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This is largely because MP3 is a crappy, old format. Try high-bitrate Opus on most samples and you're a lot less likely to get above-chance results on an ABX te

This is largely because MP3 is a crappy, old format. Try high-bitrate Opus on most samples and you're a lot less likely to get above-chance results on an ABX test, pretty much ever, at high bitrates. Ultimately though, lossy compression is always program-dependent ("program" here means the song, not the app). The encoders use psychoacoustic algorithms, and there is no way to prove they will perform well on all samples. So you will always be able to find corner cases where an encoder or format does worse and results in more audible artifacts; some of these might be encoder bugs, some might not. Therefore, it is fair to say that you might not want to rely on lossy compression for archival. But it is perfectly reasonable to use it to put music on devices to actually listen to. You say good mastering makes it easier to notice encoding artifacts, but actually, bad mastering can do that too. Over-compressed stuff (in dynamic range) with inter-sample peaks above 0dB can clip and distort after getting run through a lossy codec. As for lossless formats, though, anything above 48kHz 16 bits is complete nonsense for final delivery to consumers. All the "high resolution" stuff with higher sample rates and bit depths is just marketing bullshit, and this has been repeatedly demonstrated in trials (the well-designed ones anyway; there are plenty of terrible ones - no, comparing the 96kHz download to the 48kHz download of a song is not how you test this properly). Bit depths above 16 are useful during production (because quantization noise accumulates and is boosted by things like dynamic range compression); in practice you want to record at 24 bits for headroom reasons, and process in 32-bit float because there's no reason not to with modern computers (and many practical advantages, e.g. ~infinite dynamic range). Sample rates above 48kHz are less so; the main reason to use them is to avoid aliasing artifacts, but it is usually much more effective to do that with well-designed DSP algorithms that include internal oversampling, as opposed to just doing everything at a higher sample rate. Unless you're doing extreme pitch shifting; then higher sample rates may make sense. Videos everyone interested in audio production should watch: https://xiph.org/video/vid2.shtml https://xiph.org/video/vid2.shtml https://www.youtube.com/watch?v=-jCwIsT0X8M https://www.youtube.com/watch?v=-jCwIsT0X8M The little tidbit at the end of the second video about how 48kHz is, in some respects, twice as good as 44.1kHz, is quite neat and not something I'd realized before.

andybak 5y ago
MP3 with a good compressor and reasonable bitrate has repeatedly shown to be indistinguishable from uncompressed. The reason to avoid mp3 is to be able to squeeze the bitrate and save on storage bandwidth - but that has mattered less year on year. I'm personally baffled and irritated by this move from Apple. They'll be selling healing crystals next.
- marcan_42 5y ago
  > MP3 with a good compressor and reasonable bitrate has repeatedly shown to be indistinguishable from uncompressed. With most samples, yes. The issue, as I said, is that psychoacoustic codecs are basically heuristic by definition, and so you can pretty much always find counterexamples. It's possible to say 320kbps MP3 is indistinguishable from uncompressed for most samples; it is not possible to say it is indistinguishable for all samples, present and future. It's also the case that lossy encoding is a bad idea if you're going to be further processing the audio in any way; repeated transcodes definitely start bringing out the artifacts more. So lossless music is always something worth having as an option. Now, when you start talking about "high-resolution" 96/192k 24b stuff... yeah, that's just as good as healing crystals.
  - andybak 5y ago
    > it is not possible to say it is indistinguishable for all samples, present and future. Are there likely to be real-world cases where this happens - and the effect is detrimental enough to actually matter to anyone? Surely we're debating "when is it good enough for anyone sane and reasonable?" not "when could a hypothetical oracle be fooled 100%"?
    - marcan_42 5y ago
      It is useful to make the distinction, because some people do want to have the highest available quality (and this is not, inherently, a bad thing) - having a hard line that separates out the minor, but nonzero effects, from the pure snake oil, is useful. And as I said, really, the main reason to avoid lossy compression at this point is due to generational loss and post processing. Lossy compression should be considered a final processing step - what you do to store music that is then going to be delivered directly to a listener, unaltered. If you're going to do anything else, you'd do much better with a lossless version. That is not to say, of course, that if all you have is a lossy version, it is a major problem :-) For the record, my lossy format of choice for e.g. putting stuff on my phone is 96kbps Opus. Even that much is excellent for casual listening. But I much prefer to keep lossless FLACs as my primary archival storage - not just because that way I can take advantage of better compression formats as they come (e.g. how I moved from ~130k Vorbis to ~96k Opus), but also because compression makes a massive difference with certain kinds of processing and editing which I sometimes enjoy doing. All the psychoacoustics go out the window if you start doing things like subtracting instrumental mixes from full mixes to get vocal tracks out.

andybak 5y ago

MP3 with a good compressor and reasonable bitrate has repeatedly shown to be indistinguishable from uncompressed. The reason to avoid mp3 is to be able to squeeze the bitrate and save on storage bandwidth - but that has mattered less year on year. I'm personally baffled and irritated by this move from Apple. They'll be selling healing crystals next.

marcan_42 5y ago
> MP3 with a good compressor and reasonable bitrate has repeatedly shown to be indistinguishable from uncompressed. With most samples, yes. The issue, as I said, is that psychoacoustic codecs are basically heuristic by definition, and so you can pretty much always find counterexamples. It's possible to say 320kbps MP3 is indistinguishable from uncompressed for most samples; it is not possible to say it is indistinguishable for all samples, present and future. It's also the case that lossy encoding is a bad idea if you're going to be further processing the audio in any way; repeated transcodes definitely start bringing out the artifacts more. So lossless music is always something worth having as an option. Now, when you start talking about "high-resolution" 96/192k 24b stuff... yeah, that's just as good as healing crystals.
- andybak 5y ago
  > it is not possible to say it is indistinguishable for all samples, present and future. Are there likely to be real-world cases where this happens - and the effect is detrimental enough to actually matter to anyone? Surely we're debating "when is it good enough for anyone sane and reasonable?" not "when could a hypothetical oracle be fooled 100%"?
  - marcan_42 5y ago
    It is useful to make the distinction, because some people do want to have the highest available quality (and this is not, inherently, a bad thing) - having a hard line that separates out the minor, but nonzero effects, from the pure snake oil, is useful. And as I said, really, the main reason to avoid lossy compression at this point is due to generational loss and post processing. Lossy compression should be considered a final processing step - what you do to store music that is then going to be delivered directly to a listener, unaltered. If you're going to do anything else, you'd do much better with a lossless version. That is not to say, of course, that if all you have is a lossy version, it is a major problem :-) For the record, my lossy format of choice for e.g. putting stuff on my phone is 96kbps Opus. Even that much is excellent for casual listening. But I much prefer to keep lossless FLACs as my primary archival storage - not just because that way I can take advantage of better compression formats as they come (e.g. how I moved from ~130k Vorbis to ~96k Opus), but also because compression makes a massive difference with certain kinds of processing and editing which I sometimes enjoy doing. All the psychoacoustics go out the window if you start doing things like subtracting instrumental mixes from full mixes to get vocal tracks out.