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Java library for extracting EXIF, IPTC, XMP, ICC and other metadata from image and video files.
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/*
* Copyright 2002-2019 Drew Noakes and contributors
*
* 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.
*
* More information about this project is available at:
*
* https://drewnoakes.com/code/exif/
* https://github.com/drewnoakes/metadata-extractor
*/
package com.drew.metadata.mp3;
import com.drew.imaging.ImageProcessingException;
import com.drew.lang.SequentialReader;
import com.drew.lang.StreamReader;
import com.drew.lang.annotations.NotNull;
import com.drew.metadata.Metadata;
import java.io.IOException;
import java.io.InputStream;
/**
* Sources: http://id3.org/mp3Frame
* https://www.loc.gov/preservation/digital/formats/fdd/fdd000105.shtml
*
* @author Payton Garland
*/
public class Mp3Reader
{
public void extract(@NotNull final InputStream inputStream, @NotNull final Metadata metadata)
{
Mp3Directory directory = new Mp3Directory();
metadata.addDirectory(directory);
try {
SequentialReader reader = new StreamReader(inputStream);
int header = reader.getInt32();
// ID: MPEG-2.5, MPEG-2, or MPEG-1
int id = 0;
switch ((header & 0x000180000) >> 19) {
case 0:
throw new ImageProcessingException("MPEG-2.5 not supported.");
case 2:
directory.setString(Mp3Directory.TAG_ID, "MPEG-2");
id = 2;
break;
case 3:
directory.setString(Mp3Directory.TAG_ID, "MPEG-1");
id = 1;
break;
}
// Layer Type: 1, 2, 3, or not defined
int layer = ((header & 0x00060000) >> 17);
switch (layer) {
case 0:
directory.setString(Mp3Directory.TAG_LAYER, "Not defined");
break;
case 1:
directory.setString(Mp3Directory.TAG_LAYER, "Layer III");
break;
case 2:
directory.setString(Mp3Directory.TAG_LAYER, "Layer II");
break;
case 3:
directory.setString(Mp3Directory.TAG_LAYER, "Layer I");
break;
}
int protectionBit = ((header & 0x00010000) >> 16);
// Bitrate: depends on ID and Layer
int bitrate = ((header & 0x0000F000) >> 12);
if (bitrate != 0 && bitrate != 15)
directory.setInt(Mp3Directory.TAG_BITRATE, setBitrate(bitrate, layer, id));
// Frequency: depends on ID
int frequency = ((header & 0x00000C00) >> 10);
int[][] frequencyMapping = new int[2][3];
frequencyMapping[0] = new int[]{44100, 48000, 32000};
frequencyMapping[1] = new int[]{22050, 24000, 16000};
if (frequency <= 2) {
if (id == 2) {
directory.setInt(Mp3Directory.TAG_FREQUENCY, frequencyMapping[1][frequency]);
frequency = frequencyMapping[1][frequency];
} else if (id == 1) {
directory.setInt(Mp3Directory.TAG_FREQUENCY, frequencyMapping[0][frequency]);
frequency = frequencyMapping[0][frequency];
}
} else {
directory.addError("Invalid frequency index.");
frequency = -1;
}
int paddingBit = ((header & 0x00000200) >> 9);
// Encoding type: Stereo, Joint Stereo, Dual Channel, or Mono
int mode = ((header & 0x000000C0) >> 6);
switch (mode){
case 0:
directory.setString(Mp3Directory.TAG_MODE, "Stereo");
break;
case 1:
directory.setString(Mp3Directory.TAG_MODE, "Joint stereo");
break;
case 2:
directory.setString(Mp3Directory.TAG_MODE, "Dual channel");
break;
case 3:
directory.setString(Mp3Directory.TAG_MODE, "Mono");
break;
}
// Copyright boolean
int copyright = ((header & 0x00000008) >> 3);
switch (copyright) {
case 0:
directory.setString(Mp3Directory.TAG_COPYRIGHT, "False");
break;
case 1:
directory.setString(Mp3Directory.TAG_COPYRIGHT, "True");
break;
}
int emphasis = (header & 0x00000003);
switch (emphasis) {
case 0:
directory.setString(Mp3Directory.TAG_EMPHASIS, "none");
break;
case 1:
directory.setString(Mp3Directory.TAG_EMPHASIS, "50/15ms");
break;
case 3:
directory.setString(Mp3Directory.TAG_EMPHASIS, "CCITT j.17");
break;
}
if (frequency != -1 && bitrate != 0 && bitrate != 15) {
int frameSize = ((setBitrate(bitrate, layer, id) * 1000) * 144) / frequency;
directory.setString(Mp3Directory.TAG_FRAME_SIZE, frameSize + " bytes");
}
} catch (IOException e) {
directory.addError(e.getMessage());
} catch (ImageProcessingException e) {
directory.addError(e.getMessage());
}
}
private static int setBitrate(int bitrate, int layer, int id)
{
int[][] bitrateMapping = new int[14][6];
bitrateMapping[0] = new int[]{32, 32, 32, 32, 32, 8};
bitrateMapping[1] = new int[]{64, 48, 40, 64, 48, 16};
bitrateMapping[2] = new int[]{96, 56, 48, 96, 56, 24};
bitrateMapping[3] = new int[]{128, 64, 56, 128, 64, 32};
bitrateMapping[4] = new int[]{160, 80, 64, 160, 80, 64};
bitrateMapping[5] = new int[]{192, 96, 80, 192, 96, 80};
bitrateMapping[6] = new int[]{224, 112, 96, 224, 112, 56};
bitrateMapping[7] = new int[]{256, 128, 112, 256, 128, 64};
bitrateMapping[8] = new int[]{288, 160, 128, 28, 160, 128};
bitrateMapping[9] = new int[]{320, 192, 160, 320, 192, 160};
bitrateMapping[10] = new int[]{352, 224, 192, 352, 224, 112};
bitrateMapping[11] = new int[]{384, 256, 224, 384, 256, 128};
bitrateMapping[12] = new int[]{416, 320, 256, 416, 320, 256};
bitrateMapping[13] = new int[]{448, 384, 320, 448, 384, 320};
int xPos = 0;
int yPos = bitrate - 1;
if (id == 2) {
// MPEG-2
switch (layer) {
case 1:
xPos = 5;
break;
case 2:
xPos = 4;
break;
case 3:
xPos = 3;
break;
}
} else if (id == 1) {
// MPEG-1
switch (layer) {
case 1:
xPos = 2;
break;
case 2:
xPos = 1;
break;
case 3:
xPos = 0;
break;
}
}
return bitrateMapping[yPos][xPos];
}
/*
// https://phoxis.org/2010/05/08/synch-safe/
private static int getSyncSafeSize(int decode)
{
int a = decode & 0xFF;
int b = (decode >> 8) & 0xFF;
int c = (decode >> 16) & 0xFF;
int d = (decode >> 24) & 0xFF;
int decoded = 0x0;
decoded = decoded | a;
decoded = decoded | (b << 7);
decoded = decoded | (c << 14);
decoded = decoded | (d << 21);
return decoded;
}
*/
}