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Diffstat (limited to 'third_party/libwebrtc/modules/video_coding/jitter_buffer.h')
-rw-r--r-- | third_party/libwebrtc/modules/video_coding/jitter_buffer.h | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/video_coding/jitter_buffer.h b/third_party/libwebrtc/modules/video_coding/jitter_buffer.h new file mode 100644 index 0000000000..7ca8953428 --- /dev/null +++ b/third_party/libwebrtc/modules/video_coding/jitter_buffer.h @@ -0,0 +1,275 @@ +/* + * 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_VIDEO_CODING_JITTER_BUFFER_H_ +#define MODULES_VIDEO_CODING_JITTER_BUFFER_H_ + +#include <list> +#include <map> +#include <memory> +#include <set> +#include <vector> + +#include "api/field_trials_view.h" +#include "modules/include/module_common_types.h" +#include "modules/include/module_common_types_public.h" +#include "modules/video_coding/decoding_state.h" +#include "modules/video_coding/event_wrapper.h" +#include "modules/video_coding/include/video_coding.h" +#include "modules/video_coding/include/video_coding_defines.h" +#include "modules/video_coding/jitter_buffer_common.h" +#include "modules/video_coding/timing/inter_frame_delay.h" +#include "modules/video_coding/timing/jitter_estimator.h" +#include "rtc_base/synchronization/mutex.h" +#include "rtc_base/thread_annotations.h" + +namespace webrtc { + +// forward declarations +class Clock; +class VCMFrameBuffer; +class VCMPacket; +class VCMEncodedFrame; + +typedef std::list<VCMFrameBuffer*> UnorderedFrameList; + +struct VCMJitterSample { + VCMJitterSample() : timestamp(0), frame_size(0), latest_packet_time(-1) {} + uint32_t timestamp; + uint32_t frame_size; + int64_t latest_packet_time; +}; + +class TimestampLessThan { + public: + bool operator()(uint32_t timestamp1, uint32_t timestamp2) const { + return IsNewerTimestamp(timestamp2, timestamp1); + } +}; + +class FrameList + : public std::map<uint32_t, VCMFrameBuffer*, TimestampLessThan> { + public: + void InsertFrame(VCMFrameBuffer* frame); + VCMFrameBuffer* PopFrame(uint32_t timestamp); + VCMFrameBuffer* Front() const; + VCMFrameBuffer* Back() const; + int RecycleFramesUntilKeyFrame(FrameList::iterator* key_frame_it, + UnorderedFrameList* free_frames); + void CleanUpOldOrEmptyFrames(VCMDecodingState* decoding_state, + UnorderedFrameList* free_frames); + void Reset(UnorderedFrameList* free_frames); +}; + +class VCMJitterBuffer { + public: + VCMJitterBuffer(Clock* clock, + std::unique_ptr<EventWrapper> event, + const FieldTrialsView& field_trials); + + ~VCMJitterBuffer(); + + VCMJitterBuffer(const VCMJitterBuffer&) = delete; + VCMJitterBuffer& operator=(const VCMJitterBuffer&) = delete; + + // Initializes and starts jitter buffer. + void Start(); + + // Signals all internal events and stops the jitter buffer. + void Stop(); + + // Returns true if the jitter buffer is running. + bool Running() const; + + // Empty the jitter buffer of all its data. + void Flush(); + + // Gets number of packets received. + int num_packets() const; + + // Gets number of duplicated packets received. + int num_duplicated_packets() const; + + // Wait `max_wait_time_ms` for a complete frame to arrive. + // If found, a pointer to the frame is returned. Returns nullptr otherwise. + VCMEncodedFrame* NextCompleteFrame(uint32_t max_wait_time_ms); + + // Extract frame corresponding to input timestamp. + // Frame will be set to a decoding state. + VCMEncodedFrame* ExtractAndSetDecode(uint32_t timestamp); + + // Releases a frame returned from the jitter buffer, should be called when + // done with decoding. + void ReleaseFrame(VCMEncodedFrame* frame); + + // Returns the time in ms when the latest packet was inserted into the frame. + // Retransmitted is set to true if any of the packets belonging to the frame + // has been retransmitted. + int64_t LastPacketTime(const VCMEncodedFrame* frame, + bool* retransmitted) const; + + // Inserts a packet into a frame returned from GetFrame(). + // If the return value is <= 0, `frame` is invalidated and the pointer must + // be dropped after this function returns. + VCMFrameBufferEnum InsertPacket(const VCMPacket& packet, bool* retransmitted); + + // Returns the estimated jitter in milliseconds. + uint32_t EstimatedJitterMs(); + + void SetNackSettings(size_t max_nack_list_size, + int max_packet_age_to_nack, + int max_incomplete_time_ms); + + // Returns a list of the sequence numbers currently missing. + std::vector<uint16_t> GetNackList(bool* request_key_frame); + + private: + class SequenceNumberLessThan { + public: + bool operator()(const uint16_t& sequence_number1, + const uint16_t& sequence_number2) const { + return IsNewerSequenceNumber(sequence_number2, sequence_number1); + } + }; + typedef std::set<uint16_t, SequenceNumberLessThan> SequenceNumberSet; + + // Gets the frame assigned to the timestamp of the packet. May recycle + // existing frames if no free frames are available. Returns an error code if + // failing, or kNoError on success. `frame_list` contains which list the + // packet was in, or NULL if it was not in a FrameList (a new frame). + VCMFrameBufferEnum GetFrame(const VCMPacket& packet, + VCMFrameBuffer** frame, + FrameList** frame_list) + RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + + // Returns true if `frame` is continuous in `decoding_state`, not taking + // decodable frames into account. + bool IsContinuousInState(const VCMFrameBuffer& frame, + const VCMDecodingState& decoding_state) const + RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + // Returns true if `frame` is continuous in the `last_decoded_state_`, taking + // all decodable frames into account. + bool IsContinuous(const VCMFrameBuffer& frame) const + RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + // Looks for frames in `incomplete_frames_` which are continuous in the + // provided `decoded_state`. Starts the search from the timestamp of + // `decoded_state`. + void FindAndInsertContinuousFramesWithState( + const VCMDecodingState& decoded_state) + RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + // Looks for frames in `incomplete_frames_` which are continuous in + // `last_decoded_state_` taking all decodable frames into account. Starts + // the search from `new_frame`. + void FindAndInsertContinuousFrames(const VCMFrameBuffer& new_frame) + RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + VCMFrameBuffer* NextFrame() const RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + // Returns true if the NACK list was updated to cover sequence numbers up to + // `sequence_number`. If false a key frame is needed to get into a state where + // we can continue decoding. + bool UpdateNackList(uint16_t sequence_number) + RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + bool TooLargeNackList() const; + // Returns true if the NACK list was reduced without problem. If false a key + // frame is needed to get into a state where we can continue decoding. + bool HandleTooLargeNackList() RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + bool MissingTooOldPacket(uint16_t latest_sequence_number) const + RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + // Returns true if the too old packets was successfully removed from the NACK + // list. If false, a key frame is needed to get into a state where we can + // continue decoding. + bool HandleTooOldPackets(uint16_t latest_sequence_number) + RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + // Drops all packets in the NACK list up until `last_decoded_sequence_number`. + void DropPacketsFromNackList(uint16_t last_decoded_sequence_number); + + // Gets an empty frame, creating a new frame if necessary (i.e. increases + // jitter buffer size). + VCMFrameBuffer* GetEmptyFrame() RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + + // Attempts to increase the size of the jitter buffer. Returns true on + // success, false otherwise. + bool TryToIncreaseJitterBufferSize() RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + + // Recycles oldest frames until a key frame is found. Used if jitter buffer is + // completely full. Returns true if a key frame was found. + bool RecycleFramesUntilKeyFrame() RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + + // Update rolling average of packets per frame. + void UpdateAveragePacketsPerFrame(int current_number_packets_); + + // Cleans the frame list in the JB from old/empty frames. + // Should only be called prior to actual use. + void CleanUpOldOrEmptyFrames() RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + + // Returns true if `packet` is likely to have been retransmitted. + bool IsPacketRetransmitted(const VCMPacket& packet) const; + + // The following three functions update the jitter estimate with the + // payload size, receive time and RTP timestamp of a frame. + void UpdateJitterEstimate(const VCMJitterSample& sample, + bool incomplete_frame); + void UpdateJitterEstimate(const VCMFrameBuffer& frame, bool incomplete_frame); + void UpdateJitterEstimate(int64_t latest_packet_time_ms, + uint32_t timestamp, + unsigned int frame_size, + bool incomplete_frame); + + int NonContinuousOrIncompleteDuration() RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + + uint16_t EstimatedLowSequenceNumber(const VCMFrameBuffer& frame) const; + + // Reset frame buffer and return it to free_frames_. + void RecycleFrameBuffer(VCMFrameBuffer* frame) + RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); + + Clock* clock_; + // If we are running (have started) or not. + bool running_; + mutable Mutex mutex_; + // Event to signal when we have a frame ready for decoder. + std::unique_ptr<EventWrapper> frame_event_; + // Number of allocated frames. + int max_number_of_frames_; + UnorderedFrameList free_frames_ RTC_GUARDED_BY(mutex_); + FrameList decodable_frames_ RTC_GUARDED_BY(mutex_); + FrameList incomplete_frames_ RTC_GUARDED_BY(mutex_); + VCMDecodingState last_decoded_state_ RTC_GUARDED_BY(mutex_); + bool first_packet_since_reset_; + + // Number of packets in a row that have been too old. + int num_consecutive_old_packets_; + // Number of packets received. + int num_packets_ RTC_GUARDED_BY(mutex_); + // Number of duplicated packets received. + int num_duplicated_packets_ RTC_GUARDED_BY(mutex_); + + // Jitter estimation. + // Filter for estimating jitter. + JitterEstimator jitter_estimate_; + // Calculates network delays used for jitter calculations. + InterFrameDelay inter_frame_delay_; + VCMJitterSample waiting_for_completion_; + + // Holds the internal NACK list (the missing sequence numbers). + SequenceNumberSet missing_sequence_numbers_; + uint16_t latest_received_sequence_number_; + size_t max_nack_list_size_; + int max_packet_age_to_nack_; // Measured in sequence numbers. + int max_incomplete_time_ms_; + + // Estimated rolling average of packets per frame + float average_packets_per_frame_; + // average_packets_per_frame converges fast if we have fewer than this many + // frames. + int frame_counter_; +}; +} // namespace webrtc + +#endif // MODULES_VIDEO_CODING_JITTER_BUFFER_H_ |