/*
* Copyright (C) 2010 Preston Lacey http://javaflacencoder.sourceforge.net/
* All Rights Reserved.
*
* 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 Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package javaFlacEncoder;
/**
* MetadataBlockStreamInfo is used to declare the initial stream parameters,
* such as Sample Rate, bits per sample, and number of channels, as well as
* information on the encoded stream such as total number of samples, minimum
* and maximum block and frame sizes, and md5sum of raw audio samples. A
* StreamInfo block must be the first meta-data block in a FLAC stream, and only
* one StreamInfo block may exist.
*
* @author Preston Lacey
*/
public class MetadataBlockStreamInfo {
/** For Debugging: Higher level equals more debug statements */
static int DEBUG_LEV = 0;
/* int minimumBlockSize = 4096;//32768;//16 bits used; 16 minimum valid
int maximumBlockSize = 4096;//32768;//16 bits used; 65535 maximum valid
int minimumFrameSize = 0;//24 bits used; zero implies unknown
int maximumFrameSize = 0;//24 bits used; zero implies unknown
int sampleRate = 8000;//4096;//20 bits used, but 655350Hz max. 0 is invalid.
byte numberOfChannels = 1;//3 bits used
byte bitsPerSample = 16;//5 bits used. values 4-32 valid
long totalSamplesInStream = 0;//36 bits used. 0 implies unknown.
byte[] md5Hash;
*/
/**
* Constructor. This class defines only static methods and fields.
*/
public MetadataBlockStreamInfo() {
}
/**
* Create a FLAC StreamInfo metadata block with the given parameters. Because
* of the data stored in a StreamInfo block, this should generally be created
* only after all encoding is done.
*
* @param sc StreamConfiguration used in this FLAC stream.
* @param minFrameSize Size of smallest frame in FLAC stream.
* @param maxFrameSize Size of largest frame in FLAC stream.
* @param samplesInStream Total number of inter-channel audio samples in
* FLAC stream.
* @param md5Hash MD5 hash of the raw audio samples.
* @return EncodedElement containing created StreamInfo block.
*/
public static EncodedElement getStreamInfo(StreamConfiguration sc,
int minFrameSize, int maxFrameSize, long samplesInStream,
byte[] md5Hash) {
EncodedElement ele = new EncodedElement();
int bytes = getByteSize();
byte data[] = new byte[bytes];
ele.setData(data);
ele.setUsableBits(bytes*8);
int encodedBitsPerSample = sc.getBitsPerSample()-1;
//System.out.println("BitsPerSample : " + encodedBitsPerSample);
int index = 0;
EncodedElement.addInt(sc.getMinBlockSize(), 16, index, data);
index += 16;
EncodedElement.addInt(sc.getMaxBlockSize(), 16, index, data);
index += 16;
EncodedElement.addInt(minFrameSize, 24, index, data);
index += 24;
EncodedElement.addInt(maxFrameSize, 24, index, data);
index += 24;
EncodedElement.addInt(sc.getSampleRate(), 20, index, data);
index += 20;
EncodedElement.addInt(sc.getChannelCount()-1, 3, index, data);
index += 3;
EncodedElement.addInt(encodedBitsPerSample, 5, index, data);
index +=5;
EncodedElement.addLong(samplesInStream, 36, index, data);
index +=36;
//obs.addLong(md5Begin, 64, obs.getUsedLength());
//obs.addLong(md5End, 64, obs.getUsedLength());
for(int i = 0; i < 16; i++) {
EncodedElement.addInt(md5Hash[i], 8, index, data);
index += 8;
}
ele.setUsableBits(index);
return ele;
}
/**
* Get the expected size of a properly formed STREAMINFO metadata block.
*
* @return size of properly formed FLAC STREAMINFO metadata block.
*/
static public int getByteSize() {
int size = 0;
size += 16;
size += 16;
size += 24;
size += 24;
size += 20;
size += 3;
size += 5;
size += 36;
size += 64;
size += 64;
size = size/8;
return size;
}
}