Add more tests for H264 profile level id parsing

webrtc/common_video/h264/profile_level_id_unittest.cc

 /*
  *  Copyright (c) 2016 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.
  */
 
@@ skipping 57 matching lines @@
 
 TEST(H264ProfileLevelId, TestParsingConstrainedHigh) {
   EXPECT_EQ(kProfileConstrainedHigh, ParseProfileLevelId("640c1f")->profile);
 }
 
 TEST(H264ProfileLevelId, TestToString) {
   EXPECT_EQ("42e01f", *ProfileLevelIdToString(ProfileLevelId(
                           kProfileConstrainedBaseline, kLevel3_1)));
   EXPECT_EQ("42000a",
             *ProfileLevelIdToString(ProfileLevelId(kProfileBaseline, kLevel1)));
-  EXPECT_EQ("4D001f",
+  EXPECT_EQ("4d001f",
             ProfileLevelIdToString(ProfileLevelId(kProfileMain, kLevel3_1)));
   EXPECT_EQ("640c2a", *ProfileLevelIdToString(
                           ProfileLevelId(kProfileConstrainedHigh, kLevel4_2)));
   EXPECT_EQ("64002a",
             *ProfileLevelIdToString(ProfileLevelId(kProfileHigh, kLevel4_2)));
 }
 
 TEST(H264ProfileLevelId, TestToStringLevel1b) {
   EXPECT_EQ("42f00b", *ProfileLevelIdToString(ProfileLevelId(
                           kProfileConstrainedBaseline, kLevel1_b)));
   EXPECT_EQ("42100b", *ProfileLevelIdToString(
                           ProfileLevelId(kProfileBaseline, kLevel1_b)));
-  EXPECT_EQ("4D100b",
+  EXPECT_EQ("4d100b",
             *ProfileLevelIdToString(ProfileLevelId(kProfileMain, kLevel1_b)));
 }
 
+TEST(H264ProfileLevelId, TestToStringRoundTrip) {
+  EXPECT_EQ("42e01f", *ProfileLevelIdToString(*ParseProfileLevelId("42e01f")));
+  EXPECT_EQ("42e01f", *ProfileLevelIdToString(*ParseProfileLevelId("42E01F")));
+  EXPECT_EQ("4d100b", *ProfileLevelIdToString(*ParseProfileLevelId("4d100b")));
+  EXPECT_EQ("4d100b", *ProfileLevelIdToString(*ParseProfileLevelId("4D100B")));
+  EXPECT_EQ("640c2a", *ProfileLevelIdToString(*ParseProfileLevelId("640c2a")));
+  EXPECT_EQ("640c2a", *ProfileLevelIdToString(*ParseProfileLevelId("640C2A")));
+}
+
 TEST(H264ProfileLevelId, TestToStringInvalid) {
   EXPECT_FALSE(ProfileLevelIdToString(ProfileLevelId(kProfileHigh, kLevel1_b)));
   EXPECT_FALSE(ProfileLevelIdToString(
       ProfileLevelId(kProfileConstrainedHigh, kLevel1_b)));
   EXPECT_FALSE(ProfileLevelIdToString(
       ProfileLevelId(static_cast<Profile>(255), kLevel3_1)));
 }
 
 }  // namespace H264
 }  // namespace webrtc