Trying to find/create a function to call mp3 url [podpress]

podPress is a very complex plugin and it is not easy to find the right line of code if you are not familiar with it and getting familiar with it takes takes time.

is there a method/function that i can use to call the URL of the media file added to the post?

No, podPress has no API function. But there are several filter hooks you could use to modify URLs and other elements of the podPress output.
All hooks are listed on the Other Notes page in the section Filter Hooks of podPress.

For instance:
You could use the hook podpress_downloadlinks and write you a little filter plugin. This filter hook is to filter the podPress row below the player (all what is between <!-- Begin: podPress download link line --> and <!-- End: podPress download link line --> these comments included).

A filter which may replace certain download buttons could look like this:

add_filter('podpress_downloadlinks', 'filter_podpress_download_button_img_urls');
function filter_podpress_download_button_img_urls($podpressdownloadlinks) {
	// retrieve the URL of the download button out of the code of this line
	$result = preg_match('/\<img src=\"(.+)\" class=\"podPress_imgicon\" alt=\"\" \/\>/i', $podpressdownloadlinks, $matches);
	if ( 1 === $result ) { //  img URL found
		// if there is a download image then compare the URL (matches[1]) to discover which image it is and replace the URL with a different one
		//  (matches[0] contains the complete <img> tag)
		Switch ($matches[1]) {
			case PODPRESS_URL . '/images/audio_mp3_button.png' :
				$new_url = PODPRESS_URL . '/images/audio_mp3_icon.png'; // in this example the button URL of the download button of mp3 files gets exchanged with the icon URL
			break;
			default :
				$new_url ='';
			break;
		}
		// if the URL should be replaced then replace it. otherwise return code unchanged
		if ( '' !== $new_url ) {
			return str_replace($matches[1], $new_url, $podpressdownloadlinks);
		} else {
			return $podpressdownloadlinks;
		}
	} else {
		return $podpressdownloadlinks;
	}
}

You can put this code in the functions.php of your theme or in a php file e.g. podpress_filters.php along with:

/*
Plugin Name: podPress filters
Plugin URI:
Description: some filters for the output of podPress
Author: ntm
Version: 1.0
Author URI:
*/

(This should be placed at the beginning of the php file before the other code.)
podpress_filters.php should be placed in the plugin folder or in a separate sub folder like /wp-content/plugins/podpress_filters/podpress_filters.php. If you do that, it will among the other plugins on the plugins page of your blog and you can easily switch it on and off.

If you really like to know how podPress assembles the output then take a look in the podpress_class.php file (line 1000-1325) which retrieves the data from the wp_postmeta table and in the podpress_theme.php file which assembles the output.

But I recommend to use the filter hooks and a filter plugin.

Regards,
Tim

to 1.: bloginfo() is almost the right function. But bloginfo echos the path or any other value you could retrieve with this function. Better use get_bloginfo() instead. It returns the value and you can echo it when ever you want to. (see http://phpxref.com/xref/wordpress/wp-includes/general-template.php.source.html#l363 for the keywords you can use with this function and to see which functions this function calls to retrieve the URL)

to 2.: the phrase “Standard Podcast” is a default value which will be displayed if you do not define a title for the episode. It is not always this phrase. The phrase depends on the file type of the podcast episode (see the last 50 lines in the podpress_theme.php file).
Unfortunately that seems to be the only part of that line which one can not disable/hide via a option on the settings page. I’m going to change that in the next version of podPress.
So far the only possibility is to use the same filter hook and function. If you have only mp3 files you could use str_replace to delete the phrase.

to 3.: You can define the position of the podPress elements within the content of a post or page by using the place-holder [display_podcast]. podPress will replace that place-holder on page load. But other than that will probably be difficult. Because all the functions which insert the podPress elements are design to as filters for the content and excerpts. It uses for instance the filter hook the_content. There is no function which delivers you the code of the podPress elements if you call it with a certain ID of a post.
If you want to have the podPress elements outside of the usual posts then you probably would need to create a custom Loop which may request only certain posts and use the_content() or get_the_content(). If you don’t want to display the content again, you could use a further filter with the hook the_content to delete the post content before podPress adds the player code and the links.
That are only spontaneous ideas. I have not written such function or snippet for one of the theme files myself. But I would help you if have questions.

ps:

sorry for getting back to you so slowly.

No problem!