Sound Formats

The Speech Engine accepts audio only in certain formats. The sound formats listed below are members of an enum SOUND_FORMAT whch is used as an argument in loading the voice channel (LoadVoiceChannel or LV_SRE_LoadVoiceChannel) for decodes . The streamed audio format is set be setting the STREAM_PARM_SOUND_FORMAT to one of the below formats using StreamSetParameter or LV_SRE_StreamSetParameter.

List of Supported Sound Formats

ULAW_8KHZ

Format: mu-law

Sample Rate: 8 kHz

Bytes per Sample: 1 byte per sample

Memory: ~0.5 MB / min.

Notes: This is the standard domestic telephone format.

PCM_8KHZ

Format: PCM

Sample Rate: 8 kHz

Bytes per Sample: 2 bytes per sample

Memory: ~1 MB / min

PCM_8KHZ

Format: PCM

Sample Rate: 16 kHz

Bytes per Sample: 2 bytes per sample

Memory: ~2 MB / min

ALAW_8KHZ

Format: a-law

Sample Rate: 8 kHz

Bytes per Sample: 1 bytes per sample

Memory: ~0.5 MB / min

Deprecated Sound Formats

SPX_8KHZ

Status: Deprecated and non-functional since 9.0

SPX_16KHZ

Status: Deprecated and non-functional since 9.0

See Also

• LV_SRE_StreamSetParameter
• LV_SRE_LoadVoiceChannel
• LVSpeechPort::StreamSetParameter
• LVSpeechPort::LoadVoiceChannel