fast-beam-search support for sherpa-onnx

[uni-manjunath-ke]

I found that the fast-beam-search decoding is currently not supported in sherpa-onnx. Is this activity is planned for future? If yes, when can this be expected (timeline)?

In specific, do you plan to support fast-beam-search-with-lg. Because, currently, the fast-beam-search-with-lg is not supported by zipformer/streaming-decode.py.
Thanks

[csukuangfj]

fast_beam_search depends on k2. If you want to use fast_beam_search, please use k2-fsa/sherap.

We are going to support HLG decoding in sherpa-onnx. If you want to use a lexicon or/and an n-gram LM in decoding, then you may find HLG decoding interesting.

Please also have a look at k2-fsa/icefall#1275

[uni-manjunath-ke]

Sure, Thanks. Ya, we are interested in HLG. Hoping to see this HLG code at k2-fsa/icefall#1275 merged soon and available for usage.

[uni-manjunath-ke]

Hi @csukuangfj ,
Just wanted to confirm, if the HLG code at k2-fsa/icefall#1275 is only for CTC, or it can be used with zipformers as well. Could you please confirm. Because, we are interested in Zipformer models for now.

[uni-manjunath-ke]

Currently, I see in k2-fsa/icefall#1275 that HLG support is added for ICefall, When can we expect this support to be ported for sherpa-onnx? or Is that already ported to Sherpa-onnx? Thanks

[csukuangfj]

Currently, I see in k2-fsa/icefall#1275 that HLG support is added for ICefall, When can we expect this support to be ported for sherpa-onnx? or Is that already ported to Sherpa-onnx? Thanks

please see #349

We will finish it in two weeks.

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if the HLG code at k2-fsa/icefall#1275 is only for CTC

Yes, you are right. It is only for CTC.

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it can be used with zipformers as well

Zipformer is a kind of neural network, while ctc is a kind of loss function. They are two different things.
If you train a zipformer using CTC loss, then you can use HLG decoding with zipformer.
If you train a zipformer using transducer loss, then you cannot use HLG decoding with zipformer.

[csukuangfj]

Currently, I see in k2-fsa/icefall#1275 that HLG support is added for ICefall, When can we expect this support to be ported for sherpa-onnx? or Is that already ported to Sherpa-onnx? Thanks

@uni-manjunath-ke

#349

The C++ part is usable now.

[uni-manjunath-ke]

Thank you.