Add unittests to validate scalability structures without encoder

Bug: webrtc:10342
Change-Id: I66407e635502b7c87f8d4ab49c95f5c1326da4a0
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/176412
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31423}

modules/video_coding/BUILD.gn

@@ -974,6 +974,7 @@ if (rtc_include_tests) {
       "../../test/time_controller:time_controller",
       "../rtp_rtcp:rtp_rtcp_format",
       "../rtp_rtcp:rtp_video_header",
+      "codecs/av1:scalability_structure_tests",
       "codecs/av1:video_coding_codecs_av1_tests",
       "deprecated:nack_module",
       "//third_party/abseil-cpp/absl/memory",

modules/video_coding/codecs/av1/BUILD.gn

@@ -104,6 +104,17 @@ rtc_library("libaom_av1_encoder") {
 }
 
 if (rtc_include_tests) {
+  rtc_library("scalability_structure_tests") {
+    testonly = true
+    sources = [ "scalability_structure_unittest.cc" ]
+    deps = [
+      ":scalability_structures",
+      ":scalable_video_controller",
+      "../../../../test:test_support",
+      "//third_party/abseil-cpp/absl/types:optional",
+    ]
+  }
+
   rtc_library("video_coding_codecs_av1_tests") {
     testonly = true
 

modules/video_coding/codecs/av1/scalability_structure_l1t2.cc

@@ -47,7 +47,7 @@ FrameDependencyStructure ScalabilityStructureL1T2::DependencyStructure() const {
   FrameDependencyStructure structure;
   structure.num_decode_targets = 2;
   structure.num_chains = 1;
-  structure.decode_target_protected_by_chain = {0};
+  structure.decode_target_protected_by_chain = {0, 0};
   structure.templates = {
       Builder().T(0).Dtis("SS").ChainDiffs({0}).Build(),
       Builder().T(0).Dtis("SS").ChainDiffs({2}).Fdiffs({2}).Build(),

modules/video_coding/codecs/av1/scalability_structure_unittest.cc

@@ -0,0 +1,127 @@
+/*
+ *  Copyright (c) 2020 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 <stddef.h>
+#include <stdint.h>
+
+#include <functional>
+#include <memory>
+#include <ostream>
+#include <string>
+
+#include "absl/types/optional.h"
+#include "modules/video_coding/codecs/av1/scalability_structure_l1t2.h"
+#include "modules/video_coding/codecs/av1/scalability_structure_l2t1.h"
+#include "modules/video_coding/codecs/av1/scalability_structure_l2t1_key.h"
+#include "modules/video_coding/codecs/av1/scalability_structure_s2t1.h"
+#include "modules/video_coding/codecs/av1/scalable_video_controller.h"
+#include "test/gmock.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+using ::testing::AllOf;
+using ::testing::Each;
+using ::testing::Field;
+using ::testing::Ge;
+using ::testing::IsEmpty;
+using ::testing::Le;
+using ::testing::Lt;
+using ::testing::Not;
+using ::testing::SizeIs;
+using ::testing::TestWithParam;
+using ::testing::Values;
+
+struct SvcTestParam {
+  friend std::ostream& operator<<(std::ostream& os, const SvcTestParam& param) {
+    return os << param.name;
+  }
+
+  std::string name;
+  std::function<std::unique_ptr<ScalableVideoController>()> svc_factory;
+};
+
+class ScalabilityStructureTest : public TestWithParam<SvcTestParam> {};
+
+TEST_P(ScalabilityStructureTest,
+       NumberOfDecodeTargetsAndChainsAreInRangeAndConsistent) {
+  FrameDependencyStructure structure =
+      GetParam().svc_factory()->DependencyStructure();
+  EXPECT_GT(structure.num_decode_targets, 0);
+  EXPECT_LE(structure.num_decode_targets, 32);
+  EXPECT_GE(structure.num_chains, 0);
+  EXPECT_LE(structure.num_chains, structure.num_decode_targets);
+  if (structure.num_chains == 0) {
+    EXPECT_THAT(structure.decode_target_protected_by_chain, IsEmpty());
+  } else {
+    EXPECT_THAT(structure.decode_target_protected_by_chain,
+                AllOf(SizeIs(structure.num_decode_targets), Each(Ge(0)),
+                      Each(Le(structure.num_chains))));
+  }
+  EXPECT_THAT(structure.templates, SizeIs(Lt(size_t{64})));
+}
+
+TEST_P(ScalabilityStructureTest, TemplatesAreSortedByLayerId) {
+  FrameDependencyStructure structure =
+      GetParam().svc_factory()->DependencyStructure();
+  ASSERT_THAT(structure.templates, Not(IsEmpty()));
+  const auto& first_templates = structure.templates.front();
+  EXPECT_EQ(first_templates.spatial_id, 0);
+  EXPECT_EQ(first_templates.temporal_id, 0);
+  for (size_t i = 1; i < structure.templates.size(); ++i) {
+    const auto& prev_template = structure.templates[i - 1];
+    const auto& next_template = structure.templates[i];
+    if (next_template.spatial_id == prev_template.spatial_id &&
+        next_template.temporal_id == prev_template.temporal_id) {
+      // Same layer, next_layer_idc == 0
+    } else if (next_template.spatial_id == prev_template.spatial_id &&
+               next_template.temporal_id == prev_template.temporal_id + 1) {
+      // Next temporal layer, next_layer_idc == 1
+    } else if (next_template.spatial_id == prev_template.spatial_id + 1 &&
+               next_template.temporal_id == 0) {
+      // Next spatial layer, next_layer_idc == 2
+    } else {
+      // everything else is invalid.
+      ADD_FAILURE() << "Invalid templates order. Template #" << i
+                    << " with layer (" << next_template.spatial_id << ","
+                    << next_template.temporal_id
+                    << ") follows template with layer ("
+                    << prev_template.spatial_id << ","
+                    << prev_template.temporal_id << ").";
+    }
+  }
+}
+
+TEST_P(ScalabilityStructureTest, TemplatesMatchNumberOfDecodeTargetsAndChains) {
+  FrameDependencyStructure structure =
+      GetParam().svc_factory()->DependencyStructure();
+  EXPECT_THAT(
+      structure.templates,
+      Each(AllOf(Field(&FrameDependencyTemplate::decode_target_indications,
+                       SizeIs(structure.num_decode_targets)),
+                 Field(&FrameDependencyTemplate::chain_diffs,
+                       SizeIs(structure.num_chains)))));
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    Svc,
+    ScalabilityStructureTest,
+    Values(SvcTestParam{"L1T2", std::make_unique<ScalabilityStructureL1T2>},
+           SvcTestParam{"L2T1", std::make_unique<ScalabilityStructureL2T1>},
+           SvcTestParam{"L2T1Key",
+                        std::make_unique<ScalabilityStructureL2T1Key>},
+           SvcTestParam{"S2T1", std::make_unique<ScalabilityStructureS2T1>}),
+    [](const testing::TestParamInfo<SvcTestParam>& info) {
+      return info.param.name;
+    });
+
+}  // namespace
+}  // namespace webrtc