6.2 KiB
Codec 2 README
Codec 2 is an open source (LGPL 2.1) low bit rate speech codec: http://rowetel.com/codec2.html
Also included:
- The FreeDV API for digital voice over radio. FreeDV is an open source digital voice protocol that integrates modems, codecs, and FEC README_freedv
- APIs for raw and Ethernet packet data over radio README_data
- High performance coherent OFDM modem for HF channels README_ofdm
- High performance non-coherent FSK modem README_fsk
- An STM32 embedded version of FreeDV 1600/700D for the SM1000
- Coherent PSK modem README_cohpsk for HF channels
- FDMDV DPSK modem README_fdmdv for HF channels
Quickstart
-
Install packages (Debian/Ubuntu):
$ sudo apt install git build-essential cmake
Fedora/RH distros:
$ sudo dnf groupinstall "Development Tools" "C Development Tools and Libraries" $ sudo dnf install cmake
-
Build Codec 2:
$ git clone git@github.com:drowe67/codec2.git $ cd codec2 $ mkdir build_linux $ cd build_linux $ cmake .. $ make
-
Listen to Codec 2 (run from
codec2/build_linux
):$ ./src/c2demo ../raw/hts1a.raw hts1a_c2.raw $ aplay -f S16_LE ../raw/hts1a.raw $ aplay -f S16_LE hts1a_c2.raw
-
Compress, decompress and then play a file using Codec 2 at 2400 bit/s:
$ ./src/c2enc 2400 ../raw/hts1a.raw hts1a_c2.bit $ ./src/c2dec 2400 hts1a_c2.bit hts1a_c2_2400.raw
which can be played with:
$ aplay -f S16_LE hts1a_c2_2400.raw
Or using Codec 2 using 700C (700 bits/s):
$ ./src/c2enc 700C ../raw/hts1a.raw hts1a_c2.bit $ ./src/c2dec 700C hts1a_c2.bit hts1a_c2_700.raw $ aplay -f S16_LE hts1a_c2_700.raw
-
If you prefer a one-liner without saving to files:
$ ./src/c2enc 1300 ../raw/hts1a.raw - | ./src/c2dec 1300 - - | aplay -f S16_LE
FreeDV 2020 support (building with LPCNet)
-
Build codec2 initially without LPCNet
$ cd ~ $ git clone https://github.com/drowe67/codec2.git $ cd codec2 && mkdir build_linux && cd build_linux $ cmake ../ $ make
-
Build LPCNet:
$ cd ~ $ git clone https://github.com/drowe67/LPCNet $ cd LPCNet && mkdir build_linux && cd build_linux $ cmake -DCODEC2_BUILD_DIR=~/codec2/build_linux ../ $ make
-
(Re)build Codec 2 with LPCNet support:
$ cd ~/codec2/build_linux && rm -Rf * $ cmake -DLPCNET_BUILD_DIR=~/LPCNet/build_linux .. $ make
Programs
-
c2demo
encodes a file of speech samples, then decodes them and saves the result. -
c2enc
encodes a file of speech samples to a compressed file of encoded bits.c2dec
decodes a compressed file of bits to a file of speech samples. -
c2sim
is a simulation/development version of Codec 2. It allows selective use of the various Codec 2 algorithms. For example switching phase modelling or quantisation on and off. -
freedv_tx
&freedv_rx
are command line implementations of the FreeDV protocol, which combines Codec 2, modems, and Forward Error Correction (FEC). -
cohpsk_*
are coherent PSK (COHPSK) HF modem command line programs. -
fdmdv_*
are differential PSK HF modem command line programs (README_fdmdv). -
fsk_*
are command line programs for a non-coherent FSK modem (README_fsk). -
ldpc_*
are LDPC encoder/decoder command line programs, based on the CML library. -
ofdm_*
are OFDM PSK HF modem command line programs (README_ofdm).
Building and Running Unit Tests
CTest is used as a test framework, with support from GNU Octave scripts.
-
Install GNU Octave and libraries on Ubuntu with:
$ sudo apt install octave octave-common octave-signal liboctave-dev gnuplot python3-numpy sox valgrind
-
Install CML library with instructions at the top of
octave/ldpc.m
-
To build and run the tests:
$ cd ~/codec2 $ rm -Rf build_linux && mkdir build_linux $ cd build_linux $ cmake -DCMAKE_BUILD_TYPE=Debug .. $ make all test
-
To just run tests without rebuilding:
$ ctest
-
To get a verbose run (e.g. for test debugging):
$ ctest -V
-
To just run a single test:
$ ctest -R test_OFDM_modem_octave_port
-
To list the available tests:
$ ctest -N
Directories
cmake - cmake support files
misc - misc C programs that have been useful in development,
not reqd for Codec 2 release. Part of Debug build.
octave - Octave scripts used to support development
script - shell scripts for playing and converting raw files
src - C source code for Codec 2, FDMDV modem, COHPSK modem, FreeDV API
raw - speech files in raw format (16 bits signed linear 8 kHz)
stm32 - STM32F4 microcontroller and SM1000 FreeDV Adaptor support
unittest - Code to perform and support testing. Part of Debug build.
wav - speech files in wave file format
GDB and Dump Files
-
To compile with debug symbols for using gdb:
$ cd ~/codec2 $ rm -Rf build_linux && mkdir build_linux $ cd build_linux $ CFLAGS=-g cmake .. $ make
-
For dump file support (dump data from c2sim for input to Octave development scripts):
$ cd ~/codec2 $ rm -Rf build_linux && mkdir build_linux $ cd build_linux $ CFLAGS=-DDUMP cmake .. $ make
Building for Windows on a Linux machine
On Ubuntu 17 and above:
$ sudo apt-get install mingw-w64
$ mkdir build_windows && cd build_windows
$ cmake .. -DCMAKE_TOOLCHAIN_FILE=/home/david/freedv-dev/cmake/Toolchain-Ubuntu-mingw32.cmake -DUNITTEST=FALSE -DGENERATE_CODEBOOK=/home/david/codec2/build_linux/src/generate_codebook
$ make
Building for Windows on a Windows machine
mkdir build_windows (Or what ever you want to call your build dir)
cmake -G "MinGW Makefiles" -D CMAKE_MAKE_PROGRAM=mingw32-make.exe
Or if you use ninja for building cmake -G "Ninja" ..
mingw32-make or ninja depends on what you used in the last command
wait for it to build.