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andrew@webrtc.orgdea537b2013-04-26 14:56:511/*
2 * Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
andrew@webrtc.org6a5ccc52014-03-10 18:51:4211#include "webrtc/common_audio/resampler/push_sinc_resampler.h"
12
andrew@webrtc.org43157042015-02-11 01:09:5013#include <cstring>
14
andrew@webrtc.org43157042015-02-11 01:09:5015#include "webrtc/common_audio/include/audio_util.h"
Edward Lemur76de83e2017-07-06 17:44:3416#include "webrtc/rtc_base/checks.h"
andrew@webrtc.org43157042015-02-11 01:09:5017
andrew@webrtc.orgdea537b2013-04-26 14:56:5118namespace webrtc {
19
Peter Kastinga0ad2482015-08-24 21:52:2320PushSincResampler::PushSincResampler(size_t source_frames,
21 size_t destination_frames)
andrew@webrtc.org221798a2013-10-22 12:50:0022 : resampler_(new SincResampler(source_frames * 1.0 / destination_frames,
andrew@webrtc.org6a5ccc52014-03-10 18:51:4223 source_frames,
24 this)),
andrew@webrtc.org43157042015-02-11 01:09:5025 source_ptr_(nullptr),
26 source_ptr_int_(nullptr),
andrew@webrtc.org05f21312013-07-25 22:04:3027 destination_frames_(destination_frames),
28 first_pass_(true),
andrew@webrtc.org6a5ccc52014-03-10 18:51:4229 source_available_(0) {}
andrew@webrtc.orgdea537b2013-04-26 14:56:5130
31PushSincResampler::~PushSincResampler() {
32}
33
Peter Kastinga0ad2482015-08-24 21:52:2334size_t PushSincResampler::Resample(const int16_t* source,
35 size_t source_length,
36 int16_t* destination,
37 size_t destination_capacity) {
andrew@webrtc.org6a5ccc52014-03-10 18:51:4238 if (!float_buffer_.get())
39 float_buffer_.reset(new float[destination_frames_]);
40
41 source_ptr_int_ = source;
andrew@webrtc.org43157042015-02-11 01:09:5042 // Pass nullptr as the float source to have Run() read from the int16 source.
43 Resample(nullptr, source_length, float_buffer_.get(), destination_frames_);
andrew@webrtc.orgbce13292014-10-30 03:40:1044 FloatS16ToS16(float_buffer_.get(), destination_frames_, destination);
andrew@webrtc.org43157042015-02-11 01:09:5045 source_ptr_int_ = nullptr;
andrew@webrtc.org6a5ccc52014-03-10 18:51:4246 return destination_frames_;
47}
48
Peter Kastinga0ad2482015-08-24 21:52:2349size_t PushSincResampler::Resample(const float* source,
50 size_t source_length,
51 float* destination,
52 size_t destination_capacity) {
henrikg5c075c82015-09-17 07:24:3453 RTC_CHECK_EQ(source_length, resampler_->request_frames());
54 RTC_CHECK_GE(destination_capacity, destination_frames_);
andrew@webrtc.orgdea537b2013-04-26 14:56:5155 // Cache the source pointer. Calling Resample() will immediately trigger
56 // the Run() callback whereupon we provide the cached value.
57 source_ptr_ = source;
andrew@webrtc.org05f21312013-07-25 22:04:3058 source_available_ = source_length;
59
60 // On the first pass, we call Resample() twice. During the first call, we
61 // provide dummy input and discard the output. This is done to prime the
62 // SincResampler buffer with the correct delay (half the kernel size), thereby
63 // ensuring that all later Resample() calls will only result in one input
64 // request through Run().
65 //
66 // If this wasn't done, SincResampler would call Run() twice on the first
67 // pass, and we'd have to introduce an entire |source_frames| of delay, rather
68 // than the minimum half kernel.
69 //
70 // It works out that ChunkSize() is exactly the amount of output we need to
71 // request in order to prime the buffer with a single Run() request for
72 // |source_frames|.
73 if (first_pass_)
andrew@webrtc.org6a5ccc52014-03-10 18:51:4274 resampler_->Resample(resampler_->ChunkSize(), destination);
andrew@webrtc.org05f21312013-07-25 22:04:3075
andrew@webrtc.org6a5ccc52014-03-10 18:51:4276 resampler_->Resample(destination_frames_, destination);
andrew@webrtc.org43157042015-02-11 01:09:5077 source_ptr_ = nullptr;
andrew@webrtc.org05f21312013-07-25 22:04:3078 return destination_frames_;
andrew@webrtc.orgdea537b2013-04-26 14:56:5179}
80
Peter Kastinga0ad2482015-08-24 21:52:2381void PushSincResampler::Run(size_t frames, float* destination) {
andrew@webrtc.org05f21312013-07-25 22:04:3082 // Ensure we are only asked for the available samples. This would fail if
83 // Run() was triggered more than once per Resample() call.
henrikg5c075c82015-09-17 07:24:3484 RTC_CHECK_EQ(source_available_, frames);
andrew@webrtc.org05f21312013-07-25 22:04:3085
86 if (first_pass_) {
87 // Provide dummy input on the first pass, the output of which will be
88 // discarded, as described in Resample().
andrew@webrtc.org43157042015-02-11 01:09:5089 std::memset(destination, 0, frames * sizeof(*destination));
andrew@webrtc.org05f21312013-07-25 22:04:3090 first_pass_ = false;
andrew@webrtc.org6a5ccc52014-03-10 18:51:4291 return;
92 }
93
94 if (source_ptr_) {
andrew@webrtc.org43157042015-02-11 01:09:5095 std::memcpy(destination, source_ptr_, frames * sizeof(*destination));
andrew@webrtc.org05f21312013-07-25 22:04:3096 } else {
Peter Kastinga0ad2482015-08-24 21:52:2397 for (size_t i = 0; i < frames; ++i)
andrew@webrtc.org6a5ccc52014-03-10 18:51:4298 destination[i] = static_cast<float>(source_ptr_int_[i]);
andrew@webrtc.orgdea537b2013-04-26 14:56:5199 }
andrew@webrtc.org6a5ccc52014-03-10 18:51:42100 source_available_ -= frames;
andrew@webrtc.orgdea537b2013-04-26 14:56:51101}
102
103} // namespace webrtc