diff --git a/src/config.c b/src/config.c
index 3c850988..e2535e91 100644
--- a/src/config.c
+++ b/src/config.c
@@ -53,6 +53,7 @@ int config_init(config *cfg)
   cfg->width  = 320;
   cfg->height = 240;
   cfg->qp     = 32;
+  cfg->intra_period = 0;
 
   return 1;
 }
@@ -118,6 +119,9 @@ int config_read(config *cfg,int argc, char *argv[])
         case 'q': // QP
           cfg->qp = atoi(argv[arg]);
           break;
+        case 'p': // Intra period
+          cfg->intra_period = atoi(argv[arg]);
+          break;
         default:
           // Unknown command, print error message and ignore
           fprintf(stderr, "%c is not a known option\r\n", option);
diff --git a/src/config.h b/src/config.h
index 2adfc8c5..74e09fa9 100644
--- a/src/config.h
+++ b/src/config.h
@@ -37,6 +37,7 @@ typedef struct
   char *output;     /*!< \brief Pointer to output filename */
   char *debug;      /*!< \brief Pointer to debug output    */
   int8_t qp;        /*!< \brief Quantization parameter */
+  int16_t intra_period; /*!< \brief the period of intra frames in stream */
   int32_t frames;  /*!< \brief Number of frames to decode */
   int32_t width;   /*!< \brief frame width */
   int32_t height;  /*!< \brief frame height */
diff --git a/src/encmain.c b/src/encmain.c
index 6aca976f..3c9f9a01 100644
--- a/src/encmain.c
+++ b/src/encmain.c
@@ -73,7 +73,7 @@ int main(int argc, char *argv[])
   if (!config_init(cfg) || !config_read(cfg,argc,argv)) {
     fprintf(stderr, "/***********************************************/\r\n");
     fprintf(stderr, " *           HEVC Encoder v. " VERSION_STRING "*\r\n");
-    fprintf(stderr, " *     Tampere University of Technology  2013  *\r\n");
+    fprintf(stderr, " *     Tampere University of Technology 2014   *\r\n");
     fprintf(stderr, "/***********************************************/\r\n\r\n");
       
     fprintf(stderr, "Usage:\r\n");
@@ -81,6 +81,10 @@ int main(int argc, char *argv[])
     fprintf(stderr, "Optional parameters:\r\n");
     fprintf(stderr, "      -n <frames> : number of frames to decode\r\n");
     fprintf(stderr, "      -q <QP> : Quantization Parameter, default 32\r\n");
+    fprintf(stderr, "      -p <intra period> : Period of intra pictures, default 0\r\n");
+    fprintf(stderr, "          0: only first picture is intra\r\n");
+    fprintf(stderr, "          1: all pictures are intra\r\n");
+    fprintf(stderr, "          2-N: every Nth picture is intra\r\n");
 
     config_destroy(cfg);
     return EXIT_FAILURE;
@@ -225,6 +229,7 @@ int main(int argc, char *argv[])
     MOVE_POINTER(encoder->in.cur_pic->pred_v,encoder->ref->pics[0]->pred_v);
 
     encoder->frame++;
+    encoder->poc++;
   }
   // Coding finished
   fgetpos(output,(fpos_t*)&curpos);
diff --git a/src/encoder.c b/src/encoder.c
index f3575add..19543735 100644
--- a/src/encoder.c
+++ b/src/encoder.c
@@ -280,8 +280,15 @@ void init_encoder_input(encoder_input *input, FILE *inputfile,
 void encode_one_frame(encoder_control* encoder)
 {
 
-  // output parameters before first frame
-  if (encoder->frame == 0) {
+  /** IDR picture when: period == 0 and frame == 0
+   *                    period == 1 && frame%2 == 0
+   *                    period != 0 && frame%period == 0   
+   **/
+  if ( (encoder->cfg->intra_period == 0 && encoder->frame == 0) ||
+       (encoder->cfg->intra_period && encoder->frame % encoder->cfg->intra_period == 0 &&
+        (encoder->cfg->intra_period != 1 || encoder->frame % 2 == 0 ) ) ) {
+    encoder->poc = 0;
+
     // Video Parameter Set (VPS)
     encode_vid_parameter_set(encoder);
     bitstream_align(encoder->stream);
@@ -324,7 +331,8 @@ void encode_one_frame(encoder_control* encoder)
     bitstream_clear_buffer(encoder->stream);
   } else {
     cabac_start(&cabac);
-    encoder->in.cur_pic->slicetype = SLICE_P;
+    // When intra period == 1, all pictures are intra
+    encoder->in.cur_pic->slicetype = encoder->cfg->intra_period==1 ? SLICE_I : SLICE_P;
     encoder->in.cur_pic->type = NAL_TRAIL_R;
     scalinglist_process();
     search_slice_data(encoder);
@@ -754,7 +762,7 @@ void encode_slice_header(encoder_control* encoder)
       int j;
       int ref_negative = 1;
       int ref_positive = 0;
-      WRITE_U(encoder->stream, encoder->frame&0xf, 4, "pic_order_cnt_lsb");
+      WRITE_U(encoder->stream, encoder->poc&0xf, 4, "pic_order_cnt_lsb");
       WRITE_U(encoder->stream, 0, 1, "short_term_ref_pic_set_sps_flag");
       WRITE_UE(encoder->stream, ref_negative, "num_negative_pics");
       WRITE_UE(encoder->stream, ref_positive, "num_positive_pics");
diff --git a/src/encoder.h b/src/encoder.h
index 8d9538d8..84e2a400 100644
--- a/src/encoder.h
+++ b/src/encoder.h
@@ -61,6 +61,7 @@ typedef struct
 typedef struct
 {
   int32_t frame;
+  int32_t poc; /*!< \brief picture order count */
   config *cfg;
   encoder_input in;
   encoder_me me;