The engine accepts several different flags for use when calling LV_SRE_Decode (C API) and LVSpeechPort::Decode (C++ API). The flags can be bitwise OR'd ( "|" ) to customize behavior.
LV_DECODE_BLOCK
Normally, calls to the decode function/method will immediately return to allow the client application to continue working on other tasks while the engine processes the data. This flag blocks the client application until the engine has finished.
LV_DECODE_GENDER_MALE
LV_DECODE_GENDER_FEMALE
LV_DECODE_GENDER_MALE and LV_DECODE_GENDER_MALE identify which gender acoustic model to use during decode. If these flags are not specified, the engine automatically decodes each audio file against both gender models. While this slows the engine by requiring two decodes, evaluating against both models has a very significant positive effect on recognition accuracy. Since the engine is multit-hreaded, unless CPU loads are a serious issue, do not use these flags.
LV_DECODE_FIRST_TIME_USER
Reset caller weights in Recognition Engine (not implemented).
LV_DECODE_USE_OOV
Use the Out-Of-Vocabulary filter (OOV) during decode. The OOV filter, when set, processes each audio file against both the grammar specified by the client application, and a special grammar which detects words not in the grammar. If the engine detects these OOV words, it will not return them. Generally, the OOV filter slows the engine down without a large gain in accuracy, so client applications should use the filter only if OOV words seem to be a problem.
LV_DECODE_RETURN_EACH_DIGIT
When using standard grammars, a string of digits, monetary value etc. is passed back as a single concept. If this flag is used, each digit comes back as a separate concept. (Since each concept has a confidence score, this can be useful for determining poorly recognized individual digits.)
LV_DECODE_SRGS_GRAMMAR
Normally, you do not need to use this flag. But if you want to use a concept-phrase grammar as an SRGS grammar, and are not using the LV_ACTIVE_GRAMMAR_SET, this flag is necessary.
LV_DECODE_SEMANTIC_INTERPRETATION
This flag tells the decoder to process the parse tree return type for semantic information in the tree's tags.
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