set_banner_header.php

<?php
$products = array(
    'Media Player',
    'Video Converter'
);

$file_data = file_get_contents("template.json");
$main_json = json_decode($file_data);


$result = array();
foreach ($products as $product) {
    $result[] = replaceProductName($main_json[0], $product);
}


$json_data = json_encode($result, JSON_PRETTY_PRINT);
file_put_contents("products.json", $json_data);


function replaceProductName($json, $product)
{
    // force copy of the object
    $json = unserialize(serialize($json));

    foreach ($json as $item_id => $item) {
        if (strpos($item_id, "product_name") === false) {
            continue;
        }
        $item->text = $product;
    }
    return $json;
}

template.json

[
  {
    "slide-1": {
      "width": "300",
      "height": "250",
      "backgroundColor": "#f2f2f2",
      "border": {
        "thickness": 0,
        "color": "#000000",
        "radius": 0
      }
    },
    "image-2": {
      "top": "110px",
      "left": "90px",
      "width": "auto",
      "height": "auto",
      "zIndex": "",
      "src": "/bundles/rstmain/images/image-placeholder.gif"
    },
    "product_name": {
      "top": "30px",
      "left": "45px",
      "width": "auto",
      "height": "auto",
      "zIndex": "",
      "maxFontSize": "14",
      "font": "arial",
      "text": "Lorem Ipsum is simply dummy text of the printing and typesetting industry. ",
      "color": "#333"
    }
  }
]