src/media/drivers/amlogic_decoder/tests/unit_tests/test_pts_manager.cc

// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <gtest/gtest.h>

#include "pts_manager.h"

namespace amlogic_decoder {
namespace test {

// This particular test could reasonably be made to run in a non-driver process, but keeping it with
// the rest of the driver's unit tests for now.  This keeps the unit tests together, avoids adding
// a whole binary just for this test code, and lets any LOG() macro output work normally for easier
// test failure diagnosis.
class PtsManagerUnitTest {};

TEST(PtsManagerUnitTest, SetLookupBitWidth) {
  // H264Decoder uses 28.  Vp9Decoder uses 32.
  uint32_t bit_widths[] = {28, 32};
  for (uint32_t bit_width : bit_widths) {
    PtsManager pts_manager;
    pts_manager.SetLookupBitWidth(bit_width);
    uint64_t only_offset = static_cast<uint64_t>(1) << 63;
    only_offset += (static_cast<uint64_t>(1) << bit_width) - 1;
    pts_manager.InsertPts(only_offset, /*has_pts=*/true, 42);
    PtsManager::LookupResult result1 = pts_manager.Lookup(0);

    // Without bit width extension, the lookup would see that all offsets are > 0, and not return
    // anything, but instead the 0 is interpreted as being an overflow back to 0 from all FFs of
    // width bit_width.
    EXPECT_TRUE(result1.has_pts());
    EXPECT_EQ(42u, result1.pts());

    // Without bit width extension, the lookup would see that all offsets are > than this value,
    // and not return anything.  As is, the only_offset is logically == to this value, despite
    // this value lacking the top order 1 bit that only_offset has.
    PtsManager::LookupResult result2 =
        pts_manager.Lookup((static_cast<uint64_t>(1) << bit_width) - 1);
    EXPECT_TRUE(result2.has_pts());
    EXPECT_EQ(42u, result2.pts());

    // This value is logically below only_offset, so should not return anything.
    PtsManager::LookupResult result3 =
        pts_manager.Lookup((static_cast<uint64_t>(1) << bit_width) - 2);
    EXPECT_FALSE(result3.has_pts());
  }
}

TEST(PtsManagerUnitTest, KeepingMaxEntriesButNotMore) {
  PtsManager pts_manager;
  constexpr uint64_t kStartingPts = 1000;
  constexpr uint64_t kPtsIncrement = 100;
  constexpr uint64_t kStartingOffset = 10000;
  constexpr uint64_t kOffsetIncrement = 1000;
  uint64_t offset = kStartingOffset;
  uint64_t pts = kStartingPts;
  for (uint32_t i = 0; i < PtsManager::kMaxEntriesToKeep + 1; i++) {
    pts_manager.InsertPts(offset, /*has_pts=*/true, pts);
    offset += kOffsetIncrement;
    pts += kPtsIncrement;
  }
  PtsManager::LookupResult result_present = pts_manager.Lookup(kStartingOffset + kOffsetIncrement);
  EXPECT_FALSE(result_present.is_end_of_stream());
  EXPECT_TRUE(result_present.has_pts());
  EXPECT_EQ(kStartingPts + kOffsetIncrement, result_present.pts());
  PtsManager::LookupResult result_absent =
      pts_manager.Lookup(kStartingOffset + kOffsetIncrement - 1);
  EXPECT_FALSE(result_absent.is_end_of_stream());
  EXPECT_FALSE(result_absent.has_pts());
  EXPECT_EQ(0ull, result_absent.pts());
}

}  // namespace test
}  // namespace amlogic_decoder