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MP3 decoder/player/converter library for Java™ platform.
The newest version!
/*
* 11/19/04 : 1.0 moved to LGPL.
* VBRI header support added, E.B [email protected]
*
* 12/04/03 : VBR (XING) header support added, E.B [email protected]
*
* 02/13/99 : Java Conversion by JavaZOOM , E.B [email protected]
*
* Declarations for MPEG header class
* A few layer III, MPEG-2 LSF, and seeking modifications made by Jeff Tsay.
* Last modified : 04/19/97
*
* @(#) header.h 1.7, last edit: 6/15/94 16:55:33
* @(#) Copyright (C) 1993, 1994 Tobias Bading ([email protected])
* @(#) Berlin University of Technology
*-----------------------------------------------------------------------
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*----------------------------------------------------------------------
*/
package javazoom.jl.decoder;
/**
* Class for extracting information from a frame header.
*/
public final class Header
{
public static final int[][] frequencies =
{{22050, 24000, 16000, 1},
{44100, 48000, 32000, 1},
{11025, 12000, 8000, 1}}; // SZD: MPEG25
/**
* Constant for MPEG-2 LSF version
*/
public static final int MPEG2_LSF = 0;
public static final int MPEG25_LSF = 2; // SZD
/**
* Constant for MPEG-1 version
*/
public static final int MPEG1 = 1;
public static final int STEREO = 0;
public static final int JOINT_STEREO = 1;
public static final int DUAL_CHANNEL = 2;
public static final int SINGLE_CHANNEL = 3;
public static final int FOURTYFOUR_POINT_ONE = 0;
public static final int FOURTYEIGHT=1;
public static final int THIRTYTWO=2;
private int h_layer, h_protection_bit, h_bitrate_index,
h_padding_bit, h_mode_extension;
private int h_version;
private int h_mode;
private int h_sample_frequency;
private int h_number_of_subbands, h_intensity_stereo_bound;
private boolean h_copyright, h_original;
// VBR support added by E.B
private double[] h_vbr_time_per_frame = {-1, 384, 1152, 1152};
private boolean h_vbr;
private int h_vbr_frames;
private int h_vbr_scale;
private int h_vbr_bytes;
private byte[] h_vbr_toc;
private byte syncmode = Bitstream.INITIAL_SYNC;
private Crc16 crc;
public short checksum;
public int framesize;
public int nSlots;
private int _headerstring = -1; // E.B
Header()
{
}
public String toString()
{
StringBuffer buffer = new StringBuffer(200);
buffer.append("Layer ");
buffer.append(layer_string());
buffer.append(" frame ");
buffer.append(mode_string());
buffer.append(' ');
buffer.append(version_string());
if (!checksums())
buffer.append(" no");
buffer.append(" checksums");
buffer.append(' ');
buffer.append(sample_frequency_string());
buffer.append(',');
buffer.append(' ');
buffer.append(bitrate_string());
String s = buffer.toString();
return s;
}
/**
* Read a 32-bit header from the bitstream.
*/
void read_header(Bitstream stream, Crc16[] crcp) throws BitstreamException
{
int headerstring;
int channel_bitrate;
boolean sync = false;
do
{
headerstring = stream.syncHeader(syncmode);
_headerstring = headerstring; // E.B
if (syncmode == Bitstream.INITIAL_SYNC)
{
h_version = ((headerstring >>> 19) & 1);
if (((headerstring >>> 20) & 1) == 0) // SZD: MPEG2.5 detection
if (h_version == MPEG2_LSF)
h_version = MPEG25_LSF;
else
throw stream.newBitstreamException(Bitstream.UNKNOWN_ERROR);
if ((h_sample_frequency = ((headerstring >>> 10) & 3)) == 3)
{
throw stream.newBitstreamException(Bitstream.UNKNOWN_ERROR);
}
}
h_layer = 4 - (headerstring >>> 17) & 3;
h_protection_bit = (headerstring >>> 16) & 1;
h_bitrate_index = (headerstring >>> 12) & 0xF;
h_padding_bit = (headerstring >>> 9) & 1;
h_mode = ((headerstring >>> 6) & 3);
h_mode_extension = (headerstring >>> 4) & 3;
if (h_mode == JOINT_STEREO)
h_intensity_stereo_bound = (h_mode_extension << 2) + 4;
else
h_intensity_stereo_bound = 0; // should never be used
if (((headerstring >>> 3) & 1) == 1)
h_copyright = true;
if (((headerstring >>> 2) & 1) == 1)
h_original = true;
// calculate number of subbands:
if (h_layer == 1)
h_number_of_subbands = 32;
else
{
channel_bitrate = h_bitrate_index;
// calculate bitrate per channel:
if (h_mode != SINGLE_CHANNEL)
if (channel_bitrate == 4)
channel_bitrate = 1;
else
channel_bitrate -= 4;
if ((channel_bitrate == 1) || (channel_bitrate == 2))
if (h_sample_frequency == THIRTYTWO)
h_number_of_subbands = 12;
else
h_number_of_subbands = 8;
else if ((h_sample_frequency == FOURTYEIGHT) || ((channel_bitrate >= 3) && (channel_bitrate <= 5)))
h_number_of_subbands = 27;
else
h_number_of_subbands = 30;
}
if (h_intensity_stereo_bound > h_number_of_subbands)
h_intensity_stereo_bound = h_number_of_subbands;
// calculate framesize and nSlots
calculate_framesize();
// read framedata:
int framesizeloaded = stream.read_frame_data(framesize);
if ((framesize >=0) && (framesizeloaded != framesize))
{
// Data loaded does not match to expected framesize,
// it might be an ID3v1 TAG. (Fix 11/17/04).
throw stream.newBitstreamException(Bitstream.INVALIDFRAME);
}
if (stream.isSyncCurrentPosition(syncmode))
{
if (syncmode == Bitstream.INITIAL_SYNC)
{
syncmode = Bitstream.STRICT_SYNC;
stream.set_syncword(headerstring & 0xFFF80CC0);
}
sync = true;
}
else
{
stream.unreadFrame();
}
}
while (!sync);
stream.parse_frame();
if (h_protection_bit == 0)
{
// frame contains a crc checksum
checksum = (short) stream.get_bits(16);
if (crc == null)
crc = new Crc16();
crc.add_bits(headerstring, 16);
crcp[0] = crc;
}
else
crcp[0] = null;
if (h_sample_frequency == FOURTYFOUR_POINT_ONE)
{
/*
if (offset == null)
{
int max = max_number_of_frames(stream);
offset = new int[max];
for(int i=0; i 0) && (cf == lf))
{
offset[cf] = offset[cf-1] + h_padding_bit;
}
else
{
offset[0] = h_padding_bit;
}
*/
}
}
/**
* Parse frame to extract optionnal VBR frame.
* @param firstframe
* @author E.B ([email protected])
*/
void parseVBR(byte[] firstframe) throws BitstreamException
{
// Trying Xing header.
String xing = "Xing";
byte tmp[] = new byte[4];
int offset = 0;
// Compute "Xing" offset depending on MPEG version and channels.
if (h_version == MPEG1)
{
if (h_mode == SINGLE_CHANNEL) offset=21-4;
else offset=36-4;
}
else
{
if (h_mode == SINGLE_CHANNEL) offset=13-4;
else offset = 21-4;
}
try
{
System.arraycopy(firstframe, offset, tmp, 0, 4);
// Is "Xing" ?
if (xing.equals(new String(tmp)))
{
//Yes.
h_vbr = true;
h_vbr_frames = -1;
h_vbr_bytes = -1;
h_vbr_scale = -1;
h_vbr_toc = new byte[100];
int length = 4;
// Read flags.
byte flags[] = new byte[4];
System.arraycopy(firstframe, offset + length, flags, 0, flags.length);
length += flags.length;
// Read number of frames (if available).
if ((flags[3] & (byte) (1 << 0)) != 0)
{
System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
h_vbr_frames = (tmp[0] << 24)&0xFF000000 | (tmp[1] << 16)&0x00FF0000 | (tmp[2] << 8)&0x0000FF00 | tmp[3]&0x000000FF;
length += 4;
}
// Read size (if available).
if ((flags[3] & (byte) (1 << 1)) != 0)
{
System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
h_vbr_bytes = (tmp[0] << 24)&0xFF000000 | (tmp[1] << 16)&0x00FF0000 | (tmp[2] << 8)&0x0000FF00 | tmp[3]&0x000000FF;
length += 4;
}
// Read TOC (if available).
if ((flags[3] & (byte) (1 << 2)) != 0)
{
System.arraycopy(firstframe, offset + length, h_vbr_toc, 0, h_vbr_toc.length);
length += h_vbr_toc.length;
}
// Read scale (if available).
if ((flags[3] & (byte) (1 << 3)) != 0)
{
System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
h_vbr_scale = (tmp[0] << 24)&0xFF000000 | (tmp[1] << 16)&0x00FF0000 | (tmp[2] << 8)&0x0000FF00 | tmp[3]&0x000000FF;
length += 4;
}
//System.out.println("VBR:"+xing+" Frames:"+ h_vbr_frames +" Size:"+h_vbr_bytes);
}
}
catch (ArrayIndexOutOfBoundsException e)
{
throw new BitstreamException("XingVBRHeader Corrupted",e);
}
// Trying VBRI header.
String vbri = "VBRI";
offset = 36-4;
try
{
System.arraycopy(firstframe, offset, tmp, 0, 4);
// Is "VBRI" ?
if (vbri.equals(new String(tmp)))
{
//Yes.
h_vbr = true;
h_vbr_frames = -1;
h_vbr_bytes = -1;
h_vbr_scale = -1;
h_vbr_toc = new byte[100];
// Bytes.
int length = 4 + 6;
System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
h_vbr_bytes = (tmp[0] << 24)&0xFF000000 | (tmp[1] << 16)&0x00FF0000 | (tmp[2] << 8)&0x0000FF00 | tmp[3]&0x000000FF;
length += 4;
// Frames.
System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
h_vbr_frames = (tmp[0] << 24)&0xFF000000 | (tmp[1] << 16)&0x00FF0000 | (tmp[2] << 8)&0x0000FF00 | tmp[3]&0x000000FF;
length += 4;
//System.out.println("VBR:"+vbri+" Frames:"+ h_vbr_frames +" Size:"+h_vbr_bytes);
// TOC
// TODO
}
}
catch (ArrayIndexOutOfBoundsException e)
{
throw new BitstreamException("VBRIVBRHeader Corrupted",e);
}
}
// Functions to query header contents:
/**
* Returns version.
*/
public int version() { return h_version; }
/**
* Returns Layer ID.
*/
public int layer() { return h_layer; }
/**
* Returns bitrate index.
*/
public int bitrate_index() { return h_bitrate_index; }
/**
* Returns Sample Frequency.
*/
public int sample_frequency() { return h_sample_frequency; }
/**
* Returns Frequency.
*/
public int frequency() {return frequencies[h_version][h_sample_frequency];}
/**
* Returns Mode.
*/
public int mode() { return h_mode; }
/**
* Returns Protection bit.
*/
public boolean checksums()
{
if (h_protection_bit == 0) return true;
else return false;
}
/**
* Returns Copyright.
*/
public boolean copyright() { return h_copyright; }
/**
* Returns Original.
*/
public boolean original() { return h_original; }
/**
* Return VBR.
* @return true if VBR header is found
*/
public boolean vbr() { return h_vbr; }
/**
* Return VBR scale.
* @return scale of -1 if not available
*/
public int vbr_scale() { return h_vbr_scale; }
/**
* Return VBR TOC.
* @return vbr toc ot null if not available
*/
public byte[] vbr_toc() { return h_vbr_toc; }
/**
* Returns Checksum flag.
* Compares computed checksum with stream checksum.
*/
public boolean checksum_ok () { return (checksum == crc.checksum()); }
// Seeking and layer III stuff
/**
* Returns Layer III Padding bit.
*/
public boolean padding()
{
if (h_padding_bit == 0) return false;
else return true;
}
/**
* Returns Slots.
*/
public int slots() { return nSlots; }
/**
* Returns Mode Extension.
*/
public int mode_extension() { return h_mode_extension; }
// E.B -> private to public
public static final int bitrates[][][] = {
{{0 /*free format*/, 32000, 48000, 56000, 64000, 80000, 96000,
112000, 128000, 144000, 160000, 176000, 192000 ,224000, 256000, 0},
{0 /*free format*/, 8000, 16000, 24000, 32000, 40000, 48000,
56000, 64000, 80000, 96000, 112000, 128000, 144000, 160000, 0},
{0 /*free format*/, 8000, 16000, 24000, 32000, 40000, 48000,
56000, 64000, 80000, 96000, 112000, 128000, 144000, 160000, 0}},
{{0 /*free format*/, 32000, 64000, 96000, 128000, 160000, 192000,
224000, 256000, 288000, 320000, 352000, 384000, 416000, 448000, 0},
{0 /*free format*/, 32000, 48000, 56000, 64000, 80000, 96000,
112000, 128000, 160000, 192000, 224000, 256000, 320000, 384000, 0},
{0 /*free format*/, 32000, 40000, 48000, 56000, 64000, 80000,
96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000, 0}},
// SZD: MPEG2.5
{{0 /*free format*/, 32000, 48000, 56000, 64000, 80000, 96000,
112000, 128000, 144000, 160000, 176000, 192000 ,224000, 256000, 0},
{0 /*free format*/, 8000, 16000, 24000, 32000, 40000, 48000,
56000, 64000, 80000, 96000, 112000, 128000, 144000, 160000, 0},
{0 /*free format*/, 8000, 16000, 24000, 32000, 40000, 48000,
56000, 64000, 80000, 96000, 112000, 128000, 144000, 160000, 0}},
};
// E.B -> private to public
/**
* Calculate Frame size.
* Calculates framesize in bytes excluding header size.
*/
public int calculate_framesize()
{
if (h_layer == 1)
{
framesize = (12 * bitrates[h_version][0][h_bitrate_index]) /
frequencies[h_version][h_sample_frequency];
if (h_padding_bit != 0 ) framesize++;
framesize <<= 2; // one slot is 4 bytes long
nSlots = 0;
}
else
{
framesize = (144 * bitrates[h_version][h_layer - 1][h_bitrate_index]) /
frequencies[h_version][h_sample_frequency];
if (h_version == MPEG2_LSF || h_version == MPEG25_LSF) framesize >>= 1; // SZD
if (h_padding_bit != 0) framesize++;
// Layer III slots
if (h_layer == 3)
{
if (h_version == MPEG1)
{
nSlots = framesize - ((h_mode == SINGLE_CHANNEL) ? 17 : 32) // side info size
- ((h_protection_bit!=0) ? 0 : 2) // CRC size
- 4; // header size
}
else
{ // MPEG-2 LSF, SZD: MPEG-2.5 LSF
nSlots = framesize - ((h_mode == SINGLE_CHANNEL) ? 9 : 17) // side info size
- ((h_protection_bit!=0) ? 0 : 2) // CRC size
- 4; // header size
}
}
else
{
nSlots = 0;
}
}
framesize -= 4; // subtract header size
return framesize;
}
/**
* Returns the maximum number of frames in the stream.
* @param streamsize
* @return number of frames
*/
public int max_number_of_frames(int streamsize) // E.B
{
if (h_vbr == true) return h_vbr_frames;
else
{
if ((framesize + 4 - h_padding_bit) == 0) return 0;
else return(streamsize / (framesize + 4 - h_padding_bit));
}
}
/**
* Returns the maximum number of frames in the stream.
* @param streamsize
* @return number of frames
*/
public int min_number_of_frames(int streamsize) // E.B
{
if (h_vbr == true) return h_vbr_frames;
else
{
if ((framesize + 5 - h_padding_bit) == 0) return 0;
else return(streamsize / (framesize + 5 - h_padding_bit));
}
}
/**
* Returns ms/frame.
* @return milliseconds per frame
*/
public float ms_per_frame() // E.B
{
if (h_vbr == true)
{
double tpf = h_vbr_time_per_frame[layer()] / frequency();
if ((h_version == MPEG2_LSF) || (h_version == MPEG25_LSF)) tpf /= 2;
return ((float) (tpf * 1000));
}
else
{
float ms_per_frame_array[][] = {{8.707483f, 8.0f, 12.0f},
{26.12245f, 24.0f, 36.0f},
{26.12245f, 24.0f, 36.0f}};
return(ms_per_frame_array[h_layer-1][h_sample_frequency]);
}
}
/**
* Returns total ms.
* @param streamsize
* @return total milliseconds
*/
public float total_ms(int streamsize) // E.B
{
return(max_number_of_frames(streamsize) * ms_per_frame());
}
/**
* Returns synchronized header.
*/
public int getSyncHeader() // E.B
{
return _headerstring;
}
// functions which return header informations as strings:
/**
* Return Layer version.
*/
public String layer_string()
{
switch (h_layer)
{
case 1:
return "I";
case 2:
return "II";
case 3:
return "III";
}
return null;
}
// E.B -> private to public
public static final String bitrate_str[][][] = {
{{"free format", "32 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s",
"80 kbit/s", "96 kbit/s", "112 kbit/s", "128 kbit/s", "144 kbit/s",
"160 kbit/s", "176 kbit/s", "192 kbit/s", "224 kbit/s", "256 kbit/s",
"forbidden"},
{"free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s",
"40 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s",
"96 kbit/s", "112 kbit/s", "128 kbit/s", "144 kbit/s", "160 kbit/s",
"forbidden"},
{"free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s",
"40 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s",
"96 kbit/s", "112 kbit/s", "128 kbit/s", "144 kbit/s", "160 kbit/s",
"forbidden"}},
{{"free format", "32 kbit/s", "64 kbit/s", "96 kbit/s", "128 kbit/s",
"160 kbit/s", "192 kbit/s", "224 kbit/s", "256 kbit/s", "288 kbit/s",
"320 kbit/s", "352 kbit/s", "384 kbit/s", "416 kbit/s", "448 kbit/s",
"forbidden"},
{"free format", "32 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s",
"80 kbit/s", "96 kbit/s", "112 kbit/s", "128 kbit/s", "160 kbit/s",
"192 kbit/s", "224 kbit/s", "256 kbit/s", "320 kbit/s", "384 kbit/s",
"forbidden"},
{"free format", "32 kbit/s", "40 kbit/s", "48 kbit/s", "56 kbit/s",
"64 kbit/s", "80 kbit/s" , "96 kbit/s", "112 kbit/s", "128 kbit/s",
"160 kbit/s", "192 kbit/s", "224 kbit/s", "256 kbit/s", "320 kbit/s",
"forbidden"}},
// SZD: MPEG2.5
{{"free format", "32 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s",
"80 kbit/s", "96 kbit/s", "112 kbit/s", "128 kbit/s", "144 kbit/s",
"160 kbit/s", "176 kbit/s", "192 kbit/s", "224 kbit/s", "256 kbit/s",
"forbidden"},
{"free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s",
"40 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s",
"96 kbit/s", "112 kbit/s", "128 kbit/s", "144 kbit/s", "160 kbit/s",
"forbidden"},
{"free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s",
"40 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s",
"96 kbit/s", "112 kbit/s", "128 kbit/s", "144 kbit/s", "160 kbit/s",
"forbidden"}},
};
/**
* Return Bitrate.
* @return bitrate in bps
*/
public String bitrate_string()
{
if (h_vbr == true)
{
return Integer.toString(bitrate()/1000)+" kb/s";
}
else return bitrate_str[h_version][h_layer - 1][h_bitrate_index];
}
/**
* Return Bitrate.
* @return bitrate in bps and average bitrate for VBR header
*/
public int bitrate()
{
if (h_vbr == true)
{
return ((int) ((h_vbr_bytes * 8) / (ms_per_frame() * h_vbr_frames)))*1000;
}
else return bitrates[h_version][h_layer - 1][h_bitrate_index];
}
/**
* Return Instant Bitrate.
* Bitrate for VBR is not constant.
* @return bitrate in bps
*/
public int bitrate_instant()
{
return bitrates[h_version][h_layer - 1][h_bitrate_index];
}
/**
* Returns Frequency
* @return frequency string in kHz
*/
public String sample_frequency_string()
{
switch (h_sample_frequency)
{
case THIRTYTWO:
if (h_version == MPEG1)
return "32 kHz";
else if (h_version == MPEG2_LSF)
return "16 kHz";
else // SZD
return "8 kHz";
case FOURTYFOUR_POINT_ONE:
if (h_version == MPEG1)
return "44.1 kHz";
else if (h_version == MPEG2_LSF)
return "22.05 kHz";
else // SZD
return "11.025 kHz";
case FOURTYEIGHT:
if (h_version == MPEG1)
return "48 kHz";
else if (h_version == MPEG2_LSF)
return "24 kHz";
else // SZD
return "12 kHz";
}
return(null);
}
/**
* Returns Mode.
*/
public String mode_string()
{
switch (h_mode)
{
case STEREO:
return "Stereo";
case JOINT_STEREO:
return "Joint stereo";
case DUAL_CHANNEL:
return "Dual channel";
case SINGLE_CHANNEL:
return "Single channel";
}
return null;
}
/**
* Returns Version.
* @return MPEG-1 or MPEG-2 LSF or MPEG-2.5 LSF
*/
public String version_string()
{
switch (h_version)
{
case MPEG1:
return "MPEG-1";
case MPEG2_LSF:
return "MPEG-2 LSF";
case MPEG25_LSF: // SZD
return "MPEG-2.5 LSF";
}
return(null);
}
/**
* Returns the number of subbands in the current frame.
* @return number of subbands
*/
public int number_of_subbands() {return h_number_of_subbands;}
/**
* Returns Intensity Stereo.
* (Layer II joint stereo only).
* Returns the number of subbands which are in stereo mode,
* subbands above that limit are in intensity stereo mode.
* @return intensity
*/
public int intensity_stereo_bound() {return h_intensity_stereo_bound;}
}