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Choosing an audio codec for online streaming and recording.

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Choosing an audio codec for online streaming and recording.

Audio Codec

Are you interested in what is an audio codec and how to choose the right one to get the best result from online streaming or recording?

Audio Codecs

Imagine that we live in a completely analog world. Then there would be no need for audio codecs. What is it, you ask? It is an algorithm used to convert analog audio to digital. This is what is needed in the world of digital devices, media players and the Internet.

The quality of audio codecs has improved significantly over the years. Let’s go back, for example, to the 80s, when the first digital amplifiers appeared. Compared to the reproduction quality of a modern digital amp, the difference will be obvious. The best audio codecs offer better and more realistic sound.

But now there are so many different audio codecs. Which to choose?
Many codecs are quite specific. Some of them are proprietary, while others were created for specific applications, most often telecommunications. For voice signals, such as on your phone, you do not need to use high-fidelity audio codecs, as the reproduction of a signal with a limited audio range is more suitable in this case. But for music playback, a high-quality audio signal is certainly preferable.

If you dig deeper, you will find that different audio codecs serve different purposes in processing the original analog signal. For example, an audio codec like PCM is a lossless compression algorithm. This means that the signal is reproduced in digital form without losing a single bit of original information. Other audio codecs, such as AAC and MP3, compress audio with some loss.

Compression reduces the bits of the original content and therefore reduces the file size. If you are listening to songs on a mobile device, you can be sure that these files have been compressed to take up less space. And that is why you can save a large number of music files on your device, but their quality will differ from optimal.

Audio codecs for Epiphan Pearl and Pearl-2
Of course, it is impossible to tell in detail all the characteristics of audio codecs in one article, but it can still help to clarify some of the nuances in choosing the correct audio codec for live streaming or recording using Epiphan Pearl or Pearl- 2 .

There are 3 audio codecs available:

-PCM – Uncompressed audio codec, which may be the best option if you plan to record shows for further editing and if you are not limited by network bandwidth.

-AAC: audio codec with compression algorithm best suited for live streaming or content recording with immediate playback on media players or for uploading to the Internet. Experts believe that AAC plays better audio than MP3 with the same audio bit rate. As a rule, the newer codecs reproduce the analog signal better than their predecessors, you can trust the experts on this.

-MP3: a fairly old, but still very popular audio code compression algorithm, also suitable for live streaming or recording content with immediate playback on media players or uploading to the Internet.
Choosing the correct audio codec is important when setting up live streaming or recording with the Epiphan Pearl or Pearl-2. Sample rate and audio oversampling effects are other important parameters for improving sound quality.

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Understand audio codecs

Understand audio codecs

Audio Codecs

A codec, or, in other words, an encoder, is a software or hardware tool for encoding and decoding information (in our case, audio information) according to a certain algorithm. There are a large number of codecs on the market, but we will consider only a few of them, the most popular and in demand.

AUDIO CODECS

AOoding, or compression, can be of two types: lossy and lossless. For each type of encoding, there are different types of audio codecs. How is lossless coding different from lossy coding?

When information is encoded without loss, data compression does not lead to loss of information, and thus the decoded audio file is absolutely identical to the original. By coding in this way, the reduction in the initial volume of information reaches 20-50%. Increasingly, this method is used not only by audiomaniacs, but also by ordinary users. As disk space increases and the price of drives decreases, more and more users are choosing to store audio data encoded in this way. Today, there are quite a few algorithms that allow you to do this, but the most popular are those implemented in the FLAC, Monkey’s Audio, WavPack, and TTA codecs.

Lossy data compression is used to obtain the smallest file size. With this encoding, there is no longer a complete match between the original and its converted copy, and there is no way to recover lost information. To achieve the minimum file size, various encoding algorithms are used, from mathematical compression algorithms, in which the quality of the track is not affected, to the so-called psychoacoustic model, which involves removing the “unnecessary” sounds from the original. and reduce the frequency range. Due to the peculiarities of the perception of sound by the human ear, “unnecessary” sounds can conventionally be called those parts of the audio track, the removal of which will not be very noticeable. The very process of eliminating “unnecessary” sounds is called quantization.

There are many lossy compression methods, the most famous of which are MPEG-1 Layer 3, MPEG-2/4 AAC, Ogg Vorbis, Windows Media Audio, MusePack, etc.

Lossless compression
FLAC
One of the most popular formats for lossless audio compression is the FLAC codec. The main advantages of this audio codec are its constant updating and, of course, cross-platform: FLAC compiles on many platforms: Unixes (Linux, BSD, Solaris, OS X), Windows, BeOS and OS / 2. This comprehensive support of the operating system facilitates the widespread use of this audio encoder.

Another advantage of the FLAC audio codec is the presence (in addition to the basic encoder and decoder in the form of libraries that are included in the installation kit) a graphical shell that simplifies the encoding process, as well as external modules (plugins) for different players (including Winamp of different versions, Foobar2000, etc. etc.). The kit also includes a command-line utility for compressing and decompressing files and a utility for editing file metadata.

An interesting distinctive feature of FLAC is that it allows you to make an archival copy of an audio CD, burned to a. In the future, such a copy can easily be written to the disc in case the original disc is lost or damaged. FLAC uses eight compression rates. As with any encoder, the encoding rate and the size of the resulting file depend on the compression rate. ID3v1 and ID3v2 tags can be added to the FLAC stream. This data is not related to the format, but the decoder can pass it.

Monkey Audio
Perhaps the most popular lossless compression codec today is Monkey’s Audio. This is mainly due to the fact that this codec is free and the high-quality compression of the audio stream it provides. The only factor limiting its scope is the lack of cross-platform support: Monkey’s audio codec is present only on the Windows platform. However, support for this format is implemented in various players and, for example, a plug-in for the Winamp player comes with Monkey’s Audio. Additionally, DirectShow filters can be installed for other compatible players. Playback plugin supports all common functions and ID3 tags.

Monkey’s audio codec will certainly be appreciated by those who need the highest sound quality. The codec provides a compression of approximately 40-50%. When encoding data, several different compression rates are available, from a parameter that provides faster encoding to a parameter that performs better compression at the expense of more processor time.

What is the CODEC?

CODEC is a program that reduces the number of bytes contained in large files (similar to WinZIP) so that they can be stored on storage media and then played back. Typically used to compress and decompress multimedia files such as songs or videos (CODEC is actually short for CO compression / DEC compression, ie compression / decompression). There are audio and video codecs. MPEG-1, MPEG-2, MPEG-4, Vorbis, DivX, … are examples of CODEC.

The main difference between a CODEC and a compression algorithm like WinZIP is that in CODECs the compression / decompression is done in real time. This means that while CODEC is watching a video behind the scenes, it processes the data stream by unpacking it. A CODEC can consist of two parts: an encoder for compressing the multimedia file (encoding) and a decoder for decompressing the file (decoding). Some CODECs can contain both parts, others only one.

CODECs can be installed and updated on older computers or multimedia devices or integrated in dedicated hardware components (e.g. CD or DVD players). CODECs should not be confused with containers. A container contains one or more streams that have already been coded by CODEC. Very often you will find an audio and a video stream in the container at the same time. AVI, Ogg, MOV, ASF, … are examples of containers. while others just one of them.

CODECs should not be confused with containers. A container contains one or more streams that have already been coded by CODEC. Very often you will find an audio and a video stream in the container at the same time. AVI, Ogg, MOV, ASF, … are examples of containers. Very often you will find an audio and a video stream in the container at the same time. AVI, Ogg, MOV, ASF, … are examples of containers. Very often you will find an audio and a video stream in the container at the same time. AVI, Ogg, MOV, ASF, … are examples of containers.

Where can I find the CODEC?

If Tizio creates a document with the Word program and sends it to Caio, the latter must use the Word program to open it. If a film is compressed with the XYZ-CODEC, the same CODEC must be used for the display.
At this point the question arises: Where can the CODECs be found? CODECs are available on the Internet. There are dozens of audio and video formats and related CODECs. However, there is no point in downloading them individually and then installing them on the computer. It is much better to download a collection of CODECs like K-Lite Codec Pack. K-Lite Codec Pack is a collection of CODEC for Microsoft Windows, with which the operating system can play various audio and video formats that are not supported by default.

In addition to CODECs, the K-Lite Codec Package can also contain other tools, including: Media Player Classic for playing multimedia files, information tools such as Media Info and tools for editing CODECs. There are four versions of the K-Lite codec package:

Basic – Plays many of the popular video file formats, e.g. B. AVI, MKV, MP4, OGM and FLV
Standard: Contains everything that is required to reproduce the most commonly used formats.
Full: Supports multiple audio and video formats. It also has coding support
Mega: combines the content of “K-Lite Codec Pack (Full)” and Real Alternative. In the past, it also included QuickTime Alternative. QuickTime Alternative (with Media Player Classic) and QT Lite (without Media Player Classic) are now available as separate programs
The standard version is for the average user, while the full version is for advanced users who edit and decode videos. The K-Lite Codec Pack is updated regularly and contains everything you need to play all movies and music. Any uninstallation will also remove everything that has been installed from the package.