The DSP modules in spandsp

Guidelines

• The spandsp policy on signal data
• The spandsp policy on processor instruction sets

Telephony DSP modules

• Analogue display services (e.g. caller ID) of various types
• Bit error rate testing (BERT)
• Supervisory tone generation and detection
• DTMF generation and detection
• Bell MF tone generation and detection
• MFC/R2 tone generation and detection
• 2280Hz and 2600Hz signal tone generation, detection and filtering
• Asynchronous bit stream encoding and decoding
• HDLC encoding and decoding
• Low speed asynchronous FSK modems (V.21, V.23, Bell 103, Bell 202, etc.)
• V.17 modem transmit and receive
• V.22bis modem
• V.27ter modem transmit and receive
• V.29 modem transmit and receive
• V.42 and V.42bis processing
• V.8 modem negotiation
• Line echo cancellation for modems
• FAX protocols T.4, T.30 and T.35.
• Fax over IP protocol T.38 protocol, with gateway and termination support.
• Modem AT command processor
• Class 1 FAX modem protocol T.31
• Line echo cancellation for voice
• Generic packet loss concealment for voice
• Generic playout buffering, for jitter control
• Generic time scale modification for voice playback
• Echo cancellor disable tone generation and detection
• OKI (Dialogic) ADPCM encoding and decoding
• IMA ADPCM encoding and decoding
• G.711 A-law and mu-law handling
• G.722 wideband speech encoding and decoding
• G.726 ADPCM speech encoding and decoding
• GSM 06.10 full rate speech encoding and decoding

Basic DSP modules

• A fast but approximate four quadrant arc-tangent
• AWGN generation
• Noise generation such as Hoth noise
• Removing DC bias from a signal
• Tone generation
• Direct digital synthesis (DDS/NCO) of tones
• Complex number support
• FIR filtering
• IIR filtering
• Power metering
• Simple queuing and scheduling facilities for the library
• Logging facilities for the library
• OSS I/O

Test suites

• Constructing the CSS data for G.168 testing
• Constructing telephone line models
• Telephone line models
• Modem monitoring
• Echo canceller monitoring
• Line model tests
• DC restoration tests
• AWGN generation tests
• Noise generation tests
• Tone generation tests
• Power meter tests
• Tone generation tests
• Direct digital synthesis (DDS) tests
• DTMF generation and detection tests
• Bell MF generation and detection tests
• MFC/R2 generation and detection tests
• 2280Hz and 2600Hz signal tone tests
• Time scale modification tests
• Supervisory tone generation and detection tests
• Scheduler tests
• Analogue display service tests
• Time scale modification tests
• Playout tests
• Packet loss concealment tests
• T.4 tests
• T.31 tests
• T.38 gateway tests
• T.38 termination tests
• T.38 terminal to gateway tests
• T.38 gateway to terminal tests
• FAX tests
• BERT tests
• Asynchronous data tests
• HDLC tests
• FSK (V.21, V.23, Bell 103, Bell 202 etc.) modem tests
• V.17 modem tests
• V.22bis modem tests
• V.27ter modem tests
• V.29 modem tests
• V.42 and V.42bis tests
• V.8 tests
• Voice echo cancellation tests
• Modem echo cancellation tests
• Echo cancellor disable tone generation and detection tests
• G.168 test data for echo cancellation
• IMA ADPCM codec tests
• OKI ADPCM codec tests
• G.722 codec tests
• GSM 06.10 full rate codec tests
• FAX decoder