Make the timestamp unroll offset consistent accross PES pids.

media/formats/mp2t/timestamp_unroller_unittest.cc

Index: media/formats/mp2t/timestamp_unroller_unittest.cc
diff --git a/media/formats/mp2t/timestamp_unroller_unittest.cc b/media/formats/mp2t/timestamp_unroller_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..163cd6568ad9a09e4969b7e79f4724b43cffe50b
--- /dev/null
+++ b/media/formats/mp2t/timestamp_unroller_unittest.cc
@@ -0,0 +1,58 @@
+// Copyright 2014 The Chromium 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 <vector>
+
+#include "base/logging.h"
+#include "base/port.h"
+#include "base/test/perf_test_suite.h"
+#include "media/formats/mp2t/timestamp_unroller.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media {
+namespace mp2t {
+
+static std::vector<int64> TruncateTimestamps(
+    const std::vector<int64>& timestamps) {
+  const int nbits = 33;
+  int64 truncate_mask = (GG_INT64_C(1) << nbits) - 1;
+  std::vector<int64> truncated_timestamps(timestamps.size());
+  for (size_t k = 0; k < timestamps.size(); k++)
+    truncated_timestamps[k] = timestamps[k] & truncate_mask;
+  return truncated_timestamps;
+}
+
+static void RunUnrollTest(const std::vector<int64>& timestamps) {
+  std::vector<int64> truncated_timestamps = TruncateTimestamps(timestamps);
+
+  TimestampUnroller timestamp_unroller;
+  for (size_t k = 0; k < timestamps.size(); k++) {
+    int64 unrolled_timestamp =
+        timestamp_unroller.GetUnrolledTimestamp(truncated_timestamps[k]);
+    EXPECT_EQ(timestamps[k], unrolled_timestamp);
+  }
+}
+
+TEST(TimestampUnrollerTest, SingleStream) {
+  // Array of 64 bit timestamps.
+  // This is the expected result from unrolling these timestamps
+  // truncated to 33 bits.
+  int64 timestamps[] = {
+    GG_INT64_C(0x0000000000000000),
+    GG_INT64_C(-190),                // - 190
+    GG_INT64_C(0x00000000aaaaa9ed),  // + 0xaaaaaaab
+    GG_INT64_C(0x0000000155555498),  // + 0xaaaaaaab
+    GG_INT64_C(0x00000001ffffff43),  // + 0xaaaaaaab
+    GG_INT64_C(0x00000002aaaaa9ee),  // + 0xaaaaaaab
+    GG_INT64_C(0x0000000355555499),  // + 0xaaaaaaab
+    GG_INT64_C(0x00000003ffffff44),  // + 0xaaaaaaab
+  };
+
+  std::vector<int64> timestamps_vector(
+      timestamps, timestamps + arraysize(timestamps));
+  RunUnrollTest(timestamps_vector);
+}
+
+}  // namespace mp2t
+}  // namespace media