Mp3 Converter

Mp3 Converter is the feature to convert from WAV to MP3.

Mp3Doctor let you convert any way file to an mp3 file with different bitrates or samplerates of your choice.

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Mp3 converter

When you extract audio files (wave files) from a CD, you need to convert them to mp3 format with a Mp3 Converter. But need to do it well, to have a great sound.

This is where Mp3Doctor is the choice for you, because you can easily, without any knowledge and without the need to manipulate complex settings, you can get th best sound possible to enjoy your music.

Also you can get all the files (mp3 files) to sond at the same level, to avoid the need to move the volume control to adjust it with every new song.

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Mp3 Converter

How MP3 Works: Inside the Codec

In this chapter:

A "Perceptual" Codec

The Anatomy of an MP3 File

So what's the trick? How does the MP3 format accomplish its radical feats of compression and decompression, while still managing to maintain an acceptable level of fidelity to the original source material? The process may seem like magic, but it isn't. The entire MP3 phenomenon is made possible by the confluence of several distinct but interrelated elements: A few simple insights into the nature of human psychoacoustics, a whole lot of number crunching, and conformance to a tightly specified format for encoding and decoding audio into compact bitstreams. In this chapter, we'll take a look at these elements in detail in order to understand exactly what's going on behind the scenes of MP3 encoding and decoding software, as well as some of the chicanery that takes place between your ears.

Note that this chapter goes fairly deeply behind the scenes of MP3, and is somewhat technical in nature. You can skip this chapter if you're not interested in learning how MP3 works. If you just want to get started creating and playing MP3 audio, you can skip ahead to Chapters 3, 4, and 5.

A "Perceptual" Codec

Well-encoded MP3 files can sound pretty darn good, considering how small they are. As mentioned in Chapter 1, The Nuts and Bolts of MP3, your typical MP3 file is around one-tenth the size of the corresponding uncompressed audio source. How is this accomplished? That's a somewhat complex topic, so we've devoted this entire chapter to explaining the process.

MPEG Audio Compression in a Nutshell

Uncompressed audio, such as that found on CDs, stores more data than your brain can actually process. For example, if two notes are very similar and very close together, your brain may perceive only one of them. If two sounds are very different but one is much louder than the other, your brain may never perceive the quieter signal. And of course your ears are more sensitive to some frequencies than others. The study of these auditory phenomena is called psychoacoustics, and quite a lot is known about the process; so much so that it can be quite accurately described in tables and charts, and in mathematical models representing human hearing patterns.

MP3 encoding tools (see Chapter 5, Ripping and Encoding: Creating MP3 Files, for examples and usage details) analyze incoming source signal, break it down into mathematical patterns, and compare these patterns to psychoacoustic models stored in the encoder itself. The encoder can then discard most of the data that doesn't match the stored models, keeping that which does. The person doing the encoding can specify how many bits should be allotted to storing each second of music, which in effect sets a " tolerance" level-the lower the data storage allotment, the more data will be discarded, and the worse the resulting music will sound. The process is actually quite a bit more complex than that, and we'll go into more detail later on. This kind of compression is called [_Fi_] lossy, because data is lost in the process. However, a second compression run is also made, which shrinks the remaining data even more via more traditional means (similar to the familiar "zip" compression process).

MP3 files are composed of a series of very short frames, one after another, much like a filmstrip. Each frame of data is preceded by a header that contains extra information about the data to come. In some encodings, these frames may interact with one another. For example, if one frame has leftover storage space and the next frame doesn't have enough, they may team up for optimal results.

At the beginning or end of an MP3 file, extra information about the file itself, such as the name of the artist, the track title, the name of the album from which the track came, the recording year, genre, and personal comments may be stored. This is called " ID3" data, and will become increasingly useful as your collection grows. We'll look at the structure of MP3 files and their ID3 tags in this chapter, and the process of creating and using ID3 tags in Chapter 4, Playlists, Tags, and Skins: MP3 Options. Let's zoom in for a closer look at the entire process.

Mp3 Converter

NOTE

Always remember to set your encoder to store ID3 data during the encode process, if possible-doing so will save you a lot of work down the road.

Mp3 Converter

Selecting Bit Rates for Encoding

Bit rate refers to the speed at which a bit stream (compressed audio data in this case) will travel, or the amount of bits per second. With MP3, you usually refer to it in terms of kbps or how many thousands of bits per second. Just like the way film works with a higher number of frames producing a better picture, the more audio data that flows in a time period, the smoother and clearer the sound. "So what real difference is there in sound quality?" you might ask. Check out this MP3 bit rate page (courtesy of MP3-Tech.org, a good tech resource) where Gabriel Bouvigne ran a comparison of one track recorded at different bit rates and noted the difference. Many MP3 enthusiasts will convert to MP3 at 128 kbps (kilobytes per second) as a good medium in sound quality and file size. However, I recommend 160 kbps or VBR encoding, especially if you are a musician or if you have a sensitive ear to musical quality.

Streaming MP3 Audio and Different Bit rates

One other useful tool is this chart courtesy of Audioactive, makers of Audioactive Production Studio, a high-quality MP3 encoder. Using the chart provided, you can select a bit rate that meets your sound quality needs while being sensitive to the file size drawbacks of the higher rate if you are streaming the audio file over the Internet.

Constant Bit Rate Encoding

Constant bit rate encoding is the standard method used by most encoders. With CBR encoding, the same number of bits are added to each frame of the audio data regardless if there is silence or a wailing guitar solo. This method is good to use if you need to predict the size of the encoded file. It is simply calculated by whatever bit rate you have chosen to encode with multiplied by the length of the song.

Average Bit Rate Encoding

Average bit rate encoding (ABR) lets you choose an average bit rate and the encoder adds bits where necessary.

Variable Bit Rate Encoding

Variable bit rate encoding (VBR) is a method that seeks to keep the quality of the sound file high throughout the encoding process. Software with this technology makes a decision when to add bits to the file if the stereo separation is ever too far apart, producing a much clearer sound. The end file size will vary after encoding depending on what decisions the software has made. Simple parts of songs, including moments of silence, will not need the same amount of bits as more difficult parts and VBR encoding is able to make an intelligent decision regarding where the bits are needed most. Use this method in encoding if you want the best quality possible and are not real concerned about the file size (usually pretty close to that of regular CBR encoding, sometimes smaller) . YAMP, AudioActive Production Studio, Xing MP3 encoder, LAME, and AudioCatalyst are a few software products that use this technology.

For more good reading on bit rates and sound quality in the encoding process, read Fraunhofer's encoding basics or "enter bit rates" on chapter 2 of MP3: The Definitive Guide.

Mp3 Converter