Add detailed tests of supported avc1, avc3, and mp4a codec strings.

content/browser/media/media_canplaytype_browsertest.cc

Index: content/browser/media/media_canplaytype_browsertest.cc
diff --git a/content/browser/media/media_canplaytype_browsertest.cc b/content/browser/media/media_canplaytype_browsertest.cc
index f0f83af748a56f2aed39e444c1579f886108f740..b125d83d9b7baf74d1c38e67b746eb41d728fb4e 100644
--- a/content/browser/media/media_canplaytype_browsertest.cc
+++ b/content/browser/media/media_canplaytype_browsertest.cc
@@ -25,18 +25,18 @@ const char kPropProbably[] = "";
 const char kPropMaybe[] = "";
 #endif  // USE_PROPRIETARY_CODECS
 
-// TODO(amogh.bihani): Change the opus tests when opus is  on
-// Android. (http://crbug.com/318436).
 #if !defined(OS_ANDROID)
 const char kOggVideoProbably[] = "probably";
 const char kOggVideoMaybe[] = "maybe";
 const char kTheoraProbably[] = "probably";
 const char kOggOpusProbably[] = "probably";
+const char* kMpeg2AacProbably = kPropProbably;
 #else
 const char kOggVideoProbably[] = "";
 const char kOggVideoMaybe[] = "";
 const char kTheoraProbably[] = "";
 const char kOggOpusProbably[] = "";
+const char kMpeg2AacProbably[] = "";
 #endif  // !OS_ANDROID
 
 namespace content {
@@ -61,18 +61,57 @@ public:
   }
 
   void TestMPEGUnacceptableCombinations(std::string mime) {
-    // Codecs must be followed by valid hexadecimal number.
-    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc1.unknown\"'"));
-    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc3.unknown\"'"));
-    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.unknown\"'"));
+    // AVC codecs must be followed by valid 6-digit hexadecimal number.
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc1.12345\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc3.12345\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc1.1234567\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc3.1234567\"'"));
+    // TODO(ddorwin): These four should return "". See crbug.com/457076.
+//    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc1.number\"'"));
+//    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc3.number\"'"));
+//    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc1.12345.\"'"));
+//    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc3.12345.\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc1.123456.\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc3.123456.\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc1.123456.7\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc3.123456.7\"'"));
+
+    // AAC codecs must be followed by one or two valid hexadecimal numbers.
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.no\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.0k\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.0k.0k\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.4.\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.40.0k\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.40.\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.40k\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.40.2k\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.40.2k\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.40.2.\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.40.2.0\"'"));
+
+    // Just "mp4a" is not supported like just "avc1" is supported.

[wolenetz, 2015/02/18 22:44:33]

nit: rework comment. I kept reading this the wrong way as: "mp4a" is not
supported, just like "avc1" is supported. [comma and "just like" word order
mine]. I suspect the following is clearer: 'Unlike just "avc1" support, just
"mp4a" is not supported.'

[ddorwin, 2015/02/20 05:26:24]

Done.

+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.\"'"));
+
+    // Other names for the codecs are not supported.
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"h264\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"h.264\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"H264\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"H.264\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"aac\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"AAC\"'"));
 
     // Codecs must not end with a dot.
     EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc1.\"'"));
     EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc3.\"'"));
-    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a\"'"));
     EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.\"'"));
     EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"mp4a.40.\"'"));
 
+    // A simple substring match is not sufficient.
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"lavc1337\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\";mp4a+\"'"));
+    EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\";mp4a.40+\"'"));
+
     // Codecs not belonging to MPEG container.
     EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"vorbis\"'"));
     EXPECT_EQ(kNot, CanPlay("'" + mime + "; codecs=\"avc1, vorbis\"'"));
@@ -415,6 +454,7 @@ IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_mp4) {
 
   EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1\"'"));
   EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc3\"'"));
+  EXPECT_EQ(kNot, CanPlay("'video/mp4; codecs=\"mp4a\"'"));

[wolenetz, 2015/02/18 22:44:32]

nit: this is redundant with the "just like" portion of the
TestMPEGUnacceptableCombinations("video/mp4") call, below.

[ddorwin, 2015/02/20 05:26:24]

Done.

   EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"mp4a.40\"'"));
   EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1, mp4a.40\"'"));
   EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc3, mp4a.40\"'"));
@@ -458,6 +498,7 @@ IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_mp4) {
 
   EXPECT_EQ(kPropMaybe, CanPlay("'video/x-m4v; codecs=\"avc1\"'"));
   EXPECT_EQ(kPropMaybe, CanPlay("'video/x-m4v; codecs=\"avc3\"'"));
+  EXPECT_EQ(kNot, CanPlay("'video/x-m4v; codecs=\"mp4a\"'"));

[wolenetz, 2015/02/18 22:44:33]

nit: ditto redundant w/"just like" portion of call below.

[ddorwin, 2015/02/20 05:26:23]

Done.

   EXPECT_EQ(kPropMaybe, CanPlay("'video/x-m4v; codecs=\"mp4a.40\"'"));
   EXPECT_EQ(kPropMaybe, CanPlay("'video/x-m4v; codecs=\"avc1, mp4a.40\"'"));
   EXPECT_EQ(kPropMaybe, CanPlay("'video/x-m4v; codecs=\"avc3, mp4a.40\"'"));
@@ -498,6 +539,7 @@ IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_mp4) {
   TestMPEGUnacceptableCombinations("video/x-m4v");
 
   EXPECT_EQ(kPropMaybe, CanPlay("'audio/mp4'"));
+  EXPECT_EQ(kNot, CanPlay("'audio/mp4; codecs=\"mp4a\"'"));

[wolenetz, 2015/02/18 22:44:33]

nit ditto

[ddorwin, 2015/02/20 05:26:24]

Done.

   EXPECT_EQ(kPropMaybe, CanPlay("'audio/mp4; codecs=\"mp4a.40\"'"));
   EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"mp4a.40.2\"'"));
   EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"mp4a.40.02\"'"));
@@ -516,6 +558,7 @@ IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_mp4) {
   TestMPEGUnacceptableCombinations("audio/mp4");
 
   EXPECT_EQ(kPropMaybe, CanPlay("'audio/x-m4a'"));
+  EXPECT_EQ(kNot, CanPlay("'audio/x-m4a; codecs=\"mp4a\"'"));

[wolenetz, 2015/02/18 22:44:32]

nit ditto

[ddorwin, 2015/02/20 05:26:23]

Done.

   EXPECT_EQ(kPropMaybe, CanPlay("'audio/x-m4a; codecs=\"mp4a.40\"'"));
   EXPECT_EQ(kPropProbably, CanPlay("'audio/x-m4a; codecs=\"mp4a.40.2\"'"));
   EXPECT_EQ(kPropProbably, CanPlay("'audio/x-m4a; codecs=\"mp4a.40.02\"'"));
@@ -534,6 +577,254 @@ IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_mp4) {
   TestMPEGUnacceptableCombinations("audio/x-m4a");
 }
 
+// When modifying this test, also change CodecSupportTest_Avc3Variants.

[wolenetz, 2015/02/18 22:44:33]

nit: combine into one test that loops through all avc# or uses helper that is
parameterized by avc#?

[ddorwin, 2015/02/20 05:26:24]

Done, but I don't like it. I think I will revert. See my comment in the latest
patch set.

[wolenetz, 2015/02/23 19:57:45]

Yeah, I agree with your reasons for not doing this. Mainly I was hoping to
reduce code copy-paste and potential maintenance errors across avc1 vs avc3
versions that otherwise test for exactly the same support for the same sets of
mime+codec strings (apart from avc#). A mitigation of the wrapping of lines
could be to precompute the "base" from a supplied avc # and the rest of the
prefix of the mime string (video/mp4..., etc). I think your code searchability
comment has the most strength for why not to use a helper; if that could be
mitigated without adding yet more complexity then I would opt for using a helper
still. As it stands, no helper is better IMO.

[ddorwin, 2015/02/24 00:09:20]

Acknowledged.

+IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_Avc1Variants) {
+  // avc1 without extensions results in "maybe" for compatibility.
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1\"'"));
+
+  // Any 6-digit hexadecimal number will result in at least "maybe".
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.123456\"'"));
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.ABCDEF\"'"));
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.abcdef\"'"));
+  EXPECT_EQ(kNot,       CanPlay("'video/mp4; codecs=\"avc1.12345\"'"));

[wolenetz, 2015/02/18 22:44:33]

nit ditto for these two kNot lines: (redundant with CodecSupportTest_mp4's call
to TestMPEGUnacceptableCombinations("video/mp4"))

[ddorwin, 2015/02/20 05:26:24]

Yeah, these tests are quick, and I think it's nice to see the coverage all
together. I did remove the "mp4a" ones because that's clearly checked.

[wolenetz, 2015/02/23 19:57:44]

Acknowledged.

+  EXPECT_EQ(kNot,       CanPlay("'video/mp4; codecs=\"avc1.1234567\"'"));
+
+  // Both upper and lower case hexadecimal digits are accepted.
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E01E\"'"));

[wolenetz, 2015/02/18 22:44:32]

hmm there's more redundancy. I suspect many of these redundancy nits are fine
left as-is, to clarify each reason why they are/aren't supported.

[ddorwin, 2015/02/20 05:26:24]

Acknowledged.

+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42e01e\"'"));
+
+  // From a YouTube DASH MSE test manifest.

[wolenetz, 2015/02/18 22:44:33]

4d401e is duplicated, below.

This seems like a partial enumeration still. Is the intent to explicitly list
all kPropProbably (and maybe just a subset of kProbMaybe) avc# CanPlay cases in
this CL? If so, enumerating support expectations for "all valid levels" would be
good to include (in a helper?).

Redundancy elimination could be done by compiling the expectations into a
deduplicated set and only evaluating that set. WDYT?

[ddorwin, 2015/02/20 05:26:23]

Yes. This was an attempt to make sure we were covering some "in the wild" values
regardless of all the other rules.
Does "partial enumeration" refer to these four or the entire function? The four
are everything from an MPD. The rest of the test is not complete, especially for
maybe. It tries to cover edges, etc.
I think that would add complexity and make it difficult to ensure we are testing
what we want. What if there was a bug in the map entry? I'm not really concerned
about redundancy as long as they run quickly and the test is reasonably sized.

[wolenetz, 2015/02/23 19:57:44]

Acknowledged.
Sorry, I meant to refer to the entire function. (IOW, maybe we should test the
kProbably support for all valid avc1 variants *including* the idc_level.)
However, until and unless we actually differentiate a particular codec string's
support by more than just "valid level for any avc", we don't need such
exhaustive testing here.  IIRC, there might be some other variants of avc codec
strings that we might add support in future that do condition on a strict subset
of the "valid level for any avc", but we don't have that implemented yet, so no
need for such testing.
Yeah, I was more concerned about execution speed in this comment. If we don't
easily know *what* we're testing (or complexity to do this significantly
increases risk of errors during maintenance), then execution speed matters less,
so let's keep with what you have in PS6  ;)

+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.4d401f\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.4d401e\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.4d4015\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.640028\"'"));
+
+  //
+  // Baseline Profile (66 == 0x42).
+  //  The first four digits must be 42E0, but Chrome also allows 42[8-F]0.
+  //  (See http://crbug.com/408552#c17.)
+  //  The last two digits must be any valid level.
+  //
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E00A\"'"));
+
+  // The third digit must be 8-F.
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42001E\"'"));

[wolenetz, 2015/02/18 22:44:33]

aside: thanks for formatting these lines to line up in columns. Great idea for
readability here!

[ddorwin, 2015/02/20 05:26:24]

Acknowledged.

+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42101E\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42201E\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42301E\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42401E\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42501E\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42601E\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42701E\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42801E\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42901E\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42A01E\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42B01E\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42C01E\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42D01E\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E01E\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42F01E\"'"));
+
+  // The fourth digit must be 0.
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.42E11E\"'"));
+
+  //
+  // Main Profile (77 == 0x4D).
+  //  The first four digits must be 4D40.
+  //  The last two digits must be any valid level.
+  //
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.4D400A\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.4D401E\"'"));
+
+  // Other values are not allowed for the third and fourth digits.
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.4D301E\"'"));
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.4D501E\"'"));
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.4D411E\"'"));
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.4D4F1E\"'"));
+
+  //
+  // High Profile (100 == 0x64).
+  //  The first four digits must be 6400.
+  //  The last two digits must be any valid level.
+  //
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.64000A\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.64001E\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.64001F\"'"));
+
+  // Other values are not allowed for the third and fourth digits.
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.64101E\"'"));
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.64f01E\"'"));
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.64011E\"'"));
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.640F1E\"'"));
+
+  //
+  //  Other profiles are not known to be supported.
+  //
+
+  // Extended Profile (88 == 0x58).
+  EXPECT_EQ(kPropMaybe, CanPlay("'video/mp4; codecs=\"avc1.58A01E\"'"));
+}
+
+IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_Avc3Variants) {
+  // TODO(ddorwin): Copy the final Avc1Variants contents here and s/avc1/avc3/.

[wolenetz, 2015/02/18 22:44:33]

nit ditto: parameterize avc# and use a helper for each of #={1,3}?

[ddorwin, 2015/02/20 05:26:23]

Ditto.

[wolenetz, 2015/02/23 19:57:45]

Acknowledged.

+}
+
+// Tests AVC levels using AVC1 Baseline (0x42E0zz).
+// Other supported values for the first for hexadecimal digits should behave

[wolenetz, 2015/02/18 22:44:33]

nit: s/for hex/four hex/

[ddorwin, 2015/02/20 05:26:23]

Done.

+// the same way but are not tested.
+// For each full level, the following are tested:
+// * The hexadecimal value before it is not supported.
+// * The hexadecimal value for the main level and all sub-levels are supported.
+// * The hexadecimal value after the last sub-level it is not supported.
+// * Decimal representations of the levels are not supported.
+
+IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_AvcLevels) {
+  // Level 0 is not supported.
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E000\"'"));
+
+  // Levels 1 (0x0A), 1.1 (0x0B), 1.2 (0x0C), 1.3 (0x0D).
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E009\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E00A\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E00B\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E00C\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E00D\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E00E\"'"));
+  // Verify that decimal representations of levels are not supported.
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E001\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E010\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E011\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E012\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E013\"'"));
+
+  // Levels 2 (0x14), 2.1 (0x15), 2.2 (0x16)
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E013\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E014\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E015\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E016\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E017\"'"));
+  // Verify that decimal representations of levels are not supported.
+  // However, 20 is level 3.2.
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E002\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E020\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E021\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E022\"'"));
+
+  // Levels 3 (0x1e), 3.1 (0x1F), 3.2 (0x20)
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E01D\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E01E\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E01F\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E020\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E021\"'"));
+  // Verify that decimal representations of levels are not supported.
+  // However, 32 is level 5.
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E003\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E030\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E031\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E032\"'"));
+
+  // Levels 4 (0x28), 4.1 (0x29), 4.2 (0x2A)
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E027\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E028\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E029\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E02A\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E02B\"'"));
+  // Verify that decimal representations of levels are not supported.
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E004\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E040\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E041\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E042\"'"));
+
+  // Levels 5 (0x32), 5.1 (0x33).
+  // Note: Level 5.2 (0x34) is not considered valid.

[wolenetz, 2015/02/18 22:44:33]

The version of ISO14496-10 acolwell@ used may have been too old to include 5.2
(it's not in the March 1, 2006 "corrected version" AFAICT).
It looks like ITU-T Rec. H.264 | ISO/IEC 14496-10 version 14 was the first to
include level 5.2.

That said, we'd need to look into s/w decoder (desktop) support, and android
support before adding it as kPropProbably. Please file a bug for this.

[ddorwin, 2015/02/20 05:26:24]

Done.

+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E031\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E032\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"avc1.42E033\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E034\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E035\"'"));
+  // Verify that decimal representations of levels are not supported.
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E005\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E050\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E051\"'"));
+  EXPECT_EQ(kPropMaybe,    CanPlay("'video/mp4; codecs=\"avc1.42E052\"'"));
+}
+
+IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_Mp4aVariants) {
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a\"'"));

[wolenetz, 2015/02/18 22:44:33]

nit ditto redundancy...

[ddorwin, 2015/02/20 05:26:23]

This is specifically testing mp4a, so I think it's fine.

[wolenetz, 2015/02/23 19:57:45]

Acknowledged.

+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.\"'"));
+
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.6\"'"));

[wolenetz, 2015/02/18 22:44:33]

nit: include comments in this method identifying which ones are expected to be
"MP3" or "just a number near the MP3 number", for example. As it is, reader
could become confused about mp4a.6A: is it MP3 or not, for example.

[ddorwin, 2015/02/20 05:26:23]

Hmm. I'm not sure how to do this without adding more clutter that hurts
readability. I don't want to document "near/like AAC/66" for each of these.

I guess the pattern is that there are comments before a series of supported
values and "near" values around them.

Let me know if you have suggestions.

[wolenetz, 2015/02/23 19:57:44]

(nit) Perhaps a comment section at the top of this test that describes the
grouping/sequencing (similar to the comment at top of *_AvcLevels test, above)
would prevent clutter while improving readability here. WDYT?

[ddorwin, 2015/02/24 00:09:20]

Done.

+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.60\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.61\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.62\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.63\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.65\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.65\"'"));
+  // MPEG2 AAC Main, LC, and SSR are supported except on Android.
+  EXPECT_EQ(kMpeg2AacProbably, CanPlay("'audio/mp4; codecs=\"mp4a.66\"'"));
+  EXPECT_EQ(kMpeg2AacProbably, CanPlay("'audio/mp4; codecs=\"mp4a.67\"'"));
+  EXPECT_EQ(kMpeg2AacProbably, CanPlay("'audio/mp4; codecs=\"mp4a.68\"'"));
+  // MP3.
+  EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"mp4a.69\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.6A\"'"));
+  // MP3.
+  EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"mp4a.6B\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.6b\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.6C\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.6D\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.6E\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.6F\"'"));
+
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.76\"'"));
+
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.4\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.39\"'"));
+
+  // mp4a.40 without further extension is ambiguous and results in "maybe".
+  EXPECT_EQ(kPropMaybe,    CanPlay("'audio/mp4; codecs=\"mp4a.40\"'"));
+
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.0\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.1\"'"));
+  // MPEG4 AAC LC.
+  EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"mp4a.40.2\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.3\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.4\"'"));
+  // MPEG4 AAC SBR v1.
+  EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"mp4a.40.5\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.6\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.7\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.8\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.9\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.10\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.20\"'"));
+  // MPEG4 AAC SBR PS v2.
+  EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"mp4a.40.29\"'"));

[wolenetz, 2015/02/18 22:44:33]

nit: try mp4a.40.1D, mp4a.40.1d, mp4a.40.41 should be kNot, too (in case someone
wrongly converts 29 to or from hex).

[ddorwin, 2015/02/20 05:26:24]

Done.

+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.30\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.40\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.50\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.290\"'"));
+
+  // Allow leading zeros in aud-oti for specific MPEG4 AAC strings.
+  // See http://crbug.com/440607.
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.00\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.01\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"mp4a.40.02\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.03\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.04\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"mp4a.40.05\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.40.029\"'"));
+
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.41\"'"));
+  EXPECT_EQ(kNot,          CanPlay("'audio/mp4; codecs=\"mp4a.41.2\"'"));
+
+  EXPECT_EQ(kNot, CanPlay("'audio/mp4; codecs=\"mp4a.4.2\"'"));
+  EXPECT_EQ(kNot, CanPlay("'audio/mp4; codecs=\"mp4a.400.2\"'"));
+  EXPECT_EQ(kNot, CanPlay("'audio/mp4; codecs=\"mp4a.040.2\"'"));
+  EXPECT_EQ(kNot, CanPlay("'audio/mp4; codecs=\"mp4a.4.5\"'"));
+  EXPECT_EQ(kNot, CanPlay("'audio/mp4; codecs=\"mp4a.400.5\"'"));
+  EXPECT_EQ(kNot, CanPlay("'audio/mp4; codecs=\"mp4a.040.5\"'"));
+}
+
 IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_HLS) {
   // HLS are supported only on Android IceCreamSandwich and above (API level 14)
   std::string probablyCanPlayHLS = kNot;