Add and default to "auto" normalisation type

[roderickvd]

As discussed in #780, this adds an "auto" normalisation type, and makes it the default. This automatically picks the album or track ReplayGain values, depending on whether the current context is an album context or not.

When autoplay is enabled and the playlist is extended when an album reaches its end, then "auto" starts picking the track values until an album is put up again.

[roderickvd]

Weird that the nightly test fails, that seems totally unrelated to my changes. I'll try the CI again tomorrow.

[roderickvd]

There's one stray issue: when a song is playing from a playlist or radio, and while it's playing, that same song is played again but now from an album context, "auto" won't switch from track to album ReplayGain values until the next song. This is probably because the player does not call get_factor again when the song is already loaded. I'll look into that later, too.

[JasonLG1979]

Weird that the nightly test fails, that seems totally unrelated to my changes. I'll try the CI again tomorrow.

It's just a Error: Process completed with exit code 101. You're good.

There's one stray issue: when a song is playing from a playlist or radio, and while it's playing, that same song is played again but now from an album context, "auto" won't switch from track to album ReplayGain values until the next song. This is probably because the player does not call get_factor again when the song is already loaded. I'll look into that later, too.

Would that also mean that in that situation pausing and then playing again would would trigger the switch? If that's the case it would kinda be weird if there was a perceivable volume difference.

[roderickvd]

Would that also mean that in that situation pausing and then playing again would would trigger the switch? If that's the case it would kinda be weird if there was a perceivable volume difference.

No, it's not so much as forcing a switch, as changing the player to always call get_factor so it picks up on the right context.

[JasonLG1979]

No, it's not so much as forcing a switch, as changing the player to always call get_factor so it picks up on the right context.

As far as the audio backends are concerned there is no such thing as paused there is just start and stop. There is very little to no difference between going from nothing at the initial start up of librespot to start and going from stop to start when going from paused to play. As far as the audio backends are concerned going from play to pause to play might as well be different tracks, ofc they have no concept of tracks but you get the idea. I just want to make sure that the same is not true for the behavior of auto I would hate in your example edge case for the gain to change if play/pause was toggled.

[roderickvd]

This should do it.

@JasonLG1979 yes that would be terrible. For sure that cannot happen with this PR. The player is instructed to pick track or album ReplayGain if the context changes (i.e. album, playlist, artist, track). When you pause-unpause, you stay within the same context, and so the gain cannot change.

A bit of testing would be welcome before I merge this one. Be on the lookout for verbose messages like the following.

Playing a track from a radio or playlist:

[2021-09-05T20:49:14Z DEBUG librespot_playback::player] command=SetAutoNormaliseAsAlbum(false)
[2021-09-05T20:49:14Z INFO  librespot_playback::player] Loading <Don’t You Get the Feeling (You’ve Been Had)> with Spotify URI <spotify:track:5YCZA6n6ppuD6XT7cDCYLa>
[2021-09-05T20:49:14Z DEBUG librespot_playback::player] Normalisation Data: NormalisationData { track_gain_db: -8.870003, track_peak: 1.1344055, album_gain_db: -7.25, album_peak: 1.1367749 }
[2021-09-05T20:49:14Z DEBUG librespot_playback::player] Calculated Normalisation Factor for Track: 12.78%

Then playing the same song but now from its album:

[2021-09-05T20:50:34Z DEBUG librespot_playback::player] command=SetAutoNormaliseAsAlbum(true)
[2021-09-05T20:50:34Z DEBUG librespot_playback::player] Normalisation Data: NormalisationData { track_gain_db: -8.870003, track_peak: 1.1344055, album_gain_db: -7.25, album_peak: 1.1367749 }
[2021-09-05T20:50:34Z DEBUG librespot_playback::player] Calculated Normalisation Factor for Album: 15.40%

Or any other order of events.

[roderickvd]

Anyone been able to take this for a spin?

[JasonLG1979]

Anyone been able to take this for a spin?

I've been running it since 5b63ef6. I haven't really been reading debug logs but I haven't noticed anything that struck me as off or ran into any obvious bugs that I can tell. I'd say my quick take is that so far it seems to work fine. I will more actively listen and monitor logs tomorrow for a bit.

[roderickvd]

I'll leave this up here over the weekend, then merge it if there are no more issues.

[JasonLG1979]

Pull the trigger with this and everything else you want in 0.3 and then I'll fix any conflicts in #820 and you can merge it and then 0.3 will be good to go I think right?

[roderickvd]

Pull the trigger with this and everything else you want in 0.3 and then I'll fix any conflicts in #820 and you can merge it and then 0.3 will be good to go I think right?

Done and agreed. And what an exciting release it will be!