What is FLAC?

According to Wikipedia, this is “audio coding format for lossless compression of digital audio”. The main word here is “lossless”. It means than FLAC encoder tries to make size of audio data smaller, but it will never make its quality worse. FLAC encoder doesn’t drop any samples, doesn’t cut high/low frequencies and output audio file will be sample-to-sample equal to input audio stream. The price is pretty big size of FLAC file and some CPU resources to encode/decode it. Also, not every hardware or software is compatible with FLAC format.

What about FLAC in Audials?

Audials supports encoding to FLAC. Click on “Format” button in footer to open “Output format” dialog. Here it is possible to select FLAC as output format for “High-resolution audio”:

What is “High-Resolution audio”?

Each audio streaming service has some set of audio formats, which are used for streaming. Some services stream audio only in “lossy” formats, like MP3 or AAC. Some services also provide lossless (FLAC) tracks. Not every service has this feature, and even if it does – not every track is available in this quality.

                In Amazon Music tracks, available in lossless quality are marked by “Ultra HD” label. You can click on this label to check track is really available in FLAC, 24 bit, 96 kHz:

                In Tidal tracks, available in lossless quality, are marked by “Master” label:

I want to record track in lossless quality from Amazon Music or Tidal. Will Audials save it to FLAC?

Yes, if you follow these steps:

1. Start Audials
2. Open “Music Streaming” tab
3. Click on Amazon Music or Tidal icon:

4. In Audials mini-window select max possible quality:

5. Make sure you see “FLAC” label in selected quality format description. If you see any other format – click on “Output format” button and select FLAC as output format for “High-Resolution audio”
6. If Audials asks you to start/restart player – agree to do it:

7. Now play some track, which is available in “Master” quality for Tidal or in “Ultra HD” for AmazonMusic. Audials records it:

Is the quality good enough? Is it real lossless FLAC and not some resampled/re-encoded fake FLAC created from MP3 or AAC? Is it better than MP3 or AAC?

Yes it is. But don’t just believe our words. Let’s check this recorded file using some 3d-party tools.

First of all, we’ll use MediaInfo tool (free, available at https://mediaarea.net/en/MediaInfo) to take a look at metadata of recorded file:

As you can see – recorded file has 2 channels, FLAC format, 96 kHz sampling rate and 24 bit deps – exactly like in original player, where it was played.

But this is only metadata. It doesn’t proof high audio quality, so we need more sophisticated tools. The first one we will use is Spek – Acoustic Spectrum Analyser (free, available at http://spek.cc/). This tool shows spectrogram of audio file. You can read good article about how to use it to measure quality of audio file here: https://www.deephouseamsterdam.com/this-handy-tool-checks-the-real-quality-of-your-music-files/

Shortly: lossy formats (like MP3 or AAC) cut off high and low frequencies (usually all below 20 Hz and higher 20 kHz). If FLAC file was created from such source – it will also miss these frequencies. Let’s take a look at FLAC, recorded by Audials:

As you can see – it contains all frequencies, including very low (starting from 0 kHz) and very high (up to 45 kHz).

Ok, but maybe this FLAC file was created from bad lossy input stream and encoder just added some fake audio samples, used some resample/re-encode algorithms? Let’s use another tool to check it!

Lossless Audio Checker (free, available at https://losslessaudiochecker.com/) is based on research papers (https://losslessaudiochecker.com/#researchpapers) to find tricks like upscaling, upsampling, transcoding from lossy formats. Let’s open our file in it:

As you can see, this tool also didn’t find any problems or tricks in FLAC file, recorded by Audials.

One more audio quality checking tool - Fakin' The Funk (free version with limited functionality, https://fakinthefunk.net/ ) – specially created to find fake audio files:

We tried many other similar tools and all of them say everything is ok with FLAC files, recorded by Audials. Audials can record real FLAC, in 24 bits and 96 000 Hz. It is better than MP3 or AAC files, recorded from the same source. Also it is even possible to record audio files in such high quality on hardware which doesn’t support this level of audio quality for recording or playback (in this case Audials emulates better hardware and makes player believe it is available).

Feel free to repeat our experiments with tracks, recorded by Audials on your PC!