FileDocCategorySizeDatePackage
FlacInfoReader.javaAPI DocJaudiotagger 2.0.44589Wed Jun 08 11:59:18 BST 2011org.jaudiotagger.audio.flac

FlacInfoReader

public class FlacInfoReader extends Object
Read info from Flac file

Fields Summary
public static Logger
logger
private static final int
NO_OF_BITS_IN_BYTE
private static final int
KILOBYTES_TO_BYTES_MULTIPLIER
Constructors Summary
Methods Summary
private intcomputeBitrate(float length, long size)

        return (int) ((size / KILOBYTES_TO_BYTES_MULTIPLIER) * NO_OF_BITS_IN_BYTE / length);
public intcountMetaBlocks(java.io.File f)
Count the number of metadatablocks, useful for debugging

param
f
return
throws
CannotReadException
throws
IOException

        RandomAccessFile raf = new RandomAccessFile(f, "r");
        FlacStreamReader flacStream = new FlacStreamReader(raf);
        flacStream.findStream();


        boolean isLastBlock = false;

        int count = 0;
        while (!isLastBlock)
        {
            MetadataBlockHeader mbh = MetadataBlockHeader.readHeader(raf);
            logger.config("Found block:" + mbh.getBlockType());
            raf.seek(raf.getFilePointer() + mbh.getDataLength());
            isLastBlock = mbh.isLastBlock();
            mbh = null; //Free memory
            count++;
        }
        raf.close();
        return count;
public org.jaudiotagger.audio.generic.GenericAudioHeaderread(java.io.RandomAccessFile raf)


          
    
        FlacStreamReader flacStream = new FlacStreamReader(raf);
        flacStream.findStream();

        MetadataBlockDataStreamInfo mbdsi = null;
        boolean isLastBlock = false;

        //Search for StreamInfo Block, but even after we found it we still have to continue through all
        //the metadata blocks so that we can find the start of the audio frames which we need to calculate
        //the bitrate
        while (!isLastBlock)
        {
            MetadataBlockHeader mbh = MetadataBlockHeader.readHeader(raf);
            if (mbh.getBlockType() == BlockType.STREAMINFO)
            {
                mbdsi = new MetadataBlockDataStreamInfo(mbh, raf);
                if (!mbdsi.isValid())
                {
                    throw new CannotReadException("FLAC StreamInfo not valid");
                }
            }
            else
            {
                raf.seek(raf.getFilePointer() + mbh.getDataLength());
            }

            isLastBlock = mbh.isLastBlock();
            mbh = null; //Free memory
        }

        if (mbdsi == null)
        {
            throw new CannotReadException("Unable to find Flac StreamInfo");
        }

        GenericAudioHeader info = new GenericAudioHeader();
        info.setLength(mbdsi.getSongLength());
        info.setPreciseLength(mbdsi.getPreciseLength());
        info.setChannelNumber(mbdsi.getChannelNumber());
        info.setSamplingRate(mbdsi.getSamplingRate());
        info.setEncodingType(mbdsi.getEncodingType());
        info.setExtraEncodingInfos("");
        info.setBitrate(computeBitrate(mbdsi.getPreciseLength(), raf.length() - raf.getFilePointer()));
        return info;