blob: f31ee6435c820895e624d95cb605c4674940a102 [file] [log] [blame]
* Copyright (c) 2016 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.
#include <array>
#include <map>
#include <memory>
#include <deque>
#include <set>
#include <utility>
#include "webrtc/modules/include/module_common_types.h"
#include "webrtc/modules/video_coding/sequence_number_util.h"
#include "webrtc/rtc_base/criticalsection.h"
#include "webrtc/rtc_base/thread_annotations.h"
namespace webrtc {
namespace video_coding {
class FrameObject;
class RtpFrameObject;
// A complete frame is a frame which has received all its packets and all its
// references are known.
class OnCompleteFrameCallback {
virtual ~OnCompleteFrameCallback() {}
virtual void OnCompleteFrame(std::unique_ptr<FrameObject> frame) = 0;
class RtpFrameReferenceFinder {
explicit RtpFrameReferenceFinder(OnCompleteFrameCallback* frame_callback);
// Manage this frame until:
// - We have all information needed to determine its references, after
// which |frame_callback_| is called with the completed frame, or
// - We have too many stashed frames (determined by |kMaxStashedFrames|)
// so we drop this frame, or
// - It gets cleared by ClearTo, which also means we drop it.
void ManageFrame(std::unique_ptr<RtpFrameObject> frame);
// Notifies that padding has been received, which the reference finder
// might need to calculate the references of a frame.
void PaddingReceived(uint16_t seq_num);
// Clear all stashed frames that include packets older than |seq_num|.
void ClearTo(uint16_t seq_num);
static const uint16_t kPicIdLength = 1 << 15;
static const uint8_t kMaxTemporalLayers = 5;
static const int kMaxLayerInfo = 50;
static const int kMaxStashedFrames = 50;
static const int kMaxNotYetReceivedFrames = 100;
static const int kMaxGofSaved = 50;
static const int kMaxPaddingAge = 100;
enum FrameDecision { kStash, kHandOff, kDrop };
struct GofInfo {
GofInfo(GofInfoVP9* gof, uint16_t last_picture_id)
: gof(gof), last_picture_id(last_picture_id) {}
GofInfoVP9* gof;
uint16_t last_picture_id;
rtc::CriticalSection crit_;
// Find the relevant group of pictures and update its "last-picture-id-with
// padding" sequence number.
void UpdateLastPictureIdWithPadding(uint16_t seq_num)
// Retry stashed frames until no more complete frames are found.
void RetryStashedFrames() EXCLUSIVE_LOCKS_REQUIRED(crit_);
FrameDecision ManageFrameInternal(RtpFrameObject* frame)
// Find references for generic frames. If |picture_id| is unspecified
// then packet sequence numbers will be used to determine the references
// of the frames.
FrameDecision ManageFrameGeneric(RtpFrameObject* frame, int picture_id)
// Find references for Vp8 frames
FrameDecision ManageFrameVp8(RtpFrameObject* frame)
// Updates necessary layer info state used to determine frame references for
// Vp8.
void UpdateLayerInfoVp8(RtpFrameObject* frame,
const RTPVideoHeaderVP8& codec_header)
// Find references for Vp9 frames
FrameDecision ManageFrameVp9(RtpFrameObject* frame)
// Check if we are missing a frame necessary to determine the references
// for this frame.
bool MissingRequiredFrameVp9(uint16_t picture_id, const GofInfo& info)
// Updates which frames that have been received. If there is a gap,
// missing frames will be added to |missing_frames_for_layer_| or
// if this is an already missing frame then it will be removed.
void FrameReceivedVp9(uint16_t picture_id, GofInfo* info)
// Check if there is a frame with the up-switch flag set in the interval
// (|pid_ref|, |picture_id|) with temporal layer smaller than |temporal_idx|.
bool UpSwitchInIntervalVp9(uint16_t picture_id,
uint8_t temporal_idx,
uint16_t pid_ref) EXCLUSIVE_LOCKS_REQUIRED(crit_);
// Unwrap |frame|s picture id and its references to 16 bits.
void UnwrapPictureIds(RtpFrameObject* frame) EXCLUSIVE_LOCKS_REQUIRED(crit_);
// All picture ids are unwrapped to 16 bits.
uint16_t UnwrapPictureId(uint16_t picture_id) EXCLUSIVE_LOCKS_REQUIRED(crit_);
// Returns true if the frame is old and should be dropped.
// TODO(philipel): Remove when VP9 PID/TL0 does not jump mid-stream (should be
// around M59).
bool Vp9PidTl0Fix(const RtpFrameObject& frame,
int16_t* picture_id,
int16_t* tl0_pic_idx) EXCLUSIVE_LOCKS_REQUIRED(crit_);
// TODO(philipel): Remove when VP9 PID/TL0 does not jump mid-stream (should be
// around M59).
bool DetectVp9PicIdJump(int fixed_pid,
int fixed_tl0,
uint32_t timestamp) const
// TODO(philipel): Remove when VP9 PID/TL0 does not jump mid-stream (should be
// around M59).
bool DetectVp9Tl0PicIdxJump(int fixed_tl0, uint32_t timestamp) const
// For every group of pictures, hold two sequence numbers. The first being
// the sequence number of the last packet of the last completed frame, and
// the second being the sequence number of the last packet of the last
// completed frame advanced by any potential continuous packets of padding.
std::pair<uint16_t, uint16_t>,
last_seq_num_gop_ GUARDED_BY(crit_);
// Save the last picture id in order to detect when there is a gap in frames
// that have not yet been fully received.
int last_picture_id_ GUARDED_BY(crit_);
// Padding packets that have been received but that are not yet continuous
// with any group of pictures.
std::set<uint16_t, DescendingSeqNumComp<uint16_t>> stashed_padding_
// The last unwrapped picture id. Used to unwrap the picture id from a length
// of |kPicIdLength| to 16 bits.
int last_unwrap_ GUARDED_BY(crit_);
// Frames earlier than the last received frame that have not yet been
// fully received.
std::set<uint16_t, DescendingSeqNumComp<uint16_t, kPicIdLength>>
not_yet_received_frames_ GUARDED_BY(crit_);
// Frames that have been fully received but didn't have all the information
// needed to determine their references.
std::deque<std::unique_ptr<RtpFrameObject>> stashed_frames_ GUARDED_BY(crit_);
// Holds the information about the last completed frame for a given temporal
// layer given a Tl0 picture index.
std::array<int16_t, kMaxTemporalLayers>,
layer_info_ GUARDED_BY(crit_);
// Where the current scalability structure is in the
// |scalability_structures_| array.
uint8_t current_ss_idx_;
// Holds received scalability structures.
std::array<GofInfoVP9, kMaxGofSaved> scalability_structures_
// Holds the the Gof information for a given TL0 picture index.
std::map<uint8_t, GofInfo, DescendingSeqNumComp<uint8_t>> gof_info_
// Keep track of which picture id and which temporal layer that had the
// up switch flag set.
std::map<uint16_t, uint8_t, DescendingSeqNumComp<uint16_t, kPicIdLength>>
up_switch_ GUARDED_BY(crit_);
// For every temporal layer, keep a set of which frames that are missing.
std::array<std::set<uint16_t, DescendingSeqNumComp<uint16_t, kPicIdLength>>,
missing_frames_for_layer_ GUARDED_BY(crit_);
// How far frames have been cleared by sequence number. A frame will be
// cleared if it contains a packet with a sequence number older than
// |cleared_to_seq_num_|.
int cleared_to_seq_num_ GUARDED_BY(crit_);
OnCompleteFrameCallback* frame_callback_;
} // namespace video_coding
} // namespace webrtc