7 Adaptive Multi-Rate Wideband speech codec test vectors

26.1713GPPAdaptive Multi-Rate - Wideband (AMR-WB) speech codecGeneral descriptionSpeech codec speech processing functionsTS

A set of digital test sequences is specified in [4], thus enabling the verification of compliance, i.e. bit-exactness, to a high degree of confidence.

The test sequences are defined separately for:

– The speech codec described in [2],

– The VAD described in [6],

– The CN generation described in [7].

The adaptive multi-rate wideband speech transcoder, VAD, SCR system and comfort noise parts of the audio processing functions (see Figure 1) are defined in bit exact arithmetic. Consequently, they shall react on a given input sequence always with the corresponding bit exact output sequence, provided that the internal state variables are also always exactly in the same state at the beginning of the test.

The input test sequences provided shall force the corresponding output test sequences, provided that the tested modules are in their home‑state when starting.

The modules may be set into their home states by provoking the appropriate homing‑functions.

NOTE: This is normally done during reset (initialisation of the codec).

Special inband signalling frames (encoder‑homing‑frame and decoder‑homing‑frame) described in [2] have been defined to provoke these homing‑functions also in remotely placed modules.

At the end of the first received homing frame, the audio functions that are defined in a bit exact way shall go into their predefined home states. The output corresponding to the first homing frame is dependent on the codec state when the frame was received. Any consecutive homing frames shall produce corresponding homing frames at the output.