8fc05feed4
Includes a unittest to ensure we meet the same quality thresholds as SincResampler (modulo quantization error). BUG=webrtc:1395 Review URL: https://webrtc-codereview.appspot.com/1323011 git-svn-id: http://webrtc.googlecode.com/svn/trunk@3909 4adac7df-926f-26a2-2b94-8c16560cd09d
67 lines
2.3 KiB
C++
67 lines
2.3 KiB
C++
/*
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* Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "webrtc/common_audio/resampler/push_sinc_resampler.h"
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#include <cmath>
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#include <algorithm>
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namespace webrtc {
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PushSincResampler::PushSincResampler(int src_block_size,
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int dst_block_size)
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: resampler_(NULL),
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float_buffer_(NULL),
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source_ptr_(NULL),
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dst_size_(dst_block_size) {
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resampler_.reset(new SincResampler(src_block_size * 1.0 / dst_block_size,
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this, src_block_size));
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float_buffer_.reset(new float[dst_block_size]);
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}
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PushSincResampler::~PushSincResampler() {
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}
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int PushSincResampler::Resample(const int16_t* source,
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int source_length,
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int16_t* destination,
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int destination_capacity) {
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assert(source_length == resampler_->BlockSize());
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assert(destination_capacity >= dst_size_);
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// Cache the source pointer. Calling Resample() will immediately trigger
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// the Run() callback whereupon we provide the cached value.
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source_ptr_ = source;
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resampler_->Resample(float_buffer_.get(), dst_size_);
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for (int i = 0; i < dst_size_; ++i) {
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float clipped = std::max(std::min(float_buffer_[i], 32767.0f), -32768.0f);
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destination[i] = static_cast<int16_t>(std::floor(clipped + 0.5));
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}
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source_ptr_ = NULL;
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return dst_size_;
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}
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void PushSincResampler::Run(float* destination, int frames) {
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assert(source_ptr_ != NULL);
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assert(frames >= resampler_->BlockSize());
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// We will have exactly |BlockSize| number of source samples available. If
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// the resampler asks for more, zero pad the beginning. This will only happen
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// on the first call while priming the buffer.
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int i = 0;
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for (; i < frames - resampler_->BlockSize(); ++i) {
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destination[i] = 0;
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}
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for (int j = 0; i < frames; ++i, ++j) {
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destination[i] = static_cast<float>(source_ptr_[j]);
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}
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}
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} // namespace webrtc
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