input is not valid Modified UTF-8: illegal start byte 0x**

扫描一个视频时，视频的文件信息中，标题是乱码，致使表面上的重启，具体出错信息为：

W/dalvikvm(17090): JNI WARNING: input is not valid Modified UTF-8: illegal start byte 0xb3
W/dalvikvm(17090):              string: '³ÇÊÐÁÔÈË01'
W/dalvikvm(17090):              in Landroid/media/MediaMetadataRetriever;.extractMetadata:(I)Ljava/lang/String; (NewStringUTF)

最后经过utf8字符判断修正该问题，文件位置frameworks\base\media\jni\android_media_MediaMetadataRetriever.cpp

增长函数IsUTF8，而后在android_media_MediaMetadataRetriever_extractMetadata方法中作出判断，当不为utf-8时返回null

bool IsUTF8(const void* pBuffer, long size)  
{  
    bool IsUTF8 = true;  
    unsigned char* start = (unsigned char*)pBuffer;  
    unsigned char* end = (unsigned char*)pBuffer + size;  
    while (start < end)  
    {  
        if (*start < 0x80) // (10000000): value less then 0x80 ASCII char
        {  
            start++;  
        }  
        else if (*start < (0xC0)) // (11000000): between 0x80 and 0xC0 UTF-8 char
        {  
            IsUTF8 = false;  
            break;  
        }  
        else if (*start < (0xE0)) // (11100000): 2 bytes UTF-8 char
        {  
            if (start >= end - 1)  
                break;  
            if ((start[1] & (0xC0)) != 0x80)  
            {  
                IsUTF8 = false;  
                break;  
            }  
            start += 2;  
        }  
        else if (*start < (0xF0)) // (11110000): 3 bytes UTF-8 char 
        {  
            if (start >= end - 2)  
                break;  
            if ((start[1] & (0xC0)) != 0x80 || (start[2] & (0xC0)) != 0x80)  
            {  
                IsUTF8 = false;  
                break;  
            }  
            start += 3;  
        }  
        else  
        {  
            IsUTF8 = false;  
            break;  
        }  
    }  
    return IsUTF8;  
}

static jobject android_media_MediaMetadataRetriever_extractMetadata(JNIEnv *env, jobject thiz, jint keyCode)
{
    ALOGV("extractMetadata");
    MediaMetadataRetriever* retriever = getRetriever(env, thiz);
    if (retriever == 0) {
        jniThrowException(env, "java/lang/IllegalStateException", "No retriever available");
        return NULL;
    }
    const char* value = retriever->extractMetadata(keyCode);
    if (!value) {
        ALOGV("extractMetadata: Metadata is not found");
        return NULL;
    }
    ALOGV("extractMetadata: value (%s) for keyCode(%d)", value, keyCode);
    if (!IsUTF8(value,strlen(value)))
    {
        return NULL;
    }
    return env->NewStringUTF(value);
}

编译libmedia_jni,以后push进system/lib,删除/data/data/com.android.providers.media文件夹，重启手机便可修正问题。

转自：　http://www.xdty.org/1370