What is Podcast to me?

PodCast is derived from concept of iPod (that is why it bears the name). iPod + broadcasting = PodCast.

http://www.podcastalley.com/what_is_a_podcast.php

If you read the explanation from URL above, it is actually kind of confusing for a tech person like me. The last paragraph seems to predict similar outcome from readers.

What makes podcasting special is that it allows individuals to publish (podcast) radioshows, that interested listeners can subscribe to. Before podcasting you could of course record a radio show and put it on your website, but now people can automatically receive new shows, without having to go to a specific site and download it from there.

What it is trying to say is that the practice of uploading and downloading MP3 file has been around for sometime. Except that now, people can automatically get new uploaded file for better convenience.

All this is made practical by having this technology called RSS (really simple syndication). How does RSS work? It is actually based on Web Services. (I think the author deliberately drop this term to make it user-friendly). Web Services is a technology where you can communicate with other systems without having to login to it. Means that whenever you “call it up”, it will give you an answer regardless of whether you are a dog behind the monitor or a human, it just doesn’t care. No, what I mean is that using Web Services, the provider (the one with the MP3 files) will not have to worry about security breach because you are actually not being logged in to the system. Thus, what it does is that whenever you call for it, it will reply you with a text document formatted in XML format.

Now, with that XML document, the next thing you need to do is to comprehend it, in technical terms it is called “parsing”. The purpose of this process is to extract the information. For instance, let’s take a real example:




Try to access the following XML document: (just click on it)

http://feeds.feedburner.com/BitByBit

What the extraction process would do is to reformat it(XML document above) into the following format.

Item No	Title	Published Date
1	Bit By Bit Podcast: July 7, 2005 Show 04 "So... what IS a podcast?" The question on everyone's mind. Shownotes. Click for the show! Or Subscribe to the FEED.	7th July 2005
2	Bit By Bit Podcast: July 4, 2005 Show 03 "What are you Using?" The basic setup. Shownotes. Click for the show! Or Subscribe to the FEED.	4th July 2005
3	Bit By Bit Podcast: July 1, 2005 Show 02 "Where 'dja Get It?" An answer to the quest for "Podsafe Music." Shownotes. Click for the show! Or Subscribe to the FEED.	1st July 2005
4	National Educational Computing Conference	29th June 2005

Besides formatting, it also structures the content in such a way that there will be a hyperlink to the real MP3 files when you click on the titles.

Savvy? Ok, for those of you technical expert out there,please bear with me because this may not be the exact output even though this is the generic expectation. To really justify the actually output, we all need to analyze the data-dictionary (DTD)

http://search.yahoo.com/mrss" xmlns:itunes="http://www.itunes.com/DTDs/Podcast-1.0.dtd

DTD file is only needed by programmer who is going to develop the software or scripts that would do the parsing. Such software is known as RSS Aggregator. Well, we can also call it the XML-parser.

Thus, with PodCast now available for iPod, it means that iTunes has to somehow support the feature of RSS Aggregator (PodCast aggregator) so that it can do the parsing or XML reformatting. If you are using iTunes version 4.7.1.30, you would require an upgrade.

It is funny, if you read the paragraphs from bottom up, it makes more sense to me, perhaps for you too?

ya.. the conclusion for PodCast is this.
1. You record an audio into MP3 or etc format.
2. You then upload it to a host which has Web Services(so that it can return a XML file for the purpose of RSS).
3. Then you advertise the URL of your XML file as PodCast.

In other words, PodCast is using RSS technology, which is Web Services technology which is XML technology.

Ok, enough for now. I will share with you about how “web service” work as well as how people build a web based RSS aggregator and my thoughts on application of PodCast, in the next blog.

thanks for visiting my tech blog :)