1 /*
2 * Copyright (c) 2019 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 #include "modules/video_coding/utility/decoded_frames_history.h"
12
13 #include <algorithm>
14
15 #include "rtc_base/checks.h"
16 #include "rtc_base/logging.h"
17
18 namespace webrtc {
19 namespace video_coding {
20
21 DecodedFramesHistory::LayerHistory::LayerHistory() = default;
22 DecodedFramesHistory::LayerHistory::~LayerHistory() = default;
23
DecodedFramesHistory(size_t window_size)24 DecodedFramesHistory::DecodedFramesHistory(size_t window_size)
25 : window_size_(window_size) {}
26
27 DecodedFramesHistory::~DecodedFramesHistory() = default;
28
InsertDecoded(const VideoLayerFrameId & frameid,uint32_t timestamp)29 void DecodedFramesHistory::InsertDecoded(const VideoLayerFrameId& frameid,
30 uint32_t timestamp) {
31 last_decoded_frame_ = frameid;
32 last_decoded_frame_timestamp_ = timestamp;
33 if (static_cast<int>(layers_.size()) < frameid.spatial_layer + 1) {
34 size_t old_size = layers_.size();
35 layers_.resize(frameid.spatial_layer + 1);
36
37 for (size_t i = old_size; i < layers_.size(); ++i)
38 layers_[i].buffer.resize(window_size_);
39
40 layers_[frameid.spatial_layer].last_picture_id = frameid.picture_id;
41 layers_[frameid.spatial_layer]
42 .buffer[PictureIdToIndex(frameid.picture_id)] = true;
43 return;
44 }
45
46 int new_index = PictureIdToIndex(frameid.picture_id);
47 LayerHistory& history = layers_[frameid.spatial_layer];
48
49 RTC_DCHECK(history.last_picture_id < frameid.picture_id);
50
51 // Clears expired values from the cyclic buffer.
52 if (history.last_picture_id) {
53 int64_t id_jump = frameid.picture_id - *history.last_picture_id;
54 int last_index = PictureIdToIndex(*history.last_picture_id);
55
56 if (id_jump >= window_size_) {
57 std::fill(history.buffer.begin(), history.buffer.end(), false);
58 } else if (new_index > last_index) {
59 std::fill(history.buffer.begin() + last_index + 1,
60 history.buffer.begin() + new_index, false);
61 } else {
62 std::fill(history.buffer.begin() + last_index + 1, history.buffer.end(),
63 false);
64 std::fill(history.buffer.begin(), history.buffer.begin() + new_index,
65 false);
66 }
67 }
68
69 history.buffer[new_index] = true;
70 history.last_picture_id = frameid.picture_id;
71 }
72
WasDecoded(const VideoLayerFrameId & frameid)73 bool DecodedFramesHistory::WasDecoded(const VideoLayerFrameId& frameid) {
74 // Unseen before spatial layer.
75 if (static_cast<int>(layers_.size()) < frameid.spatial_layer + 1)
76 return false;
77
78 LayerHistory& history = layers_[frameid.spatial_layer];
79
80 if (!history.last_picture_id)
81 return false;
82
83 // Reference to the picture_id out of the stored history should happen.
84 if (frameid.picture_id <= *history.last_picture_id - window_size_) {
85 RTC_LOG(LS_WARNING) << "Referencing a frame out of the history window. "
86 "Assuming it was undecoded to avoid artifacts.";
87 return false;
88 }
89
90 if (frameid.picture_id > history.last_picture_id)
91 return false;
92
93 return history.buffer[PictureIdToIndex(frameid.picture_id)];
94 }
95
Clear()96 void DecodedFramesHistory::Clear() {
97 layers_.clear();
98 last_decoded_frame_timestamp_.reset();
99 last_decoded_frame_.reset();
100 }
101
102 absl::optional<VideoLayerFrameId>
GetLastDecodedFrameId()103 DecodedFramesHistory::GetLastDecodedFrameId() {
104 return last_decoded_frame_;
105 }
106
GetLastDecodedFrameTimestamp()107 absl::optional<uint32_t> DecodedFramesHistory::GetLastDecodedFrameTimestamp() {
108 return last_decoded_frame_timestamp_;
109 }
110
PictureIdToIndex(int64_t frame_id) const111 int DecodedFramesHistory::PictureIdToIndex(int64_t frame_id) const {
112 int m = frame_id % window_size_;
113 return m >= 0 ? m : m + window_size_;
114 }
115
116 } // namespace video_coding
117 } // namespace webrtc
118