1 /*
2 * Copyright (c) 2020 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 #include "modules/video_coding/frame_dependencies_calculator.h"
11
12 #include <stdint.h>
13
14 #include <iterator>
15 #include <set>
16
17 #include "absl/algorithm/container.h"
18 #include "absl/container/inlined_vector.h"
19 #include "api/array_view.h"
20 #include "rtc_base/checks.h"
21 #include "rtc_base/logging.h"
22
23 namespace webrtc {
24
FromBuffersUsage(int64_t frame_id,rtc::ArrayView<const CodecBufferUsage> buffers_usage)25 absl::InlinedVector<int64_t, 5> FrameDependenciesCalculator::FromBuffersUsage(
26 int64_t frame_id,
27 rtc::ArrayView<const CodecBufferUsage> buffers_usage) {
28 absl::InlinedVector<int64_t, 5> dependencies;
29 RTC_DCHECK_GT(buffers_usage.size(), 0);
30 for (const CodecBufferUsage& buffer_usage : buffers_usage) {
31 RTC_CHECK_GE(buffer_usage.id, 0);
32 if (buffers_.size() <= static_cast<size_t>(buffer_usage.id)) {
33 buffers_.resize(buffer_usage.id + 1);
34 }
35 }
36 std::set<int64_t> direct_depenendencies;
37 std::set<int64_t> indirect_depenendencies;
38
39 for (const CodecBufferUsage& buffer_usage : buffers_usage) {
40 if (!buffer_usage.referenced) {
41 continue;
42 }
43 const BufferUsage& buffer = buffers_[buffer_usage.id];
44 if (buffer.frame_id == absl::nullopt) {
45 RTC_LOG(LS_ERROR) << "Odd configuration: frame " << frame_id
46 << " references buffer #" << buffer_usage.id
47 << " that was never updated.";
48 continue;
49 }
50 direct_depenendencies.insert(*buffer.frame_id);
51 indirect_depenendencies.insert(buffer.dependencies.begin(),
52 buffer.dependencies.end());
53 }
54 // Reduce references: if frame #3 depends on frame #2 and #1, and frame #2
55 // depends on frame #1, then frame #3 needs to depend just on frame #2.
56 // Though this set diff removes only 1 level of indirection, it seems
57 // enough for all currently used structures.
58 absl::c_set_difference(direct_depenendencies, indirect_depenendencies,
59 std::back_inserter(dependencies));
60
61 // Update buffers.
62 for (const CodecBufferUsage& buffer_usage : buffers_usage) {
63 if (!buffer_usage.updated) {
64 continue;
65 }
66 BufferUsage& buffer = buffers_[buffer_usage.id];
67 buffer.frame_id = frame_id;
68 buffer.dependencies.assign(direct_depenendencies.begin(),
69 direct_depenendencies.end());
70 }
71
72 return dependencies;
73 }
74
75 } // namespace webrtc
76