/* Handle some required side effects when the video standard is
           changed.... */
        if (hdw->std_dirty) {
-               /* Rewrite the vertical resolution to be appropriate to the
-                  video standard that has been selected. */
                int nvres;
+               int gop_size;
                if (hdw->std_mask_cur & V4L2_STD_525_60) {
                        nvres = 480;
+                       gop_size = 15;
                } else {
                        nvres = 576;
+                       gop_size = 12;
                }
+               /* Rewrite the vertical resolution to be appropriate to the
+                  video standard that has been selected. */
                if (nvres != hdw->res_ver_val) {
                        hdw->res_ver_val = nvres;
                        hdw->res_ver_dirty = !0;
                }
+               /* Rewrite the GOP size to be appropriate to the video
+                  standard that has been selected. */
+               if (gop_size != hdw->enc_ctl_state.video_gop_size) {
+                       struct v4l2_ext_controls cs;
+                       struct v4l2_ext_control c1;
+                       memset(&cs, 0, sizeof(cs));
+                       memset(&c1, 0, sizeof(c1));
+                       cs.controls = &c1;
+                       cs.count = 1;
+                       c1.id = V4L2_CID_MPEG_VIDEO_GOP_SIZE;
+                       c1.value = gop_size;
+                       cx2341x_ext_ctrls(&hdw->enc_ctl_state, 0, &cs,
+                                         VIDIOC_S_EXT_CTRLS);
+               }
        }
 
        if (hdw->input_dirty && hdw->state_pathway_ok &&