If the application doesn't specify the audio format when opening the device, this hint can be used to
specify a default format that will be used.
The variable can be set to the following values:
• "U8": Unsigned 8-bit audio
• "S8": Signed 8-bit audio
• "S16LE": Signed 16-bit little-endian audio
• "S16BE": Signed 16-bit big-endian audio
• "S16": Signed 16-bit native-endian audio (default)
• "S32LE": Signed 32-bit little-endian audio
• "S32BE": Signed 32-bit big-endian audio
• "S32": Signed 32-bit native-endian audio
• "F32LE": Floating point little-endian audio
• "F32BE": Floating point big-endian audio
• "F32": Floating point native-endian audio
This hint should be set before an audio device is opened.