PipeWire backend was using generic OutputStream::try_from_device() which
lets PipeWire decide the sample rate, causing resampling even when
DAC Passthrough is enabled.
Now uses OutputStream::try_from_device_config() with custom StreamConfig
that forces the exact sample rate requested (e.g. 192kHz), just like
the legacy CPAL path.
Changes:
- Import CPAL config types (StreamConfig, SampleRate, etc.)
- Create StreamConfig with requested sample_rate and channels
- Use try_from_device_config() instead of try_from_device()
- Verify device supports the configuration
- Support exclusive mode with lower buffer size (512 samples)
This ensures bit-perfect playback:
- 192kHz track -> 192kHz hardware output
- 44.1kHz track -> 44.1kHz hardware output
- No resampling by PipeWire
vicrodh
e934894b6e