Tag: mp3 file

What is an .MP3 file?

What is an .MP3 file?

mp3 file
mp3 file

File extension: .mp3

mp3 file
mp3 file

Format Type: Lossy Compressed

Uncompressed audio formats such as WAV and AIFF offer great sound quality at the cost of large file sizes. With the rise of Internet file sharing in the mid-1990s, people quickly realized that sending uncompressed files over a dial-up connection was impractical and often impossible. Thus, MP3 (MPEG-2 Audio Layer III encoding) was born.

A three-minute song would take about 30MB to output in WAV or AIFF format, while converting to MP3 would take a tenth of the space, about 3MB. Thanks to efficient compression algorithms, MP3 has become a staple of the Internet age and has remained strong.

PS: Previously, everyone called all music players “MP3”. For example, when they met, they said, “Did you buy an MP3?”

 

Like images, smaller audio files lose clarity and detail.

However, small files sacrifice sound quality. Take the image above. On the left, you can vividly see every little wrinkle and color. However, the highly compressed image (on the right) becomes very pixelated and loses all sharpness and detail (but still makes sense). The same thing happens when compressing audio files.

Different compression formats use different methods to re-encode data in a space-efficient way. However, this space-saving method means that some data must be lost in the process. High frequencies are usually the first to be lost because most people’s ears cannot hear details in the high frequencies. The lower the encoding quality, the more frequencies and details will be lost in the audio.

That said, modern compression algorithms allow for higher bit rates, which in turn means they can achieve high compression rates with very little loss in audio quality. Bitrate indicates the amount of data transferred per second of audio content, and a general rule of thumb is: smallest bitrate = smallest file size. So if you want to maintain good quality, but still take advantage of the fact that MP3s are easy to share, you should keep your bitrate above 128 Kbps (kilobits per second).

 

 

What is an M4A/MP4 file?
File extensions: .m4a, .mp4

Format Type: Lossy Compressed

M4A (MPEG-4 Part 14) files are Apple’s answer to MP3. Often considered the successor to MP3, this Mac-focused compressed audio format has gained popularity with the birth of the iTunes Store. In the iTunes Store, M4A became the main format for music purchases through the online music store. It remains the format of choice for all audio included in apps published in the Mac and iOS app stores, as well as in Nintendo and PlayStation products.

M4A files are encoded using the lossy Advanced Audio Coding (AAC) codec, which is capable of delivering the same bitrate as MP3, but with better compression. This reduces file size while providing higher audio quality.

Although many audio players can play M4A files on various platforms, the compatibility is still not as good as MP3, so MP3 is still the most viewed.

Audio quality: Bitrate in MP3 files

In many cases, the term Bitrate is used, which is the bit rate per second that a multimedia file (Audio or Video) has. Currently the MP3 music format is one of the most widespread (Although there are currently other more current formats such as OGG Vorbis, AAC, Flac, Monkey Audio, …) however the audio quality is variable, this is due to the characteristics with which the MP3 in question has been compressed, including:

Mode: It can be of two types mainly:

Mono: With a single channel (The right and left channel go together, not separated which gives worse audio quality).

Stereo: Two channels (Right and Left, improve audio quality).
Sampling frequency: Audio CDs use 44,100 Hz (22,050 Hz per channel), although there are higher frequencies such as 48,000 Hz used in DVDs and lower, the higher the frequency, the higher the quality.

Bits: Audio CDs have 16 Bits (Although MP3 can be compressed at a lower quality such as 8 Bits).

Bitrate (Bit Rate per second): Audio CDs have about 1,400 Kbps (44100 Hz * 16 Bits * 2 channels), meaning that an Audio CD would have a bitrate of 1,400 Kbps (In MP3 format the maximum Bitrate is 320 Kbps, however, it is assumed that an MP3 with a 128 Kbps Bitrate has a quality similar to CD, although in many cases to achieve a quality similar to CD it is necessary to use a Bitrate of 192 Kbps, and to obtain CD quality it is necessary use 256 Kbps or 320 Kbps). Some of the most common Bitrates are:
8 Kbps Mono: Telephone Sound.
16 Kbps Mono: Better quality than shortwave.
32 Kbps Mono: Better quality than AM.
64 Kbps Stereo: Better quality than FM.
112 – 128 Kbps: Quality close to CD.
160 Kbps: Quality closer to CD.
192 Kbps: Virtually CD quality.
256 Kbps: Quality CD practically undisputed from an original CD.
320 Kbps: CD quality.

Coding method: It can be of two types:

VBR (Variable Bit Rate, Bit Rate Variable): Encodes the file in MP3 with a variable Bitrate.

CBR (Constant Bit Rate, Constant Bit Rate): Encodes the MP3 file with a fixed Bitrate.
In addition, another factor that influences the encoding of the MP3 file is the CODEC (Encoder-Decoder) used, one of the most common and the best result is LAME (Lame Ain’t an MP3 Encoder) which is also free.
One point to keep in mind is that if we recompress an MP3 file that originally has a 128 Kbps bitrate and convert them to 192 Kbps for example, audio quality is not really gained because the MP3 format has some quality loss (MP3 is a loss algorithm, also called lossy). which has occurred when converting the original file (Ex: CD Audio or a 320 Kbps MP3 to a 128 Kbps MP3) so this recompression does not make much sense since we will not gain in audio quality (As they say where there is no one can not get) and the only thing we will achieve in any case is to increase the initial size of the file.
The opposite case (Recompress a 320 Kbps MP3 file for example at 192 Kbps) if it makes some sense because in this case although we lose some audio quality we reduce the weight (Kilobytes or Megabytes) of each MP3 file somewhat.
In conclusion, it can be said that if we need to encode / compress an MP3 file with good quality, the “ideal” would be to do so:
To be able to start from an Audio CD, although an MP3 at 320 or 256 Kbps could also be valid for a recompression of the file.
In stereo mode (With two channels, right and left).
With at least 44100 Khz sampling rate and 16 Bits.
With a minimum bitrate of 192 Kbps or at most 256 Kbps (Using 320 Kbps would give higher quality but also increase the file size considerably).