Parsing thumbnail to custom field | CyberSEO Pro | Support Forum

I'm stuck with getting a thumbnail from this feed and parse it to a custom field $post['custom_fields']['thumb'].

I get the video/mp4 by using $post['custom_fields']['video_url'] = $post['enclosure_url'];

Now I need $post['custom_fields']['thumb'] =

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<enclosure url="https://content.kink.com/imagedb/101768/trailer/101768_trailer_high.mp4" length="0" type="video/mp4"/>
<media:rating scheme="urn:simple">adult</media:rating>
<media:content url="https://content.kink.com/imagedb/101768/trailer/101768_trailer_high.mp4" type="video/mp4"> </media:content>
<media:thumbnail url="https://content.kink.com/imagedb/101768/galleryImage/ddf_002_full.png"> </media:thumbnail>
<media:thumbnail url="https://content.kink.com/imagedb/101768/galleryImage/ddf_003_full.png"> </media:thumbnail>
<media:thumbnail url="https://content.kink.com/imagedb/101768/galleryImage/ddf_004_full.png"> </media:thumbnail>
<media:thumbnail url="https://content.kink.com/imagedb/101768/galleryImage/ddf_001_full.png"> </media:thumbnail>