What Is Compression As It Relates To Digital Audio Or Video Files? Check Out 2 Best Methods for Compressing a Podcast

An audio recording is usually a lot more complex than it seems to the listener, with a whole range of effects and processes being used on the audio file to improve or adjust it before it’s finally published.

When figuring out what is compression as it relates to digital audio or video files, you should know a few things.

One is that compression is just one of the effects used on audio files that a podcaster or other content creator might be interested in using, but focusing on making the data smaller and easier to manage.

So what is compression as it relates to digital audio or video files? Compression is the process of making an audio file smaller so that it can be stored more easily on a device, with the two most common methods being lossless or lossy.

Compressing audio files to a more manageable size might be required for a podcaster, so it’s good to understand how it works.

Although they share similar names, data compression is not the same as dynamic range compression, and it’s important to note the difference.

This extensive guide will cover all aspects of what is compression as it relates to digital audio or video files, the process behind it, and potential downsides, so you can see what it’s all about.

What is Compression As It Relates To Digital Audio Or Video Files?

Compression is a process that lets you encode information using fewer bits, effectively making it smaller in size.

The first thing you should remember when determining what is compression as it relates to digital audio or video files is that the goal of compression in audio files is to reduce the size without affecting any quality.

Compression does it by only eliminating parts that are redundant and have nothing to do with the final sound.

When you make an audio recording, it’s stored at its best quality and large size, making storing and sharing challenging.

That’s why compression is commonly used for these types of files, including recordings of podcast episodes before or after they’ve been edited and produced.

Compression is known as source coding, data compression, and bit-rate reduction. The technical aspect of compression is done relatively quickly using software or a device called an encoder.

However, it’s still important to understand what is compression as it relates to digital audio or video files and what it can potentially mean for your audio files once it’s complete.

Compressed Data vs. Sound Compression

When you’re new to audio recording and production, it can be challenging to get a handle on all the different terms and processes you must learn. A common misconception has to do with compression, as you can have both dynamic range and data compression. 

Dynamic range compression is a process that takes place during post-production. Using a compressor, you can bring the higher and lower volume levels of the audio you’ve recorded closer together, compressing them within a specific range.

The listener will hear a more balanced audio track that doesn’t have intense highs and lows, which makes for a better listening experience. 

Compared to data compression, which is mainly about making the files smaller so they can be easier to transfer and store, you can see how they’re nothing alike.

It’s likely that a podcaster will be using both methods of compression, just in different ways, so being able to differentiate between them is vital in the creation of your series.

How Does Compression Work?

Although it’s not necessary to know the ins and outs of what is compression as it relates to digital audio or video files to use it successfully, having a basic understanding of what the process entails can be helpful.

Audio data compression works like other types of data compression, removing unnecessary details from the file.

These nonessential details are commonly referred to as bits, and each file has a set number of bits. The file size shrinks as we take them out, making it easier to save or share with others.

Depending on the compression type, whether it’s lossless or lossy, this can include removing statistical redundancies or simply taking out the nonessential details to make it smaller.

The methods used will also determine whether this encoding can be reversed or not, so make sure you understand what’s involved in the process before going ahead with compression.

Having a backup of the original file is also recommended, just to be on the safe side, and it lets you edit and tinker with it in the future without losing any quality.

What Is Audio Bitrate?

Any time you discuss what is compression as it relates to digital audio or video files, it’s essential to talk about audio bitrate.

The bitrate of a compressed audio file will determine how good it sounds, so it’s not something you want to get wrong, and it’s all about finding the perfect line between file size and the overall quality of the sound.

The audio bitrate of a lossy compressed audio file refers to how much data has been encoded per second during the compression process.

When you’re working at a lower bitrate setting, you’ll get a smaller file size but with an audio quality that’s minimal as well. A higher audio bitrate will result in a larger file and better quality, which is almost always recommended.

The most common audio bitrate for an MP3 compressed file is 320 kbps, so this should be your goal if you’re planning on encoding files.

At this rate, most listeners won’t be able to tell the difference between an uncompressed file and a compressed one, especially for vocal audio recordings like those on a podcast.

Do You Need to Compress?

One of the biggest decisions you’ll need to make when creating a podcast is what file format you ultimately want your show to be available in.

Depending on the platform you’re publishing podcasts on, there might be a requirement for the type of file format you use, and some may even require multiple versions of the audio file to suit various listening options.

Generally, music producers prefer to work with uncompressed audio to ensure the best quality.

For other types of listening, a compressed format file with a high bit rate, like a 320 kbps MP3, is all you need, which means it’s okay to compress this type of audio without worrying about losing too much of the quality.

Finally, a lossless compressed format like FLAC is the most common for critical listening circumstances and might also be ideal for podcasts.

You won’t lose any audio, and the file size will be small enough to manage, but it depends on what requirements the podcast hosting platform has for file uploads, including the size and format of the file.

Types of Audio Files

When determining what is compression as it relates to digital audio or video files, you need to remember three types of files, depending on the methods and advantages you’re looking for.

• Lossless audio file: A file that has not been compressed and contains 100% of the audio data it recorded. The benefit of using lossless audio files is that they’re the best quality, but the downside is that the file sizes are large. The most commonly used lossless audio files are WAV and AIFF, (also see “What Is Best For Podcasting: WAV or MP3“).
• Compressed lossless audio file: If you compress an audio file but want to ensure that none of the audio data is lost, a compressed lossless audio file is the way to go. FLAC and Apple Lossless are the most common examples here, with the goal being they sound just the same as a WAV or AIFF but in a much smaller size.
• Compressed lossy audio file: As the name suggests, a compressed lossy audio file has lost some of its audio data as it was compressed to shrink its size. The goal is to reduce the file size without too much tampering with its audio quality, which has become easier thanks to modern technologies. The most common compressed lossy audio files are MP3 and AAC, in which many podcasts are published.