1 files changed, 76 insertions, 0 deletions
diff --git a/third_party/libwebrtc/api/video/rtp_video_frame_assembler.h b/third_party/libwebrtc/api/video/rtp_video_frame_assembler.h
new file mode 100644
index 0000000000..83162cb818
--- /dev/null
+++ b/third_party/libwebrtc/api/video/rtp_video_frame_assembler.h
@@ -0,0 +1,76 @@
+/*
+ *  Copyright (c) 2021 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 API_VIDEO_RTP_VIDEO_FRAME_ASSEMBLER_H_
+#define API_VIDEO_RTP_VIDEO_FRAME_ASSEMBLER_H_
+
+#include <cstdint>
+#include <memory>
+#include <utility>
+
+#include "absl/container/inlined_vector.h"
+#include "api/video/encoded_frame.h"
+#include "modules/rtp_rtcp/source/rtp_packet_received.h"
+
+namespace webrtc {
+// The RtpVideoFrameAssembler takes RtpPacketReceived and assembles them into
+// complete frames. A frame is considered complete when all packets of the frame
+// has been received, the bitstream data has successfully extracted, an ID has
+// been assigned, and all dependencies are known. Frame IDs are strictly
+// monotonic in decode order, dependencies are expressed as frame IDs.
+class RtpVideoFrameAssembler {
+ public:
+  // The RtpVideoFrameAssembler should return "RTP frames", but for now there
+  // is no good class for this purpose. For now return an EncodedFrame bundled
+  // with some minimal RTP information.
+  class AssembledFrame {
+   public:
+    AssembledFrame(uint16_t rtp_seq_num_start,
+                   uint16_t rtp_seq_num_end,
+                   std::unique_ptr<EncodedFrame> frame)
+        : rtp_seq_num_start_(rtp_seq_num_start),
+          rtp_seq_num_end_(rtp_seq_num_end),
+          frame_(std::move(frame)) {}
+
+    uint16_t RtpSeqNumStart() const { return rtp_seq_num_start_; }
+    uint16_t RtpSeqNumEnd() const { return rtp_seq_num_end_; }
+    std::unique_ptr<EncodedFrame> ExtractFrame() { return std::move(frame_); }
+
+   private:
+    uint16_t rtp_seq_num_start_;
+    uint16_t rtp_seq_num_end_;
+    std::unique_ptr<EncodedFrame> frame_;
+  };
+
+  // FrameVector is just a vector-like type of std::unique_ptr<EncodedFrame>.
+  // The vector type may change without notice.
+  using FrameVector = absl::InlinedVector<AssembledFrame, 3>;
+  enum PayloadFormat { kRaw, kH264, kVp8, kVp9, kAv1, kGeneric };
+
+  explicit RtpVideoFrameAssembler(PayloadFormat payload_format);
+  RtpVideoFrameAssembler(const RtpVideoFrameAssembler& other) = delete;
+  RtpVideoFrameAssembler& operator=(const RtpVideoFrameAssembler& other) =
+      delete;
+  ~RtpVideoFrameAssembler();
+
+  // Typically when a packet is inserted zero or one frame is completed. In the
+  // case of RTP packets being inserted out of order then sometime multiple
+  // frames could be completed from a single packet, hence the 'FrameVector'
+  // return type.
+  FrameVector InsertPacket(const RtpPacketReceived& packet);
+
+ private:
+  class Impl;
+  std::unique_ptr<Impl> impl_;
+};
+
+}  // namespace webrtc
+
+#endif  // API_VIDEO_RTP_VIDEO_FRAME_ASSEMBLER_H_