diff --git a/args.c b/args.c
index 782929022..7b2cc3a10 100644
--- a/args.c
+++ b/args.c
@@ -135,6 +135,17 @@ void arg_show_usage(FILE *fp, const struct arg_def *const *defs)
                      def->long_name, long_val);
 
         fprintf(fp, "  %-37s\t%s\n", option_text, def->desc);
+
+        if(def->enums)
+        {
+            const struct arg_enum_list *listptr;
+
+            fprintf(fp, "  %-37s\t  ", "");
+
+            for(listptr = def->enums; listptr->name; listptr++)
+                fprintf(fp, "%s%s", listptr->name,
+                        listptr[1].name ? ", " : "\n");
+        }
     }
 }
 
@@ -218,3 +229,37 @@ struct vpx_rational arg_parse_rational(const struct arg *arg)
 
     return rat;
 }
+
+
+int arg_parse_enum(const struct arg *arg)
+{
+    const struct arg_enum_list *listptr;
+    long int                    rawval;
+    char                       *endptr;
+
+    /* First see if the value can be parsed as a raw value */
+    rawval = strtol(arg->val, &endptr, 10);
+    if (arg->val[0] != '\0' && endptr[0] == '\0')
+    {
+        /* Got a raw value, make sure it's valid */
+        for(listptr = arg->def->enums; listptr->name; listptr++)
+            if(listptr->val == rawval)
+                return rawval;
+    }
+
+    /* Next see if it can be parsed as a string */
+    for(listptr = arg->def->enums; listptr->name; listptr++)
+        if(!strcmp(arg->val, listptr->name))
+            return listptr->val;
+
+    die("Option %s: Invalid value '%s'\n", arg->name, arg->val);
+    return 0;
+}
+
+
+int arg_parse_enum_or_int(const struct arg *arg)
+{
+    if(arg->def->enums)
+        return arg_parse_enum(arg);
+    return arg_parse_int(arg);
+}
diff --git a/args.h b/args.h
index 4fafcf8a4..7963fa6b7 100644
--- a/args.h
+++ b/args.h
@@ -22,14 +22,23 @@ struct arg
     const struct arg_def  *def;
 };
 
+struct arg_enum_list
+{
+    const char *name;
+    int         val;
+};
+#define ARG_ENUM_LIST_END {0}
+
 typedef struct arg_def
 {
     const char *short_name;
     const char *long_name;
     int         has_val;
     const char *desc;
+    const struct arg_enum_list *enums;
 } arg_def_t;
-#define ARG_DEF(s,l,v,d) {s,l,v,d}
+#define ARG_DEF(s,l,v,d) {s,l,v,d, NULL}
+#define ARG_DEF_ENUM(s,l,v,d,e) {s,l,v,d,e}
 #define ARG_DEF_LIST_END {0}
 
 struct arg arg_init(char **argv);
@@ -41,4 +50,5 @@ char **argv_dup(int argc, const char **argv);
 unsigned int arg_parse_uint(const struct arg *arg);
 int arg_parse_int(const struct arg *arg);
 struct vpx_rational arg_parse_rational(const struct arg *arg);
+int arg_parse_enum_or_int(const struct arg *arg);
 #endif
diff --git a/vp8/common/onyx.h b/vp8/common/onyx.h
index 3c199d1c2..3724b11e0 100644
--- a/vp8/common/onyx.h
+++ b/vp8/common/onyx.h
@@ -18,6 +18,7 @@ extern "C"
 #endif
 
 #include "vpx/internal/vpx_codec_internal.h"
+#include "vpx/vp8cx.h"
 #include "vpx_scale/yv12config.h"
 #include "type_aliases.h"
 #include "ppflags.h"
@@ -189,6 +190,8 @@ extern "C"
 
         struct vpx_fixed_buf         two_pass_stats_in;
         struct vpx_codec_pkt_list  *output_pkt_list;
+
+        vp8e_tuning tuning;
     } VP8_CONFIG;
 
 
diff --git a/vp8/encoder/encodeframe.c b/vp8/encoder/encodeframe.c
index 5f9e54b4b..84631c45f 100644
--- a/vp8/encoder/encodeframe.c
+++ b/vp8/encoder/encodeframe.c
@@ -507,7 +507,8 @@ void encode_mb_row(VP8_COMP *cpi,
         x->rddiv = cpi->RDDIV;
         x->rdmult = cpi->RDMULT;
 
-        activity_sum += vp8_activity_masking(cpi, x);
+        if(cpi->oxcf.tuning == VP8_TUNE_SSIM)
+            activity_sum += vp8_activity_masking(cpi, x);
 
         // Is segmentation enabled
         // MB level adjutment to quantizer
diff --git a/vp8/encoder/ethreading.c b/vp8/encoder/ethreading.c
index 0cab70253..7599568c8 100644
--- a/vp8/encoder/ethreading.c
+++ b/vp8/encoder/ethreading.c
@@ -115,7 +115,8 @@ THREAD_FUNCTION thread_encoding_proc(void *p_data)
                         x->rddiv = cpi->RDDIV;
                         x->rdmult = cpi->RDMULT;
 
-                        activity_sum += vp8_activity_masking(cpi, x);
+                        if(cpi->oxcf.tuning == VP8_TUNE_SSIM)
+                            activity_sum += vp8_activity_masking(cpi, x);
 
                         // Is segmentation enabled
                         // MB level adjutment to quantizer
diff --git a/vp8/vp8_cx_iface.c b/vp8/vp8_cx_iface.c
index edadd73e3..a833ea5cf 100644
--- a/vp8/vp8_cx_iface.c
+++ b/vp8/vp8_cx_iface.c
@@ -38,6 +38,8 @@ struct vp8_extracfg
     unsigned int                arnr_strength;    /* alt_ref Noise Reduction Strength */
     unsigned int                arnr_type;        /* alt_ref filter type */
     unsigned int                experimental;
+    vp8e_tuning                 tuning;
+
 };
 
 struct extraconfig_map
@@ -68,6 +70,7 @@ static const struct extraconfig_map extracfg_map[] =
             3,                          /* arnr_strength */
             3,                          /* arnr_type*/
             0,                          /* experimental mode */
+            0,                          /* tuning*/
         }
     }
 };
@@ -338,6 +341,7 @@ static vpx_codec_err_t set_vp8e_config(VP8_CONFIG *oxcf,
     oxcf->arnr_strength =  vp8_cfg.arnr_strength;
     oxcf->arnr_type =      vp8_cfg.arnr_type;
 
+    oxcf->tuning = vp8_cfg.tuning;
 
     /*
         printf("Current VP8 Settings: \n");
@@ -451,6 +455,7 @@ static vpx_codec_err_t set_param(vpx_codec_alg_priv_t *ctx,
         MAP(VP8E_SET_ARNR_MAXFRAMES,        xcfg.arnr_max_frames);
         MAP(VP8E_SET_ARNR_STRENGTH ,        xcfg.arnr_strength);
         MAP(VP8E_SET_ARNR_TYPE     ,        xcfg.arnr_type);
+        MAP(VP8E_SET_TUNING,                xcfg.tuning);
 
     }
 
@@ -1050,6 +1055,7 @@ static vpx_codec_ctrl_fn_map_t vp8e_ctf_maps[] =
     {VP8E_SET_ARNR_MAXFRAMES,           set_param},
     {VP8E_SET_ARNR_STRENGTH ,           set_param},
     {VP8E_SET_ARNR_TYPE     ,           set_param},
+    {VP8E_SET_TUNING,                   set_param},
     { -1, NULL},
 };
 
diff --git a/vpx/vp8cx.h b/vpx/vp8cx.h
index 5ab6fbfb7..0e6eea614 100644
--- a/vpx/vp8cx.h
+++ b/vpx/vp8cx.h
@@ -150,7 +150,8 @@ enum vp8e_enc_control_id
     VP8E_SET_ARNR_MAXFRAMES,         /**< control function to set the max number of frames blurred creating arf*/
     VP8E_SET_ARNR_STRENGTH ,         /**< control function to set the filter strength for the arf */
     VP8E_SET_ARNR_TYPE     ,         /**< control function to set the type of filter to use for the arf*/
-} ;
+    VP8E_SET_TUNING,                 /**< control function to set visual tuning */
+};
 
 /*!\brief vpx 1-D scaling mode
  *
@@ -234,6 +235,18 @@ typedef enum
 } vp8e_token_partitions;
 
 
+/*!\brief VP8 model tuning parameters
+ *
+ * Changes the encoder to tune for certain types of input material.
+ *
+ */
+typedef enum
+{
+    VP8_TUNE_PSNR,
+    VP8_TUNE_SSIM
+} vp8e_tuning;
+
+
 /*!\brief VP8 encoder control function parameter type
  *
  * Defines the data types that VP8E control functions take. Note that
@@ -263,7 +276,7 @@ VPX_CTRL_USE_TYPE(VP8E_SET_TOKEN_PARTITIONS,   vp8e_token_partitions)
 VPX_CTRL_USE_TYPE(VP8E_SET_ARNR_MAXFRAMES,     unsigned int)
 VPX_CTRL_USE_TYPE(VP8E_SET_ARNR_STRENGTH ,     unsigned int)
 VPX_CTRL_USE_TYPE(VP8E_SET_ARNR_TYPE     ,     unsigned int)
-
+VPX_CTRL_USE_TYPE(VP8E_SET_TUNING,             vp8e_tuning)
 
 VPX_CTRL_USE_TYPE(VP8E_GET_LAST_QUANTIZER,     int *)
 VPX_CTRL_USE_TYPE(VP8E_GET_LAST_QUANTIZER_64,  int *)
diff --git a/vpxenc.c b/vpxenc.c
index c77996dcf..dc235e340 100755
--- a/vpxenc.c
+++ b/vpxenc.c
@@ -997,18 +997,27 @@ static const arg_def_t arnr_strength = ARG_DEF(NULL, "arnr-strength", 1,
                                        "AltRef Strength");
 static const arg_def_t arnr_type = ARG_DEF(NULL, "arnr-type", 1,
                                    "AltRef Type");
+static const struct arg_enum_list tuning_enum[] = {
+    {"psnr", VP8_TUNE_PSNR},
+    {"ssim", VP8_TUNE_SSIM},
+    {NULL, 0}
+};
+static const arg_def_t tune_ssim = ARG_DEF_ENUM(NULL, "tune", 1,
+                                   "Material to favor", tuning_enum);
 
 static const arg_def_t *vp8_args[] =
 {
     &cpu_used, &auto_altref, &noise_sens, &sharpness, &static_thresh,
-    &token_parts, &arnr_maxframes, &arnr_strength, &arnr_type, NULL
+    &token_parts, &arnr_maxframes, &arnr_strength, &arnr_type,
+    &tune_ssim, NULL
 };
 static const int vp8_arg_ctrl_map[] =
 {
     VP8E_SET_CPUUSED, VP8E_SET_ENABLEAUTOALTREF,
     VP8E_SET_NOISE_SENSITIVITY, VP8E_SET_SHARPNESS, VP8E_SET_STATIC_THRESHOLD,
     VP8E_SET_TOKEN_PARTITIONS,
-    VP8E_SET_ARNR_MAXFRAMES, VP8E_SET_ARNR_STRENGTH , VP8E_SET_ARNR_TYPE, 0
+    VP8E_SET_ARNR_MAXFRAMES, VP8E_SET_ARNR_STRENGTH , VP8E_SET_ARNR_TYPE,
+    VP8E_SET_TUNING, 0
 };
 #endif
 
@@ -1325,7 +1334,7 @@ int main(int argc, const char **argv_)
                 if (arg_ctrl_cnt < ARG_CTRL_CNT_MAX)
                 {
                     arg_ctrls[arg_ctrl_cnt][0] = ctrl_args_map[i];
-                    arg_ctrls[arg_ctrl_cnt][1] = arg_parse_int(&arg);
+                    arg_ctrls[arg_ctrl_cnt][1] = arg_parse_enum_or_int(&arg);
                     arg_ctrl_cnt++;
                 }
             }