Browser refuses a copy that needs ffmpeg when ffmpeg is missing #6

New issue

Open

opened 2026-08-25 22:20:20 +02:00 by wokoman · 0 comments

wokoman commented

2026-08-25 22:20:20 +02:00

(Migrated from code.nolog.cz)

What to build

The browser refuses a copy that cannot possibly succeed, instead of starting it and failing file by file.

Mark a folder of FLACs on a machine without ffmpeg and press c, and the copy begins, converts nothing, and reports every file as failed. The command line does not behave this way: it checks up front whether any file in the batch needs converting, and if ffmpeg is missing it refuses before opening the device, with a message naming the fix. The browser should do the same.

Same class of divergence as #5 — a batch-level policy living in one caller instead of behind the seam that owns the batch — but in the copy direction, and independent of it.

Acceptance criteria

Marking files that need converting and starting a copy without ffmpeg installed fails immediately, before any file is touched
The message names what is wrong and both ways out: install ffmpeg, or turn transcoding off in the config
A copy where nothing needs converting is unaffected when ffmpeg is absent
The command line's behaviour is unchanged
The check lives in one place rather than being duplicated into a second caller
cargo clippy --all-targets clean; full suite passes

Blocked by

None — can start immediately.

## What to build The browser refuses a copy that cannot possibly succeed, instead of starting it and failing file by file. Mark a folder of FLACs on a machine without ffmpeg and press `c`, and the copy begins, converts nothing, and reports every file as failed. The command line does not behave this way: it checks up front whether any file in the batch needs converting, and if ffmpeg is missing it refuses before opening the device, with a message naming the fix. The browser should do the same. Same class of divergence as #5 — a batch-level policy living in one caller instead of behind the seam that owns the batch — but in the copy direction, and independent of it. ## Acceptance criteria - [ ] Marking files that need converting and starting a copy without ffmpeg installed fails immediately, before any file is touched - [ ] The message names what is wrong and both ways out: install ffmpeg, or turn transcoding off in the config - [ ] A copy where nothing needs converting is unaffected when ffmpeg is absent - [ ] The command line's behaviour is unchanged - [ ] The check lives in one place rather than being duplicated into a second caller - [ ] `cargo clippy --all-targets` clean; full suite passes ## Blocked by - None — can start immediately.