xref: /aosp_15_r20/external/webrtc/modules/video_coding/rtp_frame_reference_finder.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
1 /*
2  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef MODULES_VIDEO_CODING_RTP_FRAME_REFERENCE_FINDER_H_
12 #define MODULES_VIDEO_CODING_RTP_FRAME_REFERENCE_FINDER_H_
13 
14 #include <memory>
15 
16 #include "modules/video_coding/frame_object.h"
17 
18 namespace webrtc {
19 namespace internal {
20 class RtpFrameReferenceFinderImpl;
21 }  // namespace internal
22 
23 class RtpFrameReferenceFinder {
24  public:
25   using ReturnVector = absl::InlinedVector<std::unique_ptr<RtpFrameObject>, 3>;
26 
27   RtpFrameReferenceFinder();
28   explicit RtpFrameReferenceFinder(int64_t picture_id_offset);
29   ~RtpFrameReferenceFinder();
30 
31   // The RtpFrameReferenceFinder will hold onto the frame until:
32   //  - the required information to determine its references has been received,
33   //    in which case it (and possibly other) frames are returned, or
34   //  - There are too many stashed frames (determined by `kMaxStashedFrames`),
35   //    in which case it gets dropped, or
36   //  - It gets cleared by ClearTo, in which case its dropped.
37   //  - The frame is old, in which case it also gets dropped.
38   ReturnVector ManageFrame(std::unique_ptr<RtpFrameObject> frame);
39 
40   // Notifies that padding has been received, which the reference finder
41   // might need to calculate the references of a frame.
42   ReturnVector PaddingReceived(uint16_t seq_num);
43 
44   // Clear all stashed frames that include packets older than `seq_num`.
45   void ClearTo(uint16_t seq_num);
46 
47  private:
48   void AddPictureIdOffset(ReturnVector& frames);
49 
50   // How far frames have been cleared out of the buffer by RTP sequence number.
51   // A frame will be cleared if it contains a packet with a sequence number
52   // older than `cleared_to_seq_num_`.
53   int cleared_to_seq_num_ = -1;
54   const int64_t picture_id_offset_;
55   std::unique_ptr<internal::RtpFrameReferenceFinderImpl> impl_;
56 };
57 
58 }  // namespace webrtc
59 
60 #endif  // MODULES_VIDEO_CODING_RTP_FRAME_REFERENCE_FINDER_H_
61