offline-recognizer-ctc-impl.h
4.4 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
// 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 <memory>
#include <string>
#include <utility>
#include <vector>
#include "sherpa-onnx/csrc/offline-ctc-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) {
OfflineRecognitionResult r;
r.tokens.reserve(src.tokens.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);
r.tokens.push_back(std::move(sym));
}
r.text = std::move(text);
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)) {
config_.feat_config.nemo_normalize_type =
model_->FeatureNormalizationMethod();
if (config.decoding_method == "greedy_search") {
if (!symbol_table_.contains("<blk>") &&
!symbol_table_.contains("<eps>")) {
SHERPA_ONNX_LOGE(
"We expect that tokens.txt contains "
"the symbol <blk> or <eps> 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>"];
}
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 {
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.first), std::move(t.second));
for (int32_t i = 0; i != n; ++i) {
auto r = Convert(results[i], symbol_table_);
ss[i]->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_