Request support for 24-bit audio samples

[jrush]

Professional audio equipment often comes with 24-bit audio samples and several -only- support 24-bit samples. ALSA has support for 24-bit but PulseAudio does not, instead relying upon plughw to auto-convert everything to 16-bits. This conversion however loses information and use of this tradeoff seems odd given that much of PulseAudio is designed to maintain the quality of the audio signal.

[tanuk]

It's not entirely true that PulseAudio doesn't support 24-bit samples - many (most?) cards that use 24-bit samples, are supposed to be opened in 32-bit mode, and that format PulseAudio does support properly. What card do you have that can't be opened in 32-bit mode?

[jrush]

I'm using an Alesis io|2, which is a USB device that lets you plug into it various professional audio equipment using 1/4" jacks and XLR mic inputs.

The manufacturer's photo and description are at:

http://www.alesis.com/io2

[lennart]

jrush: are you sure your device supports only 24bit-packed samples? I'd assume it actually supports 32bit-samples but only takes the uppermost 24bits into account. PA supports 32bit perfectly and has been for a while. That should be all you need then.

[sladi]

The Creative X-Fi Extrememusic won't support any of the float32 formats either. I tried with the beta2 drivers from Creative on Debian Lenny AMD64. The hardware does support 24bit though.

[ronalde]

In #930 it is explained why pulseaudio defaults to resampling everything to a default format.