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 #ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ_COMFORT_NOISE_H_ 12 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_COMFORT_NOISE_H_ 13 14 #include "webrtc/base/constructormagic.h" 15 #include "webrtc/modules/audio_coding/neteq/audio_multi_vector.h" 16 #include "webrtc/typedefs.h" 17 18 namespace webrtc { 19 20 // Forward declarations. 21 class DecoderDatabase; 22 class SyncBuffer; 23 struct Packet; 24 25 // This class acts as an interface to the CNG generator. 26 class ComfortNoise { 27 public: 28 enum ReturnCodes { 29 kOK = 0, 30 kUnknownPayloadType, 31 kInternalError, 32 kMultiChannelNotSupported 33 }; 34 ComfortNoise(int fs_hz,DecoderDatabase * decoder_database,SyncBuffer * sync_buffer)35 ComfortNoise(int fs_hz, DecoderDatabase* decoder_database, 36 SyncBuffer* sync_buffer) 37 : fs_hz_(fs_hz), 38 first_call_(true), 39 overlap_length_(5 * fs_hz_ / 8000), 40 decoder_database_(decoder_database), 41 sync_buffer_(sync_buffer), 42 internal_error_code_(0) { 43 } 44 45 // Resets the state. Should be called before each new comfort noise period. 46 void Reset(); 47 48 // Update the comfort noise generator with the parameters in |packet|. 49 // Will delete the packet. 50 int UpdateParameters(Packet* packet); 51 52 // Generates |requested_length| samples of comfort noise and writes to 53 // |output|. If this is the first in call after Reset (or first after creating 54 // the object), it will also mix in comfort noise at the end of the 55 // SyncBuffer object provided in the constructor. 56 int Generate(size_t requested_length, AudioMultiVector* output); 57 58 // Returns the last error code that was produced by the comfort noise 59 // decoder. Returns 0 if no error has been encountered since the last reset. internal_error_code()60 int internal_error_code() { return internal_error_code_; } 61 62 private: 63 int fs_hz_; 64 bool first_call_; 65 size_t overlap_length_; 66 DecoderDatabase* decoder_database_; 67 SyncBuffer* sync_buffer_; 68 int internal_error_code_; 69 RTC_DISALLOW_COPY_AND_ASSIGN(ComfortNoise); 70 }; 71 72 } // namespace webrtc 73 #endif // WEBRTC_MODULES_AUDIO_CODING_NETEQ_COMFORT_NOISE_H_ 74