Files
2026-07-13 12:40:42 +08:00

114 lines
3.9 KiB
C++

// Copyright (c) 2024 PaddlePaddle Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#pragma once
#include <string.h>
#include <vector>
#include "paddle/phi/core/dense_tensor.h"
#include "paddle/phi/core/lod_utils.h"
#include "paddle/phi/kernels/funcs/math_function.h"
namespace phi {
template <typename T, typename Context>
void CTCAlignKernel(const Context& dev_ctx,
const DenseTensor& input,
const optional<DenseTensor>& input_length,
int blank,
bool merge_repeated,
int padding_value,
DenseTensor* output,
DenseTensor* output_length) {
T* output_data = dev_ctx.template Alloc<T>(output);
auto input_dims = vectorize<int>(input.dims());
const T* input_data = input.data<T>();
// support tensor input, no lod information
if (input.lod().empty()) {
size_t padding_value_new = static_cast<size_t>(padding_value);
const T* input_length_data = input_length.get().data<T>();
T* output_length_data = dev_ctx.template Alloc<T>(output_length);
for (size_t batch_id = 0; batch_id < (unsigned)input_dims[0]; batch_id++) {
T prev_token = -1;
size_t output_idx = 0;
for (size_t i = 0; i < (unsigned)input_length_data[batch_id]; i++) {
size_t input_ind = batch_id * input_dims[1] + i;
if ((unsigned)input_data[input_ind] != (unsigned)blank &&
!(merge_repeated && input_data[input_ind] == prev_token)) {
output_data[batch_id * input_dims[1] + output_idx] =
input_data[input_ind];
++output_idx;
}
prev_token = input_data[input_ind];
}
output_length_data[batch_id] = output_idx;
for (size_t j = output_idx; j < (unsigned)input_dims[1]; j++)
output_data[batch_id * input_dims[1] + j] = padding_value_new;
}
} else {
const size_t level = 0;
auto input_lod = ToAbsOffset(input.lod());
// check input dims and lod
PADDLE_ENFORCE_EQ(
input_dims[0],
static_cast<int64_t>(input_lod[level].back()),
common::errors::InvalidArgument(
"The first dimension %d of CTCAlign operator Input(Input) should "
"be equal to "
"the sum of all sequences' lengths %d.",
input_dims[0],
static_cast<int64_t>(input_lod[level].back())));
const size_t num_sequences = input_lod[level].size() - 1;
// merge repeated tokens and delete blank
size_t output_idx = 0;
std::vector<size_t> output_lod0(1, 0);
for (size_t seq_idx = 0; seq_idx < num_sequences; ++seq_idx) {
T prev_token = -1;
for (size_t i = input_lod[level][seq_idx];
i < input_lod[level][seq_idx + 1];
++i) {
if ((unsigned)input_data[i] != (unsigned)blank &&
!(merge_repeated && input_data[i] == prev_token)) {
output_data[output_idx] = input_data[i];
++output_idx;
}
prev_token = input_data[i];
}
output_lod0.push_back(output_idx);
}
// set output lod
LegacyLoD output_lod;
output_lod.push_back(output_lod0);
output->set_lod(output_lod);
// resize output dims
output->Resize({static_cast<int64_t>(output_lod0.back()), 1});
// for empty sequence
if (output_lod0.back() == 0) {
output->Resize({1, 1});
output_data = dev_ctx.template Alloc<T>(output);
output_data[0] = -1;
}
}
}
} // namespace phi