What is MP3PRO
One way of describing MP3PRO is to say it is comprised of two audio files woven together. The first part is a regular low bitrate MP3 file that uses the original MP3 compressor-decompressor, or "codec". The second part is another layer of audio that uses a different form of compression called Spectral Band Replication, or SBR.
SBR can be used with a range of audio codecs, not just MP3. For example, when it's combined with AAC audio compression, is called aacPlus. When combined with MP3, however, it's known as MP3PRO. It operates like an audio enhancement technology that sits on top of the existing compression.
Why use MP3PRO
The good thing about MP3PRO is that you get much better audio compression for the file size than you do with standard MP3s. Not only that, but you can still play the files on MP3 players that don't support MP3PRO, because it is backwards-compatible with MP3. The result is that you will only hear the regular MP3 audio, so you won't get the full benefit of the SBR component. If your MP3 player supports the newer format, though -- and many do -- you can reap the benefits.
How much better is it
MP3PRO delivers the equivalent of 128Kbps MP3 quality at the encoding rate of 64Kbps. This means you get twice the capacity from your storage devices, such as CDs and flash memory. By way of comparison, you can get around 15 songs on a regular audio CD, 150 songs on an MP3 data CD, and up to 300 songs on an MP3PRO data CD.
MusicMatch Jukebox, Steinberg WaveLab and CoolEdit Pro are three popular audio applications that support MP3PRO encoding. You can use these to extract audio from a CD and convert it to MP3PRO, or you can simply batch convert your existing MP3 files and free up half your disk space!
Batch converting MP3 files to MP3PRO with CoolEdit Pro:
Figure 1 - Cool Edit Pro 2Select "Batch File Convert" from the file menu.
[Figure 2 - the batch convert window]Next, click the "Add Files" button to browse your computer and select the files you want to convert to MP3PRO.
[Figure 3 - select files to convert]When you have selected all the files you want converted, click the tab at the bottom of the window labelled "2. Resample". Make sure the destination sample format is "44100Hz, 16 bit, Stereo".
[Figure 4 - set the resample options]Next, click the "3. New Format" tab, and select MP3PRO from the list of formats.
[Figure 5 - select MP3PRO as the destination format]Click the "Format Properties" button to display the MP3PRO options. A good test is to use the CBR 64Kbps 44100 Hz, Stereo option as shown in Figure 6. Later, if you want to encode at a higher quality, you should use the "VBR - High Quality Stereo" preset in the drop-down menu at the top of the window.
[Figure 6 - configure the MP3PRO output settings]Last but not least, click the fourth tab marked "Destination" and select a folder to store the new MP3PRO files in. If you are satisfied with the MP3PRO format, you can delete your original files after the conversion has been completed. If this is your first batch, you'll probably want to keep your old MP3 files so you can compare the quality with the new format.
When you're done, click "Run Batch" to set Cool Edit Pro in motion.
[Figure 7 - select an output directory]Cool Edit will now process all your files one at a time until MP3PRO versions have been created for each one. You'll then be ready to put them to the test side by side with the original in a playback test.
[Figure 8 - the Coll Edit progress window]Playing your MP3PRO filesYou can play back your MP3PRO files in Cool Edit, but if you you're a Winamp user, you'll probably want to get the MP3PRO output plug-in instead. You can download this for free.
Now you can load your original MP3 and newly created MP3PRO files and let your ears decide!