Monthly Archive for April, 2009

Why Ubuntu uses PulseAudio

Since version 8.04, Ubuntu has used PulseAudio as its default sound system. After hearing of various problems people have had with PulseAudio (like this one and this one), one may wonder why Ubuntu uses PulseAudio at all, especially since these problems can often be fixed by turning off PulseAudio with no ill effects. The rationale for the switch to PulseAudio in Ubuntu is laid out on this page:

I’m providing this link in the hopes that others don’t have to search as far for the answer as I did. Here are some highlights from that document, describing the benefits of PulseAudio:

Beyond the obvious sound mixing functionality it offers advanced audio features like “desktop bling”, hot-plug support, transparent network audio, hot moving of playback streams between audio devices, separate volume adjustments for all playback or record streams, very low latency, very precise latency estimation (even over the network), a modern zero-copy memory management, a wide range of extension modules, availability for many operating systems, and compatibility with 90% of all currently available audio applications for Linux in one way or another.

The document also has an extensive list of Use cases, which demonstrate where PulseAudio can be useful. While PulseAudio has many interesting features, the majority of these are not exposed to the user through a discoverable user interface so people don’t know they exist and, thus, don’t miss them if they disable PulseAudio.

For those that are interested, I found the above wiki page by searching for Hardy Heron release notes, leading me to this page, which linked to this blueprint, whose full specification is the wiki page.

Solving the codec problem

This is a response to John Dowdell’s Put down the Flavorade and slowly back away…. post, which is itself a reply to Tristan Nitot’s Making video a first class citizen of the Web. Here it is, starting with a quote from John Dowdell’s post:
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i.MX51 Babbage development board details

On April 19, the Release Candidate for Ubuntu 9.04 on ARM was announced. This will most likely be used as a platform for new ARM netbooks, as Canonical previously hinted at. The announcement made several references to a Babbage development board, which piqued my interest. Wanting to learn more about the board, I searched for “babbage i.mx51” but found only a couple pages of results (including BabbageJauntyRCInstall), mostly relating to the Ubuntu 9.04 announcement. Eventually I tried an image search for “i.mx51”, which turned up this image, which I suspect is the Babbage development board:

Babbage development board (?)

Here are some more details about the board with references:
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