1 files changed, 108 insertions, 0 deletions
diff --git a/webrtc/modules/rtp_rtcp/source/rtcp_packet/sli.cc b/webrtc/modules/rtp_rtcp/source/rtcp_packet/sli.cc
new file mode 100644
index 0000000000..829f3a9db9
--- /dev/null
+++ b/webrtc/modules/rtp_rtcp/source/rtcp_packet/sli.cc
@@ -0,0 +1,108 @@
+/*
+ *  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/rtp_rtcp/source/rtcp_packet/sli.h"
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/modules/rtp_rtcp/source/byte_io.h"
+
+using webrtc::RTCPUtility::RtcpCommonHeader;
+
+namespace webrtc {
+namespace rtcp {
+// RFC 4585: Feedback format.
+//
+// Common packet format:
+//
+//   0                   1                   2                   3
+//   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//  |V=2|P|   FMT   |       PT      |          length               |
+//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//  |                  SSRC of packet sender                        |
+//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//  |                  SSRC of media source                         |
+//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//  :            Feedback Control Information (FCI)                 :
+//  :                                                               :
+//
+// Slice loss indication (SLI) (RFC 4585).
+// FCI:
+//   0                   1                   2                   3
+//   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//  |            First        |        Number           | PictureID |
+//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+Sli::Macroblocks::Macroblocks(uint8_t picture_id,
+                              uint16_t first,
+                              uint16_t number) {
+  RTC_DCHECK_LE(first, 0x1fff);
+  RTC_DCHECK_LE(number, 0x1fff);
+  RTC_DCHECK_LE(picture_id, 0x3f);
+  item_ = (first << 19) | (number << 6) | picture_id;
+}
+
+void Sli::Macroblocks::Parse(const uint8_t* buffer) {
+  item_ = ByteReader<uint32_t>::ReadBigEndian(buffer);
+}
+
+void Sli::Macroblocks::Create(uint8_t* buffer) const {
+  ByteWriter<uint32_t>::WriteBigEndian(buffer, item_);
+}
+
+bool Sli::Parse(const RtcpCommonHeader& header, const uint8_t* payload) {
+  RTC_DCHECK(header.packet_type == kPacketType);
+  RTC_DCHECK(header.count_or_format == kFeedbackMessageType);
+
+  if (header.payload_size_bytes <
+      kCommonFeedbackLength + Macroblocks::kLength) {
+    LOG(LS_WARNING) << "Packet is too small to be a valid SLI packet";
+    return false;
+  }
+
+  size_t number_of_items =
+      (header.payload_size_bytes - kCommonFeedbackLength) /
+      Macroblocks::kLength;
+
+  ParseCommonFeedback(payload);
+  items_.resize(number_of_items);
+
+  const uint8_t* next_item = payload + kCommonFeedbackLength;
+  for (Macroblocks& item : items_) {
+    item.Parse(next_item);
+    next_item += Macroblocks::kLength;
+  }
+
+  return true;
+}
+
+bool Sli::Create(uint8_t* packet,
+                 size_t* index,
+                 size_t max_length,
+                 RtcpPacket::PacketReadyCallback* callback) const {
+  RTC_DCHECK(!items_.empty());
+  while (*index + BlockLength() > max_length) {
+    if (!OnBufferFull(packet, index, callback))
+      return false;
+  }
+  CreateHeader(kFeedbackMessageType, kPacketType, HeaderLength(), packet,
+               index);
+  CreateCommonFeedback(packet + *index);
+  *index += kCommonFeedbackLength;
+  for (const Macroblocks& item : items_) {
+    item.Create(packet + *index);
+    *index += Macroblocks::kLength;
+  }
+  return true;
+}
+
+}  // namespace rtcp
+}  // namespace webrtc