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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/base/thread_annotations.h"
18 #include "webrtc/modules/audio_coding/neteq/audio_multi_vector.h"
19 #include "webrtc/modules/audio_coding/neteq/defines.h"
20 #include "webrtc/modules/audio_coding/neteq/interface/neteq.h"
21 #include "webrtc/modules/audio_coding/neteq/packet.h"  // Declare PacketList.
22 #include "webrtc/modules/audio_coding/neteq/random_vector.h"
23 #include "webrtc/modules/audio_coding/neteq/rtcp.h"
24 #include "webrtc/modules/audio_coding/neteq/statistics_calculator.h"
25 #include "webrtc/system_wrappers/interface/scoped_ptr.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(const NetEq::Config& config,
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) OVERRIDE;
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) OVERRIDE;
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) OVERRIDE;
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) OVERRIDE;
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) OVERRIDE;
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) OVERRIDE;
127 
128   virtual bool SetMinimumDelay(int delay_ms) OVERRIDE;
129 
130   virtual bool SetMaximumDelay(int delay_ms) OVERRIDE;
131 
132   virtual int LeastRequiredDelayMs() const OVERRIDE;
133 
SetTargetDelay()134   virtual int SetTargetDelay() OVERRIDE { return kNotImplemented; }
135 
TargetDelay()136   virtual int TargetDelay() OVERRIDE { return kNotImplemented; }
137 
CurrentDelay()138   virtual int CurrentDelay() OVERRIDE { return kNotImplemented; }
139 
140   // Sets the playout mode to |mode|.
141   virtual void SetPlayoutMode(NetEqPlayoutMode mode) OVERRIDE;
142 
143   // Returns the current playout mode.
144   virtual NetEqPlayoutMode PlayoutMode() const OVERRIDE;
145 
146   // Writes the current network statistics to |stats|. The statistics are reset
147   // after the call.
148   virtual int NetworkStatistics(NetEqNetworkStatistics* stats) OVERRIDE;
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) OVERRIDE;
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) OVERRIDE;
158 
159   // Same as RtcpStatistics(), but does not reset anything.
160   virtual void GetRtcpStatisticsNoReset(RtcpStatistics* stats) OVERRIDE;
161 
162   // Enables post-decode VAD. When enabled, GetAudio() will return
163   // kOutputVADPassive when the signal contains no speech.
164   virtual void EnableVad() OVERRIDE;
165 
166   // Disables post-decode VAD.
167   virtual void DisableVad() OVERRIDE;
168 
169   virtual bool GetPlayoutTimestamp(uint32_t* timestamp) OVERRIDE;
170 
SetTargetNumberOfChannels()171   virtual int SetTargetNumberOfChannels() OVERRIDE { return kNotImplemented; }
172 
SetTargetSampleRate()173   virtual int SetTargetSampleRate() OVERRIDE { 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() OVERRIDE;
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() OVERRIDE;
183 
184   // Flushes both the packet buffer and the sync buffer.
185   virtual void FlushBuffers() OVERRIDE;
186 
187   virtual void PacketBufferStatistics(int* current_num_packets,
188                                       int* max_num_packets) const OVERRIDE;
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,
193                              uint32_t* timestamp) const OVERRIDE;
194 
195   // This accessor method is only intended for testing purposes.
196   const SyncBuffer* sync_buffer_for_test() const;
197 
198  protected:
199   static const int kOutputSizeMs = 10;
200   static const int kMaxFrameSize = 2880;  // 60 ms @ 48 kHz.
201   // TODO(hlundin): Provide a better value for kSyncBufferSize.
202   static const int kSyncBufferSize = 2 * kMaxFrameSize;
203 
204   // Inserts a new packet into NetEq. This is used by the InsertPacket method
205   // above. Returns 0 on success, otherwise an error code.
206   // TODO(hlundin): Merge this with InsertPacket above?
207   int InsertPacketInternal(const WebRtcRTPHeader& rtp_header,
208                            const uint8_t* payload,
209                            int length_bytes,
210                            uint32_t receive_timestamp,
211                            bool is_sync_packet)
212       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
213 
214   // Delivers 10 ms of audio data. The data is written to |output|, which can
215   // hold (at least) |max_length| elements. The number of channels that were
216   // written to the output is provided in the output variable |num_channels|,
217   // and each channel contains |samples_per_channel| elements. If more than one
218   // channel is written, the samples are interleaved.
219   // Returns 0 on success, otherwise an error code.
220   int GetAudioInternal(size_t max_length,
221                        int16_t* output,
222                        int* samples_per_channel,
223                        int* num_channels) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
224 
225   // Provides a decision to the GetAudioInternal method. The decision what to
226   // do is written to |operation|. Packets to decode are written to
227   // |packet_list|, and a DTMF event to play is written to |dtmf_event|. When
228   // DTMF should be played, |play_dtmf| is set to true by the method.
229   // Returns 0 on success, otherwise an error code.
230   int GetDecision(Operations* operation,
231                   PacketList* packet_list,
232                   DtmfEvent* dtmf_event,
233                   bool* play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
234 
235   // Decodes the speech packets in |packet_list|, and writes the results to
236   // |decoded_buffer|, which is allocated to hold |decoded_buffer_length|
237   // elements. The length of the decoded data is written to |decoded_length|.
238   // The speech type -- speech or (codec-internal) comfort noise -- is written
239   // to |speech_type|. If |packet_list| contains any SID frames for RFC 3389
240   // comfort noise, those are not decoded.
241   int Decode(PacketList* packet_list,
242              Operations* operation,
243              int* decoded_length,
244              AudioDecoder::SpeechType* speech_type)
245       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
246 
247   // Sub-method to Decode(). Performs the actual decoding.
248   int DecodeLoop(PacketList* packet_list,
249                  Operations* operation,
250                  AudioDecoder* decoder,
251                  int* decoded_length,
252                  AudioDecoder::SpeechType* speech_type)
253       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
254 
255   // Sub-method which calls the Normal class to perform the normal operation.
256   void DoNormal(const int16_t* decoded_buffer,
257                 size_t decoded_length,
258                 AudioDecoder::SpeechType speech_type,
259                 bool play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
260 
261   // Sub-method which calls the Merge class to perform the merge operation.
262   void DoMerge(int16_t* decoded_buffer,
263                size_t decoded_length,
264                AudioDecoder::SpeechType speech_type,
265                bool play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
266 
267   // Sub-method which calls the Expand class to perform the expand operation.
268   int DoExpand(bool play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
269 
270   // Sub-method which calls the Accelerate class to perform the accelerate
271   // operation.
272   int DoAccelerate(int16_t* decoded_buffer,
273                    size_t decoded_length,
274                    AudioDecoder::SpeechType speech_type,
275                    bool play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
276 
277   // Sub-method which calls the PreemptiveExpand class to perform the
278   // preemtive expand operation.
279   int DoPreemptiveExpand(int16_t* decoded_buffer,
280                          size_t decoded_length,
281                          AudioDecoder::SpeechType speech_type,
282                          bool play_dtmf) EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
283 
284   // Sub-method which calls the ComfortNoise class to generate RFC 3389 comfort
285   // noise. |packet_list| can either contain one SID frame to update the
286   // noise parameters, or no payload at all, in which case the previously
287   // received parameters are used.
288   int DoRfc3389Cng(PacketList* packet_list, bool play_dtmf)
289       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
290 
291   // Calls the audio decoder to generate codec-internal comfort noise when
292   // no packet was received.
293   void DoCodecInternalCng() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
294 
295   // Calls the DtmfToneGenerator class to generate DTMF tones.
296   int DoDtmf(const DtmfEvent& dtmf_event, bool* play_dtmf)
297       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
298 
299   // Produces packet-loss concealment using alternative methods. If the codec
300   // has an internal PLC, it is called to generate samples. Otherwise, the
301   // method performs zero-stuffing.
302   void DoAlternativePlc(bool increase_timestamp)
303       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
304 
305   // Overdub DTMF on top of |output|.
306   int DtmfOverdub(const DtmfEvent& dtmf_event,
307                   size_t num_channels,
308                   int16_t* output) const EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
309 
310   // Extracts packets from |packet_buffer_| to produce at least
311   // |required_samples| samples. The packets are inserted into |packet_list|.
312   // Returns the number of samples that the packets in the list will produce, or
313   // -1 in case of an error.
314   int ExtractPackets(int required_samples, PacketList* packet_list)
315       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
316 
317   // Resets various variables and objects to new values based on the sample rate
318   // |fs_hz| and |channels| number audio channels.
319   void SetSampleRateAndChannels(int fs_hz, size_t channels)
320       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
321 
322   // Returns the output type for the audio produced by the latest call to
323   // GetAudio().
324   NetEqOutputType LastOutputType() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
325 
326   // Updates Expand and Merge.
327   virtual void UpdatePlcComponents(int fs_hz, size_t channels)
328       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
329 
330   // Creates DecisionLogic object for the given mode.
331   virtual void CreateDecisionLogic(NetEqPlayoutMode mode)
332       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
333 
334   const scoped_ptr<CriticalSectionWrapper> crit_sect_;
335   const scoped_ptr<BufferLevelFilter> buffer_level_filter_
336       GUARDED_BY(crit_sect_);
337   const scoped_ptr<DecoderDatabase> decoder_database_ GUARDED_BY(crit_sect_);
338   const scoped_ptr<DelayManager> delay_manager_ GUARDED_BY(crit_sect_);
339   const scoped_ptr<DelayPeakDetector> delay_peak_detector_
340       GUARDED_BY(crit_sect_);
341   const scoped_ptr<DtmfBuffer> dtmf_buffer_ GUARDED_BY(crit_sect_);
342   const scoped_ptr<DtmfToneGenerator> dtmf_tone_generator_
343       GUARDED_BY(crit_sect_);
344   const scoped_ptr<PacketBuffer> packet_buffer_ GUARDED_BY(crit_sect_);
345   const scoped_ptr<PayloadSplitter> payload_splitter_ GUARDED_BY(crit_sect_);
346   const scoped_ptr<TimestampScaler> timestamp_scaler_ GUARDED_BY(crit_sect_);
347   const scoped_ptr<PostDecodeVad> vad_ GUARDED_BY(crit_sect_);
348   const scoped_ptr<ExpandFactory> expand_factory_ GUARDED_BY(crit_sect_);
349   const scoped_ptr<AccelerateFactory> accelerate_factory_
350       GUARDED_BY(crit_sect_);
351   const scoped_ptr<PreemptiveExpandFactory> preemptive_expand_factory_
352       GUARDED_BY(crit_sect_);
353 
354   scoped_ptr<BackgroundNoise> background_noise_ GUARDED_BY(crit_sect_);
355   scoped_ptr<DecisionLogic> decision_logic_ GUARDED_BY(crit_sect_);
356   scoped_ptr<AudioMultiVector> algorithm_buffer_ GUARDED_BY(crit_sect_);
357   scoped_ptr<SyncBuffer> sync_buffer_ GUARDED_BY(crit_sect_);
358   scoped_ptr<Expand> expand_ GUARDED_BY(crit_sect_);
359   scoped_ptr<Normal> normal_ GUARDED_BY(crit_sect_);
360   scoped_ptr<Merge> merge_ GUARDED_BY(crit_sect_);
361   scoped_ptr<Accelerate> accelerate_ GUARDED_BY(crit_sect_);
362   scoped_ptr<PreemptiveExpand> preemptive_expand_ GUARDED_BY(crit_sect_);
363   RandomVector random_vector_ GUARDED_BY(crit_sect_);
364   scoped_ptr<ComfortNoise> comfort_noise_ GUARDED_BY(crit_sect_);
365   Rtcp rtcp_ GUARDED_BY(crit_sect_);
366   StatisticsCalculator stats_ GUARDED_BY(crit_sect_);
367   int fs_hz_ GUARDED_BY(crit_sect_);
368   int fs_mult_ GUARDED_BY(crit_sect_);
369   int output_size_samples_ GUARDED_BY(crit_sect_);
370   int decoder_frame_length_ GUARDED_BY(crit_sect_);
371   Modes last_mode_ GUARDED_BY(crit_sect_);
372   scoped_ptr<int16_t[]> mute_factor_array_ GUARDED_BY(crit_sect_);
373   size_t decoded_buffer_length_ GUARDED_BY(crit_sect_);
374   scoped_ptr<int16_t[]> decoded_buffer_ GUARDED_BY(crit_sect_);
375   uint32_t playout_timestamp_ GUARDED_BY(crit_sect_);
376   bool new_codec_ GUARDED_BY(crit_sect_);
377   uint32_t timestamp_ GUARDED_BY(crit_sect_);
378   bool reset_decoder_ GUARDED_BY(crit_sect_);
379   uint8_t current_rtp_payload_type_ GUARDED_BY(crit_sect_);
380   uint8_t current_cng_rtp_payload_type_ GUARDED_BY(crit_sect_);
381   uint32_t ssrc_ GUARDED_BY(crit_sect_);
382   bool first_packet_ GUARDED_BY(crit_sect_);
383   int error_code_ GUARDED_BY(crit_sect_);  // Store last error code.
384   int decoder_error_code_ GUARDED_BY(crit_sect_);
385   const BackgroundNoiseMode background_noise_mode_ GUARDED_BY(crit_sect_);
386 
387   // These values are used by NACK module to estimate time-to-play of
388   // a missing packet. Occasionally, NetEq might decide to decode more
389   // than one packet. Therefore, these values store sequence number and
390   // timestamp of the first packet pulled from the packet buffer. In
391   // such cases, these values do not exactly represent the sequence number
392   // or timestamp associated with a 10ms audio pulled from NetEq. NACK
393   // module is designed to compensate for this.
394   int decoded_packet_sequence_number_ GUARDED_BY(crit_sect_);
395   uint32_t decoded_packet_timestamp_ GUARDED_BY(crit_sect_);
396 
397  private:
398   DISALLOW_COPY_AND_ASSIGN(NetEqImpl);
399 };
400 
401 }  // namespace webrtc
402 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_NETEQ_IMPL_H_
403