| /* |
| * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| #ifndef MODULES_AUDIO_CODING_NETEQ_DELAY_MANAGER_H_ |
| #define MODULES_AUDIO_CODING_NETEQ_DELAY_MANAGER_H_ |
| |
| #include <string.h> // Provide access to size_t. |
| |
| #include <memory> |
| #include <vector> |
| |
| #include "absl/types/optional.h" |
| #include "modules/audio_coding/neteq/tick_timer.h" |
| #include "rtc_base/constructormagic.h" |
| |
| namespace webrtc { |
| |
| // Forward declaration. |
| class DelayPeakDetector; |
| |
| class DelayManager { |
| public: |
| typedef std::vector<int> IATVector; |
| |
| // Create a DelayManager object. Notify the delay manager that the packet |
| // buffer can hold no more than |max_packets_in_buffer| packets (i.e., this |
| // is the number of packet slots in the buffer). Supply a PeakDetector |
| // object to the DelayManager. |
| DelayManager(size_t max_packets_in_buffer, |
| DelayPeakDetector* peak_detector, |
| const TickTimer* tick_timer); |
| |
| virtual ~DelayManager(); |
| |
| // Read the inter-arrival time histogram. Mainly for testing purposes. |
| virtual const IATVector& iat_vector() const; |
| |
| // Updates the delay manager with a new incoming packet, with |
| // |sequence_number| and |timestamp| from the RTP header. This updates the |
| // inter-arrival time histogram and other statistics, as well as the |
| // associated DelayPeakDetector. A new target buffer level is calculated. |
| // Returns 0 on success, -1 on failure (invalid sample rate). |
| virtual int Update(uint16_t sequence_number, |
| uint32_t timestamp, |
| int sample_rate_hz); |
| |
| // Calculates a new target buffer level. Called from the Update() method. |
| // Sets target_level_ (in Q8) and returns the same value. Also calculates |
| // and updates base_target_level_, which is the target buffer level before |
| // taking delay peaks into account. |
| virtual int CalculateTargetLevel(int iat_packets); |
| |
| // Notifies the DelayManager of how much audio data is carried in each packet. |
| // The method updates the DelayPeakDetector too, and resets the inter-arrival |
| // time counter. Returns 0 on success, -1 on failure. |
| virtual int SetPacketAudioLength(int length_ms); |
| |
| // Resets the DelayManager and the associated DelayPeakDetector. |
| virtual void Reset(); |
| |
| // Calculates the average inter-arrival time deviation from the histogram. |
| // The result is returned as parts-per-million deviation from the nominal |
| // inter-arrival time. That is, if the average inter-arrival time is equal to |
| // the nominal frame time, the return value is zero. A positive value |
| // corresponds to packet spacing being too large, while a negative value means |
| // that the packets arrive with less spacing than expected. |
| virtual double EstimatedClockDriftPpm() const; |
| |
| // Returns true if peak-mode is active. That is, delay peaks were observed |
| // recently. This method simply asks for the same information from the |
| // DelayPeakDetector object. |
| virtual bool PeakFound() const; |
| |
| // Reset the inter-arrival time counter to 0. |
| virtual void ResetPacketIatCount(); |
| |
| // Writes the lower and higher limits which the buffer level should stay |
| // within to the corresponding pointers. The values are in (fractions of) |
| // packets in Q8. |
| virtual void BufferLimits(int* lower_limit, int* higher_limit) const; |
| |
| // Gets the target buffer level, in (fractions of) packets in Q8. This value |
| // includes any extra delay set through the set_extra_delay_ms() method. |
| virtual int TargetLevel() const; |
| |
| // Informs the delay manager whether or not the last decoded packet contained |
| // speech. |
| virtual void LastDecodedWasCngOrDtmf(bool it_was); |
| |
| // Notify the delay manager that empty packets have been received. These are |
| // packets that are part of the sequence number series, so that an empty |
| // packet will shift the sequence numbers for the following packets. |
| virtual void RegisterEmptyPacket(); |
| |
| // Apply compression or stretching to the IAT histogram, for a change in frame |
| // size. This returns an updated histogram. This function is public for |
| // testability. |
| static IATVector ScaleHistogram(const IATVector& histogram, |
| int old_packet_length, |
| int new_packet_length); |
| |
| // Accessors and mutators. |
| // Assuming |delay| is in valid range. |
| virtual bool SetMinimumDelay(int delay_ms); |
| virtual bool SetMaximumDelay(int delay_ms); |
| virtual int base_target_level() const; |
| virtual void set_streaming_mode(bool value); |
| virtual int last_pack_cng_or_dtmf() const; |
| virtual void set_last_pack_cng_or_dtmf(int value); |
| |
| // This accessor is only intended for testing purposes. |
| const absl::optional<int>& forced_limit_probability_for_test() const { |
| return forced_limit_probability_; |
| } |
| |
| private: |
| // Sets |iat_vector_| to the default start distribution and sets the |
| // |base_target_level_| and |target_level_| to the corresponding values. |
| void ResetHistogram(); |
| |
| // Updates |iat_cumulative_sum_| and |max_iat_cumulative_sum_|. (These are |
| // used by the streaming mode.) This method is called by Update(). |
| void UpdateCumulativeSums(int packet_len_ms, uint16_t sequence_number); |
| |
| // Updates the histogram |iat_vector_|. The probability for inter-arrival time |
| // equal to |iat_packets| (in integer packets) is increased slightly, while |
| // all other entries are decreased. This method is called by Update(). |
| void UpdateHistogram(size_t iat_packets); |
| |
| // Makes sure that |target_level_| is not too large, taking |
| // |max_packets_in_buffer_| and |extra_delay_ms_| into account. This method is |
| // called by Update(). |
| void LimitTargetLevel(); |
| |
| bool first_packet_received_; |
| const size_t max_packets_in_buffer_; // Capacity of the packet buffer. |
| IATVector iat_vector_; // Histogram of inter-arrival times. |
| int iat_factor_; // Forgetting factor for updating the IAT histogram (Q15). |
| const TickTimer* tick_timer_; |
| // Time elapsed since last packet. |
| std::unique_ptr<TickTimer::Stopwatch> packet_iat_stopwatch_; |
| int base_target_level_; // Currently preferred buffer level before peak |
| // detection and streaming mode (Q0). |
| // TODO(turajs) change the comment according to the implementation of |
| // minimum-delay. |
| int target_level_; // Currently preferred buffer level in (fractions) |
| // of packets (Q8), before adding any extra delay. |
| int packet_len_ms_; // Length of audio in each incoming packet [ms]. |
| bool streaming_mode_; |
| uint16_t last_seq_no_; // Sequence number for last received packet. |
| uint32_t last_timestamp_; // Timestamp for the last received packet. |
| int minimum_delay_ms_; // Externally set minimum delay. |
| int maximum_delay_ms_; // Externally set maximum allowed delay. |
| int iat_cumulative_sum_; // Cumulative sum of delta inter-arrival times. |
| int max_iat_cumulative_sum_; // Max of |iat_cumulative_sum_|. |
| // Time elapsed since maximum was observed. |
| std::unique_ptr<TickTimer::Stopwatch> max_iat_stopwatch_; |
| DelayPeakDetector& peak_detector_; |
| int last_pack_cng_or_dtmf_; |
| const bool frame_length_change_experiment_; |
| const absl::optional<int> forced_limit_probability_; |
| |
| RTC_DISALLOW_COPY_AND_ASSIGN(DelayManager); |
| }; |
| |
| } // namespace webrtc |
| #endif // MODULES_AUDIO_CODING_NETEQ_DELAY_MANAGER_H_ |