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enginex-mr_series-sherpa-onnx/sherpa-onnx/csrc/offline-recognizer-ctc-impl.h
2024-06-05 00:26:40 +08:00

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// sherpa-onnx/csrc/offline-recognizer-ctc-impl.h
//
// Copyright (c) 2022-2023 Xiaomi Corporation
#ifndef SHERPA_ONNX_CSRC_OFFLINE_RECOGNIZER_CTC_IMPL_H_
#define SHERPA_ONNX_CSRC_OFFLINE_RECOGNIZER_CTC_IMPL_H_
#include <ios>
#include <memory>
#include <sstream>
#include <string>
#include <utility>
#include <vector>
#if __ANDROID_API__ >= 9
#include "android/asset_manager.h"
#include "android/asset_manager_jni.h"
#endif
#include "sherpa-onnx/csrc/offline-ctc-decoder.h"
#include "sherpa-onnx/csrc/offline-ctc-fst-decoder.h"
#include "sherpa-onnx/csrc/offline-ctc-greedy-search-decoder.h"
#include "sherpa-onnx/csrc/offline-ctc-model.h"
#include "sherpa-onnx/csrc/offline-recognizer-impl.h"
#include "sherpa-onnx/csrc/pad-sequence.h"
#include "sherpa-onnx/csrc/symbol-table.h"
namespace sherpa_onnx {
static OfflineRecognitionResult Convert(const OfflineCtcDecoderResult &src,
const SymbolTable &sym_table,
int32_t frame_shift_ms,
int32_t subsampling_factor) {
OfflineRecognitionResult r;
r.tokens.reserve(src.tokens.size());
r.timestamps.reserve(src.timestamps.size());
std::string text;
for (int32_t i = 0; i != src.tokens.size(); ++i) {
if (sym_table.Contains("SIL") && src.tokens[i] == sym_table["SIL"]) {
// tdnn models from yesno have a SIL token, we should remove it.
continue;
}
auto sym = sym_table[src.tokens[i]];
text.append(sym);
if (sym.size() == 1 && (sym[0] < 0x20 || sym[0] > 0x7e)) {
// for byte bpe models
// (but don't rewrite printable characters 0x20..0x7e,
// which collide with standard BPE units)
std::ostringstream os;
os << "<0x" << std::hex << std::uppercase
<< (static_cast<int32_t>(sym[0]) & 0xff) << ">";
sym = os.str();
}
r.tokens.push_back(std::move(sym));
}
r.text = std::move(text);
float frame_shift_s = frame_shift_ms / 1000. * subsampling_factor;
for (auto t : src.timestamps) {
float time = frame_shift_s * t;
r.timestamps.push_back(time);
}
return r;
}
class OfflineRecognizerCtcImpl : public OfflineRecognizerImpl {
public:
explicit OfflineRecognizerCtcImpl(const OfflineRecognizerConfig &config)
: config_(config),
symbol_table_(config_.model_config.tokens),
model_(OfflineCtcModel::Create(config_.model_config)) {
Init();
}
#if __ANDROID_API__ >= 9
OfflineRecognizerCtcImpl(AAssetManager *mgr,
const OfflineRecognizerConfig &config)
: config_(config),
symbol_table_(mgr, config_.model_config.tokens),
model_(OfflineCtcModel::Create(mgr, config_.model_config)) {
Init();
}
#endif
void Init() {
if (!config_.model_config.telespeech_ctc.empty()) {
config_.feat_config.snip_edges = true;
config_.feat_config.num_ceps = 40;
config_.feat_config.feature_dim = 40;
config_.feat_config.low_freq = 40;
config_.feat_config.high_freq = -200;
config_.feat_config.use_energy = false;
config_.feat_config.normalize_samples = false;
config_.feat_config.is_mfcc = true;
}
if (!config_.model_config.wenet_ctc.model.empty()) {
// WeNet CTC models assume input samples are in the range
// [-32768, 32767], so we set normalize_samples to false
config_.feat_config.normalize_samples = false;
}
config_.feat_config.nemo_normalize_type =
model_->FeatureNormalizationMethod();
if (!config_.ctc_fst_decoder_config.graph.empty()) {
// TODO(fangjun): Support android to read the graph from
// asset_manager
decoder_ = std::make_unique<OfflineCtcFstDecoder>(
config_.ctc_fst_decoder_config);
} else if (config_.decoding_method == "greedy_search") {
if (!symbol_table_.Contains("<blk>") &&
!symbol_table_.Contains("<eps>") &&
!symbol_table_.Contains("<blank>")) {
SHERPA_ONNX_LOGE(
"We expect that tokens.txt contains "
"the symbol <blk> or <eps> or <blank> and its ID.");
exit(-1);
}
int32_t blank_id = 0;
if (symbol_table_.Contains("<blk>")) {
blank_id = symbol_table_["<blk>"];
} else if (symbol_table_.Contains("<eps>")) {
// for tdnn models of the yesno recipe from icefall
blank_id = symbol_table_["<eps>"];
} else if (symbol_table_.Contains("<blank>")) {
// for Wenet CTC models
blank_id = symbol_table_["<blank>"];
}
decoder_ = std::make_unique<OfflineCtcGreedySearchDecoder>(blank_id);
} else {
SHERPA_ONNX_LOGE("Only greedy_search is supported at present. Given %s",
config_.decoding_method.c_str());
exit(-1);
}
}
std::unique_ptr<OfflineStream> CreateStream() const override {
return std::make_unique<OfflineStream>(config_.feat_config);
}
void DecodeStreams(OfflineStream **ss, int32_t n) const override {
if (!model_->SupportBatchProcessing()) {
// If the model does not support batch process,
// we process each stream independently.
for (int32_t i = 0; i != n; ++i) {
DecodeStream(ss[i]);
}
return;
}
auto memory_info =
Ort::MemoryInfo::CreateCpu(OrtDeviceAllocator, OrtMemTypeDefault);
int32_t feat_dim = config_.feat_config.feature_dim;
std::vector<Ort::Value> features;
features.reserve(n);
std::vector<std::vector<float>> features_vec(n);
std::vector<int64_t> features_length_vec(n);
for (int32_t i = 0; i != n; ++i) {
std::vector<float> f = ss[i]->GetFrames();
int32_t num_frames = f.size() / feat_dim;
features_vec[i] = std::move(f);
features_length_vec[i] = num_frames;
std::array<int64_t, 2> shape = {num_frames, feat_dim};
Ort::Value x = Ort::Value::CreateTensor(
memory_info, features_vec[i].data(), features_vec[i].size(),
shape.data(), shape.size());
features.push_back(std::move(x));
} // for (int32_t i = 0; i != n; ++i)
std::vector<const Ort::Value *> features_pointer(n);
for (int32_t i = 0; i != n; ++i) {
features_pointer[i] = &features[i];
}
std::array<int64_t, 1> features_length_shape = {n};
Ort::Value x_length = Ort::Value::CreateTensor(
memory_info, features_length_vec.data(), n,
features_length_shape.data(), features_length_shape.size());
Ort::Value x = PadSequence(model_->Allocator(), features_pointer,
-23.025850929940457f);
auto t = model_->Forward(std::move(x), std::move(x_length));
auto results = decoder_->Decode(std::move(t[0]), std::move(t[1]));
int32_t frame_shift_ms = 10;
for (int32_t i = 0; i != n; ++i) {
auto r = Convert(results[i], symbol_table_, frame_shift_ms,
model_->SubsamplingFactor());
ss[i]->SetResult(r);
}
}
private:
// Decode a single stream.
// Some models do not support batch size > 1, e.g., WeNet CTC models.
void DecodeStream(OfflineStream *s) const {
auto memory_info =
Ort::MemoryInfo::CreateCpu(OrtDeviceAllocator, OrtMemTypeDefault);
int32_t feat_dim = config_.feat_config.feature_dim;
std::vector<float> f = s->GetFrames();
int32_t num_frames = f.size() / feat_dim;
std::array<int64_t, 3> shape = {1, num_frames, feat_dim};
Ort::Value x = Ort::Value::CreateTensor(memory_info, f.data(), f.size(),
shape.data(), shape.size());
int64_t x_length_scalar = num_frames;
std::array<int64_t, 1> x_length_shape = {1};
Ort::Value x_length =
Ort::Value::CreateTensor(memory_info, &x_length_scalar, 1,
x_length_shape.data(), x_length_shape.size());
auto t = model_->Forward(std::move(x), std::move(x_length));
auto results = decoder_->Decode(std::move(t[0]), std::move(t[1]));
int32_t frame_shift_ms = 10;
auto r = Convert(results[0], symbol_table_, frame_shift_ms,
model_->SubsamplingFactor());
s->SetResult(r);
}
private:
OfflineRecognizerConfig config_;
SymbolTable symbol_table_;
std::unique_ptr<OfflineCtcModel> model_;
std::unique_ptr<OfflineCtcDecoder> decoder_;
};
} // namespace sherpa_onnx
#endif // SHERPA_ONNX_CSRC_OFFLINE_RECOGNIZER_CTC_IMPL_H_