Flint

PC companion for the Sony NW-A50-series Walkman and Cinder. Copies your library to the player, adds Sony's SensMe mood and tempo data to the copies, and syncs scrobbles and liked songs with Last.fm. It never modifies the files on your PC.

Status: usable, still young. Latest release: v0.2.3 (Windows and Linux, SHA-256 sums and build attestations on the release page). main may be ahead; see Unreleased in CHANGELOG.md. Replaces the Python Sony-sync tool.

Getting started

1. From Releases, download flint-windows-x64.exe. It is the only file you need.
2. Connect the Walkman as a USB drive and run flint-windows-x64.exe.
3. On Sync, pick your music folder and the player's drive (and its card, if any).
4. Press Show what would happen. Nothing is written yet.
5. Press Copy to the player.

Everything the window does is also a command, and every command has its place in the window (a test keeps the two in step): run the same file from a terminal with a command after it (Linux: flint-linux-x64). At a cmd prompt, start /wait flint-windows-x64.exe ... makes the prompt wait for it.

SensMe

The Walkman builds SensMe channels from an analysis tag in each file. Sony's Music Center writes that tag into your PC files, which can grow each one by close to a megabyte. Flint instead:

• runs Sony's own engine (MMLib11.dll, installed with Music Center for PC) once per track and caches the result, about 6 KB each;
• writes it only into the copy on the Walkman, in the same containers Sony uses (FLAC SMFM block, MP3 GEOB frame).

The player's own scanner does the rest, so it works on stock firmware as well as Cinder. Flint does not ship Sony's engine: SensMe analysis needs Music Center installed on the same PC. Nothing else in Flint does.

Already using Music Center? Tags already in your files are used as-is, and flint import reads Music Center's own analysis cache (read-only). Either way the Walkman copy carries only the ~6 KB the player reads. Full comparison: docs/MUSIC_CENTER.md.

The window

Page	What it does
Sync	Plans the copy (what's added, removed, tagged, and whether it fits), then copies. Use at most … GB on a drive keeps room free on it.
On the player	Lists what's on each drive and whether Flint put it there, with the ratings and play counts the player keeps. Takes playlists you changed on the player back to the PC. Backup steps through the copies of the player's playlists, likes and settings that Flint takes on each read, and Put back restores one.
Check	Finds FLACs that aren't really lossless, and tags that would look wrong on the player. Click a verdict (or OK, for the clean files) or type to filter.
SensMe	Analyses the library, or imports Music Center's results (Music Center folder… when Flint can't find it). Fetch lyrics gets synced lyrics from LRCLIB.
Likes & plays	Sends scrobbles to Last.fm and syncs liked songs (optionally as a Liked Songs playlist too). Fill in play counts gives tracks the player never counted their plays from the scrobble log.
Palettes	Makes Cinder colour palettes, checks them with Cinder's own rules and sends the ones that pass. Shared palettes lists everything in cinder-themes: search it, see each one by day and night, and install one onto the player in one click.
Settings	Theme, folders, the analysis cache, Last.fm key and sign-in.

Only Sync writes music, and Copy is only offered for a plan you've just seen. Changing a setting withdraws it until you look again. Each drive shows a bar: used, this copy, free.

Jobs run side by side, so a long analysis doesn't lock the window. Two jobs wait for each other only if they share something (the cache, the player, Last.fm), and a greyed button says what it's waiting for. Planning and copying wait for a running analysis, since the copies carry its results.

The theme follows Windows' light/dark setting unless you pick one in Settings (or run flint gui --light / --dark).

The window is drawn with no UI toolkit. Its layout is plain Rust, so the pictures here are rendered by Flint itself:

flint gui-preview window.svg --state planned     # fresh, ready, working, done, scanning
flint gui-preview window-dark.svg --state planned --dark
flint gui-preview check.svg --state check        # filtered, player, sensme, likes, palettes, palette-new, palette-shop, settings, signed-in

Copying a library

flint scan "D:\\Music"                                                    analyse once
flint sync "D:\\Music" --to E:\\ --to F:\\ --playlists "D:\\Playlists"          dry run
flint sync "D:\\Music" --to E:\\ --to F:\\ --playlists "D:\\Playlists" --apply  copy

• The music goes into the drive's MUSIC folder when it has one, which is where a Walkman looks. The plan names the folder it will write to and sweep.
• A sync removes only what Flint put there. Anything else in that folder is listed as kept; tick it in the window, or add --also-remove <folder> ('*' for all), to remove it with the copy.
• An album is the folder that holds the music, with any CD1/Disc 2 folders in it. Albums move as a unit and are never split between internal memory and the card. Albums that share a playlist stay on the same volume, and an album already on a volume stays there.
• The same recording on two albums (an album and a best-of, a single and its album) is found by its audio. Tick it in the window, or answer flint shared "D:\\Music" --yes N, and the sync copies it once. Cinder lists it under both albums from flint-shared.tsv. Sony's player shows the kept copy; Swap in the window (or --keep-other N) keeps the other one.
• --playlists reads .m3u, .m3u8 and MusicBee .mbp files; each reaches the player as an .m3u8.
• Each volume is filled to its free space minus 0.5 GB; --gb N sets a budget instead. --no-sensme copies without tagging.
• Cover art and lyrics (.jpg, .png, .lrc) in an album folder are copied with it; --no-extras leaves them on the PC. Flint never deletes artwork it didn't put there.
• flint lyrics "D:\\Music" --apply asks LRCLIB for synced lyrics for each track that has none to show as they are sung, and writes Song.lrc beside Song.flac in the library, where Cinder and MusicBee look and where the next sync picks it up. It never replaces a .lrc, skips tracks whose tags already hold synced lyrics, and remembers the tracks LRCLIB does not know so the next run does not ask again. Without --apply it only counts them. In the window: SensMe ▸ Fetch lyrics.
• Copies are written to a temp file and renamed, so an interrupted copy leaves the old file or the new one, never half of one. flint-manifest.tsv on each volume records what each copy came from.

Scrobbles and liked songs

The Walkman has no network, so it writes files and Flint carries them.

In the window: Settings ▸ Last.fm. Get a key on last.fm opens the page that makes an API key (any app name, no callback URL). Paste the key and secret, Save, then Sign in with Last.fm and approve in your browser. Flint never sees your password. Then use Likes & plays.

From a terminal:

flint lastfm key <api-key> <api-secret>     once — https://www.last.fm/api/account/create
flint lastfm login <your-username>          once — exchanges the password for a session key
flint lastfm status

flint scrobble E:\                          show what would be sent
flint scrobble E:\ --apply                  send it

flint likes E:\ F:\                         show what would change, both ways
flint likes E:\ F:\ --apply --playlist      apply, and write Liked Songs.m3u8
flint likes E:\ --way player               only Last.fm's changes, onto the player (or --way lastfm)
flint likes E:\ --add-only                 add likes, never remove one
flint likes E:\ --apply --leave 2          make every change except removal 2 of the list

Scrobbles. Cinder writes an Audioscrobbler .scrobbler.log at the root of the player. Flint sends the plays in batches of 50 and removes only the rows Last.fm accepted. Rejected or unreadable rows stay, with the reason printed. The player's clock has no time zone, so the log says #TZ/UNKNOWN and Flint converts each time to UTC with this PC's time zone before sending it.

Liked songs. Cinder exports cinder_loved.tsv and reads cinder_liked_import.tsv. flint likes syncs these with your Last.fm loved tracks in both directions. It remembers the last state of each side (likes-state.tsv) so it can tell an unlike from a new like:

• the first run only adds, never removes;
• a player that isn't connected causes no removals;
• a track changed on both sides keeps the like.

A run can go one way only (To the player or To Last.fm in the window). The side it doesn't write keeps what it has, and its changes wait for the next run that does. Only add, never remove stops every removal. Each removal in a comparison is listed and ticked; untick one, or use --leave N, to leave that like where it is this run.

Tracks match on artist and title, ignoring case, feat. credits and remaster/edition suffixes. Live, remix, acoustic and demo versions stay separate. --playlist also writes Liked Songs.m3u8 per volume (off by default: it reads every file's tags over USB).

Network calls use the OS's own TLS (WinHTTP on Windows). Only a session key is stored, in lastfm.conf; revoke it at last.fm/settings/applications.

Ratings, play counts and the player's own playlists

Cinder keeps three things on the player that Sony's database has no place for: star ratings and play counts (cinder_stats.tsv), smart playlists (cinder_views.conf) and the playlists you make on the player (cinder_playlists). A sync never removes any of them.

Health. On the player also shows what Cinder's own files on the drive say about the last start (version, firmware, library size, system space), and Copy a report puts that with the end of the player's logs on the clipboard, for an issue.

A copy on the PC. Each time the window reads the player, it copies what the player keeps for itself (those three, the likes, the settings, the palettes and .scrobbler.log) into backups in Flint's data folder, unless nothing has changed since the last copy. The newest 20 are kept. After a reset or a format, flint restore E:\ lists them and flint restore E:\ "<name>" --apply puts one back; it copies the player as it is first, so the restore can be undone. flint backup E:\ takes a copy by hand.

In the window, On the player shows each album's stars and plays, and counts the rated tracks, the smart playlists and the playlists made on the player. The log names each one.

flint stats E:\ --to F:\                     show ratings, counts and smart playlists
flint stats E:\ --to F:\ --apply             seed play counts, and move history with moved albums

flint playlists E:\                          list the playlists made on the player
flint playlists E:\ --to "D:\Playlists\From the player" --library "D:\Music" --apply

Ratings follow their files. The player keeps a rating under the file's path. When a sync moves an album between internal memory and the card, its ratings and play counts move with it; the window and flint sync --apply do this at the end of every copy. A track that is on neither drive keeps its row, so its rating returns if the album does. With the card out, nothing is moved.

Play counts from history. flint stats --apply gives tracks the player has never counted their plays from .scrobbler.log. A count or rating the player already has is never changed.

Playlists changed on the player. Cinder marks a playlist it has changed as EDITED until a PC has taken it. Take playlists back (or flint playlists --to) writes each changed playlist to the PC, naming the files in your music folder so any player can open it, and only then takes the mark off. The window puts them in From the player inside your playlists folder; a sync does not send that folder back, so the player does not end up with two copies. A file of the same name already on the PC that differs is kept beside the new one as .bak.

Checking for fake FLACs

flint check flags FLACs that aren't the lossless audio they claim to be. Needs FFmpeg only.

flint check "D:\Music"            every FLAC under a folder
flint check track.flac --verbose  one file, with its spectrum

Verdict	Meaning
LOSSY	Audio cuts off at a lossy encoder's lowpass
SUSPECT	Cuts off between 19.5 and 21 kHz: a high-bitrate encode, or just the master
UPSAMPLED	88.2 kHz or higher with nothing above CD/DAT bandwidth
PADDED	24-bit file using only 16 bits
DAMAGED	FFmpeg reported decode errors

Tested on transcodes of four albums: MP3 128 and 320, Opus 160, upsampled and bit-padded copies were all caught; Vorbis q6 1 of 4; LAME V0 and AAC 256 none (they keep content up to ~22 kHz). No originals were flagged. A clean result isn't proof, and SUSPECT isn't an accusation. Results are cached by audio content, so moved or retagged files aren't decoded again.

Tags. The same check, and flint lint "D:\\Music", reads every FLAC's and MP3's tags and lists what would look wrong on the player: an album folder that would show as several albums (a compilation with no album artist, or files that disagree), tracks with no number, and files with no artist or title. Fix them in your tagger before the copy.

Layout

Crate	Contents
flint-core	FLAC/ID3v2 read and write, the SensMe chunk format, decode → engine pipeline, Music Center import
flint	The program: the window with no arguments, the command line with a command
flint-gui	The window: layout in plain Rust, painted with GDI on Windows or written as SVG anywhere
sensme-helper	32-bit Windows helper that loads Sony's 32-bit engine

Building

cargo test
cargo build --release --target i686-pc-windows-gnu -p sensme-helper
FLINT_HELPER_EXE=$PWD/target/i686-pc-windows-gnu/release/sensme-helper.exe \
    cargo build --release --target x86_64-pc-windows-gnu -p flint --features embed-helper

Without --features embed-helper, Flint looks for sensme-helper.exe beside itself.

Both Windows targets cross-compile from Linux with mingw-w64.

Releasing

tools/release.sh v0.2.0 --dry-run     show what would change
tools/release.sh v0.2.0               1st run: prepare, then commit the diff it lists
tools/release.sh v0.2.0               2nd run: push, tag, wait for CI, print the release page

The first run bumps the version, moves Unreleased in CHANGELOG.md into the new version (that section becomes the release notes), updates the README link, redraws the window pictures and runs every gate. It never commits. A tag with a suffix (v0.2.0-rc1) publishes as a pre-release.

Licence

MIT. Sony's engine is not part of this repository and is not redistributed.