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  • Analog_Bridge

    • Used to convert a network stream of TLV packets into PCM and back again

    • Two usage scenarios

      • Bridge ASL to a digital network

        • ASL has a great channel driver called chan_usrp.  This driver was developed to connect ASL to specialized hardware, but does not actually require the hardware.  The USRP protocol includes signaling (TX/RX transitions) and audio transfer using UDP. The audio format is 8KHZ signed 16 bit PCM samples.  Analog_Bridge was developed to consume these packets and transcode them to several digital audio formats.

      • Transcode one digital format to another

        • The process of transcoding one digital audio format to another is to take the source audio format and convert it to a form that can then be encoded into a new format.  All of the audio formats encode PCM into digital audio and decode digital audio into PCM, so this can be used to be the basis of the transcoder. In general terms, you use two instances of Analog_Bridge, one to handle the first format of digital and the second instance to handle the other format.  These instances are then set to feed each other in the stream and presto, transcoder.