http://blog.csdn.net/morixinguan/article/details/73149058
上一节说到4412的在Android 5.0源代码中支持了许多的格式，那么这些格式最终又是怎么确定的呢？
找到以下这个文件:
android-5.0.2/frameworks/base/media/java\android/media/MediaFile.java
/*
* Copyright (C) 2007 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.
*/
package android.media;
import android.media.DecoderCapabilities;
import android.media.DecoderCapabilities.VideoDecoder;
import android.media.DecoderCapabilities.AudioDecoder;
import android.mtp.MtpConstants;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
/**
* MediaScanner helper class.
*
* {@hide}
*/
public class MediaFile {
//定义变量，用来描述对应的格式的变量
// Audio file types
public static final int FILE_TYPE_MP3 = 1;
public static final int FILE_TYPE_M4A = 2;
public static final int FILE_TYPE_WAV = 3;
public static final int FILE_TYPE_AMR = 4;
public static final int FILE_TYPE_AWB = 5;
public static final int FILE_TYPE_WMA = 6;
public static final int FILE_TYPE_OGG = 7;
public static final int FILE_TYPE_AAC = 8;
public static final int FILE_TYPE_MKA = 9;
public static final int FILE_TYPE_FLAC = 10;
private static final int FIRST_AUDIO_FILE_TYPE = FILE_TYPE_MP3;
private static final int LAST_AUDIO_FILE_TYPE = FILE_TYPE_FLAC;
// MIDI file types
public static final int FILE_TYPE_MID = 11;
public static final int FILE_TYPE_SMF = 12;
public static final int FILE_TYPE_IMY = 13;
private static final int FIRST_MIDI_FILE_TYPE = FILE_TYPE_MID;
private static final int LAST_MIDI_FILE_TYPE = FILE_TYPE_IMY;
// Video file types
public static final int FILE_TYPE_MP4 = 21;
public static final int FILE_TYPE_M4V = 22;
public static final int FILE_TYPE_3GPP = 23;
public static final int FILE_TYPE_3GPP2 = 24;
public static final int FILE_TYPE_WMV = 25;
public static final int FILE_TYPE_ASF = 26;
public static final int FILE_TYPE_MKV = 27;
public static final int FILE_TYPE_MP2TS = 28;
public static final int FILE_TYPE_AVI = 29;
public static final int FILE_TYPE_WEBM = 30;
private static final int FIRST_VIDEO_FILE_TYPE = FILE_TYPE_MP4;
private static final int LAST_VIDEO_FILE_TYPE = FILE_TYPE_WEBM;
// More video file types
public static final int FILE_TYPE_MP2PS = 200;
private static final int FIRST_VIDEO_FILE_TYPE2 = FILE_TYPE_MP2PS;
private static final int LAST_VIDEO_FILE_TYPE2 = FILE_TYPE_MP2PS;
// Image file types
public static final int FILE_TYPE_JPEG = 31;
public static final int FILE_TYPE_GIF = 32;
public static final int FILE_TYPE_PNG = 33;
public static final int FILE_TYPE_BMP = 34;
public static final int FILE_TYPE_WBMP = 35;
public static final int FILE_TYPE_WEBP = 36;
private static final int FIRST_IMAGE_FILE_TYPE = FILE_TYPE_JPEG;
private static final int LAST_IMAGE_FILE_TYPE = FILE_TYPE_WEBP;
// Playlist file types
public static final int FILE_TYPE_M3U = 41;
public static final int FILE_TYPE_PLS = 42;
public static final int FILE_TYPE_WPL = 43;
public static final int FILE_TYPE_HTTPLIVE = 44;
private static final int FIRST_PLAYLIST_FILE_TYPE = FILE_TYPE_M3U;
private static final int LAST_PLAYLIST_FILE_TYPE = FILE_TYPE_HTTPLIVE;
// Drm file types
public static final int FILE_TYPE_FL = 51;
private static final int FIRST_DRM_FILE_TYPE = FILE_TYPE_FL;
private static final int LAST_DRM_FILE_TYPE = FILE_TYPE_FL;
// Other popular file types
public static final int FILE_TYPE_TEXT = 100;
public static final int FILE_TYPE_HTML = 101;
public static final int FILE_TYPE_PDF = 102;
public static final int FILE_TYPE_XML = 103;
public static final int FILE_TYPE_MS_WORD = 104;
public static final int FILE_TYPE_MS_EXCEL = 105;
public static final int FILE_TYPE_MS_POWERPOINT = 106;
public static final int FILE_TYPE_ZIP = 107;
public static class MediaFileType {
public final int fileType;
public final String mimeType;
MediaFileType(int fileType, String mimeType) {
this.fileType = fileType;
this.mimeType = mimeType;
}
}
private static final HashMap<String, MediaFileType> sFileTypeMap
= new HashMap<String, MediaFileType>();
private static final HashMap<String, Integer> sMimeTypeMap
= new HashMap<String, Integer>();
// maps file extension to MTP format code
private static final HashMap<String, Integer> sFileTypeToFormatMap
= new HashMap<String, Integer>();
// maps mime type to MTP format code
private static final HashMap<String, Integer> sMimeTypeToFormatMap
= new HashMap<String, Integer>();
// maps MTP format code to mime type
private static final HashMap<Integer, String> sFormatToMimeTypeMap
= new HashMap<Integer, String>();
static void addFileType(String extension, int fileType, String mimeType) {
sFileTypeMap.put(extension, new MediaFileType(fileType, mimeType));
sMimeTypeMap.put(mimeType, Integer.valueOf(fileType));
}
static void addFileType(String extension, int fileType, String mimeType, int mtpFormatCode) {
addFileType(extension, fileType, mimeType);
sFileTypeToFormatMap.put(extension, Integer.valueOf(mtpFormatCode));
sMimeTypeToFormatMap.put(mimeType, Integer.valueOf(mtpFormatCode));
sFormatToMimeTypeMap.put(mtpFormatCode, mimeType);
}
private static boolean isWMAEnabled() {
List<AudioDecoder> decoders = DecoderCapabilities.getAudioDecoders();
int count = decoders.size();
for (int i = 0; i < count; i++) {
AudioDecoder decoder = decoders.get(i);
if (decoder == AudioDecoder.AUDIO_DECODER_WMA) {
return true;
}
}
return false;
}
private static boolean isWMVEnabled() {
List<VideoDecoder> decoders = DecoderCapabilities.getVideoDecoders();
int count = decoders.size();
for (int i = 0; i < count; i++) {
VideoDecoder decoder = decoders.get(i);
if (decoder == VideoDecoder.VIDEO_DECODER_WMV) {
return true;
}
}
return false;
}
static {
//添加对应的音频、视频、图片的格式
addFileType("MP3", FILE_TYPE_MP3, "audio/mpeg", MtpConstants.FORMAT_MP3);
addFileType("MPGA", FILE_TYPE_MP3, "audio/mpeg", MtpConstants.FORMAT_MP3);
addFileType("M4A", FILE_TYPE_M4A, "audio/mp4", MtpConstants.FORMAT_MPEG);
addFileType("WAV", FILE_TYPE_WAV, "audio/x-wav", MtpConstants.FORMAT_WAV);
addFileType("AMR", FILE_TYPE_AMR, "audio/amr");
addFileType("AWB", FILE_TYPE_AWB, "audio/amr-wb");
if (isWMAEnabled()) {
addFileType("WMA", FILE_TYPE_WMA, "audio/x-ms-wma", MtpConstants.FORMAT_WMA);
}
addFileType("OGG", FILE_TYPE_OGG, "audio/ogg", MtpConstants.FORMAT_OGG);
addFileType("OGG", FILE_TYPE_OGG, "application/ogg", MtpConstants.FORMAT_OGG);
addFileType("OGA", FILE_TYPE_OGG, "application/ogg", MtpConstants.FORMAT_OGG);
addFileType("AAC", FILE_TYPE_AAC, "audio/aac", MtpConstants.FORMAT_AAC);
addFileType("AAC", FILE_TYPE_AAC, "audio/aac-adts", MtpConstants.FORMAT_AAC);
addFileType("MKA", FILE_TYPE_MKA, "audio/x-matroska");
addFileType("MID", FILE_TYPE_MID, "audio/midi");
addFileType("MIDI", FILE_TYPE_MID, "audio/midi");
addFileType("XMF", FILE_TYPE_MID, "audio/midi");
addFileType("RTTTL", FILE_TYPE_MID, "audio/midi");
addFileType("SMF", FILE_TYPE_SMF, "audio/sp-midi");
addFileType("IMY", FILE_TYPE_IMY, "audio/imelody");
addFileType("RTX", FILE_TYPE_MID, "audio/midi");
addFileType("OTA", FILE_TYPE_MID, "audio/midi");
addFileType("MXMF", FILE_TYPE_MID, "audio/midi");
addFileType("MPEG", FILE_TYPE_MP4, "video/mpeg", MtpConstants.FORMAT_MPEG);
addFileType("MPG", FILE_TYPE_MP4, "video/mpeg", MtpConstants.FORMAT_MPEG);
addFileType("MP4", FILE_TYPE_MP4, "video/mp4", MtpConstants.FORMAT_MPEG);
addFileType("M4V", FILE_TYPE_M4V, "video/mp4", MtpConstants.FORMAT_MPEG);
addFileType("3GP", FILE_TYPE_3GPP, "video/3gpp", MtpConstants.FORMAT_3GP_CONTAINER);
addFileType("3GPP", FILE_TYPE_3GPP, "video/3gpp", MtpConstants.FORMAT_3GP_CONTAINER);
addFileType("3G2", FILE_TYPE_3GPP2, "video/3gpp2", MtpConstants.FORMAT_3GP_CONTAINER);
addFileType("3GPP2", FILE_TYPE_3GPP2, "video/3gpp2", MtpConstants.FORMAT_3GP_CONTAINER);
addFileType("MKV", FILE_TYPE_MKV, "video/x-matroska");
addFileType("WEBM", FILE_TYPE_WEBM, "video/webm");
addFileType("TS", FILE_TYPE_MP2TS, "video/mp2ts");
addFileType("AVI", FILE_TYPE_AVI, "video/avi");
if (isWMVEnabled()) {
addFileType("WMV", FILE_TYPE_WMV, "video/x-ms-wmv", MtpConstants.FORMAT_WMV);
addFileType("ASF", FILE_TYPE_ASF, "video/x-ms-asf");
}
addFileType("JPG", FILE_TYPE_JPEG, "image/jpeg", MtpConstants.FORMAT_EXIF_JPEG);
addFileType("JPEG", FILE_TYPE_JPEG, "image/jpeg", MtpConstants.FORMAT_EXIF_JPEG);
addFileType("GIF", FILE_TYPE_GIF, "image/gif", MtpConstants.FORMAT_GIF);
addFileType("PNG", FILE_TYPE_PNG, "image/png", MtpConstants.FORMAT_PNG);
addFileType("BMP", FILE_TYPE_BMP, "image/x-ms-bmp", MtpConstants.FORMAT_BMP);
addFileType("WBMP", FILE_TYPE_WBMP, "image/vnd.wap.wbmp");
addFileType("WEBP", FILE_TYPE_WEBP, "image/webp");
addFileType("M3U", FILE_TYPE_M3U, "audio/x-mpegurl", MtpConstants.FORMAT_M3U_PLAYLIST);
addFileType("M3U", FILE_TYPE_M3U, "application/x-mpegurl", MtpConstants.FORMAT_M3U_PLAYLIST);
addFileType("PLS", FILE_TYPE_PLS, "audio/x-scpls", MtpConstants.FORMAT_PLS_PLAYLIST);
addFileType("WPL", FILE_TYPE_WPL, "application/vnd.ms-wpl", MtpConstants.FORMAT_WPL_PLAYLIST);
addFileType("M3U8", FILE_TYPE_HTTPLIVE, "application/vnd.apple.mpegurl");
addFileType("M3U8", FILE_TYPE_HTTPLIVE, "audio/mpegurl");
addFileType("M3U8", FILE_TYPE_HTTPLIVE, "audio/x-mpegurl");
addFileType("FL", FILE_TYPE_FL, "application/x-android-drm-fl");
addFileType("TXT", FILE_TYPE_TEXT, "text/plain", MtpConstants.FORMAT_TEXT);
addFileType("HTM", FILE_TYPE_HTML, "text/html", MtpConstants.FORMAT_HTML);
addFileType("HTML", FILE_TYPE_HTML, "text/html", MtpConstants.FORMAT_HTML);
addFileType("PDF", FILE_TYPE_PDF, "application/pdf");
addFileType("DOC", FILE_TYPE_MS_WORD, "application/msword", MtpConstants.FORMAT_MS_WORD_DOCUMENT);
addFileType("XLS", FILE_TYPE_MS_EXCEL, "application/vnd.ms-excel", MtpConstants.FORMAT_MS_EXCEL_SPREADSHEET);
addFileType("PPT", FILE_TYPE_MS_POWERPOINT, "application/mspowerpoint", MtpConstants.FORMAT_MS_POWERPOINT_PRESENTATION);
addFileType("FLAC", FILE_TYPE_FLAC, "audio/flac", MtpConstants.FORMAT_FLAC);
addFileType("ZIP", FILE_TYPE_ZIP, "application/zip");
addFileType("MPG", FILE_TYPE_MP2PS, "video/mp2p");
addFileType("MPEG", FILE_TYPE_MP2PS, "video/mp2p");
}
public static boolean isAudioFileType(int fileType) {
return ((fileType >= FIRST_AUDIO_FILE_TYPE &&
fileType <= LAST_AUDIO_FILE_TYPE) ||
(fileType >= FIRST_MIDI_FILE_TYPE &&
fileType <= LAST_MIDI_FILE_TYPE));
}
public static boolean isVideoFileType(int fileType) {
return (fileType >= FIRST_VIDEO_FILE_TYPE &&
fileType <= LAST_VIDEO_FILE_TYPE)
|| (fileType >= FIRST_VIDEO_FILE_TYPE2 &&
fileType <= LAST_VIDEO_FILE_TYPE2);
}
public static boolean isImageFileType(int fileType) {
return (fileType >= FIRST_IMAGE_FILE_TYPE &&
fileType <= LAST_IMAGE_FILE_TYPE);
}
public static boolean isPlayListFileType(int fileType) {
return (fileType >= FIRST_PLAYLIST_FILE_TYPE &&
fileType <= LAST_PLAYLIST_FILE_TYPE);
}
public static boolean isDrmFileType(int fileType) {
return (fileType >= FIRST_DRM_FILE_TYPE &&
fileType <= LAST_DRM_FILE_TYPE);
}
public static MediaFileType getFileType(String path) {
int lastDot = path.lastIndexOf('.');
if (lastDot < 0)
return null;
return sFileTypeMap.get(path.substring(lastDot + 1).toUpperCase(Locale.ROOT));
}
public static boolean isMimeTypeMedia(String mimeType) {
int fileType = getFileTypeForMimeType(mimeType);
return isAudioFileType(fileType) || isVideoFileType(fileType)
|| isImageFileType(fileType) || isPlayListFileType(fileType);
}
// generates a title based on file name
public static String getFileTitle(String path) {
// extract file name after last slash
int lastSlash = path.lastIndexOf('/');
if (lastSlash >= 0) {
lastSlash++;
if (lastSlash < path.length()) {
path = path.substring(lastSlash);
}
}
// truncate the file extension (if any)
int lastDot = path.lastIndexOf('.');
if (lastDot > 0) {
path = path.substring(0, lastDot);
}
return path;
}
public static int getFileTypeForMimeType(String mimeType) {
Integer value = sMimeTypeMap.get(mimeType);
return (value == null ? 0 : value.intValue());
}
public static String getMimeTypeForFile(String path) {
MediaFileType mediaFileType = getFileType(path);
return (mediaFileType == null ? null : mediaFileType.mimeType);
}
public static int getFormatCode(String fileName, String mimeType) {
if (mimeType != null) {
Integer value = sMimeTypeToFormatMap.get(mimeType);
if (value != null) {
return value.intValue();
}
}
int lastDot = fileName.lastIndexOf('.');
if (lastDot > 0) {
String extension = fileName.substring(lastDot + 1).toUpperCase(Locale.ROOT);
Integer value = sFileTypeToFormatMap.get(extension);
if (value != null) {
return value.intValue();
}
}
return MtpConstants.FORMAT_UNDEFINED;
}
public static String getMimeTypeForFormatCode(int formatCode) {
return sFormatToMimeTypeMap.get(formatCode);
}
}
如果我们需要删除一种格式，那么就要直接删除以上的变量还有静态代码块中对应变量的方法：addFileType
例如，我不需要将M4A这种格式添加到我的Android项目中，我可以将以下的：
public static final int FILE_TYPE_M4A = 2;
addFileType("M4A", FILE_TYPE_M4A, "audio/mp4", MtpConstants.FORMAT_MPEG);
删除即可。
作者：morixinguan 发表于2017/6/18 0:35:36 原文链接
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