Thursday, 8 January 2009

Performance v Functionality!

I have spent the last week unsuccessfully trying to replace PulseAudio and Gnome Speech with ALSA and Speech-Dispatcher. I have been able to get Speech Dispatcher running with ALSA and this does significantly improve the responsiveness of Orca. However, once I enable Speech Dispatcher I have been unable to run any other applications which produce audio output. This is in all probability because I have not configured Speech Dispatcher properly, but I have followed all of the guides I can find online as well as receiving advice from members of the Speech Dispatcher mailing list to no avail. Speech Dispatcher offers many advanced features: It is able to use OSS, ALSA and PulseAudio as well as being able to run as a system service or on an individual user basis. However the fact that it offers so much functionality means it is not easy to configure. I hope that I will be able to resolve this problem but if not I face a tricky decision. Do I install ALSA and Speech Dispatcher and sacrifice multi-channel sound functionality or do I stick with PulseAudio and Gnome Speech and settle for poorer performance?

To be honest I don't think the responsiveness of Orca using PulseAudio is that bad on reasonably modern hardware and adding yourself to the PulseAudio realtime group can improve this further. Hopefully in the long run the Ubuntu, Gnome, PulseAudio and/or Orca will resolve these issues and replacing PulseAudio will be unnecessary. In the meantime if I am unable to resolve the issue than I could install and configure Speech Dispatcher but not enable it by default. This way beginners would have fully functional speech and multi-channel sound, while more advanced users could enable Speech Dispatcher and configure it themselves. I am also intending to install and configure YASR, a console based screen-reader and LinuxSpeaks, a complete console based audio desktop in the next version of Vinux.