Comparing WMA to Ogg Vorbis for Open-Source Audio Compression


Free Download Mp4Gain
picture

Comparing WMA to Ogg Vorbis for Open-Source Audio Compression

Comparing WMA to Ogg Vorbis for Open-Source Audio Compression

Let’s talk about comparing WMA to Ogg Vorbis for open-source audio compression. As an expert in audio encoding with years of experience, I’ve seen how important selecting the right audio compression format is for any project, be it for music or speech. WMA (Windows Media Audio) and Ogg Vorbis are two notable audio formats, but they approach compression in different ways, and each has distinct advantages and disadvantages. It’s like choosing the right type of container for your food; some containers keep the food fresher for longer, while others may not be suitable. In the realm of audio, the ‘container’ is the codec, and I’m here to help you understand each one’s strengths when compared to the other.

Understanding WMA and Ogg Vorbis Audio Codecs

Understanding the differences between WMA and Ogg Vorbis is the first step when deciding which one is more suitable for your needs. WMA, developed by Microsoft, is a proprietary codec often used in Windows systems. Think of it as a specific brand of tool, often designed to work best with its own ecosystem. On the other hand, Ogg Vorbis is an open-source codec, that’s free to use and modify, imagine it like a community tool that everyone contributes to, making it very flexible. These different approaches mean they have distinct characteristics regarding compression efficiency, compatibility, and licensing, all of which impact their use in different projects. From my experience, the key to mastering audio encoding is understanding each codec and choosing the right one.

Audio Compression Quality: WMA vs. Ogg Vorbis

When evaluating audio compression, one must look into the quality that WMA and Ogg Vorbis provide at various bitrates. Both codecs are designed to reduce file size, but the methods used affect audio fidelity. WMA, particularly in its more advanced versions, can achieve very good quality at low bitrates. Imagine this as a painter who can create very detailed art with fewer brushstrokes. On the other hand, Ogg Vorbis is known for its excellent quality, which is very close to the source, and it uses an adaptable approach, like a chef who adjusts the recipe depending on the ingredients, to offer an optimal result. From my professional practice, I can assure you that the “best” quality is subjective, because it depends on the source audio and intended use.

Open Source Nature and Licensing of Ogg Vorbis

The open-source nature and licensing of Ogg Vorbis are key benefits that set it apart from WMA. Ogg Vorbis is released under a very liberal license that allows it to be freely used, modified, and distributed, just like a public park, available for everyone to use and enjoy. This open model fosters innovation and adoption across different platforms. WMA, being proprietary, often involves licensing fees and might have usage restrictions, like a private club, that has a strict rules for usage. My experience shows that the open nature of Ogg Vorbis is a major advantage when you need flexibility in your audio projects, particularly if you’re looking for a low-cost solution, allowing for collaboration and contribution.

Compatibility and Platform Support

The compatibility and platform support for WMA and Ogg Vorbis vary significantly, this is very important when you want to use an audio format. WMA has deep integration with Windows and Microsoft products, similar to how a key fits its lock, so it might be the best choice within the Windows ecosystem, but might cause problems outside it. Ogg Vorbis, with its open-source nature, has become widely supported across different operating systems and software, as it is a format that welcomes all systems, becoming a universal choice. My professional experience has shown me that choosing a format that plays seamlessly across many platforms enhances the usability and reach of your projects. And for this aspect Ogg Vorbis is normally the wisest choice.

WMA and Ogg Vorbis File Size Efficiency

File size efficiency is a critical factor when dealing with audio compression, and something I look into very carefully. Both WMA and Ogg Vorbis aim to reduce file sizes, but achieve this goal with different methods. WMA can sometimes achieve slightly smaller file sizes at lower bitrates, it’s like packing more clothes in a smaller suitcase, this comes at a cost in quality. Ogg Vorbis often focuses on maintaining higher quality, and this means its files might be slightly larger, so its like choosing a bigger suitcase to avoid wrinkling the clothes. From my years of experience, I’ve learned that the ‘best’ size is the one that suits your specific needs, whether it’s saving storage space or prioritizing high-fidelity sound.

Use Cases for WMA and Ogg Vorbis

When using WMA and Ogg Vorbis, you have to consider each format’s strength, because they are designed for different use cases. WMA is common in environments where Microsoft products are dominant, like corporate presentations or Windows software. Think of it as a tool designed for a specific environment, offering the best results in that context. On the other hand, Ogg Vorbis is popular in open-source projects, video games and online streaming services because it offers flexibility and compatibility, like a tool that works well everywhere. I often find that the choice of the codec depends heavily on where and how you want to use your audio content.

Encoding and Decoding Speed

The encoding and decoding speed of WMA and Ogg Vorbis can influence performance, especially when working with many files. WMA can sometimes have faster encoding speeds, especially with specific hardware and software support, just as using a specific kitchen appliance can speed up cooking, but it depends on the hardware and software. Ogg Vorbis is often designed to be efficient across a broad range of devices, offering reliable performance even in less powerful machines, like using a manual tool that works on any situation. From my professional experience, the encoding/decoding speed might be a concern for some users, while for others the flexibility is more important, so you need to consider what you need most.

WMA has faster encoding speed, but depends on the system.

Ogg Vorbis offers a very reliable speed across different platforms.

Encoding speed depends on hardware support.

Practical Tips and Tools for Audio Compression

I have learned a lot when it comes to practical tips and tools for audio compression, and they make the process a lot smoother. Choosing a suitable bitrate is key to balance file size and audio quality, like adjusting the volume of a radio to make sure it is clear. Testing different compression settings allows you to find the best settings for your particular audio, similar to fine tuning an instrument, getting the best performance. Tools for audio compression can streamline the process, and you need to know how to use them. From my professional practice, I have seen that a well-optimized compression workflow can save you space, time and improve the audio quality of your projects.

Latest words on comparing WMA to Ogg Vorbis

So, after exploring both WMA and Ogg Vorbis for open-source audio compression, it’s clear that each has its own strengths and weaknesses, and that is why I have compared both formats today. WMA is very efficient in the Windows ecosystem, while Ogg Vorbis, being open source, gives more flexibility. The ‘best’ choice depends largely on your project’s specific requirements, from compatibility to audio quality and file size needs. Always make an informed decision that is based on your needs and objectives. For all your audio compression needs, consider using tools like Mp4Gain which helps optimize your audio files effectively.

What is the main advantage of Ogg Vorbis over WMA for audio compression?

The main advantage of Ogg Vorbis over WMA lies in its open-source nature. This means Ogg Vorbis is free to use, modify, and distribute without any licensing costs, unlike WMA which is proprietary. I’ve found that this can make Ogg Vorbis a more accessible choice for a variety of projects, especially when cost is a concern, or when you want total control over the technology.

Which audio format, WMA or Ogg Vorbis, provides better quality for audio compression?

Both WMA and Ogg Vorbis can offer excellent audio quality, but they prioritize different things. WMA often aims for smaller file sizes at lower bitrates, potentially sacrificing some quality. Ogg Vorbis is generally known for preserving higher audio fidelity, often at slightly larger file sizes. In my experience, the ‘best’ quality depends on the user’s needs and the quality of the source material.

How do the licensing terms differ between WMA and Ogg Vorbis?

The licensing terms are drastically different. WMA uses proprietary licenses, meaning users might have to pay for using it or face restrictions. Ogg Vorbis, being open source, operates under a very permissive license. That allows free use, modification and distribution. I always find this difference to be a major point when selecting one over the other for projects, especially when you plan to share and modify your content.

Is WMA or Ogg Vorbis better for audio streaming online?

Ogg Vorbis tends to be more suitable for online streaming due to its open-source nature and very wide platform support. It works well across a range of browsers and devices, providing a seamless experience for the users. WMA might be better for Windows ecosystem, but might be less compatible with other platforms, so that it can make its usability less appealing.

How do the file sizes compare between WMA and Ogg Vorbis at similar quality settings?

At similar quality settings, WMA files can sometimes be a bit smaller than Ogg Vorbis, but this is not a rule, and it can vary depending on the bitrate and encoding settings. Ogg Vorbis prioritizes quality, so its files are often a bit larger to maintain higher fidelity. For me, the most important is to balance the two to find the best result according to your needs.

In which situations is it preferable to use WMA over Ogg Vorbis?

WMA is preferable in closed ecosystems where Windows and Microsoft software are the main platforms. For example, corporate environments that use Windows, where you need compatibility with proprietary software, or systems that already use wma. In my view, if you don’t have those needs, Ogg Vorbis is normally the better choice because of its flexibility.

Does the hardware impact the encoding and decoding of WMA and Ogg Vorbis?

Yes, hardware plays a significant role. WMA might have certain hardware accelerations, especially in Windows systems, that can speed up the encoding or decoding process, while Ogg Vorbis is built to be efficient even in less powerful hardware. In my experience, that hardware optimization is very important, and can make or break the audio experience.

Can I convert WMA files to Ogg Vorbis files, and vice versa, without losing much audio quality?

Yes, you can convert between these formats, but there is some loss every time you convert between lossy formats like WMA or Ogg Vorbis. However, if the conversion is well done, using high quality settings, the loss will be minimized. I always recommend to keep the original file if possible and do as few conversions as possible.

What are the key factors to consider when choosing between WMA and Ogg Vorbis for audio compression?

The key factors to consider include the need for open source software, the desired compatibility, the quality required, and the file size needs. Also, consider if you need to use specific platform or devices, or if you need to do the encoding or decoding on the hardware. I’ve found that carefully balancing these factors leads to the most suitable choice for each particular audio project.

Are there any specific settings I should adjust when encoding with Ogg Vorbis for better results?

Yes, there are several settings you can adjust. Key settings include the bitrate, the quality mode and the encoding speed. Choosing the correct ones makes the compression better, and helps to adjust the file size. In my practice I have found that experimenting with different settings makes the difference between an acceptable and an exceptional result.

Comments:

Great breakdown! I’ve been using WMA for years on my Windows machine, but now i understand that there are better options. I think I’ll make a test to see if I can hear the difference.

– WindowsUser

This article was super helpful for my audio project. I’ve been really struggling to pick the right codec and your comparisons clarified the matter. Thanks a lot!

– AudioNewbie

Hey, I really enjoyed the explanation with the real-world examples, like the analogy of the tool brand and the park for licenses, it’s so easy to understand it that way!. Thanks for the useful knowledge

– EasyToUnderstand

I have been searching for this information for days. This is the best explanation that I’ve found. I wish i had seen this before. Now I can start working on my videos without any doubt. Thanks!.

– ResearchGuy

I’m a bit confused, you have mentioned that the audio quality of Ogg Vorbis is better than WMA, but that WMA files are smaller. Which one should I use in the end?. Could you be more specific about what to expect of each?

– ConfusedUser

Awesome article. I have to say that I really like the tips on how to optimize the audio compression, and also the explanation about file sizes. Thanks for making it so understandable.

– AudioPro

This article was very informative, and it cleared my doubts about what should I use to save my audios. Also the faq section was amazing, it answered all my questions!. Great Job!

– KnowledgeSeeker

I am impressed, great article! I was in the dark about which codec to choose. I will share it with my friend who is struggling with this topic. It’s good to learn from the pros.

– TechSavvy


Free Download Mp4Gain
picture


Mp4Gain Main Window
picture


Mp4Gain Features
picture


Free Download Mp4Gain
picture

Understanding the Impact of Psychoacoustics in MP3

Understanding the Impact of Psychoacoustics in MP3

Understanding the Impact of Psychoacoustics in MP3

Understanding the Impact of Psychoacoustics in MP3
Understanding the Impact of Psychoacoustics in MP3

Let’s talk about MP3:

As an expert in the field of audio technology, I’ve delved deep into the fascinating realm of MP3 audio compression. When you think about MP3, what comes to mind? Perhaps it’s the convenience of storing thousands of songs on a small device, or the ability to stream high-quality audio over the internet. But have you ever wondered about the intricate science behind MP3 compression and its impact on the way we experience sound?

The Science Behind MP3 Compression:

At the heart of MP3 technology lies the concept of psychoacoustics, which is the study of how humans perceive sound. Unlike traditional audio formats that capture every nuance of a sound wave, MP3 employs psychoacoustic principles to selectively remove data that is deemed less audible to the human ear. This clever approach allows for significant reduction in file size without compromising perceived audio quality.

Key Psychoacoustic Principles:

  • Masking: Our ears have a limited ability to discern quieter sounds in the presence of louder ones. MP3 takes advantage of this phenomenon by removing masked frequencies, resulting in smaller file sizes.
  • Temporal masking: Similarly, our perception of sound is affected by temporal masking, where a loud sound can obscure quieter ones that occur shortly before or after it.
  • Frequency masking: Certain frequencies can mask others, making them less audible. MP3 exploits this by discarding masked frequencies, further reducing file size.

The Impact on Audio Quality:

While MP3 compression offers undeniable benefits in terms of storage and transmission efficiency, it does come with some trade-offs in audio quality. The process of removing “unnecessary” data can lead to artifacts such as compression artifacts, which manifest as distortion or loss of detail in the audio signal. Additionally, aggressive compression settings can result in a phenomenon known as “listener fatigue,” where prolonged exposure to heavily compressed audio becomes tiresome to the ear.

Advancements in MP3 Technology:

Over the years, significant advancements have been made in MP3 technology to address these limitations. Modern audio codecs, such as AAC (Advanced Audio Coding), utilize more sophisticated algorithms and higher bitrates to achieve better compression efficiency while preserving audio quality. Additionally, perceptual coding techniques have been refined to minimize the perceptual impact of compression artifacts, providing listeners with a more enjoyable listening experience.

Real-World Applications:

The impact of psychoacoustics in MP3 extends far beyond personal music libraries. From online streaming platforms to broadcast radio, MP3 compression plays a crucial role in delivering audio content to millions of listeners worldwide. Even in professional audio production, where pristine quality is paramount, the efficiency of MP3 compression is leveraged for quick and convenient file sharing among producers, artists, and engineers.

Latest words on MP3:

In conclusion, the widespread adoption of MP3 technology has revolutionized the way we consume and distribute audio content. By harnessing the principles of psychoacoustics, MP3 compression has enabled unprecedented convenience without sacrificing too much in terms of audio quality. However, as technology continues to evolve, so too will our understanding of how to strike the perfect balance between compression efficiency and perceptual fidelity. As an expert in the field, I remain excited to witness the future innovations that will shape the audio landscape for years to come.

Comments:

MP3 compression is such a lifesaver when it comes to storing my extensive music collection on my phone! I never knew about the science behind it until reading this article. Really eye-opening stuff!

– MusicLover123

While MP3 is convenient, I’ve always noticed a difference in audio quality compared to uncompressed formats. It’s interesting to learn about the psychoacoustic principles behind it.

– Audiophile99

This article provides a great overview of MP3 compression and its impact. However, I wish it delved deeper into specific advancements in psychoacoustic modeling techniques.

– TechEnthusiast22

As a musician, I’ve encountered the challenges of balancing file size with audio quality. It’s a fine line to walk, but understanding the science behind MP3 compression definitely helps!

– GuitarGuy2024

Wow, I never realized how much goes into compressing audio files. This article breaks it down in a way that’s easy to understand. Kudos to the author!

– SoundSavvy

Thanks for shedding light on the topic of MP3 compression. It’s something we encounter every day but rarely stop to think about. Very informative!

– AudioNovice

As someone who’s always on the go, I appreciate the efficiency of MP3 compression. It allows me to carry my entire music library in my pocket!

– RoadWarrior

This article sparked my curiosity about the technical aspects of audio compression. I’d love to see more articles diving deeper into the intricacies of psychoacoustics!

– CuriousMind

While MP3 is convenient for everyday listening, I prefer lossless formats for critical listening sessions. It’s all about finding the right balance for your needs!

– HiFiEnthusiast

Great article! I’ve always wondered how MP3 compression works, and now I have a much better understanding. Keep up the fantastic work!

– AudioExplorer

M4A Digital Audio Compression

M4A Digital Audio Compression

M4A Digital Audio Compression

M4A Digital Audio Compression
M4A Digital Audio Compression

Let’s talk about M4A Digital Audio Compression

As an expert in digital audio compression, I’ll delve into the intricate world of M4A digital audio compression. M4A, a popular format for storing audio files, offers high-quality sound with efficient compression. It’s essential to understand the nuances of M4A compression to appreciate its benefits fully.

The Basics of M4A Compression

M4A compression utilizes advanced algorithms to reduce the file size of audio recordings without compromising sound quality. Unlike traditional MP3 compression, M4A employs more efficient encoding techniques, resulting in smaller file sizes while retaining the original audio fidelity.

  • M4A versus MP3 Compression
  • Efficiency of M4A Compression
  • Quality of M4A Audio Files

M4A compression has gained popularity among audio enthusiasts and professionals due to its ability to preserve the nuances of the original recording. Whether you’re a music lover or a sound engineer, understanding the principles behind M4A compression is crucial for optimizing audio storage and playback.

Advantages of M4A Compression

  • Superior Audio Quality
  • Smaller File Sizes
  • Compatibility with Multiple Devices

One of the primary advantages of M4A compression is its ability to deliver superior audio quality compared to other formats. By leveraging advanced encoding techniques, M4A files maintain high-fidelity sound while keeping file sizes manageable. This makes M4A an ideal choice for storing music libraries, podcasts, and other audio content.

Applications of M4A Compression

  • Music Streaming Services
  • Podcasting Platforms
  • Mobile Devices

M4A compression is widely used across various industries, from music streaming services to podcasting platforms. Its efficient encoding ensures seamless playback on a range of devices, including smartphones, tablets, and computers. Whether you’re listening to your favorite songs on Spotify or tuning into a podcast on Apple Podcasts, chances are you’re experiencing the benefits of M4A compression.

Future Trends in M4A Compression

  • Enhanced Compression Algorithms
  • Integration with AI and Machine Learning
  • Improved Audio Streaming Technologies

Looking ahead, the future of M4A compression is filled with exciting possibilities. Advances in compression algorithms, coupled with advancements in AI and machine learning, promise even greater efficiency and audio quality. As streaming technologies continue to evolve, M4A compression will play a pivotal role in delivering immersive audio experiences to audiences worldwide.

Latest words on M4A Digital Audio Compression

In conclusion, M4A digital audio compression offers a compelling blend of superior audio quality and efficient file sizes. As technology continues to evolve, M4A compression will remain at the forefront of audio encoding, empowering content creators and listeners alike to enjoy high-fidelity sound across various platforms and devices. Embrace the power of M4A compression and elevate your audio experience to new heights.

Comments:

This article was so helpful! I’ve always wondered about M4A compression and how it differs from other formats. Now I feel like an expert!

– MusicLover88

Great article! I appreciate the detailed explanation of M4A compression and its advantages. It’s fascinating to learn about the technology behind audio encoding.

– SoundEnthusiast22

Wow, I had no idea M4A compression was so advanced! This article opened my eyes to the world of digital audio and the importance of choosing the right format.

– PodcastFanatic99

This article left me wanting more! I wish there was a deeper dive into the technical aspects of M4A compression. Nonetheless, it was a great read!

– TechJunkie123

As a musician, I’m always looking for ways to optimize my audio files. M4A compression seems like the perfect solution for balancing quality and file size.

– MusicianLife

I’ve been using M4A files for years, but I never fully understood how they work until now. Thanks for shedding light on this fascinating topic!

– AudioPro456

Excellent article! I appreciate the author’s expertise and ability to explain complex concepts in a clear and concise manner.

– TechSavvy77

I found this article to be incredibly informative. It’s amazing to see how technology has advanced in the realm of digital audio compression.

– DigitalNomad55

Great job on this article! It provided a comprehensive overview of M4A compression and its applications in various industries.

– AudioGeek123

This article was a game-changer for me! I never realized the importance of choosing the right audio format until now. Thanks for the valuable insights!

– SoundSavant

How to choose the perfect compressor configuration

Compressors and how to use them, explained.

Compression is one of your most powerful mixing tools. It is the essential element behind any good mix.

But for your compressors to work, you must first understand what compression is.

It can seem intimidating to start learning such a broad subject, especially when the controls and how they affect the signal are difficult to understand in relation to the sound.

This article will help you understand what compression does, how to choose the perfect compressor setting, and some common mistakes to avoid.

But before…

What is compression in music?

Compression in music is the process of reducing the dynamic range of a signal. Dynamic range is the difference between the loudest and quietest parts of an audio signal.

audio compression

You must reduce the dynamic range of most audio signals to sound natural to a recording.

For example: imagine a whisper and a scream on the same audio track. If they had the same volume difference as they do in real life, it would be very annoying!

Compressors fix all of this by attenuating the loudest parts of the signal and boosting what is output so that the quieter parts are more noticeable.

Imagine a whisper and a scream on the same audio track. If they had the same volume difference as they do in real life, it would be very annoying!
Using compression
Experienced engineers often talk about how one compressor is more “musical” than another.

It is an important concept. Its dynamics is one of the fundamental aspects for its sound to be unique.

When you use a compressor to change the dynamics, the sound engineer becomes part of the musical performance.

If your compressors work properly, they will positively contribute to performance and improve recordings.

Transients: understanding high energy moments.

To understand compression, you need to know what transients are.

Transients are the first high-energy moments of a certain sound in its waveform. These explosions give our brain a lot of information about the quality of a sound.

Since transients are usually louder than the rest of the waveform, they are greatly influenced by compressors.

For example: think of a nice roaring trap. As soon as the trap enters, there is an initial peak in the waveform that narrows slowly. That initial energy spike is your transient.

transient compresor

Compression helps you find the perfect balance for a track that has good dynamic range with a beautiful, full body.
A waveform with good dynamics will have a lot of transients when some sounds hit and then decay in the composition. Transients and their final decay are what make a waveform similar to a fish bone.

There is even an overly dynamic trail. If your song is transient without a body, its sound will not be of interest to your ear.

The reverse is also true, no dynamics can lead to lifeless, exhausting sound for the human ear and a waveform that looks like a big brick.

Compression helps you find the perfect balance for a track that has good dynamic range with a beautiful, full body.

Limiter

The threshold determines the signal level at which the compressor will start operating. The threshold is measured in dB, therefore any signal above the set threshold will be compressed.

When setting the threshold, decide what part of the signal you want to reduce.
With the threshold low, the compressor gain reduction is applied to a larger portion of the signal. Setting it higher affects only the most aggressive peaks and leaves the rest intact.

To determine what the perfect threshold is, think about what you’re trying to accomplish by compressing the audio and which parts of the signal are the most troublesome.

Are strong signal transients distracting you from the rest of your mix? Or maybe your final decadence is imperceptible in the mix?

A good rule of thumb for compression is “do no harm.”
Set the threshold to hear compressor operation on the part of the signal that needs to be addressed and not lowered.

Setting the perfect threshold will depend on your needs. Play the track and tweak it on the go to find the perfect amount.

Relationship

The ratio determines the amount of gain reduction applied by the compressor when the signal exceeds the threshold. It is called a relationship because it is expressed in comparison with the unaffected signal.

The higher the first number in the report, the greater the gain reduction factor.

For example, we can say that an uncompressed signal would have a 1: 1 ratio

What is the compressor and how does it work?

The compressor, together with the equalizer, is one of the most important and most used processors in professional audio, but its operation is not always so intuitive and knowing how to master the compression technique sometimes requires years of experience. In this new article we begin to explore this fundamental processor.

What is the compressor for?

First of all, let’s start to see what the compressor’s function is: to reduce the dynamic range of an audio track, that is, to decrease the distance in volume between the weakest signal and the strongest signal. Initially created to optimize recording on magnetic tape and to avoid saturation of the input stages, the compressor is still used today during recording and mixing. Reducing dynamic range also allows us to keep multiple tracks in the mix, such as a voice, for example, always at the same volume throughout the song so that they are not dominated by the other instruments in the most crowded sections, as well as to avoid Output saturation.

Compressor

Back to basics: what is the compressor and how does it work

The controls

Now let’s see in detail what the various compressor controls are and what they are for:
— Threshold: or threshold, expressed in dB, indicates the point beyond which the compressor begins to operate.
— Ratio: is the compression ratio and indicates how much the signal will compress when it exceeds the Threshold. For example, with a 2: 1 ratio, each signal that exceeds the threshold will be halved at the output, that is, every 2 dB at input 1 will be returned at the output.
— Make Up Gain: This is the output of the compressor and is used to recover the volume lost due to compression.
— Attack: expressed in milliseconds is the time it takes for the compressor to start once the signal has passed the threshold.
— Release: always expressed in milliseconds, it indicates the time it takes for the compressor to stop compression once the signal has returned below the threshold.
— Gain reduction meter: it is not a control but a visual indicator, led or pointer, which informs how much the signal is compressed, through a scale in dB.
— Bypass: shuts down the processor, making the signal pass through the machine without alteration.

With the advent of digital and accessories, we can find controls that not all hardware compressors have:
— Knee: indicates the type of curve at the point where the compressor begins to operate, which can be abrupt (Hard Knee), soft (Soft Knee) or various intermediate values.
— Automatic: sets the time control to which it refers (attack, release or both) automatically, depending on the input signal (program dependent).
— Sidechain eq or External Sidechain: Sidechain is the signal that drives the compression circuit, where in most cases it is the signal itself to compress, but sometimes it can be a version of the input signal with different equalization, for example without low frequencies, so that they don’t start the compressor too soon. Or it can be an external signal, such as the one used on the radio where the speaker’s voice signal drives a compressor on the background music signal, so it automatically turns off when it starts to speak (Ducking), or Classic Speaker Use to activate the compressor on various instruments in the mix or the Master Buss.
— Mix: used to mix the compressed signal with the original signal. This way, you can use Parallel Compression directly on the compressor, without having to use two mixer tracks (one for the dry signal and one for the compressed signal).
Back to basics: what is the compressor and how does it work

Compressor

Compressor or limiter?

What is the difference between a compressor and a limiter?

Essentially, the compression ratio: over 10 dB ratio, the processor is considered a limiter. A separate case is the Brickwall Limiter, a compressor with immediate attack and a compression ratio of infinity to 1, so that no signal can exceed the Threshold. It is mainly used on the master buses so as not to exceed 0dBFS on the output and then send the converters to clips.

Usage examples

As we already said, the compressor is used to keep the volume excursion under control. One track in the mix: in this case, using a fairly fast attack, slow release and not too aggressive ratio, allows us to compress the signal constantly and transparently, that is, without making your intervention feel excessively.
The compressor can also serve to emphasize the attack of a percussion instrument: in one case, for example, by setting a medium slow attack.

Audio normalization or compression

The function of a compressor is to reduce the dynamic range of the signal, that is, the level difference between the strongest and weakest signal parts.

Why compression or normalize?

At the time of analog, the limited dynamics of the main musical supports (vinyl, audio and video cassettes) did not allow to reproduce the dynamics of a classical, jazz or even rock orchestra in the case of the audio cassette. Therefore, the signal was compressed to avoid distortion in the transmission medium.

audio compression or normalization

Now that the music is converted to 16-bit or more, recorded in digital format, and then streamed to CD / DVD or downloaded, the dynamics of the media is enough to faithfully reproduce the dynamics of almost any orchestra. The old technical limitations have disappeared, therefore compression is no longer essential.

However, whatever the musical genre, some sources (voices) are compressed almost systematically. The goal of modern compression is therefore to optimize sound recording, either to get closer to reality or, conversely, to create a less faithful but denser, more controlled, more powerful sound, etc., or even a sound. totaly new.

And to do all this, the compressor is satisfied with a simple principle: it reduces dynamics by attenuating the signal level when the latter exceeds a given threshold level.

Level settings

– Threshold (threshold level, in dB)

This parameter determines the threshold level from which the compressor is triggered. As long as the input signal level remains below the threshold, the compressor does not start and no treatment is applied. As soon as the source signal exceeds the threshold level, compression is applied.

– Ratio (compression ratio)

The ratio determines the amount of level reduction applied to the part of the signal that exceeds the threshold level, the rest of the signal is not processed. Depending on the compressor, the ratio can vary from 1: 1 to Inf: 1. Quésaco?

Set up a compressor

With a 1: 1 ratio, no compression is applied, the level of the input signal is equal to that of the output signal. With a ratio of 2: 1, the level of the signal portion that exceeds the threshold is divided by 2 in the output signal. With a 3: 1 ratio, it is divided by 3, etc. When the compression ratio is infinite (Inf: 1 ratio), the compressor behaves like a limiter: the output signal never exceeds the threshold level, regardless of the input level.

Therefore, the compression intensity applied to the signal is a compromise between the threshold and the compression rate setting:

The lower the threshold, the larger the compressed signal portion.
The higher the ratio, the greater the level reduction applied to the signal portion above the threshold.
Depending on the compressors, you may find other parameters, for example, an input level setting instead of the threshold, or a gain setting (also called the offset or output level) that amplifies the signal to compensate for the drop in level resulting from compression.

Time settings

– Attack (attack, in ms)

Attack corresponds to the time the compressor needs to reach the given ratio when the signal level exceeds the threshold level. A quick attack of a few milliseconds triggers strong compression as soon as the signal level exceeds the threshold; With a slower attack, the compressor passes the first transients of the signal peaks, keeping one side alive and well cut.

Set up a compressor

– Launch (launch, in ms and s)

Release corresponds to the time the compressor needs to return to the 1: 1 unit ratio when the source signal falls below the threshold level. A quick launch of a few tens of ms allows the original character to stay alive. Slower relaxation improves instrument resonance and reverberation, but can cause compression of the first peak transients when the latter are close together.

– Knee (literally knee!)

The Knee parameter determines the increase in compression, that is, the transition between the compression ratio of the unit (1: 1, no compression) and the compression ratio set to ratio.

Applications

At the output, the compressor can be used as a limiter to control signal peaks and prevent distortion from occurring in the analog / digital conversion stage.
When taking and mixing, light compression can bring out weak parts of the signal and thus reveal certain details.
In the mix, the compressor allows you to increase the average level of the audio volume output.

Destructive compression vs non-destructive

Destructive compression is compression obtained by losing information. This means that if you extract the compressed signal with this technique, you will not find the start signal.

Destructive Vs Non-Destructive Audio compression

In destructive compression techniques, there are basically methods that take advantage of the properties of the human ear. The latter listens to frequencies between 20 Hz and 20 kHz. If a song contains frequencies outside this range, we can easily delete them without losing the audio quality because the ear does not hear them. In fact, frequencies between 2 kHz and 5 kHz are generally heard correctly. In fact, less than 5 dB is required to hear frequencies in this band, while more than 20 dB is required to hear frequencies below 100 Hz or above 10 kHz. These results can be used to reduce the size of the files. For example, we can conclude that all frequencies above 15 kHz are suppressed.

audio compression

MP3 also uses the principle of masked frequencies. If in a frequency group some have a much higher noise level than others, it is not necessary to keep the frequencies low – we will not hear them. Imagine yourself in your garden listening to the birds sing. The chord goes over your head (even very high). We no longer listen to birds because the sound they make is much quieter than that of the plane. It is as if the birds no longer exist or have stopped singing. Obviously, it is not necessary to code all the frequencies present in a song so that the human ear can always perceive it well. Finally like the two ways

What do we find among non-destructive techniques?

Mainly coding techniques.

Let’s explain. A sound is a frequency. A second of music is therefore a sequence of frequencies. Imagine that in the series of samples that make up a second of music (remember that there are 44,100), we have the same frequency several times in succession, for example 10 times. If instead of storing these 10 points, we only store 1 and the number of times it is repeated, we must encode 2 digits and not 10. If we also apply this method to frequencies which are no longer identical, but very dense together (so close that the average human ear cannot distinguish them), we can still save space. This time, the compression is destructive because we are replacing one frequency with another frequency (almost identical).

MP3 also uses the algorithm of Huffman (1952) as a method of encoding information. This method is used in all compression algorithms (compression of text files, compression of images, compression of sound). It is based on the use of a variable length code and the probability that an event (in this case a frequency) will occur. The more a frequency appears, the shorter the code (low number of bits to display it). The file is read for the first time and a table appears with the frequencies that appear and the number of times they appear. We derive the right code. This encryption was last used. It is the final phase of compression. This is non-destructive coding.

MP3 works on the properties of the ear, first to reduce the size of a part, then processes the stereo sound and possibly applies encodings which end with Huffman encoding.

The use of all the reduction options mentioned depends on the location you want to give within 1 minute of your tablet and therefore on the compression speed to apply.
To encode MP3 audio files, we are talking more in terms of bit rate than compression rate.
Bit rate is the number of bits allowed in 1 second.
Therefore, we have the following relationship: the more we want to compress a song (so that it takes up the least space possible), the lower the bit rate.

Choice of compression ratio (bit rate)

Obviously, the more you compress, the worse the sound quality.
You have to compromise the file size and audio quality.
This commitment can be dictated by your needs, but also by the use you want to make of your MP3 files. It may not even be demanding if your MP3s are intended for your portable music player and are too demanding to be listened to on a stereo system.

Mp3: Audio Compression.

Audio Digitization.

Sound is a continuous wave that propagates through air or other media, formed by
pressure differences, so that it can be detected by measuring the pressure level in a
point. Sound waves have the proper and measurable characteristics of waves in general,
such as reflection, refraction and diffraction. As it is a continuous wave, a
digitization process to represent it as a series of numbers. Currently, most of
the operations carried out on sound signals are digital, since both storage and
processing and transmission of the signal in digital form offers very significant advantages over
analog methods. Digital technology is more advanced and offers greater possibilities, less
sensitivity to transmission noise and ability to include error protection codes,
as well as encryption. With the appropriate decoding mechanisms, moreover, they can be treated
simultaneously signals of different types transmitted on the same channel. The disadvantage
main aspect of the digital signal is that it requires a much greater bandwidth than that of the signal
analog, hence an exhaustive study is carried out regarding data compression,
some of whose techniques will be the center of our study.
The digitization process consists of two phases: sampling and quantization. In the sampling,
Divide the time axis into discrete segments: the sampling frequency will be the inverse of time
that mediates between one measurement and the next. At this time the quantization is performed, which, in its
In the simplest way, it is simply to measure the signal value in amplitude and save it.

Nyquist’s theorem guarantees that the frequency necessary to sample a signal that has its
Higher components at a given frequency f is at least 2f. Therefore, the range being
higher than human hearing around 20 Khz., the frequency that guarantees a sampling
suitable for any audible sound will be about 40 Khz. Specifically, to get sound
High-quality frequencies of 44.1 Khz are used, in the case of CD, for example, and up to 48 Khz.
in the case of the DAT. Other typical values ​​are submultiples of the first, 22 and 11 Khz. According to
nature of the application of course the appropriate frequencies can be much lower
such that the voice process is usually carried out at a frequency of between 6 and 20 Khz. or
even less. Regarding quantization, it is evident that the more bits used for the
axis division of amplitude, the “finer” the partition will be and therefore the less error in attributing
a concrete amplitude to the sound at every moment. For example, 8 bits offer 256 levels of
quantization and 16, 65536. The dynamic range of human hearing is about 100 dB. The
axis division can be performed at equal intervals or according to a certain density function,
looking for more resolution in certain sections if the signal in question has more components in a certain
intensity zone, as we will see in the coding techniques.
The complete process is usually called PCM (Pulse Code Modulation) and so we
We will refer to it hereinafter. It has been described in a very simplistic way, mainly
because it is widely discussed and is well known, being the field of study of
this work. However, we will go into detail at any time that is necessary for the
development of the exhibition.
1.2 Coding and Compression.
Before describing compression and encoding systems, we must pause briefly.
analysis of human auditory perception, to understand why a quantity
Significant information that the PCM provides can be discarded. The heart of the matter,
as far as we are concerned, it is based on a phenomenon known as masking.
The human ear perceives a frequency range between 20 Hz. And 20 Khz. First of all, the
sensitivity is higher in the area around 2-4 Khz., so that the sound is more
hardly audible the closer to the ends of the scale. Second is the
masking, whose properties exhaustively use the most interesting algorithms:
when the component at a certain frequency of a signal has high energy, the ear cannot
perceive lower energy components at close frequencies, both lower and higher. TO
a certain distance from the masking frequency, the effect is reduced so much that
negligible; the range of frequencies in which the phenomenon occurs is called the critical band
(critical band). Components belonging to the same critical band influence each other and
they do not affect nor are affected by those that appear outside it

Audio Data compression

Data compression or the technique that changed everything

Without pretending to extend ourselves in the description of this critical concept, it is important to know that compression is understood as a scheme that allows, by means of a “decision” algorithm based on a series of “rules” (which in the case of audio are masking and audibility threshold) reduce the amount of data to transmit a certain message. In other words: if the song “x” occupies, in the format used to encode the sound of a CD, 1 million bits, the data compression allows that song to be reproduced with maximum intelligibility using only 50,000 of those bits.

In this way, the download of a complete CD from a certain website could be carried out in a reasonable period of time. But, of course, the price to pay was high in terms of quality because such “castration” of the original message (which in turn was not “continuous”, analog, but also digital, although “linear”, without compression) meant removing many nuances of music, a disaster that in reality did not care for many consumers but it did worry, and a lot, those who bet on that High Fidelity in the reproduction of the sound that we are so passionate about and who received a wound that was almost fatal . In this sense, it is worth knowing that the “philosophical” keys to data compression are summarized in two terms: redundancy and irrelevance. In the first case, it is about reordering the available data to eliminate the ones that are repeated (for whatever reason: security, etc.), a bit like a “zip” computer file. It is a formal remodeling that does not affect the sound message at all (but it does save space to transmit / save data, making it very practical), so in this case, we are talking about lossless compression or “lossless” ” It is the second term that has the greatest scope in terms of sound quality because the idea of ​​irrelevance implies deleting irrelevant data from a certain message. And, of course, who decides what is relevant or not? Well, an algorithm, a program that, obviously, can be more or less sophisticated but still makes decisions with which everyone will agree. It is easy to understand: what may be irrelevant to such a person and / or the team may not be so to someone else. The fact is that here musical information is deleted, which, fundamentally, can no longer be recovered. Well, the algorithms in which there are losses of musical information are known as “lossy” or lossless coding algorithms. From what has been said, it is easily deduced that the difference between the concepts “lossless” and “lossy” is the one that marks the border between high and low quality digital audio, between high resolution (with recording studio quality formats or “Studio Master” on the cusp) and that “practical” sound (in principle for portable players and cars) and very often unnatural formats like the once ubiquitous MP3, which, we insist, almost ruined with the improvements provided by the CD.
ADSL, the key to accessing High End audio via the Internet
Basically it was a purely technical progress that, logically, had to come. A progress that allowed breaking the limitations that prevented downloading a song recorded in PCM at 16 bits / 44’1 kHz and, over time, the files with much higher resolution than for a good decade and a half are the usual ones in studios of recording. So, thanks to ADSL, the High End in audio via the Internet, and therefore “without physical support” is available to everyone. At this point, it will be good to briefly review the small “soup” of acronyms with which we can find ourselves, otherwise the result of the availability of open and “closed” environments (Windows, Mac), in what CODEC’s (algorithms that compress and decompress data (in this case of music) refers to the fact that compression is the norm.

 

AAC (Advanced Audio Coding): It was designed to be the successor to MP3 and, although it is a lossy CODEC, the results in terms of sound quality are superior to those of MP3 for the same bit rate. The AAC has adopted a wide range of portable audio devices such as the iPod and its derivatives for use.
AIFF (Audio Interchange File Format): It is the version of WAV created by Apple. Works with uncompressed (ie “lossless”) files that maintain full resolution and size.
 

ALE (Apple Lossless Encoder), also known as ALAC (Apple Lossless Audio Codec): Uses lossless compression to save storage space. Once unzipped for listening, the file will be bit by bit identical to a full size WAV or AIFF encoded file. As in AIFF or FLAC, in ALE / A files