@@ -820,7 +820,7 @@ static void print_report(int is_last_report, int64_t timer_start)

                 if (qp >= 0 && qp < FF_ARRAY_ELEMS(qp_histogram))

                     qp_histogram[qp]++;

                 for (j = 0; j < 32; j++)

-                    snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "%X", (int)lrintf(log(qp_histogram[j] + 1) / log(2)));

+                    snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "%X", (int)lrintf(log2(qp_histogram[j] + 1)));

             }

             if (enc->flags&CODEC_FLAG_PSNR) {

                 int j;

@@ -468,7 +468,7 @@ static char *value_string(char *buf, int buf_size, double val, const char *unit)

         int index;

         if (unit == unit_byte_str && use_byte_value_binary_prefix) {

-            index = (int) (log(val)/log(2)) / 10;

+            index = (int) log2(val) / 10;

             index = av_clip(index, 0, FF_ARRAY_ELEMS(binary_unit_prefixes) - 1);

             val  /= pow(2, index * 10);

             prefix_string = binary_unit_prefixes[index];

@@ -342,7 +342,7 @@ static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,

     // maybe some frequency division thingy

     flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125

-    flcoeffs2[0] = log(flcoeffs1[0]) / log(2);

+    flcoeffs2[0] = log2f(flcoeffs1[0]);

     tmp  = flcoeffs1[0];

     tmp2 = flcoeffs2[0];

@@ -414,7 +414,7 @@ static int bit_allocation(IMCContext *q, IMCChannel *chctx,

         highest = FFMAX(highest, chctx->flcoeffs1[i]);

     for (i = 0; i < BANDS - 1; i++)

-        chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log(chctx->flcoeffs5[i]) / log(2);

+        chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);

     chctx->flcoeffs4[BANDS - 1] = limit;

     highest = highest * 0.25;

@@ -1529,7 +1529,7 @@ static void update_last_header_values(SnowContext *s){

 }

 static int qscale2qlog(int qscale){

-    return rint(QROOT*log(qscale / (float)FF_QP2LAMBDA)/log(2))

+    return rint(QROOT*log2(qscale / (float)FF_QP2LAMBDA))

            + 61*QROOT/8; ///< 64 > 60

 }