The Role of Audio Codecs in Digital Music

Free Download Mp4Gain

The Role of Audio Codecs in Digital Music

How do audio codecs impact the quality of digital music?

Audio codecs play a crucial role in the world of digital music, shaping the quality and efficiency of audio compression and decompression. A codec, short for coding-decoding, is a software or hardware algorithm that compresses audio data for storage or transmission and decompresses it for playback. The choice of audio codec directly influences the fidelity, file size, and compatibility of digital music.

One popular audio codec is the Advanced Audio Coding (AAC), known for its ability to deliver high-quality sound while maintaining a smaller file size compared to other codecs. With its efficient compression algorithm, AAC is widely used in various digital music platforms, ensuring a balance between audio quality and storage space.

The Importance of Lossy and Lossless Audio Codecs

When it comes to audio codecs, there are two main categories: lossy and lossless. Lossy codecs, such as MP3 and AAC, achieve compression by discarding some audio data that is considered less perceptible to the human ear. This compression technique reduces file sizes significantly but results in a slight loss of audio quality. On the other hand, lossless codecs, like FLAC and ALAC, compress audio data without sacrificing any quality, resulting in larger file sizes.

Striking the Balance between Quality and File Size

Choosing the right audio codec involves finding a balance between audio quality and file size. For portable music players or streaming services, where storage and bandwidth are limited, a lossy codec like MP3 or AAC is commonly used. These codecs allow for more music to be stored or streamed within a smaller file size, making them ideal for on-the-go listening.

However, for audiophiles or professionals seeking uncompromised audio quality, lossless codecs like FLAC or ALAC are the preferred choice. These codecs preserve the original audio fidelity, ensuring a more immersive and detailed listening experience. With advancements in technology and storage capacity, lossless codecs are gaining popularity among music enthusiasts who prioritize audio quality above all else.

The Impact of Audio Codecs on Digital Music Streaming

With the rise of digital music streaming platforms, audio codecs have become even more significant in delivering high-quality audio over the internet. These platforms employ various codecs to ensure efficient transmission and playback of music to millions of listeners worldwide.

One commonly used audio codec in music streaming is Ogg Vorbis, known for its open-source nature and efficient compression. Ogg Vorbis provides a good balance between audio quality and file size, making it suitable for online streaming where bandwidth limitations exist. Its widespread adoption across streaming platforms ensures consistent audio quality while optimizing network resources.

Adaptive Streaming and Codecs

Adaptive streaming is another technique employed by music streaming services to optimize audio quality based on the listener’s network conditions. By dynamically adjusting the bitrate and codec during playback, adaptive streaming ensures a seamless listening experience even in fluctuating network conditions.

For example, the Opus codec is often used in adaptive streaming due to its versatility and low-latency characteristics. Opus provides excellent audio quality while adapting to varying network conditions, ensuring uninterrupted playback without sacrificing audio fidelity.

Final Words

Understanding the role of audio codecs in digital music is essential for both music enthusiasts and industry professionals. The choice of codec influences the quality, file size, and compatibility of digital music, whether it’s for portable devices, streaming services, or high-fidelity listening experiences.

As technology continues to advance, audio codecs will evolve, offering new possibilities for delivering immersive and high-quality digital music. Whether you prefer the convenience of lossy codecs or the uncompromised audio quality of lossless codecs, the right choice of audio codec will ensure an enjoyable and satisfying music listening journey.

Free Download Mp4Gain

Mp4Gain Main Window

Mp4Gain Features

Free Download Mp4Gain

Codecs: The Building Blocks of Digital Media

Codecs are the building blocks of digital media. They are software or hardware that encode and decode digital data streams. This means that they can take a raw digital signal, such as a video or audio recording, and compress it into a smaller file size, or they can take a compressed file and expand it back into its original form.

Codecs are essential for the transmission, storage, and playback of digital media. They are used in a wide variety of applications, including streaming video, video conferencing, and digital broadcasting.

How Codecs Work

Codecs work by using a variety of techniques to reduce the size of digital data streams. These techniques include:

Entropy coding: This technique takes advantage of the fact that some parts of a digital signal are more likely to occur than others. By assigning shorter codes to the more likely parts of the signal, entropy coding can significantly reduce the size of the file.
Transform coding: This technique breaks the digital signal down into smaller components, and then compresses each component individually. This can be more efficient than entropy coding, but it is also more complex.
Prediction: This technique uses the past values of a signal to predict future values. By predicting future values, the codec can reduce the amount of data that needs to be stored.
**

Types of Codecs

There are two main types of codecs: lossy and lossless. Lossy codecs reduce the size of a digital data stream by discarding some of the data. This can result in a loss of quality, but it also allows for much smaller file sizes. Lossless codecs do not discard any data, so they do not suffer from any loss of quality. However, they also produce larger file sizes.

Some of the most common lossy codecs include:

MPEG-1: This codec is used for a variety of applications, including video CDs and digital television.
MPEG-2: This codec is used for DVD-Video and high-definition television.
H.264: This codec is the most widely used codec for streaming video and online video.
Some of the most common lossless codecs include:

FLAC: This codec is used for lossless audio compression.
WAV: This codec is a lossless audio format that is used by many professional audio applications.
ALAC: This codec is a lossless audio format that is used by Apple’s iTunes and iPod products.
**

Conclusion

Codecs are essential for the transmission, storage, and playback of digital media. They are used in a wide variety of applications, and they have made it possible to enjoy digital media on a variety of devices.

Final Words about Codecs

Codecs are a complex topic, but they are essential for understanding how digital media works. By understanding how codecs work, you can make better decisions about the quality and size of your digital media files.

I hope this article has given you a better understanding of codecs.

Understanding Audio Codecs: MP3, AAC, and Ogg Vorbis

AIntroduction

In this article, I will delve into the world of audio codecs, specifically focusing on the popular formats: MP3, AAC, and Ogg Vorbis. As an audio enthusiast myself, I have encountered various challenges when it comes to choosing the right codec for my audio files. Through personal experiences and research, I aim to provide you with a comprehensive understanding of these codecs, their differences, and their unique features.

MP3: The Pioneer of Audio Compression

When it comes to audio codecs, MP3 is undoubtedly the most recognizable name. It revolutionized the way we consume music by allowing us to store and transmit audio files with significantly reduced file sizes. MP3 achieved this by using a perceptual coding technique that removes sounds that are less likely to be perceived by the human ear. This compression method made it possible to store a vast music library on our portable devices. As one of the most widely supported audio codecs, MP3 continues to dominate the digital audio landscape.

AAC: Advancing Audio Quality

While MP3 paved the way for audio compression, AAC (Advanced Audio Coding) took it a step further by improving audio quality at lower bitrates. Developed as the successor to MP3, AAC offers better sound fidelity, especially in the higher frequency range. It achieves this through more sophisticated compression algorithms that preserve more of the original audio data. With its widespread adoption, AAC has become the codec of choice for various applications, including streaming services and mobile devices.

Ogg Vorbis: Open Source Audio Compression

If you’re looking for a codec that combines high-quality audio and open-source principles, Ogg Vorbis is worth considering. Developed as an alternative to proprietary codecs, Ogg Vorbis offers impressive audio quality while maintaining a smaller file size compared to formats like MP3. Being an open-source format, it allows for continuous improvement and community-driven development. Ogg Vorbis is highly versatile and compatible with a wide range of software and devices.

“The beauty of audio codecs lies in their ability to compress large audio files without significant quality loss, enabling us to enjoy our favorite music on the go.” – John, an avid music listener.

Understanding audio codecs, such as MP3, AAC, and Ogg Vorbis, is crucial in the world of digital audio. Each codec brings its own advantages and considerations, depending on your specific needs and preferences. Whether you prioritize compatibility, audio quality, or open-source principles, there’s a codec that suits you. As you explore the vast realm of audio codecs, remember that mp4gain.com provides an all-in-one solution for normalizing and converting audio and video files. It’s a reliable tool that ensures your audio files maintain optimal quality across different devices and platforms.
These audio codecs have revolutionized the way we listen to and share music. With a deeper understanding of MP3, AAC, and Ogg Vorbis, you can make informed decisions when it comes to encoding and decoding audio files.

Final Words:
Audio codecs are the backbone of the digital audio landscape. Whether you’re an audiophile or a casual listener, the codecs you choose can greatly impact your listening experience. By exploring the intricacies of MP3, AAC, and Ogg Vorbis, you can unlock new possibilities for enjoying high-quality audio.

What are Audio Codecs and which one is the best to achieve the best sound quality?

Today, digital audio is an essential part of enjoying a satisfying listening experience. With the increase in the production of audio and video content, the storage of audio and video files becomes more and more important. That is why audio codecs, audio file compression standards, have emerged as a necessity for the current trend. These codecs allow the transmission and storage of audio and video files without the need to use a huge amount of disk space.

What are Audio Codecs?

Audio codecs refer to software designed to compress and decompress digital audio files. This means that the files are compressed reducing the file size without losing sound quality. This compression becomes possible thanks to codec technology. Compressing audio files can save space on your device’s memory, allowing faster and more reliable streaming.

Advantages of Audio Codecs

There are many reasons why audio codecs are so powerful and popular. Audio codecs offer a number of advantages, such as:

Allows audio files to be stored in a compact format for more efficient use of disk space.
Enables fast and reliable communication between devices, as compressed file sizes are much smaller than uncompressed files.
Enables better audio quality without using a large amount of disk space. Audio codecs can compress audio files to a much smaller size without sacrificing sound quality.
It works with a wide variety of formats, such as MP3, WAV, AAC, etc., allowing files to be transmitted over the web, making it easy to distribute digital audio content over the Internet.</ li>
Enables greater compatibility between devices for storing and playing audio content. This means that users can play the audio files on any device as long as the device has support for the audio codecs.

What Are The Most Used Audio Codecs?

There are several types of audio codecs available for commercial use. The most common codecs are:

MP3 – MP3 is the most popular audio format today. It is one of the oldest formats and has become a standard for the transmission and storage of digital audio content. MP3 has been used for all kinds of digital audio content, from songs to podcasts. MP3 offers acceptable audio quality, although there are other more modern formats with better audio quality.
AAC (Advanced Audio Coding) – AAC is a newer digital audio format. It offers better audio quality than MP3 even though the compressed file size is much larger. AAC has become the preferred audio format for the transmission and storage of digital audio content.
WAV (Waveform Audio File Format) – WAV is an uncompressed audio format that offers excellent audio quality. This means that WAV files are not compressed. These files are ideal for audio editing as they have uncompromised audio quality. However, the size of WAV files is much larger than that of compressed files.

What is the Best Audio Codec?

Each audio format has its own advantages and disadvantages. The best audio codec for your purpose will depend on your needs for storing and streaming audio content. For example, if you want to edit an audio file for use in an audio production project, then the WAV format is the best choice. If you want to stream audio content over the web, then the AAC format is the best option.

What is Mp4Gain and What is its Importance?

Mp4Gain is a software tool used to normalize the volume of audio and video files. This tool allows you to adjust the volume of files so that all files are of the same volume. This is important for audio and video files that are being streamed over the web. With Mp4Gain, users can ensure that audio and video files are played at the same volume for a better listening experience.

Which audio codec for Bluetooth is better?

Which audio codec for Bluetooth is better?

Bluetooth Audio Codec

The best codec is the one that can deliver the best sound quality. But if they were considered among the popular formats, it was difficult to choose the right option. Each one has positive and negative characteristics that influence the final choice.

Bluetooth audio codec

Which audio codec is better?
When choosing codecs, the following nuances should be taken into account:

Experts believe that the sound quality should be similar to that of CD audio. The sampling frequency must be 44.1 kHz and 16 bits. These are average values, they are observed only in the rarely used LDAC algorithm;

The aptX codec has modest performance, but it provides high-quality audio files. It is popular as the only high-definition Bluetooth codec;

All algorithms perform audio compression. This is necessary to reduce the bitrate to the maximum allowed for a particular codec. This means that when using any algorithm, the music will sound a bit distorted, in some it will be more obvious (for example, in the SBC format), in others it will be almost invisible (LDAC, aptX);

When choosing codecs, do not forget about the model and operating system of the smartphone, tablet and other devices. For Android devices, SBC or aptX is better, but for Apple it is recommended to use Advanced Audio Coding with an improved algorithm.
Below is a table with the main indicators and supported formats of popular algorithms.

Codec Sampling frequency (kHz) Bit rate indicator (kbps) Audio formats
SBC 46-48 328 MP3
CAA 42-44,1 250 MP3, AAC
LDAC 94-96 990 Lossless Formats, Hi-Res Audio
aptX 42-44,1 352 Audio CD
aptX HD 46-48 576 Lossless Formats, Hi-Res Audio

The SBC format codec is considered obsolete and is rarely used for playing music and audio files. It was originally created for the transmission of voice and sound data via Bluetooth. Over time, improved algorithms have appeared. If you want to buy wireless headphones for normal use, then it is better to give them to aptX based devices, these will transmit sound without obvious distortion, noise, squeak.

If you are using Apple devices, only AAC headphones will work. The algorithm is adjusted for this technique, you will be able to transmit the quality of the music. But when using it for Android OS devices, the sound will be distorted with interference.

For music lovers who value sound quality, the aptX HD algorithm is suitable. It has good sample rates, bitrate levels, and supports modern audio file formats. The codec characteristics convey high quality sound, the acoustics are delivered without distortion.

But if the price is not an obstacle, you can afford wireless headphones, devices, smartphones, tablets, LDAC-based players from the famous Sony company. The technique is quite expensive, the cost can amount to several hundred dollars, but the characteristics of the algorithm fully justify it.

Codecs are an important prerequisite for high-quality sound reproduction when using Bluetooth-based wireless devices and headphones. Without them, the music will be poor quality, distorted, and constant interference will make the melody shrill and vague. When using popular brand devices (Huawei, Xiaomi, iPhone), it is worth applying suitable algorithms that suit the device and the device’s operating system.

What are audio codecs?

What are audio codecs?

Audio Codec

High-quality music without interruptions or interference is every music lover’s dream. Devices with a Bluetooth system are popular. Wireless headphones provide free, wire-free listening for lightness.

Audio Codecs

When using them, it is fashionable to do movements, running, playing sports, this will not affect the operation of the device. For its operation, the Bluetooth LDAC, AAC, APTX, SBC codecs are used. Each of them has distinctive characteristics, specific functions that must be considered in advance, this will help to break the principle of operation of these systems.

Why are codecs needed
Codecs are used to improve the quality of music file transfer via Bluetooth to wireless headphones. The system was originally created for data transmission, but it had problems with audio quality. The sound was distorted by noise and the development of codecs helped eliminate the annoying problems.

The operation of the algorithm is determined by the following criteria:

Sample rate indicator. Expressed in Hz. Indicates the data recording frequency for 1 second of sound. The higher the criteria, the better the sound quality;
The bitness of the recording ((Bit-depth). The bit is used for the measurement. If we consider a CD, then 16 bits is enough to record. The indicator is enough to record music up to 96 dB. But they have progressive recording methods , for which 24 to 32 bits are used.;
Bit rate. The indicator is expressed in kb / s. Reflects the amount of data the device processes to play 1 second of audio. A high value records a large amount of audio data for 1 second.
For reference! Voice transmission between carrier networks is regulated by the session border controller. This is carrier-class software that is part of carrier’s NGN networks. It issues signaling protocols and their dialects, analyzes the quality of the media channels through which voice traffic is routed.

Types of data storage and transmission formats
There are three formats for storing and transferring data: uncompressed, lossy (lossy compression), and lossless (lossless compression).

What audio codecs are common?

Audio Codecs

Depending on whether you want to burn your audio file to CD, make it available on the Internet, or edit it with an audio editor, the different audio formats are in question. Codecs are responsible for converting to and from the various formats:

Audio Formats

PCM (pulse code modulation)

Pulse code modulation is a coding process in which an analog signal can be digitized with almost no loss. Audio material encoded in this way is ideal for further processing because it is not compressed. Data generated with this method is generally saved as wave files with the extension “.wav”.

MP3 (MPEG-1 Audio Layer 3)

The encoding process is actually called MPEG-1 Audio Layer 3 or MPEG-2 Audio Layer 3 and was developed by the Fraunhofer Institute for Integrated Circuits. The name is derived from the associated MP3 file extension of the format. It is one of the first lossy compression processes to rely on psychoacoustic effects on perception to reduce the amount of data. In addition to the original codec from the Fraunhofer Institute, there is also the open source encoder LAME. Files containing data streams encoded in this way usually end in “.mp3”. There are also other container formats that can hold MP3 data streams, such as AVI or MP4.

AAC (advanced audio coding)

AAC is a lossy encoding method that can compress audio data (on a CD) to one-sixteenth of its original size. Compared to MP3, the process can demonstrate higher compression and improved sound quality. Therefore, various online music stores and online radio stations rely on this format. MP4 is designed as a container format to store compressed audio signals. Files containing such an audio track usually end in “.mp4” or “.m4a”.

Vorbis

This open source format is patent-free and therefore can be used by software developers without license fees. The format is also suitable for streaming. Compression is lossy and better than MP3. Although many hardware playback devices now support this format, it is not as widespread as MP3. The data stream is usually embedded in an OGG container. Associated files end in “.ogg” or “.oga”.

WMA (Windows Media Audio)

WMA is an encoding process developed by Microsoft and also offers lossy compression. Many hardware playback devices now support this format, because it is very popular in the music industry due to its built-in copy protection (Digital Rights Management (DRM)). If the file contains only audio data, it ends with “.wma”. ASF is used as the container format.

Why do you need “file formats”?

Digital data used to represent analog video or audio signals can be organized in different formats. The best way to explain this is with a single image – there are multiple options for storing individual pixels in a file. For example, if the image points are stored one after the other from left to right or first from top to bottom in the file it is of course a convention that must be specified. The way a color value is stored must also be clearly defined. These and many other definitions are determined by a specification, which is then implemented in the respective file format. To store the data, a predefined encoding rule is always followed, which is ultimately decisive for the data to be interpreted correctly. You can think of individual formats as different data carriers: CDs, large and small video cassettes, audio tapes, etc. can contain audio data; however, you cannot load a cassette in the CD player. WAV, MP4, WMA or MP3 file formats are equally different.

Many file formats are actually container formats. The term is intended to make it clear that different formats can be used within a convention. For example, an MP4 file can contain different video and audio formats that can also appear in the same file at the same time.

What is a codec exactly

Has it happened to you that you download a video file and then you cannot use it in your player? Or that you finally finish editing your video clip and it takes years to upload to the Internet? You might think it is a problem with your file. You are not wrong, only the question is more specific: it is about the codec and container you are using.

Maybe they are somewhat strange terms, but they are gaining more and more popularity due to the growing community in online video and audiovisual production. So if you plan to start your career as a youtuber, take into account the information, because if you end up with a final video with a weight of 1 GB it will not be fun waiting for it to go up …

What is a codec?

Those who do video editing know full well that storage space can be a problem. It is better to have the material you record in its original format, but most of the time this involves a considerable amount of GB of space. For example, if you record an hour of content with an HD camera, you may need … up to 410 GB! This is difficult to keep it, much more if you want to transmit it to other media. This is where the topic gets interesting.

The term codec refers to the video or audio compression and decompression process. It is a tool that encodes video using algorithms and converts it into information. This way you can decrease the file size.

The choice of the codec depends on different factors. You must mainly take into account the means of reproduction for the final product. However, encoding is not enough for its reproduction, it is also required to “pack” the information in order to present it. We are talking about containers.

What are those containers?

Suppose you just finished editing a video. The final file contains both images and audio, so you require a way to display it just as you prepared it. This “package” is basically what many refer to when they talk about the format of a file. So a container can accept different codecs, while players can use certain containers. For example, the VLC player accepts almost all containers.

Lossy and lossless codecs (lossy and lossless)

There are different types of compression, as we will see later. However, all of them can be divided into two categories: with or without loss. Loss of what? Quality. For example, in the case of audio files, it is not the same to listen to a song in FLAC (Free Lossless Audio Codec) format to one in MP3 (MPEG Audio Layer III). The first is coded in such a way that almost no information is lost when compressing, that is, fidelity is maintained.

The same goes for the video. Wanting to save storage space, lossy files, ie lossy, are compressed. This makes them much easier to manage. However, it is unavoidable to deal with data loss and therefore image or audio fidelity. On the other hand, when you want to maintain the highest possible quality and have no space problem, lossless or lossless compressors are used. Again, it all depends on the purpose of your file. Will it be a web video? A projection? Film contest?

Video codecs

Below you will find a list of the most popular codecs. We will not go too far into others, since an average consumer rarely requires those who are specialized.

DV and HDV

Do you remember the tapes or cassettes to record video? This type of capture uses the DV codec, the standard defined by various electronic sales companies. Over time, HDV emerged, as they had to adjust to the demand for high-definition video.

H.264 / MPEG-4 AVC

Platforms like YouTube have made the popularity of this codec grow quite a bit, as it is their recommendation to upload your videos. It is one of the most suggested thanks to the fact that it considerably reduces the file size without sacrificing much image fidelity. Multiple cameras use the codec, as do web video and Blu-ray.

Microsoft VC-1

Microsoft has its encoding mode for Blu-ray content. It also works in your Microsoft Silverlight tool.

MJPEG (Motion JPEG)

Many video cameras used to capture material with this codec. Its name comes from the group that created it, the Joint Picture Experts Group. If the name seems familiar to you, it is because they are the same ones that created the JPEG still image compression codec.

MPEG-1

Before H.264 there was MPEG-1. This used to be the standard for online video, although the emergence of new formats has left it behind.

MPEG-2

This format is merely for compressing information to DVD video.

WMV (Windows Media Video)

This is another codec that has practically disappeared. It focuses on the Microsoft family.

Audio codecs

As we mentioned before, codecs can be used with or without data loss. As for audio, there is a huge difference not only in quality (especially with good headphones), but also in the file size. Do you prefer an entire album in MP3 or a few songs in FLAC?

ACC (Advanced Audio Coding)

YouTube, Android, iOS, iTunes and more have adopted this compression method as their standard. AAC was devised as the next step for MP3, although it still has a long way to go. However, AAC tends to be of better quality. It is a lossy codec.

FLAC (Free Lossless Audio Codec)

Recommended for true audiophiles. Its development is open source and is considered a great alternative to MP3 or CD if you want to get the best possible quality. It is also recommended because it can compress a file by up to 60% without loss of information.

MP3 (MPEG-1 Audio Layer 3)

It is currently the best known format for audio. It is not of the best quality, but its compression quality is what has made it so successful. It ignores the information that corresponds to the sounds that we do not hear in our hearing range, thus eliminating “irrelevant” space. It can be reduced between 75 and 95% of the original size.

Windows Media Audio (WMA)

This is another of Microsoft’s products. It never really took off, the MP3 format took care of it. It has two versions, one with and without loss of information, although the same extension (WMA) is used for both.

Containers

You have finished editing your video. You have already chosen the codec and now you must choose the means by which you can transport and reproduce the information you have assembled. We leave you the best known. Define which one is indicated according to the purpose of your product.

ASF (Advanced Systems Format)

This is a format that belongs to the Microsoft family. Its supported file types include .asf, .wma, and .wmv. The container works well if your devices are Microsoft, but it is not well received by other systems, not to mention the loss of popularity with other containers.

AVI (Audio Video Interleave)

We have all come across this one in one or the other download. It is still in multiple instances, but don’t consider it your first (or second) option if you’re creating content.

AVCHD

This format works with the content captured with video cameras.

Flash

Adobe has its own container, which was originally created by Macromedia. Many have made it clear that it is a limited container. For example, Mozilla Firefox no longer supports such files.

MKV (Matroska Multimedia Container)

This format increasingly gains more ground thanks to its versatility. It accepts almost any audio and video codec. It also has the ability to have multiple video, audio and text channels. It is open source, so it has a generous community.

MP4

It is one of the most popular containers. It works with the H.264 codec, making it ideal for working with online audiovisual content. As for audio, it usually uses AAC or AC3 codecs. It was created by the Motion Pictures Expert Group.

MPEG and BDAV MPEG-2

Both are used for discs, the first for DVD and the second for Blu-ray. Generally the file extensions with this codec are TS, VOB, MPG and SVCD.

Quicktime

Now we see the turn of the Apple family. Part of its appeal is the separation of information into different channels (video, audio and text). It also allows for better editing of the metadata. It compares a lot with the MP4 container.

Types of audio codecs

Types of audio codecs:

-DST (Direct Stream Transfer)
-FLAC (Free Lossless Audio Codec)
-LA (Lossless Audio)
-LPAC (Lossless Predictive Audio Codec)
-LTAC (Lossless Transform Audio Codec)
-MLP (Meridial Lossless Packing)
-Monkey’s Audio (APE)

There is a huge amount of audio formats. The most common are formats such as MP3 (MPEG-2 Audio Layer III) and WAV. Usually, the type of format corresponds to the file extension (the letters of the file name after the period, for example .mp3, .wav, .ogg, .wma).

A codec is an algorithm for encoding and compressing data in an audio format. Some file types are assigned a specific codec. For example, the MP3 format always uses the MPEG Layer-3 codec, while the MP4 format can use a range of different codecs.

Many times, the notions of codec and format are used as interchangeable. Especially when a format always uses a single codec. However, it is necessary to understand the difference between a format and a codec. In simple terms, a format can be compared to a container in which a sound or a video signal that uses a particular codec can be stored.

Some formats, such as MP4 or FLV, can store both audio and video sequences.

In the general scope of codecs (for any type of data), we can classify them as follows, depending on whether the original signal can be recovered or not after coding:

With losses (lossy). In this type of codecs, after coding, it is impossible to recover the original signal. Most codecs manage to reduce the size of the bit stream to be transmitted or stored, due to the loss of information in said bit stream. Normally this loss does not produce a large decrease in the quality of the audio perceived by the end user, and if the decrease in quality is appreciable, it is that a lot of information has had to be lost to achieve a small bit stream size, that in many occasions it is necessary, especially in the transmission of audio at a distance (telephony, digital video, television …), although this is a compromise solution between the different codecs, an issue that we will discuss in the comparative section between codecs .
Lossless (loseless). In this type of codecs, after coding, the original signal can be recovered. These types of codecs are the least common. They are usually common especially in high quality audio applications, where the size of the bit stream or stream is not decisive. If the files are to be treated later, it is not advisable to perform loss coding, since one encoding with losses after another would significantly damage the audio quality.

There is another classification of codecs, depending on the type of algorithm used in the coding:

Waveform codecs:

used for all types of digital signals. The waveform of the encoded signal must be as similar to that of the original signal
Vocoders or source codecs: used only for coding voice signals. The original signal is analyzed and synthesized to give rise to the encoded signal
Hybrids: combine characteristics of the two previous types

The waveform codecs seek to produce a reconstructed signal of the signal to be encoded, whose waveform is as similar to that of the signal to be encoded. These codecs work without knowing how the signal to be encoded was generated, which implies that in theory its operation does not depend on the signal and can work well with all types of signals, even if they are not audio.

Hybrid Codecs

These types of codecs are a mix between waveform and source. Within the hybrid codecs, the most used are the codecs in the time domain of Analysis-by-Síntesi