Implemented HEVC video demuxing and parsing

media/base/mime_util.cc

Index: media/base/mime_util.cc
diff --git a/media/base/mime_util.cc b/media/base/mime_util.cc
index 83eef2092a2cca6accc8c6aa80bf465a942262d3..92d461ee6128c58c5716db0fe005c688e974c00e 100644
--- a/media/base/mime_util.cc
+++ b/media/base/mime_util.cc
@@ -36,6 +36,7 @@ class MimeUtil {
     H264_BASELINE,
     H264_MAIN,
     H264_HIGH,
+    HEVC_MAIN,
     VP8,
     VP9,
     THEORA
@@ -199,6 +200,15 @@ static bool IsCodecSupportedOnAndroid(MimeUtil::Codec codec) {
     case MimeUtil::VORBIS:
       return true;
 
+    case MimeUtil::HEVC_MAIN:
+#if defined(ENABLE_HEVC_DEMUXING)
+      // HEVC/H.265 is supported in Lollipop+ (API Level 21), according to
+      // http://developer.android.com/reference/android/media/MediaFormat.html
+      return base::android::BuildInfo::GetInstance()->sdk_int() >= 21;
+#else
+      return false;
+#endif
+
     case MimeUtil::MPEG2_AAC_LC:
     case MimeUtil::MPEG2_AAC_MAIN:
     case MimeUtil::MPEG2_AAC_SSR:
@@ -253,6 +263,11 @@ static const char kMP4VideoCodecsExpression[] =
     // kUnambiguousCodecStringMap/kAmbiguousCodecStringMap should be the only
     // mapping from strings to codecs. See crbug.com/461009.
     "avc1.42E00A,avc1.4D400A,avc1.64000A,"
+#if defined(ENABLE_HEVC_DEMUXING)
+    // Any valid unambiguous HEVC codec id will work here, since these strings
+    // are parsed and mapped to MimeUtil::Codec enum values.
+    "hev1.1.6.L93.B0,"
+#endif
     "mp4a.66,mp4a.67,mp4a.68,mp4a.69,mp4a.6B,mp4a.40.2,mp4a.40.02,mp4a.40.5,"
     "mp4a.40.05,mp4a.40.29";
 
@@ -562,6 +577,35 @@ static bool ParseH264CodecID(const std::string& codec_id,
   return true;
 }
 
+#if defined(ENABLE_HEVC_DEMUXING)
+static bool ParseHEVCCodecID(const std::string& codec_id,
+                             MimeUtil::Codec* codec,
+                             bool* is_ambiguous) {
+  // TODO(servolk): Full HEVC codec id parsing is not implemented yet (see
+  // crbug.com/482761), but we need to recognize at least one valid unambiguous
+  // HEVC codec id, which is added kMP4VideoCodecsExpression. We need it to be
+  // unambiguous to avoid DCHECK at line 405. We also use these in unit tests.
+  if (codec_id == "hev1.1.6.L93.B0" || codec_id == "hvc1.1.6.L93.B0") {

[ddorwin, 2015/06/19 21:40:15]

Move this check to 601. You can even make this a single statement: *is_ambiguous
= !(<condition above>)

That ensures you execute the same path for all codec IDs and avoids a couple
lines of duplicate code.

[servolk, 2015/06/20 00:05:07]

Done. I've kept it a separate block of code to preserve the TODO comment and
make it more visually distinctive/noticeable.

+    *codec = MimeUtil::HEVC_MAIN;
+    *is_ambiguous = false;
+    return true;
+  }
+
+  if (base::StartsWithASCII(codec_id, "hev1.", true) ||

[ddorwin, 2015/06/19 21:40:15]

Please add a comment, possibly above the function, explaining what hev1 and hvc1
are. I think the answer is in one of the comments in this review, but we should
document it clearly.

[servolk, 2015/06/20 00:05:07]

Done (I've expanded comment from line 584 and moved it above the function).

+      base::StartsWithASCII(codec_id, "hvc1.", true)) {
+    // TODO(servolk): Implement parsing of hevc codec ids as described in
+    // ISO/IEC FDIS 14496-15 section E.3, but for now allow any
+    // HEVC tiers/profiles and let decoder decide if it can handle that.
+    // crbug.com/482761
+    *codec = MimeUtil::HEVC_MAIN;
+    *is_ambiguous = true;
+    return true;
+  }
+
+  return false;
+}
+#endif
+
 bool MimeUtil::StringToCodec(const std::string& codec_id,
                              Codec* codec,
                              bool* is_ambiguous) const {
@@ -574,8 +618,13 @@ bool MimeUtil::StringToCodec(const std::string& codec_id,
   }
 
   // If |codec_id| is not in |string_to_codec_map_|, then we assume that it is
-  // an H.264 codec ID because currently those are the only ones that can't be
-  // stored in the |string_to_codec_map_| and require parsing.
+  // either H.264 or HEVC/H.265 codec ID because currently those are the only
+  // ones that are not added to the |string_to_codec_map_| and require parsing.
+#if defined(ENABLE_HEVC_DEMUXING)
+  if (ParseHEVCCodecID(codec_id, codec, is_ambiguous)) {
+    return true;
+  }
+#endif
   return ParseH264CodecID(codec_id, codec, is_ambiguous);
 }
 
@@ -603,6 +652,7 @@ bool MimeUtil::IsCodecProprietary(Codec codec) const {
     case H264_BASELINE:
     case H264_MAIN:
     case H264_HIGH:
+    case HEVC_MAIN:
       return true;
 
     case PCM: