As a podcaster, you may receive files in different audio formats. The files themselves could be sent via different platforms such as WhatsApp, which typically uses the OPUS format, or from Apple devices that often use formats like AIFF or ALAC. In addition to these, you might also encounter WAV and MP3 formats. Let us take a look at the typical audio file formats and their common uses.
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Common types of different audio formats
MP3 – This is a popular audio format that uses lossy compression to reduce file size without significantly impacting audio quality. It is widely supported by a range of devices and applications, making it a common choice for podcasts and music downloads.
WAV – This is a lossless audio format that provides high-quality audio, but results in larger file sizes than MP3. It is commonly used for professional audio recording and editing, as well as for high-resolution music files.
AIFF – This is another lossless audio format that is commonly used for professional audio recording and editing. It is similar to WAV, but is more commonly used on Apple devices and applications.
OGG – This is an open-source audio format that uses lossy compression to reduce file size without significantly impacting audio quality. It is commonly used for podcasts and other streaming audio, as it offers a good balance between file size and quality.
FLAC – This is a lossless audio format that provides high-quality audio, but results in larger file sizes than MP3 and OGG. It is commonly used for high-resolution music files and is supported by a range of devices and applications.
ACX – This is the audio format used by Audible for audiobooks. It requires specific technical specifications for audio files, including a consistent sound floor, peak levels, and high-quality mono or stereo sound.
Also read: Major types of audio formats
The audio file format space has a problem of plenty. As a result, the challenge to convert audio files from one format to another has bother many a singer, podcaster, or audio editor at some point or another. At gaathastory, we have encountered a variety of challenges related to audio formats, from creators sending off-spec audio files to varying requirements of different podcast hosts.
At peak, we handled 18 different podcast shows across 6 languages, and published one episode per day for 2 consecutive years.Which only complicated the problem further.I am simplifying the nature of the problem, for the sake of brevity.
Input files in different formats
Initially, we stipulated that contributors should upload the audio files directly to our cloud server in 16-bit WAV format. This drive was accessible to the editors. However, we frequently received files in MP3, OPUS, and other formats. This forced us to create an intermediate step: check the audio for the right format, instead of taking the burden to convert audio file formats. If they are not uploaded in the .wav, reject the audio and ask the artist to re-send the same. On the flip side, this step began to add more time to our workflow. We decided to convert the audio files ourselves, if the received audio file met other parameters (narration style, quality, etc.) This extra step became a routine part of our workflow, albeit out of necessity.Some contributors opted to send their files via WhatsApp, which compresses audio and degrades its quality more that any other tools.In certain cases, due to a lack of alternatives, we were compelled to proceed with these degraded and heavily compressed audio files. This experience highlighted the necessity for more flexible, yet quality-conserving, solutions for handling different audio formats.
Different requirements for podcast hosts
Another issue arose with audio file delivery. Multiple times, unfortunately. Different podcast hosts have their own format preferences Megaphone, for instance, accepts only MP3 files. Spotify, with whom we had a two year long agreement, required us to upload audio files in 320 kbps MP3 format. In contrast, Spreaker was more lenient, accepting FMAC, WAV, and MP3 formats. An audiobook company wanted us to deliver the audio in 120 Kbps mp3 files. These varying requirements prompted us to explore tools for converting audio files.Also read: Major types of audio formats
Convert audio file formats for test audience
Very often, we would send test or sample files to a selected pool of listeners, before the final release. Particularly the elderly listeners or those who are less tech-savvy, we had to provide lower-bitrate MP3 files. They would typically listen to the files on their mobile devices, and in 2016-18, majority of them were still on 3G network. This meant we had to mitigate their bandwidth and latency challenge. As a result, we had to emplasize the need for a streamlined, efficient way to manage and convert audio formats.Open Source Audio Tools to the Rescue
As an open-source advocate, my first instinct was to seek out solutions for Mac and Linux computers. Some of the tools to convert audio files from one format to another include Audacity and Ocenaudio or even Ardour DAW (Digital Audio Workstation). For Mac, GarageBand is an excellent tool that is capable of converting some files. My search also extended to online platforms such as Cloudconvert and later TinyWOW. This led me to develop the below list of various software and web-based tools. Note that as on August 2023, I have personally used most of the below mentioned tools.Pros and Cons: Convert audio file formats
Converting audio files from one format to another comes with its pros and cons. On the positive side, it allows for greater flexibility and adaptability. This enables content creators to meet various platform-specific requirements. However, there are downsides such as potential loss of audio fidelity or quality due to compression. Using different formats and conversion methods may result in varying degrees of audio quality. Additionally, converting files to different compressed formats often leads to smaller file sizes. This could be beneficial for storage, but detrimental to sound quality.Open Source Tools to Convert Audio File
Desktop Software and Applications
( Note: information on availability for operating systems and mobile app was checked in September 2023)1. FFmpeg
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- Supported Platforms: Windows, Linux, Mac
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- Description: FFmpeg is a robust, command-line utility capable of converting audio files among many different formats.
2. SoX (Sound eXchange)
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- Supported Platforms: Windows, Linux, Mac
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- Description: Another command-line utility, SoX supports multiple audio formats and even offers some basic audio processing functionalities.
3. fre:ac (Free Audio Converter)
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- Supported Platforms: Windows, Linux, Mac
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- Description: This is a user-friendly GUI application that supports a range of audio formats.
4. LameXP
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- Supported Platforms: Windows
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- Description: LameXP is a free multi-format audio file converter that supports a variety of encodings.
5. Audio Converter by MediaHuman
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- Supported Platforms: Windows, Mac
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- Description: This tool offers a clean interface and supports batch conversions.
6. XRECODE
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- Supported Platforms: Windows
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- Description: This tool supports multiple file formats and batch conversions, but is only available on Windows.
7. Converter for iOS and Android (Mobile)
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- Supported Platforms: iOS, Android
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- Mobile: Yes
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- Description: These are specialized apps available on respective app stores and are open-source or have open-source variants.
More Ways to Convert Audio Files
1. Cloud Convert
This is a web-based utility that lets you convert audio files without installing any software. While not open-source, it’s free to use.2. Zamzar
Zamzar is one of the oldest online file conversion services and supports a multitude of audio, video, and document formats.3. Convertio
Convertio allows users to upload files from multiple sources including desktop, URL, Google Drive, and Dropbox. It supports various audio formats.4. Aconvert
This service also supports a variety of file formats, not limited to audio. Users can adjust the bitrate, sampling rate, and channels.5. 123apps Online Audio Converter
As the name suggests, this online tool is dedicated to audio conversions and offers options to change quality, sampling rate, and other audio settings. These services usually support a broad range of formats, making it easier for users to convert between common and more specialized audio formats.
Links and Resources
| Bouncecast | Garageband |
|---|---|
| Ocenaudio | Adobe Audition |
| Audacity | Fre:ac |
| ffmpeg | LameXP |
| AConvert | Sox |
| Websites for Converting Audio Formats | |
| tinywow | Convertio |
| Cloudconvert |
Good old AM and FM radio could play two different audio formats
Parting Thoughts
Some formats from the past, such as the Real Player format, were popular in the early days of internet audio streaming. Other notable formats from the past include WMA, AIFF, and AU. While these formats may not be as widely used today, they played a significant role in the development of audio technology. As technology continues to evolve, it is important for audiophiles and podcasters to stay updated on the latest formats and their capabilities in order to deliver the best possible listening experience to their audience.
The need to convert audio file formats becomes evident when we explore the different file formats for audio. Recently I published a post that highlighted the major types of audio file formats, ranging from mp3 to WAC, and AAC to FLAC. In this post, I thought of mentioning some of the tools we have used to convert files from one audio format to another. My focus will be on software tools and websites that can get this job done quickly- without relying on audio editing software like Audacity or Adobe Audition or Garageband. If you are looking for robust, cross-platform options, FFmpeg and SoX are the way to go. For a more user-friendly interface on desktop platforms, you might choose fre:ac. If mobile accessibility is essential, specific apps on iOS and Android stores could be useful. Most browser-based tools are not open-source, but they provide the convenience of not requiring an installation.Which is your preferred format for recording and publishing Audio files?
Frequently Asked Questions on different audio Formats
What are some of the Most Common Audio Formats?
Commonly used different audio formats include MP3, WAV, FLAC, AAC, OGG, and OPUS. MP3 is widely used for its compatibility and compression, while WAV and FLAC are better for high-quality recordings. OPUS is gaining traction for real-time applications.
Which One Should You Use while recording a podcast?
For recording, it’s advisable to use WAV or FLAC. Both are lossless formats that provide high audio quality, which is crucial for editing and post-production. This will allow you to maintain a high standard throughout your editing process.
Which Audio File Format Is Right for the final podcast episode?
MP3 is commonly used for final podcast episodes due to its broad compatibility and smaller file sizes, making it easier for listeners to download and stream. A bitrate of 128kbps is usually adequate for spoken content or podcasts.
What are audio file formats accepted by podcast hosts typically?
Podcast hosting platforms often accept multiple formats, but MP3 is almost universally supported. Other commonly accepted formats are WAV, FLAC, and OGG. Always check with your specific host to know which formats they support.
What is a lossy file format?
A lossy file format, like MP3 or AAC, compresses audio data by removing some audio information, sacrificing some quality for smaller file sizes. While it’s usually sufficient for general use, it’s not ideal for professional editing.
What is lossless compression?
Lossless compression, seen in formats like WAV and FLAC, retains all the audio information during compression. This ensures high quality but results in larger file sizes, making it ideal for recording and editing, but less so for streaming.
What is an uncompressed file?
An uncompressed file like PCM WAV does not apply any form of compression, offering the highest audio quality. However, these files are significantly larger and are usually converted to a compressed format for distribution.
What’s the suggested minimum specifications for audio recording for podcast episodes?
For MP3, aim for a bitrate of at least 128kbps. For OGG, a quality setting of 4 is a good start. For WAV and FLAC, use 16-bit depth with a 44.1 kHz sample rate. These settings offer a good balance between quality and file size.
Which settings should I use for recording a file in OPUS format?
For recording audio in OPUS on an Android device, a bitrate of 64 kbps is typically sufficient for speech. Using a 48 kHz sample rate can provide a good balance between quality and file size. Ensure your recording app supports these settings.
Note:
Understanding these different audio formats can help you navigate the world of podcasting more effectively. Most podcast hosting companies require files to be in MP3 format due to its balance of quality and file size. In some rare cases, wav is the most commonly required format by podcast hosting companies, knowing about other formats like OPUS, AIFF, WAV, OGG, FLAC, and ACX can be beneficial, especially when dealing with different audio sources or platforms.
This post was published under a series of posts on audio recording for podcasts. This post was updated on 21 Feb 2024
