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_INCLUDE_AUDIO_DECODER_H_ 12 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_INCLUDE_AUDIO_DECODER_H_ 13 14 #include <stdlib.h> // NULL 15 16 #include "webrtc/base/constructormagic.h" 17 #include "webrtc/modules/audio_coding/codecs/cng/webrtc_cng.h" 18 #include "webrtc/typedefs.h" 19 20 namespace webrtc { 21 22 // This is the interface class for decoders in NetEQ. Each codec type will have 23 // and implementation of this class. 24 class AudioDecoder { 25 public: 26 enum SpeechType { 27 kSpeech = 1, 28 kComfortNoise = 2 29 }; 30 31 // Used by PacketDuration below. Save the value -1 for errors. 32 enum { kNotImplemented = -2 }; 33 34 AudioDecoder() = default; 35 virtual ~AudioDecoder() = default; 36 37 // Decodes |encode_len| bytes from |encoded| and writes the result in 38 // |decoded|. The maximum bytes allowed to be written into |decoded| is 39 // |max_decoded_bytes|. Returns the total number of samples across all 40 // channels. If the decoder produced comfort noise, |speech_type| 41 // is set to kComfortNoise, otherwise it is kSpeech. The desired output 42 // sample rate is provided in |sample_rate_hz|, which must be valid for the 43 // codec at hand. 44 int Decode(const uint8_t* encoded, 45 size_t encoded_len, 46 int sample_rate_hz, 47 size_t max_decoded_bytes, 48 int16_t* decoded, 49 SpeechType* speech_type); 50 51 // Same as Decode(), but interfaces to the decoders redundant decode function. 52 // The default implementation simply calls the regular Decode() method. 53 int DecodeRedundant(const uint8_t* encoded, 54 size_t encoded_len, 55 int sample_rate_hz, 56 size_t max_decoded_bytes, 57 int16_t* decoded, 58 SpeechType* speech_type); 59 60 // Indicates if the decoder implements the DecodePlc method. 61 virtual bool HasDecodePlc() const; 62 63 // Calls the packet-loss concealment of the decoder to update the state after 64 // one or several lost packets. The caller has to make sure that the 65 // memory allocated in |decoded| should accommodate |num_frames| frames. 66 virtual size_t DecodePlc(size_t num_frames, int16_t* decoded); 67 68 // Resets the decoder state (empty buffers etc.). 69 virtual void Reset() = 0; 70 71 // Notifies the decoder of an incoming packet to NetEQ. 72 virtual int IncomingPacket(const uint8_t* payload, 73 size_t payload_len, 74 uint16_t rtp_sequence_number, 75 uint32_t rtp_timestamp, 76 uint32_t arrival_timestamp); 77 78 // Returns the last error code from the decoder. 79 virtual int ErrorCode(); 80 81 // Returns the duration in samples-per-channel of the payload in |encoded| 82 // which is |encoded_len| bytes long. Returns kNotImplemented if no duration 83 // estimate is available, or -1 in case of an error. 84 virtual int PacketDuration(const uint8_t* encoded, size_t encoded_len) const; 85 86 // Returns the duration in samples-per-channel of the redandant payload in 87 // |encoded| which is |encoded_len| bytes long. Returns kNotImplemented if no 88 // duration estimate is available, or -1 in case of an error. 89 virtual int PacketDurationRedundant(const uint8_t* encoded, 90 size_t encoded_len) const; 91 92 // Detects whether a packet has forward error correction. The packet is 93 // comprised of the samples in |encoded| which is |encoded_len| bytes long. 94 // Returns true if the packet has FEC and false otherwise. 95 virtual bool PacketHasFec(const uint8_t* encoded, size_t encoded_len) const; 96 97 // If this is a CNG decoder, return the underlying CNG_dec_inst*. If this 98 // isn't a CNG decoder, don't call this method. 99 virtual CNG_dec_inst* CngDecoderInstance(); 100 101 virtual size_t Channels() const = 0; 102 103 protected: 104 static SpeechType ConvertSpeechType(int16_t type); 105 106 virtual int DecodeInternal(const uint8_t* encoded, 107 size_t encoded_len, 108 int sample_rate_hz, 109 int16_t* decoded, 110 SpeechType* speech_type) = 0; 111 112 virtual int DecodeRedundantInternal(const uint8_t* encoded, 113 size_t encoded_len, 114 int sample_rate_hz, 115 int16_t* decoded, 116 SpeechType* speech_type); 117 118 private: 119 RTC_DISALLOW_COPY_AND_ASSIGN(AudioDecoder); 120 }; 121 122 } // namespace webrtc 123 #endif // WEBRTC_MODULES_AUDIO_CODING_NETEQ_INCLUDE_AUDIO_DECODER_H_ 124
