Packet buffer for the new jitter buffer.
BUG=webrtc:5514
R=stefan@webrtc.org, mflodman@webrtc.org
Review URL: https://codereview.webrtc.org/1772383002
Cr-Commit-Position: refs/heads/master@{#12194}
diff --git a/webrtc/modules/video_coding/packet_buffer.cc b/webrtc/modules/video_coding/packet_buffer.cc
new file mode 100644
index 0000000..0a05baa
--- /dev/null
+++ b/webrtc/modules/video_coding/packet_buffer.cc
@@ -0,0 +1,204 @@
+/*
+ * 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 "webrtc/modules/video_coding/packet_buffer.h"
+
+#include <algorithm>
+#include <limits>
+
+#include "webrtc/base/checks.h"
+#include "webrtc/modules/video_coding/frame_object.h"
+#include "webrtc/modules/video_coding/sequence_number_util.h"
+
+namespace webrtc {
+namespace video_coding {
+
+PacketBuffer::PacketBuffer(size_t start_buffer_size,
+ size_t max_buffer_size,
+ OnCompleteFrameCallback* frame_callback)
+ : size_(start_buffer_size),
+ max_size_(max_buffer_size),
+ last_seq_num_(0),
+ first_seq_num_(0),
+ initialized_(false),
+ data_buffer_(start_buffer_size),
+ sequence_buffer_(start_buffer_size),
+ frame_callback_(frame_callback) {
+ RTC_DCHECK_LE(start_buffer_size, max_buffer_size);
+ // Buffer size must always be a power of 2.
+ RTC_DCHECK((start_buffer_size & (start_buffer_size - 1)) == 0);
+ RTC_DCHECK((max_buffer_size & (max_buffer_size - 1)) == 0);
+}
+
+bool PacketBuffer::InsertPacket(const VCMPacket& packet) {
+ rtc::CritScope lock(&crit_);
+ uint16_t seq_num = packet.seqNum;
+ int index = seq_num % size_;
+
+ if (!initialized_) {
+ first_seq_num_ = seq_num - 1;
+ last_seq_num_ = seq_num;
+ initialized_ = true;
+ }
+
+ if (sequence_buffer_[index].used) {
+ // Duplicate packet, do nothing.
+ if (data_buffer_[index].seqNum == packet.seqNum)
+ return true;
+
+ // The packet buffer is full, try to expand the buffer.
+ while (ExpandBufferSize() && sequence_buffer_[seq_num % size_].used) {
+ }
+ index = seq_num % size_;
+
+ // Packet buffer is still full.
+ if (sequence_buffer_[index].used)
+ return false;
+ }
+
+ if (AheadOf(seq_num, last_seq_num_))
+ last_seq_num_ = seq_num;
+
+ sequence_buffer_[index].frame_begin = packet.isFirstPacket;
+ sequence_buffer_[index].frame_end = packet.markerBit;
+ sequence_buffer_[index].seq_num = packet.seqNum;
+ sequence_buffer_[index].continuous = false;
+ sequence_buffer_[index].used = true;
+ data_buffer_[index] = packet;
+
+ FindCompleteFrames(seq_num);
+ return true;
+}
+
+void PacketBuffer::ClearTo(uint16_t seq_num) {
+ rtc::CritScope lock(&crit_);
+ int index = first_seq_num_ % size_;
+ while (AheadOf<uint16_t>(seq_num, first_seq_num_ + 1)) {
+ index = (index + 1) % size_;
+ first_seq_num_ = Add<1 << 16>(first_seq_num_, 1);
+ sequence_buffer_[index].used = false;
+ }
+}
+
+bool PacketBuffer::ExpandBufferSize() {
+ if (size_ == max_size_)
+ return false;
+
+ size_t new_size = std::min(max_size_, 2 * size_);
+ std::vector<VCMPacket> new_data_buffer(new_size);
+ std::vector<ContinuityInfo> new_sequence_buffer(new_size);
+ for (size_t i = 0; i < size_; ++i) {
+ if (sequence_buffer_[i].used) {
+ int index = sequence_buffer_[i].seq_num % new_size;
+ new_sequence_buffer[index] = sequence_buffer_[i];
+ new_data_buffer[index] = data_buffer_[i];
+ }
+ }
+ size_ = new_size;
+ sequence_buffer_ = std::move(new_sequence_buffer);
+ data_buffer_ = std::move(new_data_buffer);
+ return true;
+}
+
+bool PacketBuffer::IsContinuous(uint16_t seq_num) const {
+ int index = seq_num % size_;
+ int prev_index = index > 0 ? index - 1 : size_ - 1;
+ if (!sequence_buffer_[index].used)
+ return false;
+ if (sequence_buffer_[index].frame_begin)
+ return true;
+ if (!sequence_buffer_[prev_index].used)
+ return false;
+ if (sequence_buffer_[prev_index].continuous)
+ return true;
+
+ return false;
+}
+
+void PacketBuffer::FindCompleteFrames(uint16_t seq_num) {
+ int index = seq_num % size_;
+ while (IsContinuous(seq_num)) {
+ sequence_buffer_[index].continuous = true;
+
+ // If the frame is complete, find the first packet of the frame and
+ // create a FrameObject.
+ if (sequence_buffer_[index].frame_end) {
+ int rindex = index;
+ uint16_t start_seq_num = seq_num;
+ while (!sequence_buffer_[rindex].frame_begin) {
+ rindex = rindex > 0 ? rindex - 1 : size_ - 1;
+ start_seq_num--;
+ }
+
+ std::unique_ptr<FrameObject> frame(
+ new RtpFrameObject(this, 1, start_seq_num, seq_num));
+ frame_callback_->OnCompleteFrame(std::move(frame));
+ }
+
+ index = (index + 1) % size_;
+ ++seq_num;
+ }
+}
+
+void PacketBuffer::ReturnFrame(RtpFrameObject* frame) {
+ rtc::CritScope lock(&crit_);
+ int index = frame->first_packet() % size_;
+ int end = (frame->last_packet() + 1) % size_;
+ uint16_t seq_num = frame->first_packet();
+ while (index != end) {
+ if (sequence_buffer_[index].seq_num == seq_num) {
+ sequence_buffer_[index].used = false;
+ sequence_buffer_[index].continuous = false;
+ }
+ index = (index + 1) % size_;
+ ++seq_num;
+ }
+
+ index = first_seq_num_ % size_;
+ while (AheadOf<uint16_t>(last_seq_num_, first_seq_num_) &&
+ !sequence_buffer_[index].used) {
+ ++first_seq_num_;
+ index = (index + 1) % size_;
+ }
+}
+
+bool PacketBuffer::GetBitstream(const RtpFrameObject& frame,
+ uint8_t* destination) {
+ rtc::CritScope lock(&crit_);
+
+ int index = frame.first_packet() % size_;
+ int end = (frame.last_packet() + 1) % size_;
+ uint16_t seq_num = frame.first_packet();
+ while (index != end) {
+ if (!sequence_buffer_[index].used ||
+ sequence_buffer_[index].seq_num != seq_num) {
+ return false;
+ }
+
+ const uint8_t* source = data_buffer_[index].dataPtr;
+ size_t length = data_buffer_[index].sizeBytes;
+ memcpy(destination, source, length);
+ destination += length;
+ index = (index + 1) % size_;
+ ++seq_num;
+ }
+ return true;
+}
+
+void PacketBuffer::Flush() {
+ rtc::CritScope lock(&crit_);
+ for (size_t i = 0; i < size_; ++i) {
+ sequence_buffer_[i].used = false;
+ sequence_buffer_[i].continuous = false;
+ }
+}
+
+} // namespace video_coding
+} // namespace webrtc