1 /* 2 * Copyright (c) 2015 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/codecs/g722/audio_decoder_g722.h" 12 13 #include <string.h> 14 15 #include "webrtc/base/checks.h" 16 #include "webrtc/modules/audio_coding/codecs/g722/g722_interface.h" 17 18 namespace webrtc { 19 20 AudioDecoderG722::AudioDecoderG722() { 21 WebRtcG722_CreateDecoder(&dec_state_); 22 WebRtcG722_DecoderInit(dec_state_); 23 } 24 25 AudioDecoderG722::~AudioDecoderG722() { 26 WebRtcG722_FreeDecoder(dec_state_); 27 } 28 29 bool AudioDecoderG722::HasDecodePlc() const { 30 return false; 31 } 32 33 int AudioDecoderG722::DecodeInternal(const uint8_t* encoded, 34 size_t encoded_len, 35 int sample_rate_hz, 36 int16_t* decoded, 37 SpeechType* speech_type) { 38 RTC_DCHECK_EQ(sample_rate_hz, 16000); 39 int16_t temp_type = 1; // Default is speech. 40 size_t ret = 41 WebRtcG722_Decode(dec_state_, encoded, encoded_len, decoded, &temp_type); 42 *speech_type = ConvertSpeechType(temp_type); 43 return static_cast<int>(ret); 44 } 45 46 void AudioDecoderG722::Reset() { 47 WebRtcG722_DecoderInit(dec_state_); 48 } 49 50 int AudioDecoderG722::PacketDuration(const uint8_t* encoded, 51 size_t encoded_len) const { 52 // 1/2 encoded byte per sample per channel. 53 return static_cast<int>(2 * encoded_len / Channels()); 54 } 55 56 size_t AudioDecoderG722::Channels() const { 57 return 1; 58 } 59 60 AudioDecoderG722Stereo::AudioDecoderG722Stereo() { 61 WebRtcG722_CreateDecoder(&dec_state_left_); 62 WebRtcG722_CreateDecoder(&dec_state_right_); 63 WebRtcG722_DecoderInit(dec_state_left_); 64 WebRtcG722_DecoderInit(dec_state_right_); 65 } 66 67 AudioDecoderG722Stereo::~AudioDecoderG722Stereo() { 68 WebRtcG722_FreeDecoder(dec_state_left_); 69 WebRtcG722_FreeDecoder(dec_state_right_); 70 } 71 72 int AudioDecoderG722Stereo::DecodeInternal(const uint8_t* encoded, 73 size_t encoded_len, 74 int sample_rate_hz, 75 int16_t* decoded, 76 SpeechType* speech_type) { 77 RTC_DCHECK_EQ(sample_rate_hz, 16000); 78 int16_t temp_type = 1; // Default is speech. 79 // De-interleave the bit-stream into two separate payloads. 80 uint8_t* encoded_deinterleaved = new uint8_t[encoded_len]; 81 SplitStereoPacket(encoded, encoded_len, encoded_deinterleaved); 82 // Decode left and right. 83 size_t decoded_len = WebRtcG722_Decode(dec_state_left_, encoded_deinterleaved, 84 encoded_len / 2, decoded, &temp_type); 85 size_t ret = WebRtcG722_Decode( 86 dec_state_right_, &encoded_deinterleaved[encoded_len / 2], 87 encoded_len / 2, &decoded[decoded_len], &temp_type); 88 if (ret == decoded_len) { 89 ret += decoded_len; // Return total number of samples. 90 // Interleave output. 91 for (size_t k = ret / 2; k < ret; k++) { 92 int16_t temp = decoded[k]; 93 memmove(&decoded[2 * k - ret + 2], &decoded[2 * k - ret + 1], 94 (ret - k - 1) * sizeof(int16_t)); 95 decoded[2 * k - ret + 1] = temp; 96 } 97 } 98 *speech_type = ConvertSpeechType(temp_type); 99 delete[] encoded_deinterleaved; 100 return static_cast<int>(ret); 101 } 102 103 size_t AudioDecoderG722Stereo::Channels() const { 104 return 2; 105 } 106 107 void AudioDecoderG722Stereo::Reset() { 108 WebRtcG722_DecoderInit(dec_state_left_); 109 WebRtcG722_DecoderInit(dec_state_right_); 110 } 111 112 // Split the stereo packet and place left and right channel after each other 113 // in the output array. 114 void AudioDecoderG722Stereo::SplitStereoPacket(const uint8_t* encoded, 115 size_t encoded_len, 116 uint8_t* encoded_deinterleaved) { 117 // Regroup the 4 bits/sample so |l1 l2| |r1 r2| |l3 l4| |r3 r4| ..., 118 // where "lx" is 4 bits representing left sample number x, and "rx" right 119 // sample. Two samples fit in one byte, represented with |...|. 120 for (size_t i = 0; i + 1 < encoded_len; i += 2) { 121 uint8_t right_byte = ((encoded[i] & 0x0F) << 4) + (encoded[i + 1] & 0x0F); 122 encoded_deinterleaved[i] = (encoded[i] & 0xF0) + (encoded[i + 1] >> 4); 123 encoded_deinterleaved[i + 1] = right_byte; 124 } 125 126 // Move one byte representing right channel each loop, and place it at the 127 // end of the bytestream vector. After looping the data is reordered to: 128 // |l1 l2| |l3 l4| ... |l(N-1) lN| |r1 r2| |r3 r4| ... |r(N-1) r(N)|, 129 // where N is the total number of samples. 130 for (size_t i = 0; i < encoded_len / 2; i++) { 131 uint8_t right_byte = encoded_deinterleaved[i + 1]; 132 memmove(&encoded_deinterleaved[i + 1], &encoded_deinterleaved[i + 2], 133 encoded_len - i - 2); 134 encoded_deinterleaved[encoded_len - 1] = right_byte; 135 } 136 } 137 138 } // namespace webrtc 139
