henrik.lundin@webrtc.org | 9a40081 | 2013-01-29 12:09:21 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2012 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 | |
| 11 | #include "webrtc/modules/audio_coding/neteq4/accelerate.h" |
| 12 | |
| 13 | #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h" |
| 14 | |
| 15 | namespace webrtc { |
| 16 | |
| 17 | Accelerate::ReturnCodes Accelerate::Process( |
| 18 | const int16_t* input, |
| 19 | int input_length, |
| 20 | AudioMultiVector<int16_t>* output, |
| 21 | int16_t* length_change_samples) { |
| 22 | // Input length must be (almost) 30 ms. |
| 23 | static const int k15ms = 120; // 15 ms = 120 samples at 8 kHz sample rate. |
| 24 | if (num_channels_ == 0 || |
| 25 | input_length / num_channels_ < (2 * k15ms - 1) * fs_mult_) { |
| 26 | // Length of input data too short to do accelerate. Simply move all data |
| 27 | // from input to output. |
| 28 | output->PushBackInterleaved(input, input_length); |
| 29 | return kError; |
| 30 | } |
| 31 | return TimeStretch::Process(input, input_length, output, |
| 32 | length_change_samples); |
| 33 | } |
| 34 | |
| 35 | void Accelerate::SetParametersForPassiveSpeech(int /*len*/, |
| 36 | int16_t* best_correlation, |
| 37 | int* /*peak_index*/) const { |
| 38 | // When the signal does not contain any active speech, the correlation does |
| 39 | // not matter. Simply set it to zero. |
| 40 | *best_correlation = 0; |
| 41 | } |
| 42 | |
| 43 | Accelerate::ReturnCodes Accelerate::CheckCriteriaAndStretch( |
| 44 | const int16_t* input, int input_length, size_t peak_index, |
| 45 | int16_t best_correlation, bool active_speech, |
| 46 | AudioMultiVector<int16_t>* output) const { |
| 47 | // Check for strong correlation or passive speech. |
| 48 | if ((best_correlation > kCorrelationThreshold) || !active_speech) { |
| 49 | // Do accelerate operation by overlap add. |
| 50 | |
| 51 | // Pre-calculate common multiplication with |fs_mult_|. |
| 52 | // 120 corresponds to 15 ms. |
| 53 | size_t fs_mult_120 = fs_mult_ * 120; |
| 54 | |
| 55 | assert(fs_mult_120 >= peak_index); // Should be handled in Process(). |
| 56 | // Copy first part; 0 to 15 ms. |
| 57 | output->PushBackInterleaved(input, fs_mult_120 * num_channels_); |
| 58 | // Copy the |peak_index| starting at 15 ms to |temp_vector|. |
| 59 | AudioMultiVector<int16_t> temp_vector(num_channels_); |
| 60 | temp_vector.PushBackInterleaved(&input[fs_mult_120 * num_channels_], |
| 61 | peak_index * num_channels_); |
| 62 | // Cross-fade |temp_vector| onto the end of |output|. |
| 63 | output->CrossFade(temp_vector, peak_index); |
| 64 | // Copy the last unmodified part, 15 ms + pitch period until the end. |
| 65 | output->PushBackInterleaved( |
| 66 | &input[(fs_mult_120 + peak_index) * num_channels_], |
| 67 | input_length - (fs_mult_120 + peak_index) * num_channels_); |
| 68 | |
| 69 | if (active_speech) { |
| 70 | return kSuccess; |
| 71 | } else { |
| 72 | return kSuccessLowEnergy; |
| 73 | } |
| 74 | } else { |
| 75 | // Accelerate not allowed. Simply move all data from decoded to outData. |
| 76 | output->PushBackInterleaved(input, input_length); |
| 77 | return kNoStretch; |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | } // namespace webrtc |