modules/video_coding refactorings

webrtc/modules/video_coding/main/source/session_info.cc

Index: webrtc/modules/video_coding/main/source/session_info.cc
diff --git a/webrtc/modules/video_coding/main/source/session_info.cc b/webrtc/modules/video_coding/main/source/session_info.cc
deleted file mode 100644
index a8d3d585c688736400535b63a327f84bedc7aeba..0000000000000000000000000000000000000000
--- a/webrtc/modules/video_coding/main/source/session_info.cc
+++ /dev/null
@@ -1,580 +0,0 @@
-/*
- *  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.
- */
-
-#include "webrtc/modules/video_coding/main/source/session_info.h"
-
-#include "webrtc/base/logging.h"
-#include "webrtc/modules/video_coding/main/source/packet.h"
-
-namespace webrtc {
-
-namespace {
-
-uint16_t BufferToUWord16(const uint8_t* dataBuffer) {
-  return (dataBuffer[0] << 8) | dataBuffer[1];
-}
-
-}  // namespace
-
-VCMSessionInfo::VCMSessionInfo()
-    : session_nack_(false),
-      complete_(false),
-      decodable_(false),
-      frame_type_(kVideoFrameDelta),
-      packets_(),
-      empty_seq_num_low_(-1),
-      empty_seq_num_high_(-1),
-      first_packet_seq_num_(-1),
-      last_packet_seq_num_(-1) {
-}
-
-void VCMSessionInfo::UpdateDataPointers(const uint8_t* old_base_ptr,
-                                        const uint8_t* new_base_ptr) {
-  for (PacketIterator it = packets_.begin(); it != packets_.end(); ++it)
-    if ((*it).dataPtr != NULL) {
-      assert(old_base_ptr != NULL && new_base_ptr != NULL);
-      (*it).dataPtr = new_base_ptr + ((*it).dataPtr - old_base_ptr);
-    }
-}
-
-int VCMSessionInfo::LowSequenceNumber() const {
-  if (packets_.empty())
-    return empty_seq_num_low_;
-  return packets_.front().seqNum;
-}
-
-int VCMSessionInfo::HighSequenceNumber() const {
-  if (packets_.empty())
-    return empty_seq_num_high_;
-  if (empty_seq_num_high_ == -1)
-    return packets_.back().seqNum;
-  return LatestSequenceNumber(packets_.back().seqNum, empty_seq_num_high_);
-}
-
-int VCMSessionInfo::PictureId() const {
-  if (packets_.empty())
-    return kNoPictureId;
-  if (packets_.front().codecSpecificHeader.codec == kRtpVideoVp8) {
-    return packets_.front().codecSpecificHeader.codecHeader.VP8.pictureId;
-  } else if (packets_.front().codecSpecificHeader.codec == kRtpVideoVp9) {
-    return packets_.front().codecSpecificHeader.codecHeader.VP9.picture_id;
-  } else {
-    return kNoPictureId;
-  }
-}
-
-int VCMSessionInfo::TemporalId() const {
-  if (packets_.empty())
-    return kNoTemporalIdx;
-  if (packets_.front().codecSpecificHeader.codec == kRtpVideoVp8) {
-    return packets_.front().codecSpecificHeader.codecHeader.VP8.temporalIdx;
-  } else if (packets_.front().codecSpecificHeader.codec == kRtpVideoVp9) {
-    return packets_.front().codecSpecificHeader.codecHeader.VP9.temporal_idx;
-  } else {
-    return kNoTemporalIdx;
-  }
-}
-
-bool VCMSessionInfo::LayerSync() const {
-  if (packets_.empty())
-    return false;
-  if (packets_.front().codecSpecificHeader.codec == kRtpVideoVp8) {
-    return packets_.front().codecSpecificHeader.codecHeader.VP8.layerSync;
-  } else if (packets_.front().codecSpecificHeader.codec == kRtpVideoVp9) {
-    return
-        packets_.front().codecSpecificHeader.codecHeader.VP9.temporal_up_switch;
-  } else {
-    return false;
-  }
-}
-
-int VCMSessionInfo::Tl0PicId() const {
-  if (packets_.empty())
-    return kNoTl0PicIdx;
-  if (packets_.front().codecSpecificHeader.codec == kRtpVideoVp8) {
-    return packets_.front().codecSpecificHeader.codecHeader.VP8.tl0PicIdx;
-  } else if (packets_.front().codecSpecificHeader.codec == kRtpVideoVp9) {
-    return packets_.front().codecSpecificHeader.codecHeader.VP9.tl0_pic_idx;
-  } else {
-    return kNoTl0PicIdx;
-  }
-}
-
-bool VCMSessionInfo::NonReference() const {
-  if (packets_.empty() ||
-      packets_.front().codecSpecificHeader.codec != kRtpVideoVp8)
-    return false;
-  return packets_.front().codecSpecificHeader.codecHeader.VP8.nonReference;
-}
-
-void VCMSessionInfo::SetGofInfo(const GofInfoVP9& gof_info, size_t idx) {
-  if (packets_.empty() ||
-      packets_.front().codecSpecificHeader.codec != kRtpVideoVp9 ||
-      packets_.front().codecSpecificHeader.codecHeader.VP9.flexible_mode) {
-    return;
-  }
-  packets_.front().codecSpecificHeader.codecHeader.VP9.temporal_idx =
-      gof_info.temporal_idx[idx];
-  packets_.front().codecSpecificHeader.codecHeader.VP9.temporal_up_switch =
-      gof_info.temporal_up_switch[idx];
-  packets_.front().codecSpecificHeader.codecHeader.VP9.num_ref_pics =
-      gof_info.num_ref_pics[idx];
-  for (uint8_t i = 0; i < gof_info.num_ref_pics[idx]; ++i) {
-    packets_.front().codecSpecificHeader.codecHeader.VP9.pid_diff[i] =
-        gof_info.pid_diff[idx][i];
-  }
-}
-
-void VCMSessionInfo::Reset() {
-  session_nack_ = false;
-  complete_ = false;
-  decodable_ = false;
-  frame_type_ = kVideoFrameDelta;
-  packets_.clear();
-  empty_seq_num_low_ = -1;
-  empty_seq_num_high_ = -1;
-  first_packet_seq_num_ = -1;
-  last_packet_seq_num_ = -1;
-}
-
-size_t VCMSessionInfo::SessionLength() const {
-  size_t length = 0;
-  for (PacketIteratorConst it = packets_.begin(); it != packets_.end(); ++it)
-    length += (*it).sizeBytes;
-  return length;
-}
-
-int VCMSessionInfo::NumPackets() const {
-  return packets_.size();
-}
-
-size_t VCMSessionInfo::InsertBuffer(uint8_t* frame_buffer,
-                                    PacketIterator packet_it) {
-  VCMPacket& packet = *packet_it;
-  PacketIterator it;
-
-  // Calculate the offset into the frame buffer for this packet.
-  size_t offset = 0;
-  for (it = packets_.begin(); it != packet_it; ++it)
-    offset += (*it).sizeBytes;
-
-  // Set the data pointer to pointing to the start of this packet in the
-  // frame buffer.
-  const uint8_t* packet_buffer = packet.dataPtr;
-  packet.dataPtr = frame_buffer + offset;
-
-  // We handle H.264 STAP-A packets in a special way as we need to remove the
-  // two length bytes between each NAL unit, and potentially add start codes.
-  // TODO(pbos): Remove H264 parsing from this step and use a fragmentation
-  // header supplied by the H264 depacketizer.
-  const size_t kH264NALHeaderLengthInBytes = 1;
-  const size_t kLengthFieldLength = 2;
-  if (packet.codecSpecificHeader.codec == kRtpVideoH264 &&
-      packet.codecSpecificHeader.codecHeader.H264.packetization_type ==
-          kH264StapA) {
-    size_t required_length = 0;
-    const uint8_t* nalu_ptr = packet_buffer + kH264NALHeaderLengthInBytes;
-    while (nalu_ptr < packet_buffer + packet.sizeBytes) {
-      size_t length = BufferToUWord16(nalu_ptr);
-      required_length +=
-          length + (packet.insertStartCode ? kH264StartCodeLengthBytes : 0);
-      nalu_ptr += kLengthFieldLength + length;
-    }
-    ShiftSubsequentPackets(packet_it, required_length);
-    nalu_ptr = packet_buffer + kH264NALHeaderLengthInBytes;
-    uint8_t* frame_buffer_ptr = frame_buffer + offset;
-    while (nalu_ptr < packet_buffer + packet.sizeBytes) {
-      size_t length = BufferToUWord16(nalu_ptr);
-      nalu_ptr += kLengthFieldLength;
-      frame_buffer_ptr += Insert(nalu_ptr,
-                                 length,
-                                 packet.insertStartCode,
-                                 const_cast<uint8_t*>(frame_buffer_ptr));
-      nalu_ptr += length;
-    }
-    packet.sizeBytes = required_length;
-    return packet.sizeBytes;
-  }
-  ShiftSubsequentPackets(
-      packet_it,
-      packet.sizeBytes +
-          (packet.insertStartCode ? kH264StartCodeLengthBytes : 0));
-
-  packet.sizeBytes = Insert(packet_buffer,
-                            packet.sizeBytes,
-                            packet.insertStartCode,
-                            const_cast<uint8_t*>(packet.dataPtr));
-  return packet.sizeBytes;
-}
-
-size_t VCMSessionInfo::Insert(const uint8_t* buffer,
-                              size_t length,
-                              bool insert_start_code,
-                              uint8_t* frame_buffer) {
-  if (insert_start_code) {
-    const unsigned char startCode[] = {0, 0, 0, 1};
-    memcpy(frame_buffer, startCode, kH264StartCodeLengthBytes);
-  }
-  memcpy(frame_buffer + (insert_start_code ? kH264StartCodeLengthBytes : 0),
-         buffer,
-         length);
-  length += (insert_start_code ? kH264StartCodeLengthBytes : 0);
-
-  return length;
-}
-
-void VCMSessionInfo::ShiftSubsequentPackets(PacketIterator it,
-                                            int steps_to_shift) {
-  ++it;
-  if (it == packets_.end())
-    return;
-  uint8_t* first_packet_ptr = const_cast<uint8_t*>((*it).dataPtr);
-  int shift_length = 0;
-  // Calculate the total move length and move the data pointers in advance.
-  for (; it != packets_.end(); ++it) {
-    shift_length += (*it).sizeBytes;
-    if ((*it).dataPtr != NULL)
-      (*it).dataPtr += steps_to_shift;
-  }
-  memmove(first_packet_ptr + steps_to_shift, first_packet_ptr, shift_length);
-}
-
-void VCMSessionInfo::UpdateCompleteSession() {
-  if (HaveFirstPacket() && HaveLastPacket()) {
-    // Do we have all the packets in this session?
-    bool complete_session = true;
-    PacketIterator it = packets_.begin();
-    PacketIterator prev_it = it;
-    ++it;
-    for (; it != packets_.end(); ++it) {
-      if (!InSequence(it, prev_it)) {
-        complete_session = false;
-        break;
-      }
-      prev_it = it;
-    }
-    complete_ = complete_session;
-  }
-}
-
-void VCMSessionInfo::UpdateDecodableSession(const FrameData& frame_data) {
-  // Irrelevant if session is already complete or decodable
-  if (complete_ || decodable_)
-    return;
-  // TODO(agalusza): Account for bursty loss.
-  // TODO(agalusza): Refine these values to better approximate optimal ones.
-  // Do not decode frames if the RTT is lower than this.
-  const int64_t kRttThreshold = 100;
-  // Do not decode frames if the number of packets is between these two
-  // thresholds.
-  const float kLowPacketPercentageThreshold = 0.2f;
-  const float kHighPacketPercentageThreshold = 0.8f;
-  if (frame_data.rtt_ms < kRttThreshold
-      || frame_type_ == kVideoFrameKey
-      || !HaveFirstPacket()
-      || (NumPackets() <= kHighPacketPercentageThreshold
-                          * frame_data.rolling_average_packets_per_frame
-          && NumPackets() > kLowPacketPercentageThreshold
-                            * frame_data.rolling_average_packets_per_frame))
-    return;
-
-  decodable_ = true;
-}
-
-bool VCMSessionInfo::complete() const {
-  return complete_;
-}
-
-bool VCMSessionInfo::decodable() const {
-  return decodable_;
-}
-
-// Find the end of the NAL unit which the packet pointed to by |packet_it|
-// belongs to. Returns an iterator to the last packet of the frame if the end
-// of the NAL unit wasn't found.
-VCMSessionInfo::PacketIterator VCMSessionInfo::FindNaluEnd(
-    PacketIterator packet_it) const {
-  if ((*packet_it).completeNALU == kNaluEnd ||
-      (*packet_it).completeNALU == kNaluComplete) {
-    return packet_it;
-  }
-  // Find the end of the NAL unit.
-  for (; packet_it != packets_.end(); ++packet_it) {
-    if (((*packet_it).completeNALU == kNaluComplete &&
-        (*packet_it).sizeBytes > 0) ||
-        // Found next NALU.
-        (*packet_it).completeNALU == kNaluStart)
-      return --packet_it;
-    if ((*packet_it).completeNALU == kNaluEnd)
-      return packet_it;
-  }
-  // The end wasn't found.
-  return --packet_it;
-}
-
-size_t VCMSessionInfo::DeletePacketData(PacketIterator start,
-                                        PacketIterator end) {
-  size_t bytes_to_delete = 0;  // The number of bytes to delete.
-  PacketIterator packet_after_end = end;
-  ++packet_after_end;
-
-  // Get the number of bytes to delete.
-  // Clear the size of these packets.
-  for (PacketIterator it = start; it != packet_after_end; ++it) {
-    bytes_to_delete += (*it).sizeBytes;
-    (*it).sizeBytes = 0;
-    (*it).dataPtr = NULL;
-  }
-  if (bytes_to_delete > 0)
-    ShiftSubsequentPackets(end, -static_cast<int>(bytes_to_delete));
-  return bytes_to_delete;
-}
-
-size_t VCMSessionInfo::BuildVP8FragmentationHeader(
-    uint8_t* frame_buffer,
-    size_t frame_buffer_length,
-    RTPFragmentationHeader* fragmentation) {
-  size_t new_length = 0;
-  // Allocate space for max number of partitions
-  fragmentation->VerifyAndAllocateFragmentationHeader(kMaxVP8Partitions);
-  fragmentation->fragmentationVectorSize = 0;
-  memset(fragmentation->fragmentationLength, 0,
-         kMaxVP8Partitions * sizeof(size_t));
-  if (packets_.empty())
-      return new_length;
-  PacketIterator it = FindNextPartitionBeginning(packets_.begin());
-  while (it != packets_.end()) {
-    const int partition_id =
-        (*it).codecSpecificHeader.codecHeader.VP8.partitionId;
-    PacketIterator partition_end = FindPartitionEnd(it);
-    fragmentation->fragmentationOffset[partition_id] =
-        (*it).dataPtr - frame_buffer;
-    assert(fragmentation->fragmentationOffset[partition_id] <
-           frame_buffer_length);
-    fragmentation->fragmentationLength[partition_id] =
-        (*partition_end).dataPtr + (*partition_end).sizeBytes - (*it).dataPtr;
-    assert(fragmentation->fragmentationLength[partition_id] <=
-           frame_buffer_length);
-    new_length += fragmentation->fragmentationLength[partition_id];
-    ++partition_end;
-    it = FindNextPartitionBeginning(partition_end);
-    if (partition_id + 1 > fragmentation->fragmentationVectorSize)
-      fragmentation->fragmentationVectorSize = partition_id + 1;
-  }
-  // Set all empty fragments to start where the previous fragment ends,
-  // and have zero length.
-  if (fragmentation->fragmentationLength[0] == 0)
-      fragmentation->fragmentationOffset[0] = 0;
-  for (int i = 1; i < fragmentation->fragmentationVectorSize; ++i) {
-    if (fragmentation->fragmentationLength[i] == 0)
-      fragmentation->fragmentationOffset[i] =
-          fragmentation->fragmentationOffset[i - 1] +
-          fragmentation->fragmentationLength[i - 1];
-    assert(i == 0 ||
-           fragmentation->fragmentationOffset[i] >=
-           fragmentation->fragmentationOffset[i - 1]);
-  }
-  assert(new_length <= frame_buffer_length);
-  return new_length;
-}
-
-VCMSessionInfo::PacketIterator VCMSessionInfo::FindNextPartitionBeginning(
-    PacketIterator it) const {
-  while (it != packets_.end()) {
-    if ((*it).codecSpecificHeader.codecHeader.VP8.beginningOfPartition) {
-      return it;
-    }
-    ++it;
-  }
-  return it;
-}
-
-VCMSessionInfo::PacketIterator VCMSessionInfo::FindPartitionEnd(
-    PacketIterator it) const {
-  assert((*it).codec == kVideoCodecVP8);
-  PacketIterator prev_it = it;
-  const int partition_id =
-      (*it).codecSpecificHeader.codecHeader.VP8.partitionId;
-  while (it != packets_.end()) {
-    bool beginning =
-        (*it).codecSpecificHeader.codecHeader.VP8.beginningOfPartition;
-    int current_partition_id =
-        (*it).codecSpecificHeader.codecHeader.VP8.partitionId;
-    bool packet_loss_found = (!beginning && !InSequence(it, prev_it));
-    if (packet_loss_found ||
-        (beginning && current_partition_id != partition_id)) {
-      // Missing packet, the previous packet was the last in sequence.
-      return prev_it;
-    }
-    prev_it = it;
-    ++it;
-  }
-  return prev_it;
-}
-
-bool VCMSessionInfo::InSequence(const PacketIterator& packet_it,
-                                const PacketIterator& prev_packet_it) {
-  // If the two iterators are pointing to the same packet they are considered
-  // to be in sequence.
-  return (packet_it == prev_packet_it ||
-      (static_cast<uint16_t>((*prev_packet_it).seqNum + 1) ==
-          (*packet_it).seqNum));
-}
-
-size_t VCMSessionInfo::MakeDecodable() {
-  size_t return_length = 0;
-  if (packets_.empty()) {
-    return 0;
-  }
-  PacketIterator it = packets_.begin();
-  // Make sure we remove the first NAL unit if it's not decodable.
-  if ((*it).completeNALU == kNaluIncomplete ||
-      (*it).completeNALU == kNaluEnd) {
-    PacketIterator nalu_end = FindNaluEnd(it);
-    return_length += DeletePacketData(it, nalu_end);
-    it = nalu_end;
-  }
-  PacketIterator prev_it = it;
-  // Take care of the rest of the NAL units.
-  for (; it != packets_.end(); ++it) {
-    bool start_of_nalu = ((*it).completeNALU == kNaluStart ||
-        (*it).completeNALU == kNaluComplete);
-    if (!start_of_nalu && !InSequence(it, prev_it)) {
-      // Found a sequence number gap due to packet loss.
-      PacketIterator nalu_end = FindNaluEnd(it);
-      return_length += DeletePacketData(it, nalu_end);
-      it = nalu_end;
-    }
-    prev_it = it;
-  }
-  return return_length;
-}
-
-void VCMSessionInfo::SetNotDecodableIfIncomplete() {
-  // We don't need to check for completeness first because the two are
-  // orthogonal. If complete_ is true, decodable_ is irrelevant.
-  decodable_ = false;
-}
-
-bool
-VCMSessionInfo::HaveFirstPacket() const {
-  return !packets_.empty() && (first_packet_seq_num_ != -1);
-}
-
-bool
-VCMSessionInfo::HaveLastPacket() const {
-  return !packets_.empty() && (last_packet_seq_num_ != -1);
-}
-
-bool
-VCMSessionInfo::session_nack() const {
-  return session_nack_;
-}
-
-int VCMSessionInfo::InsertPacket(const VCMPacket& packet,
-                                 uint8_t* frame_buffer,
-                                 VCMDecodeErrorMode decode_error_mode,
-                                 const FrameData& frame_data) {
-  if (packet.frameType == kEmptyFrame) {
-    // Update sequence number of an empty packet.
-    // Only media packets are inserted into the packet list.
-    InformOfEmptyPacket(packet.seqNum);
-    return 0;
-  }
-
-  if (packets_.size() == kMaxPacketsInSession) {
-    LOG(LS_ERROR) << "Max number of packets per frame has been reached.";
-    return -1;
-  }
-
-  // Find the position of this packet in the packet list in sequence number
-  // order and insert it. Loop over the list in reverse order.
-  ReversePacketIterator rit = packets_.rbegin();
-  for (; rit != packets_.rend(); ++rit)
-    if (LatestSequenceNumber(packet.seqNum, (*rit).seqNum) == packet.seqNum)
-      break;
-
-  // Check for duplicate packets.
-  if (rit != packets_.rend() &&
-      (*rit).seqNum == packet.seqNum && (*rit).sizeBytes > 0)
-    return -2;
-
-  if (packet.codec == kVideoCodecH264) {
-    frame_type_ = packet.frameType;
-    if (packet.isFirstPacket &&
-        (first_packet_seq_num_ == -1 ||
-         IsNewerSequenceNumber(first_packet_seq_num_, packet.seqNum))) {
-      first_packet_seq_num_ = packet.seqNum;
-    }
-    if (packet.markerBit &&
-        (last_packet_seq_num_ == -1 ||
-         IsNewerSequenceNumber(packet.seqNum, last_packet_seq_num_))) {
-      last_packet_seq_num_ = packet.seqNum;
-    }
-  } else {
-    // Only insert media packets between first and last packets (when
-    // available).
-    // Placing check here, as to properly account for duplicate packets.
-    // Check if this is first packet (only valid for some codecs)
-    // Should only be set for one packet per session.
-    if (packet.isFirstPacket && first_packet_seq_num_ == -1) {
-      // The first packet in a frame signals the frame type.
-      frame_type_ = packet.frameType;
-      // Store the sequence number for the first packet.
-      first_packet_seq_num_ = static_cast<int>(packet.seqNum);
-    } else if (first_packet_seq_num_ != -1 &&
-               IsNewerSequenceNumber(first_packet_seq_num_, packet.seqNum)) {
-      LOG(LS_WARNING) << "Received packet with a sequence number which is out "
-                         "of frame boundaries";
-      return -3;
-    } else if (frame_type_ == kEmptyFrame && packet.frameType != kEmptyFrame) {
-      // Update the frame type with the type of the first media packet.
-      // TODO(mikhal): Can this trigger?
-      frame_type_ = packet.frameType;
-    }
-
-    // Track the marker bit, should only be set for one packet per session.
-    if (packet.markerBit && last_packet_seq_num_ == -1) {
-      last_packet_seq_num_ = static_cast<int>(packet.seqNum);
-    } else if (last_packet_seq_num_ != -1 &&
-               IsNewerSequenceNumber(packet.seqNum, last_packet_seq_num_)) {
-      LOG(LS_WARNING) << "Received packet with a sequence number which is out "
-                         "of frame boundaries";
-      return -3;
-    }
-  }
-
-  // The insert operation invalidates the iterator |rit|.
-  PacketIterator packet_list_it = packets_.insert(rit.base(), packet);
-
-  size_t returnLength = InsertBuffer(frame_buffer, packet_list_it);
-  UpdateCompleteSession();
-  if (decode_error_mode == kWithErrors)
-    decodable_ = true;
-  else if (decode_error_mode == kSelectiveErrors)
-    UpdateDecodableSession(frame_data);
-  return static_cast<int>(returnLength);
-}
-
-void VCMSessionInfo::InformOfEmptyPacket(uint16_t seq_num) {
-  // Empty packets may be FEC or filler packets. They are sequential and
-  // follow the data packets, therefore, we should only keep track of the high
-  // and low sequence numbers and may assume that the packets in between are
-  // empty packets belonging to the same frame (timestamp).
-  if (empty_seq_num_high_ == -1)
-    empty_seq_num_high_ = seq_num;
-  else
-    empty_seq_num_high_ = LatestSequenceNumber(seq_num, empty_seq_num_high_);
-  if (empty_seq_num_low_ == -1 || IsNewerSequenceNumber(empty_seq_num_low_,
-                                                        seq_num))
-    empty_seq_num_low_ = seq_num;
-}
-
-}  // namespace webrtc