Enable screen detection mode 2 in all intra mode

Change-Id: I235de24065ee575a9f68672137f67fd2a57beedf

aom/aomcx.h

diff --git a/aom/aomcx.h b/aom/aomcx.h
index 4b39f34..e5ce630 100644
--- a/aom/aomcx.h
+++ b/aom/aomcx.h
@@ -1596,9 +1596,10 @@
   /*!\brief Codec control to set the screen content detection mode,
    * aom_screen_detection_mode parameter.
    *
-   * - 1: AOM_SCREEN_DETECTION_STANDARD = standard (default)
+   * - 1: AOM_SCREEN_DETECTION_STANDARD = standard (default in good quality and
+       realtime modes)
    * - 2: AOM_SCREEN_DETECTION_ANTIALIASING_AWARE = anti-aliased text and
-   *   graphics aware
+   *   graphics aware (default in all intra mode)
    */
   AV1E_SET_SCREEN_CONTENT_DETECTION_MODE = 171,
 
@@ -1743,7 +1744,6 @@
  *   * --enable-cdef=3
  *   * --enable-chroma-deltaq=1
  *   * --deltaq-mode=6
- *   * --screen-detection-mode=2
  * AOM_TUNE_IQ additionally sets the following options:
  *   * --enable-adaptive-sharpness=1
  */

av1/arg_defs.c

diff --git a/av1/arg_defs.c b/av1/arg_defs.c
index 1086567..ad28435 100644
--- a/av1/arg_defs.c
+++ b/av1/arg_defs.c
@@ -714,9 +714,10 @@
       "Enable low complexity decode (0: false (default), 1: true). As of now, "
       "this only supports good-quality encoding (speed 1 to 3) for vertical "
       "videos between 608p and 720p."),
-  .screen_detection_mode =
-      ARG_DEF(NULL, "screen-detection-mode", 1,
-              "Screen content detection mode (1: standard (default), "
-              "2: anti-aliased text and graphics aware)"),
+  .screen_detection_mode = ARG_DEF(
+      NULL, "screen-detection-mode", 1,
+      "Screen content detection mode (1: standard (default in good quality and "
+      "realtime modes), 2: anti-aliased text and graphics aware (default in "
+      "all intra mode))"),
 #endif  // CONFIG_AV1_ENCODER
 };

av1/av1_cx_iface.c

diff --git a/av1/av1_cx_iface.c b/av1/av1_cx_iface.c
index 5727aea..69140cc 100644
--- a/av1/av1_cx_iface.c
+++ b/av1/av1_cx_iface.c
@@ -1928,8 +1928,6 @@
     extra_cfg->enable_chroma_deltaq = 1;
     // Enable "Variance Boost" deltaq mode, optimized for images.
     extra_cfg->deltaq_mode = DELTA_Q_VARIANCE_BOOST;
-    // Enable "anti-aliased text and graphics aware" screen detection mode.
-    extra_cfg->screen_detection_mode = AOM_SCREEN_DETECTION_ANTIALIASING_AWARE;
   }
   if (extra_cfg->tuning == AOM_TUNE_IQ) {
     // Enable adaptive sharpness to adjust loop filter levels according to QP.
@@ -3017,14 +3015,20 @@
 
     priv->extra_cfg = default_extra_cfg;
     // Special handling:
-    // By default, if omitted: --enable-cdef=1, --qm-min=5, and --qm-max=9
-    // Here we set its default values to 0, 4, and 10 respectively when
-    // --allintra is turned on.
-    // However, if users set --enable-cdef, --qm-min, or --qm-max, either from
-    // the command line or aom_codec_control(), the encoder still respects it.
+    // By default, if omitted: --enable-cdef=1, --screen-detection-mode=1,
+    // --qm-min=5, and --qm-max=9.
+    // Here we set its default values to --enable-cdef=0,
+    // --screen-detection-mode=2, --qm-min=4, and --qm-max=10 when --allintra
+    // is turned on.
+    // However, if users set --enable-cdef, --screen-detection-mode, --qm-min,
+    // or --qm-max, either from the command line or aom_codec_control(), the
+    // encoder still respects it.
     if (priv->cfg.g_usage == AOM_USAGE_ALL_INTRA) {
       // CDEF has been found to blur images, so it's disabled in all-intra mode
       priv->extra_cfg.enable_cdef = 0;
+      // Enable "anti-aliased text and graphics aware" screen detection mode.
+      priv->extra_cfg.screen_detection_mode =
+          AOM_SCREEN_DETECTION_ANTIALIASING_AWARE;
       // These QM min/max values have been found to be beneficial for images,
       // when used with an alternative QM formula (see
       // aom_get_qmlevel_allintra()).