Use CharacterEncodingDetector in metadataretriever

instead of media scanner. This way the java MediaMetadataRetriever API
will give the same result as the media scanner.
Also apply some tweaks to the encoding detector to improve handling of
ISO-8859-1 tags.

Bug: 16302581, 17205395

Change-Id: I1682a7a6a8bf04cffaa455044ba72dd7fd152d49

3 files changed, 146 insertions, 1 deletions

diff --git a/include/media/CharacterEncodingDetector.h b/include/media/CharacterEncodingDetector.h
new file mode 100644
index 0000000..deaa377
--- /dev/null
+++ b/include/media/CharacterEncodingDetector.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _CHARACTER_ENCODING_DETECTOR_H
+#define _CHARACTER_ENCODING_DETECTOR_H
+
+#include <media/mediascanner.h>
+
+#include "StringArray.h"
+
+#include "unicode/ucnv.h"
+#include "unicode/ucsdet.h"
+#include "unicode/ustring.h"
+
+namespace android {
+
+class CharacterEncodingDetector {
+
+    public:
+    CharacterEncodingDetector();
+        ~CharacterEncodingDetector();
+
+        void addTag(const char *name, const char *value);
+        size_t size();
+
+        void detectAndConvert();
+        status_t getTag(int index, const char **name, const char**value);
+
+    private:
+        const UCharsetMatch *getPreferred(
+                const char *input, size_t len,
+                const UCharsetMatch** ucma, size_t matches,
+                bool *goodmatch, int *highestmatch);
+
+        bool isFrequent(const uint16_t *values, uint32_t c);
+
+        // cached name and value strings, for native encoding support.
+        // TODO: replace these with byte blob arrays that don't require the data to be
+        // singlenullbyte-terminated
+        StringArray     mNames;
+        StringArray     mValues;
+
+        UConverter*     mUtf8Conv;
+};
+
+
+
+};  // namespace android
+
+#endif
diff --git a/include/media/StringArray.h b/include/media/StringArray.h
new file mode 100644
index 0000000..ae47085
--- /dev/null
+++ b/include/media/StringArray.h
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//
+// Sortable array of strings.  STL-ish, but STL-free.
+//  
+#ifndef _LIBS_MEDIA_STRING_ARRAY_H
+#define _LIBS_MEDIA_STRING_ARRAY_H
+
+#include <stdlib.h>
+#include <string.h>
+
+namespace android {
+
+//
+// An expanding array of strings.  Add, get, sort, delete.
+//
+class StringArray {
+public:
+    StringArray();
+    virtual ~StringArray();
+
+    //
+    // Add a string.  A copy of the string is made.
+    //
+    bool push_back(const char* str);
+
+    //
+    // Delete an entry.
+    //
+    void erase(int idx);
+
+    //
+    // Sort the array.
+    //
+    void sort(int (*compare)(const void*, const void*));
+
+    //
+    // Pass this to the sort routine to do an ascending alphabetical sort.
+    //
+    static int cmpAscendingAlpha(const void* pstr1, const void* pstr2);
+
+    //
+    // Get the #of items in the array.
+    //
+    inline int size(void) const { return mCurrent; }
+
+    //
+    // Return entry N.
+    // [should use operator[] here]
+    //
+    const char* getEntry(int idx) const {
+        return (unsigned(idx) >= unsigned(mCurrent)) ? NULL : mArray[idx];
+    }
+
+    //
+    // Set entry N to specified string.
+    // [should use operator[] here]
+    //
+    void setEntry(int idx, const char* str);
+
+private:
+    int     mMax;
+    int     mCurrent;
+    char**  mArray;
+};
+
+}; // namespace android
+
+#endif // _LIBS_MEDIA_STRING_ARRAY_H
diff --git a/include/media/mediascanner.h b/include/media/mediascanner.h
index 5213bdc..d555279 100644
--- a/include/media/mediascanner.h
+++ b/include/media/mediascanner.h
@@ -122,7 +122,6 @@ public:
 protected:
     // default encoding from MediaScanner::mLocale
     String8 mLocale;
-    CharacterEncodingDetector *mEncodingDetector;
 };
 
 }; // namespace android