Translating JSON/API Results

I’m hoping that someone has had to do what I’m attempting to do and knows of a WP plugin or even 3rd party solution. I’m using the GeoDirectory plugin and trying to connect their recently released API to a mobile development framework that supports custom JSON feeds. The issue is that the GeoDirectory API formatting is different than what the mobile framework needs to parse. I’ve included a cleaned up example of what GeoDirectory produces and what the mobile development framework expects. I’m essentially looking to take the input, modify it, and re-output it in the correct format in realtime. Thanks for any help anyone can provide.

GeoDirectory Output:

[
  {
    "id": $id,
    "date": "$date",
    "date_gmt": "$date_gmt",
    "guid": {
      "rendered": "$guid"
    },
    "modified": "$modified",
    "modified_gmt": "$modified_gmt",
    "slug": "$slug",
    "type": "$type",
    "link": "$link",
    "title": {
      "rendered": "$title"
    },
    "content": {
      "rendered": "$content"
    },
    "excerpt": {
      "rendered": "$excerpt"
    },
    "gd_data": {
      "post_id": "$post_id",
      "post_title": "$post_title",
      "post_status": "$post_status",
      "default_category": {
        "raw": "$default_category_raw",
        "rendered": "$default_category_rendered"
      },
      "claimed": "$claimed",
      "is_featured": "$is_featured",
      "featured_image": "$featured_image",
      "post_address": "$post_address",
      "post_city": "$post_city",
      "post_region": "$post_region",
      "post_country": "$post_country",
      "post_zip": "$post_zip",
      "post_latitude": "$post_latitude",
      "post_longitude": "$post_longitude",
      "geodir_contact": "$geodir_contact",
      "geodir_email": "$geodir_email",
      "geodir_website": "$geodir_website",
      "geodir_twitter": "$geodir_twitter",
      "geodir_facebook": "$geodir_facebook",
      "geodir_special_offers": "$geodir_special_offers",
  }
]

Mobile Framework Supported:

{
  "dedup": true,
  "generated_in": "0.010000 s",
  "items": [
    {
      "address": "$post_address",
      "author": "",
      "commentsEnabled": false,
      "content": "$content",
      "contentTemplate": null,
      "date": "$date",
      "email": "$geodir_email",
      "id": $post_id,
      "images": [
        {
          "id": "$post_id",
          "url": "$featured_image"
        }
      ],
      "isFeatured": "$is_featured",
      "latitude": "$post_latitude",
      "longitude": "$post_longitude",
      "phoneNumber": "$geodir_contact",
      "subsections": {
        "$default_category_raw": [
          "$default_category_rendered"
        ]
      },
      "subtype": "mcms",
      "summary": "$excerpt",
      "title": "$post_title",
      "type": "maps",
      "website": "$geodir_website"
    }
  ],
  "next_page": null,
  "stat": "ok"
}