The term MP4 is most often associated with video, while the term MP3 is almost universally recognized to be about music. How can then one convert MP4 to MP3, and what can be the reason to do so?

A decade ago, audio compression was the biggest thing in multimedia applications. There was a time when the only kind of audio you could possibly download from the internet was minuscule midi files. And that was about the limit of what you could carry from one computer to another, because all the removable medium you had in those days was the measly floppy disk. But then came the MP3.

Now, the same thing has happened with video. With the help of modern video compression technologies, it has become possible to put small yet high-quality video files on hand-held, portable personal video players. And the commonest type of file used by these is the MP4.

However, not all MP4 files contain video. The MP4 file format is able to contain video, but nothing says that it has to contain video. It may just contain an audio stream, and that would play perfectly well in any capable MP4 player. In fact, the hugely popular online music store iTunes sells its music in MP4 format. You shall notice that iTunes files have the .m4a extension. This is Apple's way of indicating that these are MP4 files with only an audio stream in them, and no video.

But not everyone owns an iPod or some other MP4 player. MP3 players have been with us for a decade or more, and MP4 players haven't yet been able to beat them in numbers. So when you want to listen that catchy tune you caught on your friend's iPod, but own only a couple-of-years-old MP3 player, you need a tool that can convert MP4 to MP3.

The good news is that the audio stream inside MP4 files is nothing other than the good old MP3, merely inserted in a different package. So it is really trivial to extract this stream and save it as a different file that can be played on your old player. Several free tools are available online for this job. Get yourself one and convert MP4 to MP3 to your heart's content!

With the advent of the Sony PSP, there is an increasing demand for movies in the mp4 format. But many of you would already have your movies in CDs and DVDs. So getting movies freshly in the form of mp4 would require substantial investment. Thankfully there are software platforms available which help you to convert mpeg files to mp4. once you convert mpeg to mp4 your problem is solved and now you can see the same film both on your PSP and on your TV using a DVD player.

There are a number of software platforms that support conversion of mpeg to mp4. The software you choose depends on your requirements. You can get a software that helps you to convert across all platforms. ImTOO PSP Video Converter  allows you to work with DVD, VCD, AVI, MPEG, GIF, Flash, WMV, WMA, WAV, MP3, MP4, M4A, OGG, AAC etc. Such a software helps you to work with anything you want. It is a one stop solution for everything. Such software platforms can easily be downloaded from the internet, but those would be the shareware versions with limitations in usage. If you are satisfied with the product you can order for a full version over the net.

You can also use the PSP Movie Creator. Specially developed for the PSP, this software also allows you to convert your video files for your PSP. The hardware and software support you require to use PSP Movie Creator is:

Operating System - Windows 98 or higher
CPU - Pentium II 300 MMX or equivalent as a minimum
DVD Drive - DVD-R(W)/+R(W) Drive
Memory (RAM) – minimum 64meg memory
Hard Drive – minimum 4 GB, ideally 8GB of free space in a drive partition
Sony Memory Stick - At least a 512 MB Pro Duo Card. For 5-10 min movies 32MB card will do
USB Cable - PSP USB Cable

If you are using he trial version would be able to convert only 5 minutes of a movie. To convert entire movies you will have to get a full version.
So there are plenty of software that support conversion from MPEG to MP4. You just have to find one that suits you. 

As the PSP storms the market there is increasing concern as to what will happen to all those movies that were stored in various formats. Since PSP supports only mp4, if you have movies stored in other formats, you got to change them into mp4. so if you have a file in DivX you have to convert the DivX to mp4. Thankfully with the advent of new technology and new devices, new software has also hit the market which allows you to convert DivX to mp4. So now you have the option of playing the previous formats stored in either CDs or DVDs in your DVD player, and at the same time you can use the mp4 format for your PSP device. 

When choosing a software for the conversion of DivX to mp4 have an idea as to what you need. It will be better to opt for a software like ImTOO PSP as the options it provides are numerous and you can convert any of DVD, VCD, AVI, MPEG, GIF, Flash, WMV, WMA, WAV, MP3, MP4, M4A, OGG, AAC to mp4. It makes sense that you download a trial version before you buy the full version. Almost all the software have their trial versions available on the internet. They come with limited usage but you can at least get a hang of it. If you a tech savvy person you can do with complicated software with extra features. If you are one who isn’t into much computers then a simple, easy-to-use software should be the right choice. 

Of course you have the PSP Movie Creator also where you can convert DivX to mp4 and that too is without much hassle. However before buying the software make sure your system supports the following hardware requirements. 

Operating System - Windows 98 or higher 

CPU - Pentium II 300 MMX or equivalent as a minimum 

- DVD-R(W)/+R(W) Drive 

Memory (RAM) – minimum 64meg memory 

Hard Drive – minimum 4 GB, ideally 8GB of free space in a drive partition 

Sony Memory Stick - At least a 512 MB Pro Duo Card. For 5-10 min movies 32MB card will do 

USB Cable - PSP USB Cable 

If you are using he trial version would be able to convert only 5 minutes of a movie. To convert entire movies you will have to get a full version.