Fix: Adding list of supported codecs for MP4 containers

net/base/mime_util.cc

Index: net/base/mime_util.cc
diff --git a/net/base/mime_util.cc b/net/base/mime_util.cc
index fdb16fd8f7ef0b0f22b2d2e232198587ce19344d..3542ad9340a756304e7134441317d01555c43b33 100644
--- a/net/base/mime_util.cc
+++ b/net/base/mime_util.cc
@@ -81,6 +81,9 @@ class MimeUtil : public PlatformMimeUtil {
   bool IsSupportedStrictMediaMimeType(
       const std::string& mime_type,
       const std::vector<std::string>& codecs) const;
+  bool IsSupportedStrictMP4OrHLSMediaMimeType(
+      const std::string& mime_type,
+      const std::vector<std::string>& codecs) const;
 
   void RemoveProprietaryMediaTypesAndCodecsForTests();
 
@@ -90,12 +93,19 @@ class MimeUtil : public PlatformMimeUtil {
   typedef base::hash_set<std::string> MimeMappings;
   typedef std::map<std::string, MimeMappings> StrictMappings;
 
+  typedef std::vector<std::string> MimeExpressionMappings;
+  typedef std::map<std::string, MimeExpressionMappings>
+      StrictExpressionMappings;
+
   MimeUtil();
 
   // Returns true if |codecs| is nonempty and all the items in it are present in
   // |supported_codecs|.
   static bool AreSupportedCodecs(const MimeMappings& supported_codecs,
                                  const std::vector<std::string>& codecs);
+  static bool AreSupportedCodecsWithProfile(
+      const MimeExpressionMappings& supported_codecs,
+      const std::vector<std::string>& codecs);
 
   // For faster lookup, keep hash sets.
   void InitializeMimeTypeMaps();
@@ -112,6 +122,7 @@ class MimeUtil : public PlatformMimeUtil {
   MimeMappings codecs_map_;
 
   StrictMappings strict_format_map_;
+  StrictExpressionMappings strict_mp4_format_map_;
 };  // class MimeUtil
 
 // This variable is Leaky because we need to access it from WorkerPool threads.
@@ -444,6 +455,16 @@ static const MediaFormatStrict format_codec_mappings[] = {
   { "audio/x-mp3", "" }
 };
 
+static const MediaFormatStrict format_mp4_codec_mappings[] = {
+    {"audio/mp4", "mp4a,mp4a.40,mp4a.40.?"},

[acolwell GONE FROM CHROMIUM, 2014/05/12 14:54:18]

mp4a is not valid. mp4a.67 should be added to this list as well since that is
what is used for MPEG2 AAC in an MP4 container. This applies everywhere below as
well.

[amogh.bihani, 2014/05/15 09:05:53]

Done.

+    {"audio/x-m4a", "mp4a,mp4a.40,mp4a.40.?"},
+    {"video/mp4", "avc1,avc3,avc1.??????,avc3.??????,mp4a,mp4a.40,mp4a.40.?"},

[acolwell GONE FROM CHROMIUM, 2014/05/12 14:54:18]

nit: perhaps move this into a static constant so it is a little clearer that
these are all using the exact same value.

[amogh.bihani, 2014/05/15 09:05:53]

Done.

+    {"video/x-m4v", "avc1,avc3,avc1.??????,avc3.??????,mp4a,mp4a.40,mp4a.40.?"},
+    {"application/x-mpegurl",
+     "avc1,avc3,avc1.??????,avc3.??????,mp4a,mp4a.40,mp4a.40.?"},
+    {"application/vnd.apple.mpegurl",
+     "avc1,avc3,avc1.??????,avc3.??????,mp4a,mp4a.40,mp4a.40.?"}};
+
 MimeUtil::MimeUtil() {
   InitializeMimeTypeMaps();
 }
@@ -461,6 +482,31 @@ bool MimeUtil::AreSupportedCodecs(const MimeMappings& supported_codecs,
   return !codecs.empty();
 }
 
+bool MimeUtil::AreSupportedCodecsWithProfile(
+    const MimeExpressionMappings& supported_codecs,
+    const std::vector<std::string>& codecs) {
+  for (size_t i = 0; i < codecs.size(); ++i) {
+    bool codec_matched = false;
+    for (size_t j = 0; j < supported_codecs.size(); ++j) {
+      if (MatchPattern(static_cast<base::StringPiece>(codecs[i]),

[acolwell GONE FROM CHROMIUM, 2014/05/12 14:54:18]

nit: reverse condition & continue

[amogh.bihani, 2014/05/15 09:05:53]

Done.

+                       static_cast<base::StringPiece>(supported_codecs[j]))) {
+        codec_matched = true;
+        std::vector<std::string> split_string;
+        base::SplitString(codecs[i], '.', &split_string);
+        if (split_string.size() > 1 &&
+            !IsUpperCaseHexNumber(split_string.back())) {

[acolwell GONE FROM CHROMIUM, 2014/05/12 14:54:18]

I don't think we should enforce upper case here. You'll likely break existing
sites for no good reason.

[amogh.bihani, 2014/05/15 09:05:53]

Done.

+          codec_matched = false;

[acolwell GONE FROM CHROMIUM, 2014/05/12 14:54:18]

nit: just return false here and move codec_matched = true  right before the
break below since that is when you know you actually have a match.

[amogh.bihani, 2014/05/15 09:05:53]

Done.

+        }
+        break;
+      }
+    }
+    // Return false if any of the codecs is not matching.
+    if (!codec_matched)
+      return false;
+  }
+  return !codecs.empty();
+}
+
 void MimeUtil::InitializeMimeTypeMaps() {
   for (size_t i = 0; i < arraysize(supported_image_types); ++i)
     image_map_.insert(supported_image_types[i]);
@@ -521,6 +567,17 @@ void MimeUtil::InitializeMimeTypeMaps() {
     }
     strict_format_map_[format_codec_mappings[i].mime_type] = codecs;
   }
+  for (size_t i = 0; i < arraysize(format_mp4_codec_mappings); ++i) {
+    std::vector<std::string> mime_type_codecs;
+    ParseCodecString(
+        format_mp4_codec_mappings[i].codecs_list, &mime_type_codecs, false);
+
+    MimeExpressionMappings codecs;
+    for (size_t j = 0; j < mime_type_codecs.size(); ++j) {
+      codecs.push_back(mime_type_codecs[j]);
+    }
+    strict_mp4_format_map_[format_mp4_codec_mappings[i].mime_type] = codecs;
+  }
 }
 
 bool MimeUtil::IsSupportedImageMimeType(const std::string& mime_type) const {
@@ -703,7 +760,8 @@ void MimeUtil::ParseCodecString(const std::string& codecs,
 }
 
 bool MimeUtil::IsStrictMediaMimeType(const std::string& mime_type) const {
-  if (strict_format_map_.find(mime_type) == strict_format_map_.end())
+  if (strict_format_map_.find(mime_type) == strict_format_map_.end() &&
+      strict_mp4_format_map_.find(mime_type) == strict_mp4_format_map_.end())
     return false;
   return true;
 }
@@ -716,6 +774,15 @@ bool MimeUtil::IsSupportedStrictMediaMimeType(
       AreSupportedCodecs(it->second, codecs);
 }
 
+bool MimeUtil::IsSupportedStrictMP4OrHLSMediaMimeType(
+    const std::string& mime_type,
+    const std::vector<std::string>& codecs) const {
+  StrictExpressionMappings::const_iterator it =
+      strict_mp4_format_map_.find(mime_type);
+  return (it != strict_mp4_format_map_.end() &&
+          AreSupportedCodecsWithProfile(it->second, codecs));
+}
+
 void MimeUtil::RemoveProprietaryMediaTypesAndCodecsForTests() {
   for (size_t i = 0; i < arraysize(proprietary_media_types); ++i) {
     non_image_map_.erase(proprietary_media_types[i]);
@@ -796,6 +863,13 @@ bool IsSupportedStrictMediaMimeType(const std::string& mime_type,
   return g_mime_util.Get().IsSupportedStrictMediaMimeType(mime_type, codecs);
 }
 
+bool IsSupportedStrictMP4OrHLSMediaMimeType(
+    const std::string& mime_type,
+    const std::vector<std::string>& codecs) {
+  return g_mime_util.Get().IsSupportedStrictMP4OrHLSMediaMimeType(mime_type,
+                                                                  codecs);
+}
+
 void ParseCodecString(const std::string& codecs,
                       std::vector<std::string>* codecs_out,
                       const bool strip) {