2 * 11/19/04 : 1.0 moved to LGPL.
3 * VBRI header support added, E.B javalayer@javazoom.net
5 * 12/04/03 : VBR (XING) header support added, E.B javalayer@javazoom.net
7 * 02/13/99 : Java Conversion by JavaZOOM , E.B javalayer@javazoom.net
9 * Declarations for MPEG header class
10 * A few layer III, MPEG-2 LSF, and seeking modifications made by Jeff Tsay.
11 * Last modified : 04/19/97
13 * @(#) header.h 1.7, last edit: 6/15/94 16:55:33
14 * @(#) Copyright (C) 1993, 1994 Tobias Bading (bading@cs.tu-berlin.de)
15 * @(#) Berlin University of Technology
16 *-----------------------------------------------------------------------
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU Library General Public License as published
19 * by the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU Library General Public License for more details.
27 * You should have received a copy of the GNU Library General Public
28 * License along with this program; if not, write to the Free Software
29 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
30 *----------------------------------------------------------------------
34 * Class for extracting information from a frame header.
36 @LATTICE("HI<HNS,HNS<H,C<H,NS<FS,FS<H,FS<HV,H<SYNC,HV<SYNC,HV<T,SYNC*,HV*,FS*,HI*")
37 // @METHODDEFAULT("OUT<V,V<THIS,THIS<SH,SH<IN,SH*,THISLOC=THIS,GLOBALLOC=IN")
38 @METHODDEFAULT("THIS,THISLOC=THIS,RETURNLOC=THIS")
39 public final class Header {
41 public static final int[][] frequencies = { { 22050, 24000, 16000, 1 },
42 { 44100, 48000, 32000, 1 }, { 11025, 12000, 8000, 1 } }; // SZD: MPEG25
45 * Constant for MPEG-2 LSF version
47 public static final int MPEG2_LSF = 0;
48 public static final int MPEG25_LSF = 2; // SZD
51 * Constant for MPEG-1 version
53 public static final int MPEG1 = 1;
55 public static final int STEREO = 0;
56 public static final int JOINT_STEREO = 1;
57 public static final int DUAL_CHANNEL = 2;
58 public static final int SINGLE_CHANNEL = 3;
59 public static final int FOURTYFOUR_POINT_ONE = 0;
60 public static final int FOURTYEIGHT = 1;
61 public static final int THIRTYTWO = 2;
66 private int h_protection_bit;
68 private int h_bitrate_index;
70 private int h_padding_bit;
72 private int h_mode_extension;
74 private int h_version;
78 private int h_sample_frequency;
80 private int h_number_of_subbands;
82 private int h_intensity_stereo_bound;
84 private boolean h_copyright;
86 private boolean h_original;
87 // VBR support added by E.B
89 private double[] h_vbr_time_per_frame = { -1.0, 384.0, 1152.0, 1152.0 };
91 private boolean h_vbr;
93 private int h_vbr_frames;
95 private int h_vbr_scale;
97 private int h_vbr_bytes;
99 private byte[] h_vbr_toc;
102 private byte syncmode = Bitstream.INITIAL_SYNC;
107 public short checksum;
109 public int framesize;
114 private int _headerstring = -1; // E.B
117 private SideInfoBuffer sib;
119 private BitReserve br;
124 @LATTICE("OUT<BUF,BUF<THIS,THISLOC=THIS,RETURNLOC=OUT")
125 public String toString() {
126 @LOC("BUF") StringBuffer buffer = new StringBuffer(200);
127 buffer.append("Layer ");
128 buffer.append(layer_string());
129 buffer.append(" frame ");
130 buffer.append(mode_string());
132 buffer.append(version_string());
134 buffer.append(" no");
135 buffer.append(" checksums");
137 buffer.append(sample_frequency_string());
140 buffer.append(bitrate_string());
142 @LOC("OUT") String s = buffer.toString();
147 * Read a 32-bit header from the bitstream.
149 int read_header(Bitstream stream, Crc16[] crcp) throws BitstreamException {
152 boolean sync = false;
154 headerstring = stream.syncHeader(syncmode);
155 if (headerstring == -1) {
158 _headerstring = headerstring; // E.B
159 if (syncmode == Bitstream.INITIAL_SYNC) {
160 h_version = ((headerstring >>> 19) & 1);
161 if (((headerstring >>> 20) & 1) == 0) // SZD: MPEG2.5 detection
162 if (h_version == MPEG2_LSF)
163 h_version = MPEG25_LSF;
165 throw stream.newBitstreamException(Bitstream.UNKNOWN_ERROR);
166 if ((h_sample_frequency = ((headerstring >>> 10) & 3)) == 3) {
167 throw stream.newBitstreamException(Bitstream.UNKNOWN_ERROR);
170 h_layer = 4 - (headerstring >>> 17) & 3;
171 h_protection_bit = (headerstring >>> 16) & 1;
172 h_bitrate_index = (headerstring >>> 12) & 0xF;
173 h_padding_bit = (headerstring >>> 9) & 1;
174 h_mode = ((headerstring >>> 6) & 3);
175 h_mode_extension = (headerstring >>> 4) & 3;
176 if (h_mode == JOINT_STEREO)
177 h_intensity_stereo_bound = (h_mode_extension << 2) + 4;
179 h_intensity_stereo_bound = 0; // should never be used
180 if (((headerstring >>> 3) & 1) == 1)
182 if (((headerstring >>> 2) & 1) == 1)
184 // calculate number of subbands:
186 h_number_of_subbands = 32;
188 channel_bitrate = h_bitrate_index;
189 // calculate bitrate per channel:
190 if (h_mode != SINGLE_CHANNEL)
191 if (channel_bitrate == 4)
194 channel_bitrate -= 4;
195 if ((channel_bitrate == 1) || (channel_bitrate == 2))
196 if (h_sample_frequency == THIRTYTWO)
197 h_number_of_subbands = 12;
199 h_number_of_subbands = 8;
200 else if ((h_sample_frequency == FOURTYEIGHT)
201 || ((channel_bitrate >= 3) && (channel_bitrate <= 5)))
202 h_number_of_subbands = 27;
204 h_number_of_subbands = 30;
206 if (h_intensity_stereo_bound > h_number_of_subbands)
207 h_intensity_stereo_bound = h_number_of_subbands;
208 // calculate framesize and nSlots
209 calculate_framesize();
211 int framesizeloaded = stream.read_frame_data(framesize);
212 if ((framesize >= 0) && (framesizeloaded != framesize)) {
213 // Data loaded does not match to expected framesize,
214 // it might be an ID3v1 TAG. (Fix 11/17/04).
215 throw stream.newBitstreamException(Bitstream.INVALIDFRAME);
217 if (stream.isSyncCurrentPosition(syncmode)) {
218 if (syncmode == Bitstream.INITIAL_SYNC) {
219 syncmode = Bitstream.STRICT_SYNC;
220 stream.set_syncword(headerstring & 0xFFF80CC0);
224 stream.unreadFrame();
227 stream.parse_frame();
228 if (h_protection_bit == 0) {
229 // frame contains a crc checksum
230 checksum = (short) stream.get_bits(16);
233 crc.add_bits(headerstring, 16);
237 if (h_sample_frequency == FOURTYFOUR_POINT_ONE) {
239 * if (offset == null) { int max = max_number_of_frames(stream); offset =
240 * new int[max]; for(int i=0; i<max; i++) offset[i] = 0; } // E.B :
241 * Investigate more int cf = stream.current_frame(); int lf =
242 * stream.last_frame(); if ((cf > 0) && (cf == lf)) { offset[cf] =
243 * offset[cf-1] + h_padding_bit; } else { offset[0] = h_padding_bit; }
250 * Parse frame to extract optionnal VBR frame.
253 * @author E.B (javalayer@javazoom.net)
255 void parseVBR(byte[] firstframe) throws BitstreamException {
256 // Trying Xing header.
257 String xing = "Xing";
258 byte tmp[] = new byte[4];
260 // Compute "Xing" offset depending on MPEG version and channels.
261 if (h_version == MPEG1) {
262 if (h_mode == SINGLE_CHANNEL)
267 if (h_mode == SINGLE_CHANNEL)
273 System.arraycopy(firstframe, offset, tmp, 0, 4);
275 if (xing.equals(new String(tmp))) {
281 h_vbr_toc = new byte[100];
285 byte flags[] = new byte[4];
286 System.arraycopy(firstframe, offset + length, flags, 0, flags.length);
287 length += flags.length;
288 // Read number of frames (if available).
289 if ((flags[3] & (byte) (1 << 0)) != 0) {
290 System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
292 (tmp[0] << 24) & 0xFF000000 | (tmp[1] << 16) & 0x00FF0000 | (tmp[2] << 8)
293 & 0x0000FF00 | tmp[3] & 0x000000FF;
296 // Read size (if available).
297 if ((flags[3] & (byte) (1 << 1)) != 0) {
298 System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
300 (tmp[0] << 24) & 0xFF000000 | (tmp[1] << 16) & 0x00FF0000 | (tmp[2] << 8)
301 & 0x0000FF00 | tmp[3] & 0x000000FF;
304 // Read TOC (if available).
305 if ((flags[3] & (byte) (1 << 2)) != 0) {
306 System.arraycopy(firstframe, offset + length, h_vbr_toc, 0, h_vbr_toc.length);
307 length += h_vbr_toc.length;
309 // Read scale (if available).
310 if ((flags[3] & (byte) (1 << 3)) != 0) {
311 System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
313 (tmp[0] << 24) & 0xFF000000 | (tmp[1] << 16) & 0x00FF0000 | (tmp[2] << 8)
314 & 0x0000FF00 | tmp[3] & 0x000000FF;
317 // System.out.println("VBR:"+xing+" Frames:"+ h_vbr_frames
318 // +" Size:"+h_vbr_bytes);
320 } catch (ArrayIndexOutOfBoundsException e) {
321 throw new BitstreamException("XingVBRHeader Corrupted", e);
324 // Trying VBRI header.
325 String vbri = "VBRI";
328 System.arraycopy(firstframe, offset, tmp, 0, 4);
330 if (vbri.equals(new String(tmp))) {
336 h_vbr_toc = new byte[100];
339 System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
341 (tmp[0] << 24) & 0xFF000000 | (tmp[1] << 16) & 0x00FF0000 | (tmp[2] << 8) & 0x0000FF00
342 | tmp[3] & 0x000000FF;
345 System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
347 (tmp[0] << 24) & 0xFF000000 | (tmp[1] << 16) & 0x00FF0000 | (tmp[2] << 8) & 0x0000FF00
348 | tmp[3] & 0x000000FF;
350 // System.out.println("VBR:"+vbri+" Frames:"+ h_vbr_frames
351 // +" Size:"+h_vbr_bytes);
355 } catch (ArrayIndexOutOfBoundsException e) {
356 throw new BitstreamException("VBRIVBRHeader Corrupted", e);
360 // Functions to query header contents:
364 public int version() {
376 * Returns bitrate index.
378 public int bitrate_index() {
379 return h_bitrate_index;
383 * Returns Sample Frequency.
385 public int sample_frequency() {
386 return h_sample_frequency;
392 public int frequency() {
393 return frequencies[h_version][h_sample_frequency];
404 * Returns Protection bit.
406 public boolean checksums() {
407 if (h_protection_bit == 0)
416 public boolean copyright() {
423 public boolean original() {
430 * @return true if VBR header is found
432 public boolean vbr() {
439 * @return scale of -1 if not available
441 public int vbr_scale() {
448 * @return vbr toc ot null if not available
450 public byte[] vbr_toc() {
455 * Returns Checksum flag. Compares computed checksum with stream checksum.
458 public boolean checksum_ok() {
459 return (checksum == crc.checksum());
462 // Seeking and layer III stuff
464 * Returns Layer III Padding bit.
466 public boolean padding() {
467 if (h_padding_bit == 0)
481 * Returns Mode Extension.
483 public int mode_extension() {
484 return h_mode_extension;
487 // E.B -> private to public
488 public static final int bitrates[][][] = {
490 { 0 /* free format */, 32000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 144000,
491 160000, 176000, 192000, 224000, 256000, 0 },
492 { 0 /* free format */, 8000, 16000, 24000, 32000, 40000, 48000, 56000, 64000, 80000,
493 96000, 112000, 128000, 144000, 160000, 0 },
494 { 0 /* free format */, 8000, 16000, 24000, 32000, 40000, 48000, 56000, 64000, 80000,
495 96000, 112000, 128000, 144000, 160000, 0 } },
498 { 0 /* free format */, 32000, 64000, 96000, 128000, 160000, 192000, 224000, 256000,
499 288000, 320000, 352000, 384000, 416000, 448000, 0 },
500 { 0 /* free format */, 32000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 160000,
501 192000, 224000, 256000, 320000, 384000, 0 },
502 { 0 /* free format */, 32000, 40000, 48000, 56000, 64000, 80000, 96000, 112000, 128000,
503 160000, 192000, 224000, 256000, 320000, 0 } },
506 { 0 /* free format */, 32000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 144000,
507 160000, 176000, 192000, 224000, 256000, 0 },
508 { 0 /* free format */, 8000, 16000, 24000, 32000, 40000, 48000, 56000, 64000, 80000,
509 96000, 112000, 128000, 144000, 160000, 0 },
510 { 0 /* free format */, 8000, 16000, 24000, 32000, 40000, 48000, 56000, 64000, 80000,
511 96000, 112000, 128000, 144000, 160000, 0 } },
515 // E.B -> private to public
517 * Calculate Frame size. Calculates framesize in bytes excluding header size.
519 public int calculate_framesize() {
523 (12 * bitrates[h_version][0][h_bitrate_index])
524 / frequencies[h_version][h_sample_frequency];
525 if (h_padding_bit != 0)
527 framesize <<= 2; // one slot is 4 bytes long
531 (144 * bitrates[h_version][h_layer - 1][h_bitrate_index])
532 / frequencies[h_version][h_sample_frequency];
533 if (h_version == MPEG2_LSF || h_version == MPEG25_LSF)
534 framesize >>= 1; // SZD
535 if (h_padding_bit != 0)
539 if (h_version == MPEG1) {
540 nSlots = framesize - ((h_mode == SINGLE_CHANNEL) ? 17 : 32) // side
543 - ((h_protection_bit != 0) ? 0 : 2) // CRC size
545 } else { // MPEG-2 LSF, SZD: MPEG-2.5 LSF
546 nSlots = framesize - ((h_mode == SINGLE_CHANNEL) ? 9 : 17) // side
549 - ((h_protection_bit != 0) ? 0 : 2) // CRC size
556 framesize -= 4; // subtract header size
561 * Returns the maximum number of frames in the stream.
564 * @return number of frames
566 public int max_number_of_frames(int streamsize) // E.B
571 if ((framesize + 4 - h_padding_bit) == 0)
574 return (streamsize / (framesize + 4 - h_padding_bit));
579 * Returns the maximum number of frames in the stream.
582 * @return number of frames
584 public int min_number_of_frames(int streamsize) // E.B
589 if ((framesize + 5 - h_padding_bit) == 0)
592 return (streamsize / (framesize + 5 - h_padding_bit));
599 * @return milliseconds per frame
601 @LATTICE("OUT<THIS,THISLOC=THIS,RETURNLOC=OUT")
602 public float ms_per_frame() // E.B
605 @LOC("OUT") double tpf = h_vbr_time_per_frame[layer()] / frequency();
606 if ((h_version == MPEG2_LSF) || (h_version == MPEG25_LSF))
608 return ((float) (tpf * 1000));
610 @LOC("OUT") float ms_per_frame_array[][] =
611 { { 8.707483f, 8.0f, 12.0f }, { 26.12245f, 24.0f, 36.0f }, { 26.12245f, 24.0f, 36.0f } };
612 return (ms_per_frame_array[h_layer - 1][h_sample_frequency]);
620 * @return total milliseconds
622 public float total_ms(int streamsize) // E.B
624 return (max_number_of_frames(streamsize) * ms_per_frame());
628 * Returns synchronized header.
630 public int getSyncHeader() // E.B
632 return _headerstring;
635 // functions which return header informations as strings:
637 * Return Layer version.
639 public String layer_string() {
651 // E.B -> private to public
652 public static final String bitrate_str[][][] = {
654 { "free format", "32 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s",
655 "96 kbit/s", "112 kbit/s", "128 kbit/s", "144 kbit/s", "160 kbit/s", "176 kbit/s",
656 "192 kbit/s", "224 kbit/s", "256 kbit/s", "forbidden" },
657 { "free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s", "40 kbit/s",
658 "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s", "96 kbit/s", "112 kbit/s",
659 "128 kbit/s", "144 kbit/s", "160 kbit/s", "forbidden" },
660 { "free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s", "40 kbit/s",
661 "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s", "96 kbit/s", "112 kbit/s",
662 "128 kbit/s", "144 kbit/s", "160 kbit/s", "forbidden" } },
665 { "free format", "32 kbit/s", "64 kbit/s", "96 kbit/s", "128 kbit/s", "160 kbit/s",
666 "192 kbit/s", "224 kbit/s", "256 kbit/s", "288 kbit/s", "320 kbit/s", "352 kbit/s",
667 "384 kbit/s", "416 kbit/s", "448 kbit/s", "forbidden" },
668 { "free format", "32 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s",
669 "96 kbit/s", "112 kbit/s", "128 kbit/s", "160 kbit/s", "192 kbit/s", "224 kbit/s",
670 "256 kbit/s", "320 kbit/s", "384 kbit/s", "forbidden" },
671 { "free format", "32 kbit/s", "40 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s",
672 "80 kbit/s", "96 kbit/s", "112 kbit/s", "128 kbit/s", "160 kbit/s", "192 kbit/s",
673 "224 kbit/s", "256 kbit/s", "320 kbit/s", "forbidden" } },
676 { "free format", "32 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s",
677 "96 kbit/s", "112 kbit/s", "128 kbit/s", "144 kbit/s", "160 kbit/s", "176 kbit/s",
678 "192 kbit/s", "224 kbit/s", "256 kbit/s", "forbidden" },
679 { "free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s", "40 kbit/s",
680 "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s", "96 kbit/s", "112 kbit/s",
681 "128 kbit/s", "144 kbit/s", "160 kbit/s", "forbidden" },
682 { "free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s", "40 kbit/s",
683 "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s", "96 kbit/s", "112 kbit/s",
684 "128 kbit/s", "144 kbit/s", "160 kbit/s", "forbidden" } }, };
689 * @return bitrate in bps
691 public String bitrate_string() {
693 return Integer.toString(bitrate() / 1000) + " kb/s";
695 return bitrate_str[h_version][h_layer - 1][h_bitrate_index];
701 * @return bitrate in bps and average bitrate for VBR header
703 public int bitrate() {
705 return ((int) ((h_vbr_bytes * 8) / (ms_per_frame() * h_vbr_frames))) * 1000;
707 return bitrates[h_version][h_layer - 1][h_bitrate_index];
711 * Return Instant Bitrate. Bitrate for VBR is not constant.
713 * @return bitrate in bps
715 public int bitrate_instant() {
716 return bitrates[h_version][h_layer - 1][h_bitrate_index];
722 * @return frequency string in kHz
724 public String sample_frequency_string() {
725 switch (h_sample_frequency) {
727 if (h_version == MPEG1)
729 else if (h_version == MPEG2_LSF)
734 case FOURTYFOUR_POINT_ONE:
735 if (h_version == MPEG1)
737 else if (h_version == MPEG2_LSF)
743 if (h_version == MPEG1)
745 else if (h_version == MPEG2_LSF)
757 public String mode_string() {
762 return "Joint stereo";
764 return "Dual channel";
766 return "Single channel";
774 * @return MPEG-1 or MPEG-2 LSF or MPEG-2.5 LSF
776 public String version_string() {
782 case MPEG25_LSF: // SZD
783 return "MPEG-2.5 LSF";
789 * Returns the number of subbands in the current frame.
791 * @return number of subbands
793 public int number_of_subbands() {
794 return h_number_of_subbands;
798 * Returns Intensity Stereo. (Layer II joint stereo only). Returns the number
799 * of subbands which are in stereo mode, subbands above that limit are in
800 * intensity stereo mode.
804 public int intensity_stereo_bound() {
805 return h_intensity_stereo_bound;
808 public void setSideInfoBuf(SideInfoBuffer sib) {
812 public void setBitReserve(BitReserve br) {
816 public SideInfoBuffer getSideInfoBuffer() {
820 public BitReserve getBitReserve() {