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,H<T,HV<T,SYNC*,HV,FS*,HI*")
37 @METHODDEFAULT("THIS<IN,THISLOC=THIS,GLOBALLOC=THIS,RETURNLOC=THIS")
38 public final class Header {
40 public static final int[][] frequencies = { { 22050, 24000, 16000, 1 },
41 { 44100, 48000, 32000, 1 }, { 11025, 12000, 8000, 1 } }; // SZD: MPEG25
44 * Constant for MPEG-2 LSF version
46 public static final int MPEG2_LSF = 0;
47 public static final int MPEG25_LSF = 2; // SZD
50 * Constant for MPEG-1 version
52 public static final int MPEG1 = 1;
54 public static final int STEREO = 0;
55 public static final int JOINT_STEREO = 1;
56 public static final int DUAL_CHANNEL = 2;
57 public static final int SINGLE_CHANNEL = 3;
58 public static final int FOURTYFOUR_POINT_ONE = 0;
59 public static final int FOURTYEIGHT = 1;
60 public static final int THIRTYTWO = 2;
65 private int h_protection_bit;
67 private int h_bitrate_index;
69 private int h_padding_bit;
71 private int h_mode_extension;
73 private int h_version;
77 private int h_sample_frequency;
79 private int h_number_of_subbands;
81 private int h_intensity_stereo_bound;
83 private boolean h_copyright;
85 private boolean h_original;
86 // VBR support added by E.B
88 private double[] h_vbr_time_per_frame = { -1.0, 384.0, 1152.0, 1152.0 };
90 private boolean h_vbr;
92 private int h_vbr_frames;
94 private int h_vbr_scale;
96 private int h_vbr_bytes;
98 private byte[] h_vbr_toc;
101 private byte syncmode = Bitstream.INITIAL_SYNC;
106 public short checksum;
108 public int framesize;
113 private int _headerstring = -1; // E.B
116 private SideInfoBuffer sib;
118 private BitReserve br;
126 @LATTICE("OUT<BUF,BUF<THIS,THISLOC=THIS,RETURNLOC=OUT")
127 public String toString() {
128 @LOC("BUF") StringBuffer buffer = new StringBuffer(200);
129 buffer.append("Layer ");
130 buffer.append(layer_string());
131 buffer.append(" frame ");
132 buffer.append(mode_string());
134 buffer.append(version_string());
136 buffer.append(" no");
137 buffer.append(" checksums");
139 buffer.append(sample_frequency_string());
142 buffer.append(bitrate_string());
144 @LOC("OUT") String s = buffer.toString();
149 * Read a 32-bit header from the bitstream.
151 int read_header(Bitstream stream, Crc16[] crcp) throws BitstreamException {
154 boolean sync = false;
156 headerstring = stream.syncHeader(syncmode);
157 if (headerstring == -1) {
160 _headerstring = headerstring; // E.B
161 if (syncmode == Bitstream.INITIAL_SYNC) {
162 h_version = ((headerstring >>> 19) & 1);
163 if (((headerstring >>> 20) & 1) == 0) // SZD: MPEG2.5 detection
164 if (h_version == MPEG2_LSF)
165 h_version = MPEG25_LSF;
167 throw stream.newBitstreamException(Bitstream.UNKNOWN_ERROR);
168 if ((h_sample_frequency = ((headerstring >>> 10) & 3)) == 3) {
169 throw stream.newBitstreamException(Bitstream.UNKNOWN_ERROR);
172 h_layer = 4 - (headerstring >>> 17) & 3;
173 h_protection_bit = (headerstring >>> 16) & 1;
174 h_bitrate_index = (headerstring >>> 12) & 0xF;
175 h_padding_bit = (headerstring >>> 9) & 1;
176 h_mode = ((headerstring >>> 6) & 3);
177 h_mode_extension = (headerstring >>> 4) & 3;
178 if (h_mode == JOINT_STEREO)
179 h_intensity_stereo_bound = (h_mode_extension << 2) + 4;
181 h_intensity_stereo_bound = 0; // should never be used
182 if (((headerstring >>> 3) & 1) == 1)
184 if (((headerstring >>> 2) & 1) == 1)
186 // calculate number of subbands:
188 h_number_of_subbands = 32;
190 channel_bitrate = h_bitrate_index;
191 // calculate bitrate per channel:
192 if (h_mode != SINGLE_CHANNEL)
193 if (channel_bitrate == 4)
196 channel_bitrate -= 4;
197 if ((channel_bitrate == 1) || (channel_bitrate == 2))
198 if (h_sample_frequency == THIRTYTWO)
199 h_number_of_subbands = 12;
201 h_number_of_subbands = 8;
202 else if ((h_sample_frequency == FOURTYEIGHT)
203 || ((channel_bitrate >= 3) && (channel_bitrate <= 5)))
204 h_number_of_subbands = 27;
206 h_number_of_subbands = 30;
208 if (h_intensity_stereo_bound > h_number_of_subbands)
209 h_intensity_stereo_bound = h_number_of_subbands;
210 // calculate framesize and nSlots
211 calculate_framesize();
213 int framesizeloaded = stream.read_frame_data(framesize);
214 if ((framesize >= 0) && (framesizeloaded != framesize)) {
215 // Data loaded does not match to expected framesize,
216 // it might be an ID3v1 TAG. (Fix 11/17/04).
217 throw stream.newBitstreamException(Bitstream.INVALIDFRAME);
219 if (stream.isSyncCurrentPosition(syncmode)) {
220 if (syncmode == Bitstream.INITIAL_SYNC) {
221 syncmode = Bitstream.STRICT_SYNC;
222 stream.set_syncword(headerstring & 0xFFF80CC0);
226 stream.unreadFrame();
229 stream.parse_frame();
230 if (h_protection_bit == 0) {
231 // frame contains a crc checksum
232 checksum = (short) stream.get_bits(16);
235 crc.add_bits(headerstring, 16);
239 if (h_sample_frequency == FOURTYFOUR_POINT_ONE) {
241 * if (offset == null) { int max = max_number_of_frames(stream); offset =
242 * new int[max]; for(int i=0; i<max; i++) offset[i] = 0; } // E.B :
243 * Investigate more int cf = stream.current_frame(); int lf =
244 * stream.last_frame(); if ((cf > 0) && (cf == lf)) { offset[cf] =
245 * offset[cf-1] + h_padding_bit; } else { offset[0] = h_padding_bit; }
252 * Parse frame to extract optionnal VBR frame.
255 * @author E.B (javalayer@javazoom.net)
257 void parseVBR(byte[] firstframe) throws BitstreamException {
258 // Trying Xing header.
259 String xing = "Xing";
260 byte tmp[] = new byte[4];
262 // Compute "Xing" offset depending on MPEG version and channels.
263 if (h_version == MPEG1) {
264 if (h_mode == SINGLE_CHANNEL)
269 if (h_mode == SINGLE_CHANNEL)
275 System.arraycopy(firstframe, offset, tmp, 0, 4);
277 if (xing.equals(new String(tmp))) {
283 h_vbr_toc = new byte[100];
287 byte flags[] = new byte[4];
288 System.arraycopy(firstframe, offset + length, flags, 0, flags.length);
289 length += flags.length;
290 // Read number of frames (if available).
291 if ((flags[3] & (byte) (1 << 0)) != 0) {
292 System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
294 (tmp[0] << 24) & 0xFF000000 | (tmp[1] << 16) & 0x00FF0000 | (tmp[2] << 8)
295 & 0x0000FF00 | tmp[3] & 0x000000FF;
298 // Read size (if available).
299 if ((flags[3] & (byte) (1 << 1)) != 0) {
300 System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
302 (tmp[0] << 24) & 0xFF000000 | (tmp[1] << 16) & 0x00FF0000 | (tmp[2] << 8)
303 & 0x0000FF00 | tmp[3] & 0x000000FF;
306 // Read TOC (if available).
307 if ((flags[3] & (byte) (1 << 2)) != 0) {
308 System.arraycopy(firstframe, offset + length, h_vbr_toc, 0, h_vbr_toc.length);
309 length += h_vbr_toc.length;
311 // Read scale (if available).
312 if ((flags[3] & (byte) (1 << 3)) != 0) {
313 System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
315 (tmp[0] << 24) & 0xFF000000 | (tmp[1] << 16) & 0x00FF0000 | (tmp[2] << 8)
316 & 0x0000FF00 | tmp[3] & 0x000000FF;
319 // System.out.println("VBR:"+xing+" Frames:"+ h_vbr_frames
320 // +" Size:"+h_vbr_bytes);
322 } catch (ArrayIndexOutOfBoundsException e) {
323 throw new BitstreamException("XingVBRHeader Corrupted", e);
326 // Trying VBRI header.
327 String vbri = "VBRI";
330 System.arraycopy(firstframe, offset, tmp, 0, 4);
332 if (vbri.equals(new String(tmp))) {
338 h_vbr_toc = new byte[100];
341 System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
343 (tmp[0] << 24) & 0xFF000000 | (tmp[1] << 16) & 0x00FF0000 | (tmp[2] << 8) & 0x0000FF00
344 | tmp[3] & 0x000000FF;
347 System.arraycopy(firstframe, offset + length, tmp, 0, tmp.length);
349 (tmp[0] << 24) & 0xFF000000 | (tmp[1] << 16) & 0x00FF0000 | (tmp[2] << 8) & 0x0000FF00
350 | tmp[3] & 0x000000FF;
352 // System.out.println("VBR:"+vbri+" Frames:"+ h_vbr_frames
353 // +" Size:"+h_vbr_bytes);
357 } catch (ArrayIndexOutOfBoundsException e) {
358 throw new BitstreamException("VBRIVBRHeader Corrupted", e);
362 // Functions to query header contents:
366 @RETURNLOC("THIS,Header.HV")
367 public int version() {
374 @RETURNLOC("THIS,Header.H")
380 * Returns bitrate index.
382 public int bitrate_index() {
383 return h_bitrate_index;
387 * Returns Sample Frequency.
389 @RETURNLOC("THIS,Header.H")
390 public int sample_frequency() {
391 return h_sample_frequency;
397 @RETURNLOC("THIS,Header.FS")
398 public int frequency() {
399 return frequencies[h_version][h_sample_frequency];
405 @RETURNLOC("THIS,Header.H")
411 * Returns Protection bit.
413 @RETURNLOC("THIS,Header.H")
414 public boolean checksums() {
415 if (h_protection_bit == 0)
424 public boolean copyright() {
431 public boolean original() {
438 * @return true if VBR header is found
440 public boolean vbr() {
447 * @return scale of -1 if not available
449 public int vbr_scale() {
456 * @return vbr toc ot null if not available
458 public byte[] vbr_toc() {
463 * Returns Checksum flag. Compares computed checksum with stream checksum.
466 public boolean checksum_ok() {
467 return (checksum == crc.checksum());
470 // Seeking and layer III stuff
472 * Returns Layer III Padding bit.
474 public boolean padding() {
475 if (h_padding_bit == 0)
484 @RETURNLOC("THIS,Header.NS")
490 * Returns Mode Extension.
492 @RETURNLOC("THIS,Header.H")
493 public int mode_extension() {
494 return h_mode_extension;
497 // E.B -> private to public
498 public static final int bitrates[][][] = {
500 { 0 /* free format */, 32000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 144000,
501 160000, 176000, 192000, 224000, 256000, 0 },
502 { 0 /* free format */, 8000, 16000, 24000, 32000, 40000, 48000, 56000, 64000, 80000,
503 96000, 112000, 128000, 144000, 160000, 0 },
504 { 0 /* free format */, 8000, 16000, 24000, 32000, 40000, 48000, 56000, 64000, 80000,
505 96000, 112000, 128000, 144000, 160000, 0 } },
508 { 0 /* free format */, 32000, 64000, 96000, 128000, 160000, 192000, 224000, 256000,
509 288000, 320000, 352000, 384000, 416000, 448000, 0 },
510 { 0 /* free format */, 32000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 160000,
511 192000, 224000, 256000, 320000, 384000, 0 },
512 { 0 /* free format */, 32000, 40000, 48000, 56000, 64000, 80000, 96000, 112000, 128000,
513 160000, 192000, 224000, 256000, 320000, 0 } },
516 { 0 /* free format */, 32000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 144000,
517 160000, 176000, 192000, 224000, 256000, 0 },
518 { 0 /* free format */, 8000, 16000, 24000, 32000, 40000, 48000, 56000, 64000, 80000,
519 96000, 112000, 128000, 144000, 160000, 0 },
520 { 0 /* free format */, 8000, 16000, 24000, 32000, 40000, 48000, 56000, 64000, 80000,
521 96000, 112000, 128000, 144000, 160000, 0 } },
525 // E.B -> private to public
527 * Calculate Frame size. Calculates framesize in bytes excluding header size.
529 public int calculate_framesize() {
533 (12 * bitrates[h_version][0][h_bitrate_index])
534 / frequencies[h_version][h_sample_frequency];
535 if (h_padding_bit != 0)
537 framesize <<= 2; // one slot is 4 bytes long
541 (144 * bitrates[h_version][h_layer - 1][h_bitrate_index])
542 / frequencies[h_version][h_sample_frequency];
543 if (h_version == MPEG2_LSF || h_version == MPEG25_LSF)
544 framesize >>= 1; // SZD
545 if (h_padding_bit != 0)
549 if (h_version == MPEG1) {
550 nSlots = framesize - ((h_mode == SINGLE_CHANNEL) ? 17 : 32) // side
553 - ((h_protection_bit != 0) ? 0 : 2) // CRC size
555 } else { // MPEG-2 LSF, SZD: MPEG-2.5 LSF
556 nSlots = framesize - ((h_mode == SINGLE_CHANNEL) ? 9 : 17) // side
559 - ((h_protection_bit != 0) ? 0 : 2) // CRC size
566 framesize -= 4; // subtract header size
571 * Returns the maximum number of frames in the stream.
574 * @return number of frames
576 public int max_number_of_frames(int streamsize) // E.B
581 if ((framesize + 4 - h_padding_bit) == 0)
584 return (streamsize / (framesize + 4 - h_padding_bit));
589 * Returns the maximum number of frames in the stream.
592 * @return number of frames
594 public int min_number_of_frames(int streamsize) // E.B
599 if ((framesize + 5 - h_padding_bit) == 0)
602 return (streamsize / (framesize + 5 - h_padding_bit));
609 * @return milliseconds per frame
611 @LATTICE("OUT<THIS,THISLOC=THIS,RETURNLOC=OUT")
612 public float ms_per_frame() // E.B
615 @LOC("OUT") double tpf = h_vbr_time_per_frame[layer()] / frequency();
616 if ((h_version == MPEG2_LSF) || (h_version == MPEG25_LSF))
618 return ((float) (tpf * 1000));
620 @LOC("OUT") float ms_per_frame_array[][] =
621 { { 8.707483f, 8.0f, 12.0f }, { 26.12245f, 24.0f, 36.0f }, { 26.12245f, 24.0f, 36.0f } };
622 return (ms_per_frame_array[h_layer - 1][h_sample_frequency]);
630 * @return total milliseconds
632 public float total_ms(int streamsize) // E.B
634 return (max_number_of_frames(streamsize) * ms_per_frame());
638 * Returns synchronized header.
640 public int getSyncHeader() // E.B
642 return _headerstring;
645 // functions which return header informations as strings:
647 * Return Layer version.
649 @RETURNLOC("THIS,Header.H")
650 public String layer_string() {
662 // E.B -> private to public
663 public static final String bitrate_str[][][] = {
665 { "free format", "32 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s",
666 "96 kbit/s", "112 kbit/s", "128 kbit/s", "144 kbit/s", "160 kbit/s", "176 kbit/s",
667 "192 kbit/s", "224 kbit/s", "256 kbit/s", "forbidden" },
668 { "free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s", "40 kbit/s",
669 "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s", "96 kbit/s", "112 kbit/s",
670 "128 kbit/s", "144 kbit/s", "160 kbit/s", "forbidden" },
671 { "free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s", "40 kbit/s",
672 "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s", "96 kbit/s", "112 kbit/s",
673 "128 kbit/s", "144 kbit/s", "160 kbit/s", "forbidden" } },
676 { "free format", "32 kbit/s", "64 kbit/s", "96 kbit/s", "128 kbit/s", "160 kbit/s",
677 "192 kbit/s", "224 kbit/s", "256 kbit/s", "288 kbit/s", "320 kbit/s", "352 kbit/s",
678 "384 kbit/s", "416 kbit/s", "448 kbit/s", "forbidden" },
679 { "free format", "32 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s",
680 "96 kbit/s", "112 kbit/s", "128 kbit/s", "160 kbit/s", "192 kbit/s", "224 kbit/s",
681 "256 kbit/s", "320 kbit/s", "384 kbit/s", "forbidden" },
682 { "free format", "32 kbit/s", "40 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s",
683 "80 kbit/s", "96 kbit/s", "112 kbit/s", "128 kbit/s", "160 kbit/s", "192 kbit/s",
684 "224 kbit/s", "256 kbit/s", "320 kbit/s", "forbidden" } },
687 { "free format", "32 kbit/s", "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s",
688 "96 kbit/s", "112 kbit/s", "128 kbit/s", "144 kbit/s", "160 kbit/s", "176 kbit/s",
689 "192 kbit/s", "224 kbit/s", "256 kbit/s", "forbidden" },
690 { "free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s", "40 kbit/s",
691 "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s", "96 kbit/s", "112 kbit/s",
692 "128 kbit/s", "144 kbit/s", "160 kbit/s", "forbidden" },
693 { "free format", "8 kbit/s", "16 kbit/s", "24 kbit/s", "32 kbit/s", "40 kbit/s",
694 "48 kbit/s", "56 kbit/s", "64 kbit/s", "80 kbit/s", "96 kbit/s", "112 kbit/s",
695 "128 kbit/s", "144 kbit/s", "160 kbit/s", "forbidden" } }, };
700 * @return bitrate in bps
703 @RETURNLOC("THIS,Header.FS")
704 public String bitrate_string() {
705 @LOC("THIS,Header.T") String kbs = " kb/s";
707 return Integer.toString(bitrate() / 1000) + kbs;
709 return bitrate_str[h_version][h_layer - 1][h_bitrate_index];
716 * @return bitrate in bps and average bitrate for VBR header
718 @RETURNLOC("THIS,Header.FS")
719 public int bitrate() {
721 return ((int) ((h_vbr_bytes * 8) / (ms_per_frame() * h_vbr_frames))) * 1000;
723 return bitrates[h_version][h_layer - 1][h_bitrate_index];
728 * Return Instant Bitrate. Bitrate for VBR is not constant.
730 * @return bitrate in bps
732 public int bitrate_instant() {
733 return bitrates[h_version][h_layer - 1][h_bitrate_index];
739 * @return frequency string in kHz
741 @RETURNLOC("THIS,Header.FS")
742 public String sample_frequency_string() {
743 switch (h_sample_frequency) {
745 if (h_version == MPEG1)
747 else if (h_version == MPEG2_LSF)
752 case FOURTYFOUR_POINT_ONE:
753 if (h_version == MPEG1)
755 else if (h_version == MPEG2_LSF)
761 if (h_version == MPEG1)
763 else if (h_version == MPEG2_LSF)
775 @RETURNLOC("THIS,Header.H")
776 public String mode_string() {
781 return "Joint stereo";
783 return "Dual channel";
785 return "Single channel";
793 * @return MPEG-1 or MPEG-2 LSF or MPEG-2.5 LSF
795 @RETURNLOC("THIS,Header.HV")
796 public String version_string() {
802 case MPEG25_LSF: // SZD
803 return "MPEG-2.5 LSF";
809 * Returns the number of subbands in the current frame.
811 * @return number of subbands
813 public int number_of_subbands() {
814 return h_number_of_subbands;
818 * Returns Intensity Stereo. (Layer II joint stereo only). Returns the number
819 * of subbands which are in stereo mode, subbands above that limit are in
820 * intensity stereo mode.
824 public int intensity_stereo_bound() {
825 return h_intensity_stereo_bound;
828 public void setSideInfoBuf(SideInfoBuffer sib) {
832 public void setBitReserve(BitReserve br) {
836 @RETURNLOC("THIS,Header.T")
837 public SideInfoBuffer getSideInfoBuffer() {
841 @RETURNLOC("THIS,Header.T")
842 public BitReserve getBitReserve() {
846 @RETURNLOC("THIS,Header.T")
847 public int getIdx() {
851 public int setIdx(int idx) {
852 return this.idx = idx;