Fix DAB+ audio sample rate issues using ffmpeg resampling #419
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Hi folks - I was frustrated at the inabilyt to listen to 32k (and other non-48kHz DAB stations (the majority of DAB+ stations).
I fixed my local system and figure i would share the solution as a PR incase it is of wider value.
Description
This PR addresses an issue where DAB+ audio streams with sample rates other than 48kHz (common with 32kHz DAB+ broadcasts) would play at the incorrect speed ("chipmunk effect") in the web client, as OpenWebRX expects a consistent 48kHz input.
Changes
Pipeline Update (owrx/dab/dablin.py): Modified the dablin command execution to pipe its output through ffmpeg. This forces an explicit resample to 48kHz (f32le) before passing the data to the OpenWebRX audio chain.
Dependencies (docker/scripts/install-dependencies.sh): Added sox to the dependency list (useful for audio debugging/transcoding) and relies on ffmpeg for the runtime pipeline (which is typically available or easily added).
Evaluation
Verified on a Docker deployment (Raspberry Pi / ARM64). Stations that previously played with speed artifacts now play correctly.
Related Issues
Fixes audio synchronization for non-48kHz DAB stations.