magento 2 how to upload images and videos in custom module

Finally i got the answer

I refer this module and implement in my custom module

Find below useful code :

following below steps

1) create layout.xml

[vendor]/[module]/operation/view/adminhtml/layout/layout_edit.xml

<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">

    <body>
            <referenceContainer name="content">
                <uiComponent name="sample_form"/>
            </referenceContainer>
            <referenceContainer name="sample_form">
                <block name="gallery" class="[vendor]\[module]\Block\Adminhtml\Grid\Helper\Form\Gallery">
                    <arguments>
                        <argument name="config" xsi:type="array">
                            <item name="label" xsi:type="string" translate="true">Images</item>
                            <item name="collapsible" xsi:type="boolean">true</item>
                            <item name="opened" xsi:type="boolean">false</item>
                            <item name="sortOrder" xsi:type="string">22</item>
                            <item name="canShow" xsi:type="boolean">true</item>
                            <item name="componentType" xsi:type="string">fieldset</item>
                        </argument>
                    </arguments>
                    <block class="[vendor]\[module]\Block\Adminhtml\Grid\Helper\Form\Gallery\Content" as="content" template="[vendor]_[[module]::helper/gallery.phtml">
                        <arguments>
                            <argument name="config" xsi:type="array">
                                <item name="parentComponent" xsi:type="string">sample_form.sample_form.block_gallery.block_gallery</item>

                            </argument>
                        </arguments>

                    </block>
                </block>
            </referenceContainer>

    </body>
</page>

2) Create helper block

[vendor]/[module]/Block/Adminhtml/Grid/Helper/Form/Gallery.php

namespace [vendor]\[module]\Block\Adminhtml\Grid\Helper\Form;

use Magento\Framework\Registry;
use Magento\Catalog\Model\Product;
use Magento\Eav\Model\Entity\Attribute;
use Magento\Catalog\Api\Data\ProductInterface;

class Gallery extends \Magento\Catalog\Block\Adminhtml\Product\Helper\Form\Gallery
{
    /**
     * @var here you set your ui form 
     */
    protected $formName = 'sample_form';

}

3) Create helper form block

[vendor]\[module]\Block\Adminhtml\Grid\Helper\Form\Gallery\Content.php

namespace [vendor]\[module]\Block\Adminhtml\Grid\Helper\Form\Gallery;

use Magento\Framework\Data\Form\Element\AbstractElement;
use Magento\Backend\Block\Media\Uploader;
use Magento\Framework\View\Element\AbstractBlock;
use Magento\Framework\App\Filesystem\DirectoryList;

class Content extends \Magento\Catalog\Block\Adminhtml\Product\Helper\Form\Gallery\Content
{


    protected function _prepareLayout()
    {
        $this->addChild('uploader', 'Magento\Backend\Block\Media\Uploader');

        $a = $this->getUploader()->getConfig()->setUrl(
            $this->_urlBuilder->addSessionParam()->getUrl('[vendor]/grid_gallery/upload')/* here set you upload Controller */
        )->setFileField(
            'image'
        )->setFilters(
            [
                'images' => [
                    'label' => __('Images (.gif, .jpg, .png)'),
                    'files' => ['*.gif', '*.jpg', '*.jpeg', '*.png'],
                ],
            ]
        );

    }


    public function getImageTypes()
    {
        return '[]';
    }

    public function getMediaAttributes()
    {
        return '[]';
    }

}

Note :- you should extends properly above both blocks

4) Create template

You should copy gallery.phtml form vendor/magento/module-product-video/view/adminhtml/templates/helper/gallery.phtml and modified it as par your requirement and pest in your module [vendor]/[module]/view/adminhtml/templates/helper/gallery.phtml

Please let me know in comment if you need any help