7f72c13d9a
* Don't reset model state and feature extractor on endpointing * support passing decoding_method from commandline * Add modified_beam_search to Python API * fix C API example * Fix style issues
80 lines
2.3 KiB
C++
80 lines
2.3 KiB
C++
// sherpa-onnx/csrc/online-transducer-decoder.h
|
|
//
|
|
// Copyright (c) 2023 Xiaomi Corporation
|
|
|
|
#ifndef SHERPA_ONNX_CSRC_ONLINE_TRANSDUCER_DECODER_H_
|
|
#define SHERPA_ONNX_CSRC_ONLINE_TRANSDUCER_DECODER_H_
|
|
|
|
#include <vector>
|
|
|
|
#include "onnxruntime_cxx_api.h" // NOLINT
|
|
#include "sherpa-onnx/csrc/hypothesis.h"
|
|
|
|
namespace sherpa_onnx {
|
|
|
|
struct OnlineTransducerDecoderResult {
|
|
/// The decoded token IDs so far
|
|
std::vector<int64_t> tokens;
|
|
|
|
/// number of trailing blank frames decoded so far
|
|
int32_t num_trailing_blanks = 0;
|
|
|
|
// Cache decoder_out for endpointing
|
|
Ort::Value decoder_out;
|
|
|
|
// used only in modified beam_search
|
|
Hypotheses hyps;
|
|
|
|
OnlineTransducerDecoderResult()
|
|
: tokens{}, num_trailing_blanks(0), decoder_out{nullptr}, hyps{} {}
|
|
|
|
OnlineTransducerDecoderResult(const OnlineTransducerDecoderResult &other);
|
|
|
|
OnlineTransducerDecoderResult &operator=(
|
|
const OnlineTransducerDecoderResult &other);
|
|
|
|
OnlineTransducerDecoderResult(OnlineTransducerDecoderResult &&other);
|
|
|
|
OnlineTransducerDecoderResult &operator=(
|
|
OnlineTransducerDecoderResult &&other);
|
|
};
|
|
|
|
class OnlineTransducerDecoder {
|
|
public:
|
|
virtual ~OnlineTransducerDecoder() = default;
|
|
|
|
/* Return an empty result.
|
|
*
|
|
* To simplify the decoding code, we add `context_size` blanks
|
|
* to the beginning of the decoding result, which will be
|
|
* stripped by calling `StripPrecedingBlanks()`.
|
|
*/
|
|
virtual OnlineTransducerDecoderResult GetEmptyResult() const = 0;
|
|
|
|
/** Strip blanks added by `GetEmptyResult()`.
|
|
*
|
|
* @param r It is changed in-place.
|
|
*/
|
|
virtual void StripLeadingBlanks(OnlineTransducerDecoderResult * /*r*/) const {
|
|
}
|
|
|
|
/** Run transducer beam search given the output from the encoder model.
|
|
*
|
|
* @param encoder_out A 3-D tensor of shape (N, T, joiner_dim)
|
|
* @param result It is modified in-place.
|
|
*
|
|
* @note There is no need to pass encoder_out_length here since for the
|
|
* online decoding case, each utterance has the same number of frames
|
|
* and there are no paddings.
|
|
*/
|
|
virtual void Decode(Ort::Value encoder_out,
|
|
std::vector<OnlineTransducerDecoderResult> *result) = 0;
|
|
|
|
// used for endpointing. We need to keep decoder_out after reset
|
|
virtual void UpdateDecoderOut(OnlineTransducerDecoderResult *result) {}
|
|
};
|
|
|
|
} // namespace sherpa_onnx
|
|
|
|
#endif // SHERPA_ONNX_CSRC_ONLINE_TRANSDUCER_DECODER_H_
|