FreeDV demodulator: Difference between revisions

Latest revision as of 02:38, 10 December 2020

FreeDV demodulator is a GNU Radio block wrapping the codec2 library freedv_api for receiving digital voice signals.

Input is a stream of modulated signal data. Output is voice audio.

Mode: select one of the 9 signal formats. (depending upon modes enabled in the linked codec2 library)

'1600' Initial mode. 8 kHz in and out.

'700' Deprecated.

700B Deprecated.

2400A Input rate 48 kHz

2400B Input rate 48 kHz

800XA Input rate = Output rate = 8 kHz

700C Input rate = Output rate = 8 kHz

700D Input rate = Output rate = 8 kHz

'2020' low-bitrate - input rate is 4 kHz, Output rate 8 kHz

This flowgraph can be found at [1]

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 for receiving digital voice signals.
-Input is a stream of modulated siganl data. Output is voice audio.
+Input is a stream of modulated signal data. Output is voice audio.
 == Parameters ==
@@ Line 39: / Line 39: @@
 == Example Flowgraph ==
-Insert description of flowgraph here, then show a screenshot of the flowgraph and the output if there is an interesting GUI.  Currently we have no standard method of uploading the actual flowgraph to the wiki or git repo, unfortunately.  The plan is to have an example flowgraph showing how the block might be used, for every block, and the flowgraphs will live in the git repo.
+This flowgraph can be found at [https://github.com/gnuradio/gnuradio/blob/master/gr-vocoder/examples/grfreedv.grc]
+[[File:Grfreedv_fg.png|800px]]
 == Source Files ==