diff --git a/common/base.c b/common/base.c
index 3427727..9559e59 100644
--- a/common/base.c
+++ b/common/base.c
@@ -989,6 +989,8 @@ REALIGN_STACK int x264_param_parse( x264_param_t *p, const char *name, const cha
     }
     OPT("bluray-compat")
         p->b_bluray_compat = atobool(value);
+    OPT("psp-compat")
+        p->b_psp_compat = atobool(value);
     OPT("avcintra-class")
         p->i_avcintra_class = atoi(value);
     OPT("avcintra-flavor")
diff --git a/encoder/encoder.c b/encoder/encoder.c
index 20e620a..a81162f 100644
--- a/encoder/encoder.c
+++ b/encoder/encoder.c
@@ -2115,11 +2115,14 @@ int x264_encoder_headers( x264_t *h, x264_nal_t **pp_nal, int *pi_nal )
         return -1;
 
     /* identify ourselves */
-    nal_start( h, NAL_SEI, NAL_PRIORITY_DISPOSABLE );
-    if( x264_sei_version_write( h, &h->out.bs ) )
-        return -1;
-    if( nal_end( h ) )
-        return -1;
+    if( !h->param.b_psp_compat )
+    {
+        nal_start( h, NAL_SEI, NAL_PRIORITY_DISPOSABLE );
+        if( x264_sei_version_write( h, &h->out.bs ) )
+            return -1;
+        if( nal_end( h ) )
+            return -1;
+    }
 
     frame_size = encoder_encapsulate_nals( h, 0 );
     if( frame_size < 0 )
@@ -3728,7 +3731,7 @@ int     x264_encoder_encode( x264_t *h,
     if( h->fenc->b_keyframe )
     {
         /* Avid's decoder strictly wants two SEIs for AVC-Intra so we can't insert the x264 SEI */
-        if( h->param.b_repeat_headers && h->fenc->i_frame == 0 && !h->param.i_avcintra_class )
+        if( h->param.b_repeat_headers && h->fenc->i_frame == 0 && !h->param.i_avcintra_class && !h->param.b_psp_compat )
         {
             /* identify ourself */
             nal_start( h, NAL_SEI, NAL_PRIORITY_DISPOSABLE );
diff --git a/encoder/set.c b/encoder/set.c
index ec47193..0ed8ccb 100644
--- a/encoder/set.c
+++ b/encoder/set.c
@@ -169,14 +169,25 @@ void x264_sps_init( x264_sps_t *sps, int i_id, x264_param_t *param )
     sps->i_log2_max_frame_num = 4;
     while( (1 << sps->i_log2_max_frame_num) <= max_frame_num )
         sps->i_log2_max_frame_num++;
+    /* PMP-PSP compatibility: match XviD4PSP 5 reference SPS (log2_max_frame_num_minus4=5, pic_order_cnt_type=0) */
+    if( param->b_psp_compat )
+        sps->i_log2_max_frame_num = 9;
 
     sps->i_poc_type = param->i_bframe || param->b_interlaced || param->i_avcintra_class ? 0 : 2;
+    if( param->b_psp_compat && sps->i_poc_type == 2 )
+        sps->i_poc_type = 0;
     if( sps->i_poc_type == 0 )
     {
         int max_delta_poc = (param->i_bframe + 2) * (!!param->i_bframe_pyramid + 1) * 2;
         sps->i_log2_max_poc_lsb = 4;
         while( (1 << sps->i_log2_max_poc_lsb) <= max_delta_poc * 2 )
             sps->i_log2_max_poc_lsb++;
+        /* PMP-PSP compatibility: match XviD4PSP 5 reference SPS
+         * (log2_max_poc_lsb_minus4=6). x264's minimal window makes
+         * pic_order_cnt_lsb wrap every 8 frames; the PSP ME decoder
+         * hangs on MSB wraparound, so widen the field to 10 bits. */
+        if( param->b_psp_compat )
+            sps->i_log2_max_poc_lsb = 10;
     }
 
     sps->b_vui = 1;
diff --git a/x264.c b/x264.c
index 8158315..c4f8db9 100644
--- a/x264.c
+++ b/x264.c
@@ -925,6 +925,7 @@ static void help( x264_param_t *defaults, int longhelp )
     H0( "      --frames <integer>      Maximum number of frames to encode\n" );
     H0( "      --level <string>        Specify level (as defined by Annex A)\n" );
     H1( "      --bluray-compat         Enable compatibility hacks for Blu-ray support\n" );
+    H1( "      --psp-compat            PMP/PSP: force log2_max_frame_num_minus4=5, pic_order_cnt_type=0\n" );
     H1( "      --avcintra-class <integer> Use compatibility hacks for AVC-Intra class\n"
         "                                  - %s\n", stringify_names( buf, x264_avcintra_class_names ) );
     H1( "      --avcintra-flavor <string> AVC-Intra flavor [\"%s\"]\n"
@@ -1031,6 +1032,7 @@ static struct option long_options[] =
     { "b-pyramid",            required_argument, NULL, 0 },
     { "open-gop",             no_argument,       NULL, 0 },
     { "bluray-compat",        no_argument,       NULL, 0 },
+    { "psp-compat",           no_argument,       NULL, 0 },
     { "avcintra-class",       required_argument, NULL, 0 },
     { "avcintra-flavor",      required_argument, NULL, 0 },
     { "min-keyint",           required_argument, NULL, 'i' },
diff --git a/x264.h b/x264.h
index b3223cd..e6a8f50 100644
--- a/x264.h
+++ b/x264.h
@@ -371,6 +371,7 @@ typedef struct x264_param_t
     int         i_bframe_pyramid;   /* Keep some B-frames as references: 0=off, 1=strict hierarchical, 2=normal */
     int         b_open_gop;
     int         b_bluray_compat;
+    int         b_psp_compat;   /* PMP/PSP: force log2_max_frame_num_minus4=5, pic_order_cnt_type=0 */
     int         i_avcintra_class;
     int         i_avcintra_flavor;