Kamaelia docs : Kamaelia.Codec.Vorbis

Kamaelia.Codec.Vorbis

component AOAudioPlaybackAdaptor
component VorbisDecode

Simple Vorbis Decoder Component, and Audio Playback Adaptor

Kamaelia.Codec.Vorbis.AOAudioPlaybackAdaptor

class AOAudioPlaybackAdaptor(Axon.Component.component)

AOAudioPlaybackAdaptor() -> new AOAudioPlaybackAdaptor

Expects to recieve data from standard inbox, and plays it using libao. When it recieves a message on the control port: Sends a producerConsumed to its outbox. Then shutsdown.

Requires libao and pyao (python bindings)

Example

A simple player:

Pipeline(
    ReadFileAdaptor("somefile.ogg"),
    VorbisDecode(),
    AOAudioPlaybackAdaptor(),
).run()

Inboxes

control : If a message is received here, the component shutsdown
inbox : Any raw PCM encoded data recieved here is played through the default oss playback device

Outboxes

outbox : UNUSED
signal : When the component shutsdown, it sends a producerFinished message out this outbox

Methods defined here

Warning!

You should be using the inbox/outbox interface, not these methods (except construction). This documentation is designed as a roadmap as to their functionalilty for maintainers and new component developers.

init(self)

x.__init__(...) initializes x; see x.__class__.__doc__ for signature

main(self)

Performs the logic described above

Kamaelia.Codec.Vorbis.VorbisDecode

class VorbisDecode(Axon.Component.component)

VorbisDecode() -> new VorbisDecoder

A Vorbis decoder accepts data on its inbox "inbox", as would be read from an ogg vorbis file, decodes it and sends on the decompressed data on out of its outbox "outbox". It doesn't provide any further information at this stage, such as bitrate, or any other frills.

Requires libvorbissimple and python bindings (see kamaelia downloads)

Example

A simple player:

Pipeline(
    ReadFileAdaptor("somefile.ogg"),
    VorbisDecode(),
    AOAudioPlaybackAdaptor(),
).run()

This component expects to recieve OGG VORBIS data as you would get from a .ogg file containing vorbis data. (rather than raw vorbis data)

Inboxes

control : Receiving a message here causes component shutdown
inbox : Ogg wrapped vorbis data

Outboxes

outbox : As data is decompresessed it is sent to this outbox
signal : When the component shuts down, it sends on a producerFinished message

Methods defined here

Warning!

init(self)

x.__init__(...) initializes x; see x.__class__.__doc__ for signature

main(self)

This contains no user serviceable parts :-)

Theory of operation is simple. It simply repeatedly asks the decoder object for audio. That decoded audio is sent to the component's outbox. If the decoder object responds with RETRY, the component retries. If the decoder object responds with NEEDDATA, the component waits for data on any inbox until some is available (from an inbox)

Feedback

Got a problem with the documentation? Something unclear that could be clearer? Want to help improve it? Constructive criticism is very welcome - especially if you can suggest a better rewording!

Please leave you feedback here in reply to the documentation thread in the Kamaelia blog.

-- Automatic documentation generator, 20 Jul 2008 at 03:02:36 UTC/GMT

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