Handling data sparsity via item metadata embedding into deep collaborative recommender system

75% of what people are watching on Netflix comes from recommendations

Lossless audio files use a type of compression that keeps 100% of the original audio information intact. If you wanted to convert your CD collection into files that sound exactly the same but take up less storage space, lossless files are the way to go. FLAC and ALAC are both examples of lossless audio file formats.

Lossless audio can also be used to preserve 100% of the information in a hi-res audio source like SACD or DVD-Audio (or music that is mastered in the studio at hi-res bit-depths and sample rates).

If you want to make sure you’re listening to hi-res lossless audio (as opposed to CD-quality lossless audio), you need to look for a badge or other indicator on a track that clearly designates it as “hi-res” or “hi-res lossless.”

No. Even though all hi-res tracks have a higher resolution than CD-quality tracks, there are still different levels. The most common hi-res combination is 24-bit/96kHz, but it’s possible to find hi-res files that go as high as 32-bit/384kHz.

As a lossy format, MP3s technically don’t have either fixed bit-depths or sample rates. But they do have a maximum bit-rate of 320 kilobits per second (kbps), which can’t preserve all of the information in a CD audio track, so there would be no point in trying to use them for hi-res audio, which contains even more info. As a result, hi-res audio is usually compressed losslessly.

MQA (Master Quality Authenticated) is a proprietary digital audio format that is capable of reproducing 24-bit/96kHz audio and thus it qualifies as hi-res audio. It’s also the format of choice for Tidal’s top-tier Masters tracks. However, there is some controversy within the audiophile community around MQA because, technically, it is not a lossless format. It also requires dedicated hardware to be able to hear it at its highest quality. Those who believe that true hi-res audio can only be delivered using lossless formats feel that MQA is inferior.

If you’re a vinyl lover, you can convert your albums and singles into hi-res audio files, though this may be overkill. Hi-res files tend to be larger than CD-quality files, and there’s no evidence to suggest that a hi-res file will capture more info from your records than CD-quality.

Speaking of CDs, these audio tracks cannot be improved by using hi-res. You’ll only end up with a much larger file at exactly the same quality. Stick with a 16-bit/44.1kHz lossless file if you intend on ripping your CDs.

Playing any digital audio is comprised of two steps: a decoding step, where the hi-res file or stream in question is turned into a format known as pulse-coded-modulation (PCM), and a digital-to-analog (DAC) step where the PCM signal is turned into an analog signal your speakers or headphones can actually play.

A hi-res digital audio player like the SR35 from Astell&Kern can play virtually every hi-res audio format in the world, whether it’s saved on your computer or streamed from Apple Music. Just plug in a set of headphones and you’re good to go.

Another example is a recent Sonos speaker like the Era 100. It does it all too, though Sonos limits its hi-res support to 24-bit/48kHz, so those who want to explore higher sample rates will have to look elsewhere.

What Is Lossless Music? The term "lossless" was essentially created to be a foil — or to mean the opposite — of "compressed" or "lossy"; these are digital music files that have had a lot of their details, specifically their high and low frequencies, stripped away in order to save space on your smartphone or computer.

The term "lossless" doesn't mean uncompressed, however, but it refers to a type of compressed digital audio file that uses advanced data compression algorithms so that the audio track doesn't "lose" any detail in the compression process.

For context, the average size of a compressed audio file, like a MP3 or a AAC, is about 1/4 the size of its original recording. The average size of a lossless compressed audio file, such as FLAC or ALAC (Apple Lossless), is now a little more than 1/2 the size of its original recording.

When somebody refers to a "lossless" track, they typically mean that it's the same quality as a CD or vinyl record (16-bit/44.1 kHz). This was the highest resolution audio that many lossless streaming services (like Tidal, Deezer and Qobuz) offered for years, but many of them now offer ever higher resolution audio files, which are also a type of lossless music.

For example, Tidal gives its HiFi subscribers the option of listening to Master Quality Authenticated (MQA) certified tracks (up to 24bit/96kHz), while Amazon Music HD gives its subscribers the ability to listen to "Ultra HD" (up to 24-bit/192kHz).

Max resolution: Every lossless streaming service is capable of streaming CD quality (16-bit/44.1 kHz) audio, but that's really the bare minimum requirement. A lot of lossless streaming services now offer significantly higher-resolution tracks that are Master Quality Authenticated (MQA, up to 24bit/96kHz) or "Ultra HD" (up to 24-bit/192kHz).

Price: When Apple released a lossless tier of Apple Music at no extra cost, it definitely disrupted the existing lossless streaming market. In fact, every one of them was forced to lower its base price from between $15 —$20 to around $10 (which is the cost of Apple Music). However, most lossless streaming services charge more than $10 for lossless streaming, that's higher than CD quality. These more premium plans also can great you access to more features, like live concerts and discounts if you want to purchase certain lossless tracks.

As a premium user of Pandora, if you listen to music for 1h, you will use 86.4mb per hour

Another monster sneaking on your data… The iHeartRadio music streaming service offers a 128kbps bitrate option. That’s the only option. That equals to 57.6mb. Just like in the case of Pandora.