_log2_16bit(RK_U32 v)
     return n;
 }
 
+RK_S32 axb_div_c(RK_S32 a, RK_S32 b, RK_S32 c)
+{
+    RK_U32 left = 32;
+    RK_U32 right = 0;
+    RK_U32 shift;
+    RK_S32 sign = 1;
+    RK_S32 tmp;
+
+    if (a == 0 || b == 0)
+        return 0;
+    else if ((a * b / b) == a && c != 0)
+        return (a * b / c);
+
+    if (a < 0) {
+        sign = -1;
+        a = -a;
+    }
+    if (b < 0) {
+        sign *= -1;
+        b = -b;
+    }
+    if (c < 0) {
+        sign *= -1;
+        c = -c;
+    }
+
+    if (c == 0)
+        return 0x7FFFFFFF * sign;
+
+    if (b > a) {
+        tmp = b;
+        b = a;
+        a = tmp;
+    }
+
+    for (--left; (((RK_U32)a << left) >> left) != (RK_U32)a; --left)
+        ;
+
+    left--;
+
+    while (((RK_U32)b >> right) > (RK_U32)c)
+        right++;
+
+    if (right > left) {
+        return 0x7FFFFFFF * sign;
+    } else {
+        shift = left - right;
+        return (RK_S32)((((RK_U32)a << shift) /
+                         (RK_U32)c * (RK_U32)b) >> shift) * sign;
+    }
+}