[1:v]split=4[a][b][c][d];
[a]crop=427:480:0:0,scale=480:360,drawtext=text=CAM1:fontcolor=yellow:fontsize=36:x=8:y=8:box=1,drawtext=text='%{pts\:hms}':fontcolor=white:fontsize=22:x=8:y=48:box=1[v1];
[b]crop=427:480:427:0,scale=480:360,drawtext=text=CAM2:fontcolor=yellow:fontsize=36:x=8:y=8:box=1,drawtext=text='%{pts\:hms}':fontcolor=white:fontsize=22:x=8:y=48:box=1[v2];
[c]crop=427:480:0:0,scale=480:360,drawtext=text=CAM3:fontcolor=yellow:fontsize=36:x=8:y=8:box=1,drawtext=text='%{pts\:hms}':fontcolor=white:fontsize=22:x=8:y=48:box=1[v3];
[d]crop=427:480:427:0,scale=480:360,drawtext=text=CAM4:fontcolor=yellow:fontsize=36:x=8:y=8:box=1,drawtext=text='%{pts\:hms}':fontcolor=white:fontsize=22:x=8:y=48:box=1[v4]