/*
* Entagged Audio Tag library
* Copyright (c) 2003-2005 Raphaël Slinckx <raphael@slinckx.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.jaudiotagger.audio.mp4;
import org.jaudiotagger.audio.exceptions.CannotReadException;
import org.jaudiotagger.audio.exceptions.CannotReadVideoException;
import org.jaudiotagger.audio.generic.GenericAudioHeader;
import org.jaudiotagger.audio.mp4.atom.*;
import org.jaudiotagger.logging.ErrorMessage;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.util.logging.Logger;
/**
* Read audio info from file.
* <p/>
* <p/>
* The info is held in the mvdh and mdhd fields as shown below
* <pre>
* |--- ftyp
* |--- moov
* |......|
* |......|----- mvdh
* |......|----- trak
* |...............|----- mdia
* |.......................|---- mdhd
* |.......................|---- minf
* |..............................|---- smhd
* |..............................|---- stbl
* |......................................|--- stsd
* |.............................................|--- mp4a
* |......|----- udta
* |
* |--- mdat
* </pre>
*/
public class Mp4InfoReader {
// Logger Object
public static Logger logger = Logger.getLogger("org.jaudiotagger.audio.mp4.atom");
public GenericAudioHeader read(RandomAccessFile raf) throws CannotReadException, IOException {
Mp4AudioHeader info = new Mp4AudioHeader();
//File Identification
Mp4BoxHeader ftypHeader = Mp4BoxHeader.seekWithinLevel(raf, Mp4NotMetaFieldKey.FTYP.getFieldName());
if (ftypHeader == null) {
throw new CannotReadException(ErrorMessage.MP4_FILE_NOT_CONTAINER.getMsg());
}
ByteBuffer ftypBuffer = ByteBuffer.allocate(ftypHeader.getLength() - Mp4BoxHeader.HEADER_LENGTH);
raf.getChannel().read(ftypBuffer);
ftypBuffer.rewind();
Mp4FtypBox ftyp = new Mp4FtypBox(ftypHeader, ftypBuffer);
ftyp.processData();
info.setBrand(ftyp.getMajorBrand());
//Get to the facts everything we are interested in is within the moov box, so just load data from file
//once so no more file I/O needed
Mp4BoxHeader moovHeader = Mp4BoxHeader.seekWithinLevel(raf, Mp4NotMetaFieldKey.MOOV.getFieldName());
if (moovHeader == null) {
throw new CannotReadException(ErrorMessage.MP4_FILE_NOT_AUDIO.getMsg());
}
ByteBuffer moovBuffer = ByteBuffer.allocate(moovHeader.getLength() - Mp4BoxHeader.HEADER_LENGTH);
raf.getChannel().read(moovBuffer);
moovBuffer.rewind();
//Level 2-Searching for "mvhd" somewhere within "moov", we make a slice after finding header
//so all get() methods will be relative to mvdh positions
Mp4BoxHeader boxHeader = Mp4BoxHeader.seekWithinLevel(moovBuffer, Mp4NotMetaFieldKey.MVHD.getFieldName());
if (boxHeader == null) {
throw new CannotReadException(ErrorMessage.MP4_FILE_NOT_AUDIO.getMsg());
}
ByteBuffer mvhdBuffer = moovBuffer.slice();
Mp4MvhdBox mvhd = new Mp4MvhdBox(boxHeader, mvhdBuffer);
info.setPreciseLength(mvhd.getLength());
//Advance position, TODO should we put this in box code ?
mvhdBuffer.position(mvhdBuffer.position() + boxHeader.getDataLength());
//Level 2-Searching for "trak" within "moov"
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.TRAK.getFieldName());
int endOfFirstTrackInBuffer = mvhdBuffer.position() + boxHeader.getDataLength();
if (boxHeader == null) {
throw new CannotReadException(ErrorMessage.MP4_FILE_NOT_AUDIO.getMsg());
}
//Level 3-Searching for "mdia" within "trak"
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.MDIA.getFieldName());
if (boxHeader == null) {
throw new CannotReadException(ErrorMessage.MP4_FILE_NOT_AUDIO.getMsg());
}
//Level 4-Searching for "mdhd" within "mdia"
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.MDHD.getFieldName());
if (boxHeader == null) {
throw new CannotReadException(ErrorMessage.MP4_FILE_NOT_AUDIO.getMsg());
}
Mp4MdhdBox mdhd = new Mp4MdhdBox(boxHeader, mvhdBuffer.slice());
info.setSamplingRate(mdhd.getSampleRate());
//Level 4-Searching for "hdlr" within "mdia"
/*We dont currently need to process this because contains nothing we want
mvhdBuffer.position(mvhdBuffer.position() + boxHeader.getDataLength());
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.HDLR.getFieldName());
if (boxHeader == null)
{
throw new CannotReadException(ErrorMessage.MP4_FILE_NOT_AUDIO.getMsg());
}
Mp4HdlrBox hdlr = new Mp4HdlrBox(boxHeader, mvhdBuffer.slice());
hdlr.processData();
*/
//Level 4-Searching for "minf" within "mdia"
mvhdBuffer.position(mvhdBuffer.position() + boxHeader.getDataLength());
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.MINF.getFieldName());
if (boxHeader == null) {
throw new CannotReadException(ErrorMessage.MP4_FILE_NOT_AUDIO.getMsg());
}
//Level 5-Searching for "smhd" within "minf"
//Only an audio track would have a smhd frame
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.SMHD.getFieldName());
if (boxHeader == null) {
throw new CannotReadException(ErrorMessage.MP4_FILE_NOT_AUDIO.getMsg());
}
mvhdBuffer.position(mvhdBuffer.position() + boxHeader.getDataLength());
//Level 5-Searching for "stbl within "minf"
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.STBL.getFieldName());
if (boxHeader == null) {
throw new CannotReadException(ErrorMessage.MP4_FILE_NOT_AUDIO.getMsg());
}
//Level 6-Searching for "stsd within "stbl" and process it direct data, dont think these are mandatory so dont throw
//exception if unable to find
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.STSD.getFieldName());
if (boxHeader != null) {
Mp4StsdBox stsd = new Mp4StsdBox(boxHeader, mvhdBuffer);
stsd.processData();
int positionAfterStsdHeaderAndData = mvhdBuffer.position();
///Level 7-Searching for "mp4a within "stsd"
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.MP4A.getFieldName());
if (boxHeader != null) {
ByteBuffer mp4aBuffer = mvhdBuffer.slice();
Mp4Mp4aBox mp4a = new Mp4Mp4aBox(boxHeader, mp4aBuffer);
mp4a.processData();
//Level 8-Searching for "esds" within mp4a to get No Of Channels and bitrate
boxHeader = Mp4BoxHeader.seekWithinLevel(mp4aBuffer, Mp4NotMetaFieldKey.ESDS.getFieldName());
if (boxHeader != null) {
Mp4EsdsBox esds = new Mp4EsdsBox(boxHeader, mp4aBuffer.slice());
//Set Bitrate in kbps
info.setBitrate(esds.getAvgBitrate() / 1000);
//Set Number of Channels
info.setChannelNumber(esds.getNumberOfChannels());
info.setKind(esds.getKind());
info.setProfile(esds.getAudioProfile());
info.setEncodingType(EncoderType.AAC.getDescription());
}
} else {
//Level 7 -Searching for drms within stsd instead (m4p files)
mvhdBuffer.position(positionAfterStsdHeaderAndData);
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.DRMS.getFieldName());
if (boxHeader != null) {
Mp4DrmsBox drms = new Mp4DrmsBox(boxHeader, mvhdBuffer);
drms.processData();
//Level 8-Searching for "esds" within drms to get No Of Channels and bitrate
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.ESDS.getFieldName());
if (boxHeader != null) {
Mp4EsdsBox esds = new Mp4EsdsBox(boxHeader, mvhdBuffer.slice());
//Set Bitrate in kbps
info.setBitrate(esds.getAvgBitrate() / 1000);
//Set Number of Channels
info.setChannelNumber(esds.getNumberOfChannels());
info.setKind(esds.getKind());
info.setProfile(esds.getAudioProfile());
info.setEncodingType(EncoderType.DRM_AAC.getDescription());
}
}
//Level 7-Searching for alac (Apple Lossless) instead
else {
mvhdBuffer.position(positionAfterStsdHeaderAndData);
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.ALAC.getFieldName());
if (boxHeader != null) {
//Process First Alac
Mp4AlacBox alac = new Mp4AlacBox(boxHeader, mvhdBuffer);
alac.processData();
//Level 8-Searching for 2nd "alac" within box that contains the info we really want
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.ALAC.getFieldName());
if (boxHeader != null) {
alac = new Mp4AlacBox(boxHeader, mvhdBuffer);
alac.processData();
info.setEncodingType(EncoderType.APPLE_LOSSLESS.getDescription());
info.setChannelNumber(alac.getChannels());
info.setBitrate(alac.getBitRate() / 1000);
}
}
}
}
}
//Set default channels if couldnt calculate it
if (info.getChannelNumber() == -1) {
info.setChannelNumber(2);
}
//Set default bitrate if couldnt calculate it
if (info.getBitRateAsNumber() == -1) {
info.setBitrate(128);
}
//This is the most likley option if cant find a match
if (info.getEncodingType().equals("")) {
info.setEncodingType(EncoderType.AAC.getDescription());
}
info.setTotalSamples((long) (mvhd.getLength() * info.getSampleRateAsNumber()));
//logger.info(info.toString());
//Level 2-Searching for another "trak" within "moov", if more than one track exists then probably
//video so reject it, unless it fits into certain encoding patterns
mvhdBuffer.position(endOfFirstTrackInBuffer);
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.TRAK.getFieldName());
if (boxHeader != null) {
//We only allow multiple tracks as audio if they follow the format used by the winamp encoder or
//are marked as being audio only and if track contains a nmhd atom rather than smhd.
//TODO this probably too restrictive but it fixes the test cases we have
if (ftyp.getMajorBrand().equals(Mp4FtypBox.Brand.ISO14496_1_VERSION_2.getId())
|| ftyp.getMajorBrand().equals(Mp4FtypBox.Brand.APPLE_AUDIO_ONLY.getId())
|| ftyp.getMajorBrand().equals(Mp4FtypBox.Brand.APPLE_AUDIO.getId())) {
//Ok, need to do further checks on this track to ensure it is a scene descriptor
//Level 3-Searching for "mdia" within "trak"
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.MDIA.getFieldName());
if (boxHeader == null) {
throw new CannotReadVideoException(ErrorMessage.MP4_FILE_IS_VIDEO.getMsg());
}
//Level 4-Searching for "mdhd" within "mdia"
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.MDHD.getFieldName());
if (boxHeader == null) {
throw new CannotReadVideoException(ErrorMessage.MP4_FILE_IS_VIDEO.getMsg());
}
//Level 4-Searching for "minf" within "mdia"
mvhdBuffer.position(mvhdBuffer.position() + boxHeader.getDataLength());
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.MINF.getFieldName());
if (boxHeader == null) {
throw new CannotReadVideoException(ErrorMessage.MP4_FILE_IS_VIDEO.getMsg());
}
//Level 5-Searching for "nmhd" within "minf"
//Only an audio track would have a nmhd frame
boxHeader = Mp4BoxHeader.seekWithinLevel(mvhdBuffer, Mp4NotMetaFieldKey.NMHD.getFieldName());
if (boxHeader == null) {
throw new CannotReadVideoException(ErrorMessage.MP4_FILE_IS_VIDEO.getMsg());
}
} else {
//logger.info(ErrorMessage.MP4_FILE_IS_VIDEO.getMsg() + ":" + ftyp.getMajorBrand());
throw new CannotReadVideoException(ErrorMessage.MP4_FILE_IS_VIDEO.getMsg());
}
}
//Build AtomTree to ensure it is valid, this means we can detect any problems early on
Mp4AtomTree atomTree = new Mp4AtomTree(raf, false);
return info;
}
}