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/*
* Copyright (c) 2013 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_DECISION_LOGIC_H_
#define MODULES_AUDIO_CODING_NETEQ_DECISION_LOGIC_H_
#include "modules/audio_coding/neteq/defines.h"
#include "modules/audio_coding/neteq/tick_timer.h"
#include "rtc_base/constructormagic.h"
namespace webrtc {
// Forward declarations.
class BufferLevelFilter;
class DecoderDatabase;
class DelayManager;
class Expand;
class PacketBuffer;
class SyncBuffer;
struct Packet;
// This is the class for the decision tree implementation.
class DecisionLogic final {
public:
// Static factory function which creates different types of objects depending
// on the |playout_mode|.
static DecisionLogic* Create(int fs_hz,
size_t output_size_samples,
bool disallow_time_stretching,
DecoderDatabase* decoder_database,
const PacketBuffer& packet_buffer,
DelayManager* delay_manager,
BufferLevelFilter* buffer_level_filter,
const TickTimer* tick_timer);
static const int kReinitAfterExpands = 100;
static const int kMaxWaitForPacket = 10;
// Constructor.
DecisionLogic(int fs_hz,
size_t output_size_samples,
bool disallow_time_stretching,
DecoderDatabase* decoder_database,
const PacketBuffer& packet_buffer,
DelayManager* delay_manager,
BufferLevelFilter* buffer_level_filter,
const TickTimer* tick_timer);
~DecisionLogic();
// Resets object to a clean state.
void Reset();
// Resets parts of the state. Typically done when switching codecs.
void SoftReset();
// Sets the sample rate and the output block size.
void SetSampleRate(int fs_hz, size_t output_size_samples);
// Returns the operation that should be done next. |sync_buffer| and |expand|
// are provided for reference. |decoder_frame_length| is the number of samples
// obtained from the last decoded frame. If there is a packet available, it
// should be supplied in |next_packet|; otherwise it should be NULL. The mode
// resulting from the last call to NetEqImpl::GetAudio is supplied in
// |prev_mode|. If there is a DTMF event to play, |play_dtmf| should be set to
// true. The output variable |reset_decoder| will be set to true if a reset is
// required; otherwise it is left unchanged (i.e., it can remain true if it
// was true before the call). This method end with calling
// GetDecisionSpecialized to get the actual return value.
Operations GetDecision(const SyncBuffer& sync_buffer,
const Expand& expand,
size_t decoder_frame_length,
const Packet* next_packet,
Modes prev_mode,
bool play_dtmf,
size_t generated_noise_samples,
bool* reset_decoder);
// These methods test the |cng_state_| for different conditions.
bool CngRfc3389On() const { return cng_state_ == kCngRfc3389On; }
bool CngOff() const { return cng_state_ == kCngOff; }
// Resets the |cng_state_| to kCngOff.
void SetCngOff() { cng_state_ = kCngOff; }
// Reports back to DecisionLogic whether the decision to do expand remains or
// not. Note that this is necessary, since an expand decision can be changed
// to kNormal in NetEqImpl::GetDecision if there is still enough data in the
// sync buffer.
void ExpandDecision(Operations operation);
// Adds |value| to |sample_memory_|.
void AddSampleMemory(int32_t value) { sample_memory_ += value; }
// Accessors and mutators.
void set_sample_memory(int32_t value) { sample_memory_ = value; }
size_t noise_fast_forward() const { return noise_fast_forward_; }
size_t packet_length_samples() const { return packet_length_samples_; }
void set_packet_length_samples(size_t value) {
packet_length_samples_ = value;
}
void set_prev_time_scale(bool value) { prev_time_scale_ = value; }
int postpone_decoding_level_for_test() const {
return postpone_decoding_level_;
}
private:
// The value 5 sets maximum time-stretch rate to about 100 ms/s.
static const int kMinTimescaleInterval = 5;
enum CngState { kCngOff, kCngRfc3389On, kCngInternalOn };
// Updates the |buffer_level_filter_| with the current buffer level
// |buffer_size_packets|.
void FilterBufferLevel(size_t buffer_size_packets, Modes prev_mode);
// Returns the operation given that the next available packet is a comfort
// noise payload (RFC 3389 only, not codec-internal).
Operations CngOperation(Modes prev_mode,
uint32_t target_timestamp,
uint32_t available_timestamp,
size_t generated_noise_samples);
// Returns the operation given that no packets are available (except maybe
// a DTMF event, flagged by setting |play_dtmf| true).
Operations NoPacket(bool play_dtmf);
// Returns the operation to do given that the expected packet is available.
Operations ExpectedPacketAvailable(Modes prev_mode, bool play_dtmf);
// Returns the operation to do given that the expected packet is not
// available, but a packet further into the future is at hand.
Operations FuturePacketAvailable(const SyncBuffer& sync_buffer,
const Expand& expand,
size_t decoder_frame_length,
Modes prev_mode,
uint32_t target_timestamp,
uint32_t available_timestamp,
bool play_dtmf,
size_t generated_noise_samples);
// Checks if enough time has elapsed since the last successful timescale
// operation was done (i.e., accelerate or preemptive expand).
bool TimescaleAllowed() const {
return !timescale_countdown_ || timescale_countdown_->Finished();
}
// Checks if the current (filtered) buffer level is under the target level.
bool UnderTargetLevel() const;
// Checks if |timestamp_leap| is so long into the future that a reset due
// to exceeding kReinitAfterExpands will be done.
bool ReinitAfterExpands(uint32_t timestamp_leap) const;
// Checks if we still have not done enough expands to cover the distance from
// the last decoded packet to the next available packet, the distance beeing
// conveyed in |timestamp_leap|.
bool PacketTooEarly(uint32_t timestamp_leap) const;
// Checks if num_consecutive_expands_ >= kMaxWaitForPacket.
bool MaxWaitForPacket() const;
DecoderDatabase* decoder_database_;
const PacketBuffer& packet_buffer_;
DelayManager* delay_manager_;
BufferLevelFilter* buffer_level_filter_;
const TickTimer* tick_timer_;
int fs_mult_;
size_t output_size_samples_;
CngState cng_state_; // Remember if comfort noise is interrupted by other
// event (e.g., DTMF).
size_t noise_fast_forward_ = 0;
size_t packet_length_samples_;
int sample_memory_;
bool prev_time_scale_;
bool disallow_time_stretching_;
std::unique_ptr<TickTimer::Countdown> timescale_countdown_;
int num_consecutive_expands_;
const int postpone_decoding_level_;
RTC_DISALLOW_COPY_AND_ASSIGN(DecisionLogic);
};
} // namespace webrtc
#endif // MODULES_AUDIO_CODING_NETEQ_DECISION_LOGIC_H_