What's the benefit of learning to play faster than you need to? I understand wanting to play slower, but why faster?
You want to play within your abilities, not right at the very edge of them. This technique nudges the edges out.
Fair enough. Never heard this technique before. Note that such a technique wouldn't translate to other skills like dancing, singing, sawing a piece of wood. Doing those things faster I can't imagine would be of any help in improving how you do them at normal speed.
I imagine the lossy encoding process could use a bunch of stacked filters to cut away imperceptible frequencies, but filters in the general case are implemented by summing delayed copies of the input and can smear the output in the phase domain. (There’s a branch of filters that avoid this but require computing the introduced delay and shifting the output to compensate.) It’s a noticeable problem in audio production…
Is it possible to run the recorded input through the filters twice, doing the second pass in reverse to cancel out the phase shift?
Yeah, I think that’s traditionally the route when you’re not running with near-real-time constraints. I’m out of practice with DSP/filter math but I think there’s a constraint such that any theoretical filter that doesn’t impact phase must be symmetrical around the time axis such that it requires “knowledge from the future” that’s not available in real time.
EDIT: And I think with the two-pass approach you need to calculate the filter such that you get the desired effect after two applications instead of one.
Where did you hear this from? For the vast majority, Apple Music gets the same masters as sent to every other service.
They describe the entire program in detail here: https://www.apple.com/apple-music/apple-digital-masters/docs... Even if receiving the same sources, the encoding process is their own and aims to have zero clipping.
Yeah, the ADM certified stuff, as far as I know, is a small percentage of the music on there. The distributors I've worked with don't let you have a separate Apple Music version in the same release (a lot of them don't even let you pick which stores it goes to, it's just bulk submit everywhere), so it's extra work and/or cost to make an AM specific version. And only the top mastering talent seem to be ADM certified- I don't see many advertising it (some do). I figure if an ADM master is made, that one is submitted everywhere, but it's really a minority of the releases. Most of them maybe conform to it by happenstance by way of just making a nice sounding master, but I'm not aware of Apple rejecting loud releases, for example. You can submit a song mastered at +6 LUFS but they will just turn it down when someone plays it.
At 1080p60, YouTube uses 12Mbps, and 251Kbps Opus or 192Kbps AAC. That's a factor 50 smaller. Insignificant.
> At 1080p60, YouTube uses 12Mbps It does not. That's a recommended bitrate for a live streamer (Streamer -> youtube). Coming out of youtube, the numbers are quiet different. For example, a random 4k video I just pulled had a video bitrate of 4.5Mbps. A 720p video I pulled of a talking head had a 369kbps video stream. That is to say, a podcast style video is likely to have a nearly 50:50 split on audio/video.
But now you're comparing median video bitstream with peak audio bitstream.
YouTube uses variable bitrate for audio, which can vary dramatically in size. Your example of podcasts or "talking heads" is actually perfect. Most encoders are extremely efficient at compressing voices, as they will only have to encode 30-300Hz, and voices have less data variation than images.
Image encoding is just very complex. It'll get better and better, but audio encoders of the same generation will also improve.
There's no "end-to-end drm" for audio. Any audio can be captured near losslessly by plugging in a USB-C to 3.5mm adapter, and a sound card on the other end. There's also no HDCP-like mechanism for sound, so if you're willing to put the work into it, you could make a fake USB DAC that produces a bit perfect capture of the audio output.
Just use DAC with S/PDIF output, and another one with S/PDIF input. Well, either way it's hard enough to block casual users, so... it works