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1-bit 1.4, the one that goes in the car

1-bit 1.4 is on the App Store. CarPlay browse + Now Playing on the head unit, offline downloads, an in-app log viewer, and an optional DSD-domain DSP chain. Bridge 0.1.4 ships alongside with public-mode hosting and CarPlay-optimized variants. Same bit-exact DSD over DoP, no transcoding.

Updated

  • 1-bit
  • iOS
  • DSD
  • audio
  • release

1-bit 1.4 is on the App Store. Same URL, new build, free update.

Last release I shipped a codename that lied about the version. This time I went the other way. Open Settings → About in 1.4, tap the easter-egg card, and instead of a single-line codename you get a small poem: “One hundred three commits deep, while the tired engineers sleep. Offline downloads finally stand, CarPlay grids across the land. Tap the text and clear the view, version 1.4 is ready for you.” The two main features are right there in the verse, so I’ll keep the writeup short.

What’s new

CarPlayBrowse, search, tap-to-play, and a Now Playing view on a CarPlay head unit — reading the same on-device library that’s on your phone. Uses Apple’s CarPlay Audio entitlement, so it’s a real CarPlay app, not a screen mirror. DSD is hidden from CarPlay because DoP markers can’t survive head-unit playback; everything else plays.
Offline downloadsPick a track, an album, a playlist, save it to the iPhone. Files live in app-private storage, are hidden from Files, and are excluded from iCloud backup (so they don’t quietly fill your iCloud quota). Delete the download, delete the share, or uninstall the app — they’re gone.
Diagnostic logs in SettingsA rolling buffer of recent log lines lives at Settings → Logs. The logs stay on the device. A Share button is there for the rare case I ask you to send them — never automatic, never on by default.
DSD-domain DSP (Beta)An optional on-device chain — decimator, sigma-delta modulator, volume stage — that stays in the DSD domain instead of converting to PCM first. Off by default. Beta because thermal headroom on older iPhones can still surface the odd crackle, and I’d rather call that out than pretend it’s settled.

And on the bridge side

Bridge 0.1.4 ships alongside — 44 commits since 0.1.3, wire protocol unchanged at v1.

Two big themes. Public-mode hosting: bridge init —public spins up a bridge intended for a small VPS, with native Let’s Encrypt provisioning via autocert, a single-user admin auth layer, and an endpoints filter so the public listener only exposes /v1/health and the /v1/share/… family. CarPlay-optimized variants: a new optimize-… variant class and a two-channel priority queue so on-demand CarPlay transcodes don’t sit behind a lifetime Upscale backlog. Plus a tile-grid Library Inspector, a Prometheus /metrics endpoint on the admin listener, and a background orphan-sidecar GC sweeper. Full release notes on the bridge releases page.

What got refined

A small carve-out in the iOS pinning policy: bridges deployed with a custom domain and a public Let’s Encrypt cert are now ATS-trusted, while LAN, Tailscale-magic-DNS, IP-literal, and mDNS hosts still pin against the fingerprint captured at pairing. The shape of what the app sends — paths, byte ranges, MusicBrainz IDs — is identical. The Settings screen got an IA pass to make room for the v1.4 surfaces. The deployment target is now iOS 26.1. The unfiltered changelog is in the pull requests on the 1-bit repo.

Same audio path

No transcoding. No resampling. No mixer in the path. DSD goes out as DoP to your USB DAC; PCM goes out at the file’s native sample rate. The phone moves bytes; the DAC does the DAC’s job. How DSD playback is handled →

The unromantic version

If you have 1-bit installed: open the App Store and tap update. Your existing SMB shares, bridge pairings, and Settings carry over. Offline downloads, the DSP chain, and the log viewer are all off by default — you turn them on only if and when you want them. CarPlay shows up the moment you plug into a head unit.

If you’re new: it’s a free download, iPhone or iPad, iOS 26.1 or later. Bring a NAS or a bridge, a USB DAC for DSD, and music you actually like.

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