Make keyint_min auto by default

Gives more reasonable default settings when using short GOPs.

common/common.c

@@ -70,7 +70,7 @@ void x264_param_default( x264_param_t *param )
     /* Encoder parameters */
     param->i_frame_reference = 3;
     param->i_keyint_max = 250;
-    param->i_keyint_min = 25;
+    param->i_keyint_min = X264_KEYINT_MIN_AUTO;
     param->i_bframe = 3;
     param->i_scenecut_threshold = 40;
     param->i_bframe_adaptive = X264_B_ADAPT_FAST;

encoder/encoder.c

@@ -577,6 +577,8 @@ static int x264_validate_parameters( x264_t *h )
         x264_log( h, X264_LOG_WARNING, "ref > 1 + intra-refresh is not supported\n" );
         h->param.i_frame_reference = 1;
     }
+    if( h->param.i_keyint_min == X264_KEYINT_MIN_AUTO )
+        h->param.i_keyint_min = h->param.i_keyint_max / 10;
     h->param.i_keyint_min = x264_clip3( h->param.i_keyint_min, 1, h->param.i_keyint_max/2+1 );
     h->param.rc.i_lookahead = x264_clip3( h->param.rc.i_lookahead, 0, X264_LOOKAHEAD_MAX );
     {

x264.c

@@ -363,7 +363,7 @@ static void Help( x264_param_t *defaults, int longhelp )
     H0( "Frame-type options:\n" );
     H0( "\n" );
     H0( "  -I, --keyint <integer>      Maximum GOP size [%d]\n", defaults->i_keyint_max );
-    H2( "  -i, --min-keyint <integer>  Minimum GOP size [%d]\n", defaults->i_keyint_min );
+    H2( "  -i, --min-keyint <integer>  Minimum GOP size [auto]\n" );
     H2( "      --no-scenecut           Disable adaptive I-frame decision\n" );
     H2( "      --scenecut <integer>    How aggressively to insert extra I-frames [%d]\n", defaults->i_scenecut_threshold );
     H2( "      --intra-refresh         Use Periodic Intra Refresh instead of IDR frames\n" );

x264.h

@@ -35,7 +35,7 @@
 
 #include <stdarg.h>
 
-#define X264_BUILD 92
+#define X264_BUILD 93
 
 /* x264_t:
  *      opaque handler for encoder */
@@ -101,6 +101,7 @@ typedef struct x264_t x264_t;
 #define X264_B_PYRAMID_NONE          0
 #define X264_B_PYRAMID_STRICT        1
 #define X264_B_PYRAMID_NORMAL        2
+#define X264_KEYINT_MIN_AUTO         0
 
 static const char * const x264_direct_pred_names[] = { "none", "spatial", "temporal", "auto", 0 };
 static const char * const x264_motion_est_names[] = { "dia", "hex", "umh", "esa", "tesa", 0 };