Kamaelia docs : Kamaelia.Audio.Codec.PyMedia.Decoder

Compressed audio decoding using PyMedia

Decodes compressed audio data sent to its "inbox" inbox and outputs the raw audio data from its "outbox" outbox. Decoding done using the PyMedia library.

Example Usage

Playing a MP3 file, known to be 128bkps, 44100Hz 16bit stereo:

Pipeline( RateControlledFileReader("my.mp3", readmode="bytes", rate=128*1024/8),
          Decoder("mp3"),
          Output(44100, 2, "S16_LE"),
        ).run()

How does it work?

Set up Decoder by specifying the filetype/codec to the initializer. What codecs are supported depends on your PyMedia installation.

Send raw binary data strings containing the compressed audio data to the "inbox" inbox, and raw binary data strings containing the uncompressed raw audio data will be sent out of the "outbox" outbox.

This component will terminate if a shutdownMicroprocess or producerFinished message is sent to the "control" inbox. The message will be forwarded on out of the "signal" outbox just before termination.


Kamaelia.Audio.Codec.PyMedia.Decoder.Decoder

class Decoder(Axon.Component.component)

Decoder(fileExtension) -> new pymedia Audio Decoder.

Send raw data from a compressed audio file (which had the specified extension) to the "inbox" inbox, and decompressed blocks of raw audio data are emitted from the "outbox" outbox.

Keyword arguments:

  • codec -- The codec (ones supported depend on your local installation)

Inboxes

  • control : Shutdown signalling
  • inbox : compressed audio data

Outboxes

  • outbox : raw audio samples
  • signal : Shutdown signalling
  • needData : requests for more data (value is suggested minimum number of bytes
  • format : dictionary detailing sample_rate, sample_format and channels

Methods defined here

__init__(self, codec)

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

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, 19 Oct 2008 at 14:29:09 UTC/GMT

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