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      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_NETEQ_IMPL_H_
     12 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_NETEQ_IMPL_H_
     13 
     14 #include <vector>
     15 
     16 #include "webrtc/base/constructormagic.h"
     17 #include "webrtc/modules/audio_coding/neteq/audio_multi_vector.h"
     18 #include "webrtc/modules/audio_coding/neteq/defines.h"
     19 #include "webrtc/modules/audio_coding/neteq/interface/neteq.h"
     20 #include "webrtc/modules/audio_coding/neteq/packet.h"  // Declare PacketList.
     21 #include "webrtc/modules/audio_coding/neteq/random_vector.h"
     22 #include "webrtc/modules/audio_coding/neteq/rtcp.h"
     23 #include "webrtc/modules/audio_coding/neteq/statistics_calculator.h"
     24 #include "webrtc/system_wrappers/interface/scoped_ptr.h"
     25 #include "webrtc/system_wrappers/interface/thread_annotations.h"
     26 #include "webrtc/typedefs.h"
     27 
     28 namespace webrtc {
     29 
     30 // Forward declarations.
     31 class Accelerate;
     32 class BackgroundNoise;
     33 class BufferLevelFilter;
     34 class ComfortNoise;
     35 class CriticalSectionWrapper;
     36 class DecisionLogic;
     37 class DecoderDatabase;
     38 class DelayManager;
     39 class DelayPeakDetector;
     40 class DtmfBuffer;
     41 class DtmfToneGenerator;
     42 class Expand;
     43 class Merge;
     44 class Normal;
     45 class PacketBuffer;
     46 class PayloadSplitter;
     47 class PostDecodeVad;
     48 class PreemptiveExpand;
     49 class RandomVector;
     50 class SyncBuffer;
     51 class TimestampScaler;
     52 struct AccelerateFactory;
     53 struct DtmfEvent;
     54 struct ExpandFactory;
     55 struct PreemptiveExpandFactory;
     56 
     57 class NetEqImpl : public webrtc::NetEq {
     58  public:
     59   // Creates a new NetEqImpl object. The object will assume ownership of all
     60   // injected dependencies, and will delete them when done.
     61   NetEqImpl(int fs,
     62             BufferLevelFilter* buffer_level_filter,
     63             DecoderDatabase* decoder_database,
     64             DelayManager* delay_manager,
     65             DelayPeakDetector* delay_peak_detector,
     66             DtmfBuffer* dtmf_buffer,
     67             DtmfToneGenerator* dtmf_tone_generator,
     68             PacketBuffer* packet_buffer,
     69             PayloadSplitter* payload_splitter,
     70             TimestampScaler* timestamp_scaler,
     71             AccelerateFactory* accelerate_factory,
     72             ExpandFactory* expand_factory,
     73             PreemptiveExpandFactory* preemptive_expand_factory,
     74             bool create_components = true);
     75 
     76   virtual ~NetEqImpl();
     77 
     78   // Inserts a new packet into NetEq. The |receive_timestamp| is an indication
     79   // of the time when the packet was received, and should be measured with
     80   // the same tick rate as the RTP timestamp of the current payload.
     81   // Returns 0 on success, -1 on failure.
     82   virtual int InsertPacket(const WebRtcRTPHeader& rtp_header,
     83                            const uint8_t* payload,
     84                            int length_bytes,
     85                            uint32_t receive_timestamp);
     86 
     87   // Inserts a sync-packet into packet queue. Sync-packets are decoded to
     88   // silence and are intended to keep AV-sync intact in an event of long packet
     89   // losses when Video NACK is enabled but Audio NACK is not. Clients of NetEq
     90   // might insert sync-packet when they observe that buffer level of NetEq is
     91   // decreasing below a certain threshold, defined by the application.
     92   // Sync-packets should have the same payload type as the last audio payload
     93   // type, i.e. they cannot have DTMF or CNG payload type, nor a codec change
     94   // can be implied by inserting a sync-packet.
     95   // Returns kOk on success, kFail on failure.
     96   virtual int InsertSyncPacket(const WebRtcRTPHeader& rtp_header,
     97                                uint32_t receive_timestamp);
     98 
     99   // Instructs NetEq to deliver 10 ms of audio data. The data is written to
    100   // |output_audio|, which can hold (at least) |max_length| elements.
    101   // The number of channels that were written to the output is provided in
    102   // the output variable |num_channels|, and each channel contains
    103   // |samples_per_channel| elements. If more than one channel is written,
    104   // the samples are interleaved.
    105   // The speech type is written to |type|, if |type| is not NULL.
    106   // Returns kOK on success, or kFail in case of an error.
    107   virtual int GetAudio(size_t max_length, int16_t* output_audio,
    108                        int* samples_per_channel, int* num_channels,
    109                        NetEqOutputType* type);
    110 
    111   // Associates |rtp_payload_type| with |codec| and stores the information in
    112   // the codec database. Returns kOK on success, kFail on failure.
    113   virtual int RegisterPayloadType(enum NetEqDecoder codec,
    114                                   uint8_t rtp_payload_type);
    115 
    116   // Provides an externally created decoder object |decoder| to insert in the
    117   // decoder database. The decoder implements a decoder of type |codec| and
    118   // associates it with |rtp_payload_type|. Returns kOK on success, kFail on
    119   // failure.
    120   virtual int RegisterExternalDecoder(AudioDecoder* decoder,
    121                                       enum NetEqDecoder codec,
    122                                       uint8_t rtp_payload_type);
    123 
    124   // Removes |rtp_payload_type| from the codec database. Returns 0 on success,
    125   // -1 on failure.
    126   virtual int RemovePayloadType(uint8_t rtp_payload_type);
    127 
    128   virtual bool SetMinimumDelay(int delay_ms);
    129 
    130   virtual bool SetMaximumDelay(int delay_ms);
    131 
    132   virtual int LeastRequiredDelayMs() const;
    133 
    134   virtual int SetTargetDelay() { return kNotImplemented; }
    135 
    136   virtual int TargetDelay() { return kNotImplemented; }
    137 
    138   virtual int CurrentDelay() { return kNotImplemented; }
    139 
    140   // Sets the playout mode to |mode|.
    141   virtual void SetPlayoutMode(NetEqPlayoutMode mode);
    142 
    143   // Returns the current playout mode.
    144   virtual NetEqPlayoutMode PlayoutMode() const;
    145 
    146   // Writes the current network statistics to |stats|. The statistics are reset
    147   // after the call.
    148   virtual int NetworkStatistics(NetEqNetworkStatistics* stats);
    149 
    150   // Writes the last packet waiting times (in ms) to |waiting_times|. The number
    151   // of values written is no more than 100, but may be smaller if the interface
    152   // is polled again before 100 packets has arrived.
    153   virtual void WaitingTimes(std::vector<int>* waiting_times);
    154 
    155   // Writes the current RTCP statistics to |stats|. The statistics are reset
    156   // and a new report period is started with the call.
    157   virtual void GetRtcpStatistics(RtcpStatistics* stats);
    158 
    159   // Same as RtcpStatistics(), but does not reset anything.
    160   virtual void GetRtcpStatisticsNoReset(RtcpStatistics* stats);
    161 
    162   // Enables post-decode VAD. When enabled, GetAudio() will return
    163   // kOutputVADPassive when the signal contains no speech.
    164   virtual void EnableVad();
    165 
    166   // Disables post-decode VAD.
    167   virtual void DisableVad();
    168 
    169   virtual bool GetPlayoutTimestamp(uint32_t* timestamp);
    170 
    171   virtual int SetTargetNumberOfChannels() { return kNotImplemented; }
    172 
    173   virtual int SetTargetSampleRate() { return kNotImplemented; }
    174 
    175   // Returns the error code for the last occurred error. If no error has
    176   // occurred, 0 is returned.
    177   virtual int LastError();
    178 
    179   // Returns the error code last returned by a decoder (audio or comfort noise).
    180   // When LastError() returns kDecoderErrorCode or kComfortNoiseErrorCode, check
    181   // this method to get the decoder's error code.
    182   virtual int LastDecoderError();
    183 
    184   // Flushes both the packet buffer and the sync buffer.
    185   virtual void FlushBuffers();
    186 
    187   virtual void PacketBufferStatistics(int* current_num_packets,
    188                                       int* max_num_packets) const;
    189 
    190   // Get sequence number and timestamp of the latest RTP.
    191   // This method is to facilitate NACK.
    192   virtual int DecodedRtpInfo(int* sequence_number, uint32_t* timestamp) const;
    193 
    194   // Sets background noise mode.
    195   virtual void SetBackgroundNoiseMode(NetEqBackgroundNoiseMode mode);
    196 
    197   // Gets background noise mode.
    198   virtual NetEqBackgroundNoiseMode BackgroundNoiseMode() const;
    199 
    200   // This accessor method is only intended for testing purposes.
    201   virtual const SyncBuffer* sync_buffer_for_test() const;
    202 
    203  protected:
    204   static const int kOutputSizeMs = 10;
    205   static const int kMaxFrameSize = 2880;  // 60 ms @ 48 kHz.
    206   // TODO(hlundin): Provide a better value for kSyncBufferSize.
    207   static const int kSyncBufferSize = 2 * kMaxFrameSize;
    208 
    209   // Inserts a new packet into NetEq. This is used by the InsertPacket method
    210   // above. Returns 0 on success, otherwise an error code.
    211   // TODO(hlundin): Merge this with InsertPacket above?
    212   int InsertPacketInternal(const WebRtcRTPHeader& rtp_header,
    213                            const uint8_t* payload,
    214                            int length_bytes,
    215                            uint32_t receive_timestamp,
    216                            bool is_sync_packet)
    217       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    218 
    219   // Delivers 10 ms of audio data. The data is written to |output|, which can
    220   // hold (at least) |max_length| elements. The number of channels that were
    221   // written to the output is provided in the output variable |num_channels|,
    222   // and each channel contains |samples_per_channel| elements. If more than one
    223   // channel is written, the samples are interleaved.
    224   // Returns 0 on success, otherwise an error code.
    225   int GetAudioInternal(size_t max_length,
    226                        int16_t* output,
    227                        int* samples_per_channel,
    228                        int* num_channels) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    229 
    230   // Provides a decision to the GetAudioInternal method. The decision what to
    231   // do is written to |operation|. Packets to decode are written to
    232   // |packet_list|, and a DTMF event to play is written to |dtmf_event|. When
    233   // DTMF should be played, |play_dtmf| is set to true by the method.
    234   // Returns 0 on success, otherwise an error code.
    235   int GetDecision(Operations* operation,
    236                   PacketList* packet_list,
    237                   DtmfEvent* dtmf_event,
    238                   bool* play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    239 
    240   // Decodes the speech packets in |packet_list|, and writes the results to
    241   // |decoded_buffer|, which is allocated to hold |decoded_buffer_length|
    242   // elements. The length of the decoded data is written to |decoded_length|.
    243   // The speech type -- speech or (codec-internal) comfort noise -- is written
    244   // to |speech_type|. If |packet_list| contains any SID frames for RFC 3389
    245   // comfort noise, those are not decoded.
    246   int Decode(PacketList* packet_list,
    247              Operations* operation,
    248              int* decoded_length,
    249              AudioDecoder::SpeechType* speech_type)
    250       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    251 
    252   // Sub-method to Decode(). Performs the actual decoding.
    253   int DecodeLoop(PacketList* packet_list,
    254                  Operations* operation,
    255                  AudioDecoder* decoder,
    256                  int* decoded_length,
    257                  AudioDecoder::SpeechType* speech_type)
    258       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    259 
    260   // Sub-method which calls the Normal class to perform the normal operation.
    261   void DoNormal(const int16_t* decoded_buffer,
    262                 size_t decoded_length,
    263                 AudioDecoder::SpeechType speech_type,
    264                 bool play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    265 
    266   // Sub-method which calls the Merge class to perform the merge operation.
    267   void DoMerge(int16_t* decoded_buffer,
    268                size_t decoded_length,
    269                AudioDecoder::SpeechType speech_type,
    270                bool play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    271 
    272   // Sub-method which calls the Expand class to perform the expand operation.
    273   int DoExpand(bool play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    274 
    275   // Sub-method which calls the Accelerate class to perform the accelerate
    276   // operation.
    277   int DoAccelerate(int16_t* decoded_buffer,
    278                    size_t decoded_length,
    279                    AudioDecoder::SpeechType speech_type,
    280                    bool play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    281 
    282   // Sub-method which calls the PreemptiveExpand class to perform the
    283   // preemtive expand operation.
    284   int DoPreemptiveExpand(int16_t* decoded_buffer,
    285                          size_t decoded_length,
    286                          AudioDecoder::SpeechType speech_type,
    287                          bool play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    288 
    289   // Sub-method which calls the ComfortNoise class to generate RFC 3389 comfort
    290   // noise. |packet_list| can either contain one SID frame to update the
    291   // noise parameters, or no payload at all, in which case the previously
    292   // received parameters are used.
    293   int DoRfc3389Cng(PacketList* packet_list, bool play_dtmf)
    294       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    295 
    296   // Calls the audio decoder to generate codec-internal comfort noise when
    297   // no packet was received.
    298   void DoCodecInternalCng() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    299 
    300   // Calls the DtmfToneGenerator class to generate DTMF tones.
    301   int DoDtmf(const DtmfEvent& dtmf_event, bool* play_dtmf)
    302       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    303 
    304   // Produces packet-loss concealment using alternative methods. If the codec
    305   // has an internal PLC, it is called to generate samples. Otherwise, the
    306   // method performs zero-stuffing.
    307   void DoAlternativePlc(bool increase_timestamp)
    308       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    309 
    310   // Overdub DTMF on top of |output|.
    311   int DtmfOverdub(const DtmfEvent& dtmf_event,
    312                   size_t num_channels,
    313                   int16_t* output) const EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    314 
    315   // Extracts packets from |packet_buffer_| to produce at least
    316   // |required_samples| samples. The packets are inserted into |packet_list|.
    317   // Returns the number of samples that the packets in the list will produce, or
    318   // -1 in case of an error.
    319   int ExtractPackets(int required_samples, PacketList* packet_list)
    320       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    321 
    322   // Resets various variables and objects to new values based on the sample rate
    323   // |fs_hz| and |channels| number audio channels.
    324   void SetSampleRateAndChannels(int fs_hz, size_t channels)
    325       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    326 
    327   // Returns the output type for the audio produced by the latest call to
    328   // GetAudio().
    329   NetEqOutputType LastOutputType() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    330 
    331   // Updates Expand and Merge.
    332   virtual void UpdatePlcComponents(int fs_hz, size_t channels)
    333       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    334 
    335   // Creates DecisionLogic object for the given mode.
    336   virtual void CreateDecisionLogic(NetEqPlayoutMode mode)
    337       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
    338 
    339   const scoped_ptr<CriticalSectionWrapper> crit_sect_;
    340   const scoped_ptr<BufferLevelFilter> buffer_level_filter_
    341       GUARDED_BY(crit_sect_);
    342   const scoped_ptr<DecoderDatabase> decoder_database_ GUARDED_BY(crit_sect_);
    343   const scoped_ptr<DelayManager> delay_manager_ GUARDED_BY(crit_sect_);
    344   const scoped_ptr<DelayPeakDetector> delay_peak_detector_
    345       GUARDED_BY(crit_sect_);
    346   const scoped_ptr<DtmfBuffer> dtmf_buffer_ GUARDED_BY(crit_sect_);
    347   const scoped_ptr<DtmfToneGenerator> dtmf_tone_generator_
    348       GUARDED_BY(crit_sect_);
    349   const scoped_ptr<PacketBuffer> packet_buffer_ GUARDED_BY(crit_sect_);
    350   const scoped_ptr<PayloadSplitter> payload_splitter_ GUARDED_BY(crit_sect_);
    351   const scoped_ptr<TimestampScaler> timestamp_scaler_ GUARDED_BY(crit_sect_);
    352   const scoped_ptr<PostDecodeVad> vad_ GUARDED_BY(crit_sect_);
    353   const scoped_ptr<ExpandFactory> expand_factory_ GUARDED_BY(crit_sect_);
    354   const scoped_ptr<AccelerateFactory> accelerate_factory_
    355       GUARDED_BY(crit_sect_);
    356   const scoped_ptr<PreemptiveExpandFactory> preemptive_expand_factory_
    357       GUARDED_BY(crit_sect_);
    358 
    359   scoped_ptr<BackgroundNoise> background_noise_ GUARDED_BY(crit_sect_);
    360   scoped_ptr<DecisionLogic> decision_logic_ GUARDED_BY(crit_sect_);
    361   scoped_ptr<AudioMultiVector> algorithm_buffer_ GUARDED_BY(crit_sect_);
    362   scoped_ptr<SyncBuffer> sync_buffer_ GUARDED_BY(crit_sect_);
    363   scoped_ptr<Expand> expand_ GUARDED_BY(crit_sect_);
    364   scoped_ptr<Normal> normal_ GUARDED_BY(crit_sect_);
    365   scoped_ptr<Merge> merge_ GUARDED_BY(crit_sect_);
    366   scoped_ptr<Accelerate> accelerate_ GUARDED_BY(crit_sect_);
    367   scoped_ptr<PreemptiveExpand> preemptive_expand_ GUARDED_BY(crit_sect_);
    368   RandomVector random_vector_ GUARDED_BY(crit_sect_);
    369   scoped_ptr<ComfortNoise> comfort_noise_ GUARDED_BY(crit_sect_);
    370   Rtcp rtcp_ GUARDED_BY(crit_sect_);
    371   StatisticsCalculator stats_ GUARDED_BY(crit_sect_);
    372   int fs_hz_ GUARDED_BY(crit_sect_);
    373   int fs_mult_ GUARDED_BY(crit_sect_);
    374   int output_size_samples_ GUARDED_BY(crit_sect_);
    375   int decoder_frame_length_ GUARDED_BY(crit_sect_);
    376   Modes last_mode_ GUARDED_BY(crit_sect_);
    377   scoped_ptr<int16_t[]> mute_factor_array_ GUARDED_BY(crit_sect_);
    378   size_t decoded_buffer_length_ GUARDED_BY(crit_sect_);
    379   scoped_ptr<int16_t[]> decoded_buffer_ GUARDED_BY(crit_sect_);
    380   uint32_t playout_timestamp_ GUARDED_BY(crit_sect_);
    381   bool new_codec_ GUARDED_BY(crit_sect_);
    382   uint32_t timestamp_ GUARDED_BY(crit_sect_);
    383   bool reset_decoder_ GUARDED_BY(crit_sect_);
    384   uint8_t current_rtp_payload_type_ GUARDED_BY(crit_sect_);
    385   uint8_t current_cng_rtp_payload_type_ GUARDED_BY(crit_sect_);
    386   uint32_t ssrc_ GUARDED_BY(crit_sect_);
    387   bool first_packet_ GUARDED_BY(crit_sect_);
    388   int error_code_ GUARDED_BY(crit_sect_);  // Store last error code.
    389   int decoder_error_code_ GUARDED_BY(crit_sect_);
    390 
    391   // These values are used by NACK module to estimate time-to-play of
    392   // a missing packet. Occasionally, NetEq might decide to decode more
    393   // than one packet. Therefore, these values store sequence number and
    394   // timestamp of the first packet pulled from the packet buffer. In
    395   // such cases, these values do not exactly represent the sequence number
    396   // or timestamp associated with a 10ms audio pulled from NetEq. NACK
    397   // module is designed to compensate for this.
    398   int decoded_packet_sequence_number_ GUARDED_BY(crit_sect_);
    399   uint32_t decoded_packet_timestamp_ GUARDED_BY(crit_sect_);
    400 
    401  private:
    402   DISALLOW_COPY_AND_ASSIGN(NetEqImpl);
    403 };
    404 
    405 }  // namespace webrtc
    406 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_NETEQ_IMPL_H_
    407