Missing audio index normalization in audio device open functions

[nanang]

Audio device open APIs, as described in the specifications, treat any negative device ID value indifferently, i.e: as default or first available device. However, some new audio device APIs differentiate -1 and -2 as PJMEDIA_AUD_DEFAULT_CAPTURE_DEV and PJMEDIA_AUD_DEFAULT_PLAYBACK_DEV, such as pjmedia_aud_dev_default_param().

Unfortunately some device open API implementations are currently not normalizing the negative audio index before calling pjmedia_aud_dev_default_param(). So for example, on a system without input device, calling pjmedia_snd_port_create_player() with device index param set to -1 (=PJMEDIA_AUD_DEFAULT_CAPTURE_DEV) will return error PJMEDIA_EAUD_NODEFDEV.

Thanks Daljeet Singh for the report.

[nanang]

In 5140:

Fix #1871: fixed missing audio index normalization in audio device open functions.