NAME utaudio - connect to Sun Ray audio services SYNOPSIS /opt/SUNWut/bin/utaudio csh setenv AUDIODEV `utaudio` ksh export AUDIODEV=`utaudio` sh AUDIODEV=`utaudio`;export AUDIODEV DESCRIPTION utaudio enables standard Solaris audio services using the utadem(7D) audio device emulator driver. After connecting to a Sun Ray session, utadem(7D) is asked to create a new audio device. From this device, utaudio creates device files in the /tmp/SUNWut/dev directory. It then echoes the root dev- ice name to standard output, for the purposes of setting the AUDIODEV environment variable. Standard audio applications can then open the new audio pseudo-device and perform audio play and record operations. APPLICATION PROGRAM INTERFACE Applications that use the /dev/audio interface may open the device pointed to by the AUDIODEV environment variable and use the AUDIO_GETDEV ioctl to determine which audio device is being used. The utaudio driver will return the string "SUNW,CS4231" in the name field of the audio_device struc- ture to indicate compatibility with other Ultra platforms. The version field will contain "a" and the config field will contain "pseudo." The AUDIO_SETINFO ioctl controls device configuration param- eters. When an application modifies the record.buffer_size field using the AUDIO_SETINFO ioctl, the daemon will con- strain it to be non-zero and up to a maximum of 8180 bytes. Audio Data Formats The utaudio daemon supports u-law and A-law with 8-bit precision, or 16-bit linear PCM at any sample rate from 8000 Hz to 48 kHz for one or two channels. The Sun Ray standard for sampling rate is 48 kHz, so using that rate will yield the best quality. The input and output data formats for playing and recording do not have to match. Some input devices do not support 2- channel capture, but two channels will be reproduced by duplication in the case where two channels are requested and the device supports only one. Audio Ports The record.avail_ports and play.avail_ports fields of the audio_info structure report the available input and output ports for the currently connected Sun Ray appliance. Currently only AUDIO_MICROPHONE and AUDIO_LINE_IN are supported, and most devices will have both inputs. The Sun Ray audio model supports individual volume controls for the two, so it is pos- sible that the volume setting will change with input changes. This has the feature of always maintaining the correct level for each input. For output, AUDIO_LINE_OUT is always selected and does not have variable gain. AUDIO_SPEAKER and AUDIO_HEADPHONE are supported normally, and they share a level control, but in general, comfortable settings for the speaker will also be comfortable for headphone use. Either one or both outputs can be selected simul- taneously. The Sun Ray specification supports a third, automatic switching mode that can be accessed by deselecting both speaker and headphone, or by select- ing only line out. The utsettings(1) command may also be used to control the device's outputs. In automatic mode, the settings track the physical connection of the headphone. EXIT STATUS The following exit values are returned: 0 Normal completion -- daemon back grounded 1 Either the X11 server, or the session could not be contacted, or there was a problem creating the new pseudo audio device. ENVIRONMENT utaudio requires that the DISPLAY environment variable be set to an X11(7) display to which the user has access to rendezvous with the Sun Ray session. This is usually set-up automatically in the Sun Ray environment. An alternate driver emulator, or different unit number can be specified in the UT_ADEM environment variable. The results of utaudio should be placed in the AUDIODEV environment variable. FILES The following files are used: /tmp/SUNWut/dev/utaudio/<n> numbered audio data pseudo-device file nodes /tmp/SUNWut/dev/utaudio/<n>ctl matching control pseudo-device file nodes ATTRIBUTES See attributes(5) for descriptions of the following attri- butes: ____________________________________________________________ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | | Architecture | SPARC | | Availability | SUNWuto | |_____________________________|_____________________________| SEE ALSO utsettings(1), X11(7), utadem(7D), audio(7I), steamio(7I), ioctl(2), priocntl(2), attributes(5), environ(5) NOTES The audio(7I) interface does not have an interface for dynamically changing audio devices such as that offered by Sun Ray. It is not possible to track the comings and goings of sessions, or changes in audio hardware using this device interface. The utaudio daemon makes a best-effort attempt to report changes in device control ability and to make the device appear as flexible as possible, then match that abil- ity to the actual Sun Ray hardware being run. If a session is disconnected or moving, audio output will continue as if there were actual hardware connection, even though no samples are actually being transmitted or played. On the other hand, audio input will stop for lack of a con- nected device.
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