summaryrefslogtreecommitdiff
path: root/www/docs/mpeghdr.t
diff options
context:
space:
mode:
authorBjörn Stenberg <bjorn@haxx.se>2002-09-25 12:29:28 +0000
committerBjörn Stenberg <bjorn@haxx.se>2002-09-25 12:29:28 +0000
commit7aa3c1770a290817c75437fd61480dee1d084988 (patch)
treee27a7b9cc4c430e4bdbb5ce74c7908433208ddee /www/docs/mpeghdr.t
parent5b662ff3dec68ae67864f3ce86aa75725fcb4400 (diff)
downloadrockbox-7aa3c1770a290817c75437fd61480dee1d084988.tar.gz
rockbox-7aa3c1770a290817c75437fd61480dee1d084988.zip
Updated docs
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2410 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'www/docs/mpeghdr.t')
-rw-r--r--www/docs/mpeghdr.t761
1 files changed, 761 insertions, 0 deletions
diff --git a/www/docs/mpeghdr.t b/www/docs/mpeghdr.t
new file mode 100644
index 0000000000..1bf9207402
--- /dev/null
+++ b/www/docs/mpeghdr.t
@@ -0,0 +1,761 @@
1#define _PAGE_ MPEG Audio Frame Header
2#include "head.t"
3
4<P>This is a brief and informal document targeted to those who want to deal
5with the MPEG format. If you are one of them, you probably already know what
6is MPEG audio. If not, jump to <A
7HREF="http://www.mp3.com/">http://www.mp3.com/</A> or <A
8HREF="http://www.layer3.org/">http://www.layer3.org/</A> where you will find
9more details and also more links. This document does not cover compression and
10decompression algorithm.
11
12<P>NOTE: You cannot just search the Internet and find the MPEG audio specs. It
13is copyrighted and you will have to pay quite a bit to get the Paper. That's why
14I made this. Information I got is gathered from the Internet, and mostly originate
15from program sources I found available for free. Despite my intention to always
16specify the information sources, I am not able to do it this time. Sorry, I did
17not maintain the list. :-(
18<P><B>These are not a decoding specs, it just informs you how to read the </B><A
19HREF="#MPEG HEADER"><B>MPEG headers</B></A><B> and the </B> <A HREF="#MPEGTAG"
20TARGET=""><B>MPEG TAG</B></A><B>. MPEG Version 1, 2 and 2.5 and Layer I, II
21and III are supported, the MP3 TAG (ID3v1 and ID3v1.1) also.</B>. Those of you
22who use Delphi may find <A
23HREF="http://www.dv.co.yu/mpgscript/mpgtools.htm">MPGTools Delphi unit (freeware source)</A>
24useful, it is where I implemented this stuff.
25
26<P>I do not claim information presented in this document is accurate. At first
27I just gathered it from different sources. It was not an easy task but I needed
28it. Later, I received lots of comments as feedback when I published this document.
29I think this last release is highly accurate due to comments and corrections I
30received.
31<P>This document is last updated on December 22, 1999.
32<P ALIGN="center"><FONT SIZE="5"><B>MPEG Audio Compression Basics</B></FONT>
33
34<P>This is one of many methods to compress audio in digital form trying to consume
35as little space as possible but keep audio quality as good as possible. MPEG compression
36showed up as one of the best achievements in this area.
37<P>This is a lossy compression, which means, you will certainly loose some audio
38information when you use this compression methods. But, this lost can hardly be
39noticed because the compression method tries to control it. By using several quite
40complicate and demanding mathematical algorithms it will only loose those parts
41of sound that are hard to be heard even in the original form. This leaves more
42space for information that is important. This way you can compress audio up to
4312 times (you may choose compression ratio) which is really significant. Due to
44its quality MPEG audio became very popular.
45<P>MPEG standards MPEG-1, MPEG-2 and MPEG-4 are known but this document covers
46first two of them. There is an unofficial MPEG-2.5 which is rarely used. It is
47also covered.
48<P><B>MPEG-1 audio</B> (described in ISO/IEC 11172-3) describes three Layers of audio coding with the following properties:
49<LI>one or two audio channels
50<LI>sample rate 32kHz, 44.1kHz or 48kHz.
51<LI>bit rates from 32kbps up to 448kbps<BR>
52Each layer has its merits.
53
54<P><B>MPEG-2 audio</B> (described in ISO/IEC 13818-3) has two extensions to MPEG-1, usually referred as MPEG-2/LSF and MPEG-2/Multichannel.
55<P>MPEG-2/LSF has the following properties:
56<LI>one or two audio channels
57<LI>sample rates half those of MPEG-1
58<LI>bit rates from 8 kbps up to 256kbps.
59
60<P>MPEG-2/Multichannel has the following properties:
61<LI>up to 5 full range audio channels and an LFE-channel (Low Frequency
62Enhancement <> subwoofer!)
63<LI>sample rates the same as those of MPEG-1
64<LI>highest possible bitrate goes up to about 1Mbps for 5.1
65
66
67<P ALIGN="center"><A NAME="MPEG HEADER"></A><FONT SIZE="5"><B>MPEG Audio Frame
68Header</B></FONT>
69
70<P>An MPEG audio file is built up from smaller parts called frames. Generally,
71frames are independent items. Each frame has its own header and audio informations.
72There is no file header. Therefore, you can cut any part of MPEG file and play
73it correctly (this should be done on frame boundaries but most applications will
74handle incorrect headers). For Layer III, this is not 100% correct. Due to internal
75data organization in MPEG version 1 Layer III files, frames are often dependent
76of each other and they cannot be cut off just like that.
77<P>When you want to read info about an MPEG file, it is usually enough to find
78the first frame, read its header and assume that the other frames are the same
79This may not be always the case. Variable bitrate MPEG files may use so called
80bitrate switching, which means that bitrate changes according to the content of
81each frame. This way lower bitrates may be used in frames where it will not reduce
82sound quality. This allows making better compression while keeping high quality
83of sound.
84<P>The frame header is constituted by the very first four bytes (32bits) in a
85frame. The first eleven bits (or first twelve bits, see below about frame sync)
86of a frame header are always set and they are called &quot;frame sync&quot;. Therefore,
87you can search through the file for the first occurence of frame sync (meaning
88that you have to find a byte with a value of 255, and followed by a byte with
89its three (or four) most significant bits set). Then you read the whole header
90and check if the values are correct. You will see in the following table the exact
91meaning of each bit in the header, and which values may be checked for validity.
92Each value that is specified as reserved, invalid, bad, or not allowed should
93indicate an invalid header. Remember, this is not enough, frame sync can be easily
94(and very frequently) found in any binary file. Also it is likely that MPEG file
95contains garbage on it's beginning which also may contain false sync. Thus, you
96have to check two or more frames in a row to assure you are really dealing with
97MPEG audio file.
98<P>Frames may have a CRC check. The CRC is 16 bits long
99and, if it exists, it follows the frame header. After the CRC comes the audio
100data. You may calculate the length of the frame and use it if you need to read
101other headers too or just want to calculate the CRC of the frame, to compare
102it with the one you read from the file. This is actually a very good method to
103check the MPEG header validity.
104
105<P>Here is &quot;graphical&quot; presentation of the header content. Characters
106from A to M are used to indicate different fields. In the table, you can see
107details about the content of each field.
108<P ALIGN="center">
109<B><TT><FONT SIZE="5">
110AAAAAAAA AAABBCCD EEEEFFGH IIJJKLMM
111</FONT>
112</TT></B>
113
114<P><CENTER>
115
116<TABLE BORDER="0" CELLSPACING=7>
117<TR VALIGN=TOP BGCOLOR="#E2E2E2">
118<TD>Sign</TD><TD>Length<BR>(bits)</TD><TD>Position<BR>(bits)</TD><TD>Description</TD>
119</TR>
120
121<TR VALIGN=TOP>
122<TD>A</TD><TD>11</TD><TD>(31-21)</TD><TD>Frame sync (all bits set)</TD>
123</TR>
124
125<TR VALIGN=TOP>
126<TD>B</TD><TD>2</TD><TD>(20,19)</TD><TD>MPEG Audio version ID<BR>
12700 - MPEG Version 2.5<BR>01 - reserved<BR>10 - MPEG Version 2 (ISO/IEC 13818-3)<BR>11 - MPEG Version 1 (ISO/IEC 11172-3)
128<P>Note: MPEG Version 2.5 is not official standard. Bit No 20 in frame header
129is used to indicate version 2.5. Applications that do not support this MPEG version
130expect this bit always to be set, meaning that frame sync (A) is twelve bits long,
131not eleve as stated here. Accordingly, B is one bit long (represents only bit
132No 19). I recommend using methodology presented here, since this allows you to
133distinguish all three versions and keep full compatibility.
134</TD>
135</TR>
136
137<TR VALIGN=TOP><TD>C</TD><TD>2</TD><TD>(18,17)</TD>
138<TD>Layer description<BR>
13900 - reserved<BR>
14001 - Layer III<BR>
14110 - Layer II<BR>
14211 - Layer I</TD>
143</TR>
144
145<TR VALIGN=TOP>
146<TD>D</TD><TD>1</TD><TD>(16)</TD>
147<TD>Protection bit<BR>
1480 - Protected by CRC (16bit crc follows header)<BR>
1491 - Not protected</TD>
150</TR>
151<TR VALIGN=TOP><TD>E</TD><TD>4</TD><TD>(15,12)</TD><TD>Bitrate index<BR>
152<TABLE BORDER="1" CELLSPACING="0" CELLPADING="0">
153<TR><TD>bits</TD><TD>V1,L1</TD><TD>V1,L2</TD><TD>V1,L3</TD><TD>V2,L1</TD><TD>V2, L2 &amp; L3</TD></TR>
154<TR><TD>0000</TD><TD>free</TD><TD>free</TD><TD>free</TD><TD>free</TD><TD>free</TD></TR>
155<TR><TD>0001</TD><TD>32</TD><TD>32</TD><TD>32</TD><TD>32</TD><TD>8</TD></TR>
156<TR><TD>0010</TD><TD>64</TD><TD>48</TD><TD>40</TD><TD>48</TD><TD>16</TD></TR>
157<TR><TD>0011</TD><TD>96</TD><TD>56</TD><TD>48</TD><TD>56</TD><TD>24</TD></TR>
158<TR><TD>0100</TD><TD>128</TD><TD>64</TD><TD>56</TD><TD>64</TD><TD>32</TD></TR>
159<TR><TD>0101</TD><TD>160</TD><TD>80</TD><TD>64</TD><TD>80</TD><TD>40</TD></TR>
160<TR><TD>0110</TD><TD>192</TD><TD>96</TD><TD>80</TD><TD>96</TD><TD>48</TD></TR>
161<TR><TD>0111</TD><TD>224</TD><TD>112</TD><TD>96</TD><TD>112</TD><TD>56</TD></TR>
162<TR><TD>1000</TD><TD>256</TD><TD>128</TD><TD>112</TD><TD>128</TD><TD>64</TD></TR>
163<TR><TD>1001</TD><TD>288</TD><TD>160</TD><TD>128</TD><TD>144</TD><TD>80</TD></TR>
164<TR><TD>1010</TD><TD>320</TD><TD>192</TD><TD>160</TD><TD>160</TD><TD>96</TD></TR>
165<TR><TD>1011</TD><TD>352</TD><TD>224</TD><TD>192</TD><TD>176</TD><TD>112</TD></TR>
166<TR><TD>1100</TD><TD>384</TD><TD>256</TD><TD>224</TD><TD>192</TD><TD>128</TD></TR>
167<TR><TD>1101</TD><TD>416</TD><TD>320</TD><TD>256</TD><TD>224</TD><TD>144</TD></TR>
168<TR><TD>1110</TD><TD>448</TD><TD>384</TD><TD>320</TD><TD>256</TD><TD>160</TD></TR>
169<TR><TD>1111</TD><TD>bad</TD><TD>bad</TD><TD>bad</TD><TD>bad</TD><TD>bad</TD></TR>
170</TABLE>
171<P>
172NOTES: All values are in kbps<BR>
173V1 - MPEG Version 1<BR>
174V2 - MPEG Version 2 and Version 2.5<BR>
175L1 - Layer I<BR>
176L2 - Layer II<BR>
177L3 - Layer III<BR>
178&quot;free&quot; means free format. If the correct fixed bitrate (such files cannot
179use variable bitrate) is different than those presented in upper table it must
180be determined by the application. This may be implemented only for internal purposes
181since third party applications have no means to find out correct bitrate. Howewer,
182this is not impossible to do but demands lot's of efforts.<BR>
183&quot;bad&quot; means that this is not an allowed value
184
185<P>MPEG files may have variable bitrate (VBR). This means that bitrate in the file may change. I have learned about two used methods:
186<LI>bitrate switching. Each frame may be created with different bitrate. It may be used in all layers. Layer III decoders must support this method. Layer I & II decoders may support it.
187<LI>bit reservoir. Bitrate may be borrowed (within limits) from previous frames
188in order to provide more bits to demanding parts of the input signal. This causes,
189however, that the frames are no longer independent, which means you should not
190cut this files. This is supported only in Layer III.
191<P>More about VBR you may find on <A HREF="http://www.xingtech.com/">Xing Tech
192site</A>
193<P>For Layer II there are some combinations of bitrate and mode which are not
194allowed. Here is a list of allowed combinations.
195<TABLE BORDER=1 CELLSPACING=0>
196<TR>
197<TD>bitrate</TD>
198<TD>allowed modes</TD>
199</TR>
200<TR>
201<TD>free</TD>
202<TD>all</TD>
203</TR>
204<TR>
205<TD>32</TD>
206<TD>single channel</TD>
207</TR>
208<TR>
209<TD>48</TD>
210<TD>single channel</TD>
211</TR>
212<TR>
213<TD>56</TD>
214<TD>single channel</TD>
215</TR>
216<TR>
217<TD>64</TD>
218<TD>all</TD>
219</TR>
220<TR>
221<TD>80</TD>
222<TD>single channel</TD>
223</TR>
224<TR>
225<TD>96</TD>
226<TD>all</TD>
227</TR>
228<TR>
229<TD>112</TD>
230<TD>all</TD>
231</TR>
232<TR>
233<TD>128</TD>
234<TD>all</TD>
235</TR>
236<TR>
237<TD>160</TD>
238<TD>all</TD>
239</TR>
240<TR>
241<TD>192</TD>
242<TD>all</TD>
243</TR>
244<TR>
245<TD>224</TD>
246<TD>stereo, intensity stereo, dual channel</TD>
247</TR>
248<TR>
249<TD>256</TD>
250<TD>stereo, intensity stereo, dual channel</TD>
251</TR>
252<TR>
253<TD>320</TD>
254<TD>stereo, intensity stereo, dual channel</TD>
255</TR>
256<TR>
257<TD>384</TD>
258<TD>stereo, intensity stereo, dual channel</TD>
259</TR>
260</TABLE>
261</TD></TR>
262<TR VALIGN=TOP>
263<TD>F</TD><TD>2</TD><TD>(11,10)</TD>
264<TD>Sampling rate frequency index (values are in Hz)
265<TABLE BORDER="1" CELLSPACING="0" CELLPADING="0">
266<TR><TD>bits</TD><TD>MPEG1</TD><TD>MPEG2</TD><TD>MPEG2.5</TD></TR>
267<TR><TD>00</TD><TD>44100</TD><TD>22050</TD><TD>11025</TD></TR>
268<TR><TD>01</TD><TD>48000</TD><TD>24000</TD><TD>12000</TD></TR>
269<TR><TD>10</TD><TD>32000</TD><TD>16000</TD><TD>8000</TD></TR>
270<TR><TD>11</TD><TD>reserv.</TD><TD>reserv.</TD><TD>reserv.</TD></TR>
271</TABLE>
272</TD></TR>
273
274<TR VALIGN=TOP>
275<TD>G</TD><TD>1</TD><TD>(9)</TD>
276<TD>Padding bit<BR>
2770 - frame is not padded<BR>
2781 - frame is padded with one extra slot<BR>
279
280Padding is used to fit the bit rates exactly. For an example: 128k 44.1kHz layer II uses a lot of 418 bytes and some of 417 bytes long frames to get the exact 128k bitrate. For Layer I slot is 32 bits long, for Layer II and Layer III slot is 8 bits long.
281
282
283
284<P><B>How to calculate frame length</B>
285
286<P>First, let's distinguish two terms frame size and frame length. Frame size
287is the number of samples contained in a frame. It is constant and always 384 samples
288for Layer I and 1152 samples for Layer II and Layer III. Frame length is length
289of a frame when compressed. It is calculated in slots. One slot is 4 bytes long
290for Layer I, and one byte long for Layer II and Layer III. When you are reading
291MPEG file you must calculate this to be able to find each consecutive frame. Remember,
292frame length may change from frame to frame due to padding or bitrate switching.
293<P>Read the BitRate, SampleRate and Padding of the frame header.
294<P>For Layer I files us this formula:
295<P ALIGN=CENTER>FrameLengthInBytes = (12 * BitRate / SampleRate + Padding) * 4
296<P ALIGN=LEFT>For Layer II & III files use this formula:
297<P ALIGN=CENTER>FrameLengthInBytes = 144 * BitRate / SampleRate + Padding
298<P>Example:<BR>
299Layer III, BitRate=128000, SampleRate=441000, Padding=0<BR>
300&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ==&gt;&nbsp; FrameSize=417 bytes
301</TD></TR>
302
303<TR VALIGN=TOP><TD>H</TD><TD>1</TD><TD>(8)</TD>
304<TD>Private bit. It may be freely used for specific needs of an application, i.e. if it has to trigger some application specific events.</TD>
305</TR>
306
307<TR VALIGN=TOP><TD>I</TD><TD>2</TD><TD>(7,6)</TD>
308<TD>Channel Mode<BR>
30900 - Stereo<BR>
31001 - Joint stereo (Stereo)<BR>
31110 - Dual channel (Stereo)<BR>
31211 - Single channel (Mono)</TD>
313</TR>
314
315<TR VALIGN=TOP><TD>J</TD><TD>2</TD><TD>(5,4)</TD>
316<TD>Mode extension (Only if Joint stereo)
317<P>Mode extension is used to join informations that are of no use for stereo effect, thus reducing needed resources. These bits are dynamically determined by an encoder in Joint stereo mode.
318
319<P>Complete frequency range of MPEG file is divided in subbands There are 32 subbands. For Layer I & II these two bits determine frequency range (bands) where intensity stereo is applied. For Layer III these two bits determine which type of joint stereo
320
321is used (intensity stereo or m/s stereo). Frequency range is determined within decompression algorythm.
322
323<TABLE BORDER="0" CELLSPACING="2" CELLPADDING="0">
324<TR><TD ALIGN=CENTER>Layer I and II</TD><TD ALIGN=CENTER>Layer III</TD></TR>
325<TR VALIGN=TOP><TD>
326<TABLE BORDER="1" CELLSPACING="0" CELLPADING="0">
327<TR><TD>value</TD><TD>Layer I &amp; II</TD></TR>
328<TR><TD>00</TD><TD>bands 4 to 31</TD></TR>
329<TR><TD>01</TD><TD>bands 8 to 31</TD></TR>
330<TR><TD>10</TD><TD>bands 12 to 31</TD></TR>
331<TR><TD>11</TD><TD>bands 16 to 31</TD></TR></TABLE>
332</TD>
333
334<TD>
335<TABLE BORDER="1" CELLSPACING="0" CELLPADING="0" WIDTH="212">
336<TR ALIGN=CENTER><TD>Intensity stereo</TD><TD>MS stereo</TD></TR>
337<TR ALIGN=CENTER><TD>off</TD><TD>off</TD></TR>
338<TR ALIGN=CENTER><TD>on</TD><TD>off</TD></TR>
339<TR ALIGN=CENTER><TD>off</TD><TD>on</TD></TR>
340<TR ALIGN=CENTER><TD>on</TD><TD>on</TD></TR></TABLE>
341</TD></TR></TABLE>
342</TD></TR>
343
344<TR VALIGN=TOP><TD>K</TD><TD>1</TD><TD>(3)</TD>
345<TD>Copyright<BR>
3460 - Audio is not copyrighted<BR>
3471 - Audio is copyrighted</TD>
348</TR>
349
350<TR VALIGN=TOP><TD>L</TD><TD>1</TD><TD>(2)</TD>
351<TD>Original<BR>
3520 - Copy of original media<BR>
3531 - Original media</TD>
354</TR>
355
356<TR VALIGN=TOP>
357<TD>M</TD><TD>2</TD><TD>(1,0)</TD>
358<TD>Emphasis<BR>
35900 - none<BR>
36001 - 50/15 ms<BR>
36110 - reserved<BR>
36211 - CCIT J.17</TD>
363</TR></TABLE>
364<P>&nbsp;</P></CENTER>
365
366<P ALIGN="center"><A NAME="MPEGTAG"></A><FONT SIZE="5"><B>MPEG Audio Tag ID3v1</B></FONT>
367<P>The TAG is used to describe the MPEG Audio file. It contains information
368about artist, title, album, publishing year and genre. There is some extra
369space for comments. It is exactly 128 bytes long and is located at very end of
370the audio data. You can get it by reading the last 128 bytes of the MPEG audio
371file.
372
373<P ALIGN="center"><FONT SIZE="5"><B><TT>
374AAABBBBB BBBBBBBB BBBBBBBB BBBBBBBB<BR>
375BCCCCCCC CCCCCCCC CCCCCCCC CCCCCCCD<BR>
376DDDDDDDD DDDDDDDD DDDDDDDD DDDDDEEE<BR>
377EFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFG<BR>
378</TT></B></FONT>
379
380<CENTER>
381
382<TABLE BORDER="0" WIDTH="500">
383<TR VALIGN=TOP BGCOLOR=#E2E2E2>
384<TD>Sign</TD><TD>Length<BR>(bytes)</TD><TD>Position<BR>
385(bytes)</TD><TD>Description</TD></TR>
386<TR VALIGN=TOP><TD>A</TD><TD>3</TD><TD>(0-2)</TD>
387<TD>Tag identification. Must contain 'TAG' if tag exists and is
388correct.</TD>
389</TR>
390<TR><TD>B</TD><TD>30</TD><TD>(3-32)</TD><TD>Title</TD></TR>
391<TR><TD>C</TD><TD>30</TD><TD>(33-62)</TD><TD>Artist</TD></TR>
392<TR><TD>D</TD><TD>30</TD><TD>(63-92)</TD><TD>Album</TD></TR>
393<TR><TD>E</TD><TD>4</TD><TD>(93-96)</TD><TD>Year</TD></TR>
394<TR><TD>F</TD><TD>30</TD><TD>(97-126)</TD><TD>Comment</TD></TR>
395<TR><TD>G</TD><TD>1</TD><TD>(127)</TD><TD>Genre</TD></TR></TABLE>
396</CENTER>
397
398<P>The specification asks for all fields to be padded with null character
399(ASCII 0). However, not all applications respect this (an example is WinAmp
400which pads fields with &lt;space&gt;, ASCII 32).
401
402<P>There is a small change proposed in <B>ID3v1.1</B> structure. The last byte
403of the Comment field may be used to specify the track number of a song in an
404album. It should contain a null character (ASCII 0) if the information is
405unknown.
406
407<P>Genre is a numeric field which may have one of the following values:
408
409<CENTER>
410<TABLE BORDER="0" WIDTH="90%">
411<TR>
412<TD WIDTH="1%">0</TD>
413<TD WIDTH="20%">'Blues'</TD>
414<TD WIDTH="1%">20</TD>
415<TD WIDTH="20%">'Alternative'</TD>
416<TD WIDTH="1%">40</TD>
417<TD WIDTH="20%">'AlternRock'</TD>
418<TD WIDTH="1%">60</TD>
419<TD WIDTH="20%">'Top 40'</TD>
420</TR>
421<TR>
422<TD>1</TD>
423<TD>'Classic Rock'</TD>
424<TD>21</TD>
425<TD>'Ska'</TD>
426<TD>41</TD>
427<TD>'Bass'</TD>
428<TD>61</TD>
429<TD>'Christian Rap'</TD>
430</TR>
431<TR>
432<TD>2</TD>
433<TD>'Country'</TD>
434<TD>22</TD>
435<TD>'Death Metal'</TD>
436<TD>42</TD>
437<TD>'Soul'</TD>
438<TD>62</TD>
439<TD>'Pop/Funk'</TD>
440</TR>
441<TR>
442<TD>3</TD>
443<TD>'Dance'</TD>
444<TD>23</TD>
445<TD>'Pranks'</TD>
446<TD>43</TD>
447<TD>'Punk'</TD>
448<TD>63</TD>
449<TD>'Jungle'</TD>
450</TR>
451<TR>
452<TD>4</TD>
453<TD>'Disco'</TD>
454<TD>24</TD>
455<TD>'Soundtrack'</TD>
456<TD>44</TD>
457<TD>'Space'</TD>
458<TD>64</TD>
459<TD>'Native American'</TD>
460</TR>
461<TR>
462<TD>5</TD>
463<TD>'Funk'</TD>
464<TD>25</TD>
465<TD>'Euro-Techno'</TD>
466<TD>45</TD>
467<TD>'Meditative'</TD>
468<TD>65</TD>
469<TD>'Cabaret'</TD>
470</TR>
471<TR>
472<TD>6</TD>
473<TD>'Grunge'</TD>
474<TD>26</TD>
475<TD>'Ambient'</TD>
476<TD>46</TD>
477<TD>'Instrumental Pop'</TD>
478<TD>66</TD>
479<TD>'New Wave'</TD>
480</TR>
481<TR>
482<TD>7</TD>
483<TD>'Hip-Hop'</TD>
484<TD>27</TD>
485<TD>'Trip-Hop'</TD>
486<TD>47</TD>
487<TD>'Instrumental Rock'</TD>
488<TD>67</TD>
489<TD>'Psychadelic'</TD>
490</TR>
491<TR>
492<TD>8</TD>
493<TD>'Jazz'</TD>
494<TD>28</TD>
495<TD>'Vocal'</TD>
496<TD>48</TD>
497<TD>'Ethnic'</TD>
498<TD>68</TD>
499<TD>'Rave'</TD>
500</TR>
501<TR>
502<TD>9</TD>
503<TD>'Metal'</TD>
504<TD>29</TD>
505<TD>'Jazz+Funk'</TD>
506<TD>49</TD>
507<TD>'Gothic'</TD>
508<TD>69</TD>
509<TD>'Showtunes'</TD>
510</TR>
511<TR>
512<TD>10</TD>
513<TD>'New Age'</TD>
514<TD>30</TD>
515<TD>'Fusion'</TD>
516<TD>50</TD>
517<TD>'Darkwave'</TD>
518<TD>70</TD>
519<TD>'Trailer'</TD>
520</TR>
521<TR>
522<TD>11</TD>
523<TD>'Oldies'</TD>
524<TD>31</TD>
525<TD>'Trance'</TD>
526<TD>51</TD>
527<TD>'Techno-Industrial'</TD>
528<TD>71</TD>
529<TD>'Lo-Fi'</TD>
530</TR>
531<TR>
532<TD>12</TD>
533<TD>'Other'</TD>
534<TD>32</TD>
535<TD>'Classical'</TD>
536<TD>52</TD>
537<TD>'Electronic'</TD>
538<TD>72</TD>
539<TD>'Tribal'</TD>
540</TR>
541<TR>
542<TD>13</TD>
543<TD>'Pop'</TD>
544<TD>33</TD>
545<TD>'Instrumental'</TD>
546<TD>53</TD>
547<TD>'Pop-Folk'</TD>
548<TD>73</TD>
549<TD>'Acid Punk'</TD>
550</TR>
551<TR>
552<TD>14</TD>
553<TD>'R&amp;B'</TD>
554<TD>34</TD>
555<TD>'Acid'</TD>
556<TD>54</TD>
557<TD>'Eurodance'</TD>
558<TD>74</TD>
559<TD>'Acid Jazz'</TD>
560</TR>
561<TR>
562<TD>15</TD>
563<TD>'Rap'</TD>
564<TD>35</TD>
565<TD>'House'</TD>
566<TD>55</TD>
567<TD>'Dream'</TD>
568<TD>75</TD>
569<TD>'Polka'</TD>
570</TR>
571<TR>
572<TD>16</TD>
573<TD>'Reggae'</TD>
574<TD>36</TD>
575<TD>'Game'</TD>
576<TD>56</TD>
577<TD>'Southern Rock'</TD>
578<TD>76</TD>
579<TD>'Retro'</TD>
580</TR>
581<TR>
582<TD>17</TD>
583<TD>'Rock'</TD>
584<TD>37</TD>
585<TD>'Sound Clip'</TD>
586<TD>57</TD>
587<TD>'Comedy'</TD>
588<TD>77</TD>
589<TD>'Musical'</TD>
590</TR>
591<TR>
592<TD>18</TD>
593<TD>'Techno'</TD>
594<TD>38</TD>
595<TD>'Gospel'</TD>
596<TD>58</TD>
597<TD>'Cult'</TD>
598<TD>78</TD>
599<TD>'Rock &amp; Roll'</TD>
600</TR>
601<TR>
602<TD>19</TD>
603<TD>'Industrial'</TD>
604<TD>39</TD>
605<TD>'Noise'</TD>
606<TD>59</TD>
607<TD>'Gangsta'</TD>
608<TD>79</TD>
609<TD>'Hard Rock'</TD>
610</TR>
611</TABLE>
612<DIV ALIGN="LEFT"><BR>
613WinAmp expanded this table with next codes: </DIV>
614<TABLE BORDER="0" WIDTH="90%">
615<TR>
616<TD WIDTH="1%">80</TD>
617<TD WIDTH="20%">'Folk'</TD>
618<TD>92</TD>
619<TD>'Progressive Rock'</TD>
620<TD>104</TD>
621<TD>'Chamber Music'</TD>
622<TD>116</TD>
623<TD>'Ballad'</TD>
624</TR>
625<TR>
626<TD>81</TD>
627<TD>'Folk-Rock'</TD>
628<TD WIDTH="1%">93</TD>
629<TD WIDTH="20%">'Psychedelic Rock'</TD>
630<TD>105</TD>
631<TD>'Sonata'</TD>
632<TD>117</TD>
633<TD>'Poweer Ballad'</TD>
634</TR>
635<TR>
636<TD>82</TD>
637<TD>'National Folk'</TD>
638<TD>94</TD>
639<TD>'Symphonic Rock'</TD>
640<TD WIDTH="1%">106</TD>
641<TD WIDTH="20%">'Symphony'</TD>
642<TD>118</TD>
643<TD>'Rhytmic Soul'</TD>
644</TR>
645<TR>
646<TD>83</TD>
647<TD>'Swing'</TD>
648<TD>95</TD>
649<TD>'Slow Rock'</TD>
650<TD>107</TD>
651<TD>'Booty Brass'</TD>
652<TD WIDTH="1%">119</TD>
653<TD WIDTH="20%">'Freestyle'</TD>
654</TR>
655<TR>
656<TD>84</TD>
657<TD>'Fast Fusion'</TD>
658<TD>96</TD>
659<TD>'Big Band'</TD>
660<TD>108</TD>
661<TD>'Primus'</TD>
662<TD>120</TD>
663<TD>'Duet'</TD>
664</TR>
665<TR>
666<TD>85</TD>
667<TD>'Bebob'</TD>
668<TD>97</TD>
669<TD>'Chorus'</TD>
670<TD>109</TD>
671<TD>'Porn Groove'</TD>
672<TD>121</TD>
673<TD>'Punk Rock'</TD>
674</TR>
675<TR>
676<TD>86</TD>
677<TD>'Latin'</TD>
678<TD>98</TD>
679<TD>'Easy Listening'</TD>
680<TD>110</TD>
681<TD>'Satire'</TD>
682<TD>122</TD>
683<TD>'Drum Solo'</TD>
684</TR>
685<TR>
686<TD>87</TD>
687<TD>'Revival'</TD>
688<TD>99</TD>
689<TD>'Acoustic'</TD>
690<TD>111</TD>
691<TD>'Slow Jam'</TD>
692<TD>123</TD>
693<TD>'A Capela'</TD>
694</TR>
695<TR>
696<TD>88</TD>
697<TD>'Celtic'</TD>
698<TD>100</TD>
699<TD>'Humour'</TD>
700<TD>112</TD>
701<TD>'Club'</TD>
702<TD>124</TD>
703<TD>'Euro-House'</TD>
704</TR>
705<TR>
706<TD>89</TD>
707<TD>'Bluegrass'</TD>
708<TD>101</TD>
709<TD>'Speech'</TD>
710<TD>113</TD>
711<TD>'Tango'</TD>
712<TD>125</TD>
713<TD>'Dance Hall'</TD>
714</TR>
715<TR>
716<TD>90</TD>
717<TD>'Avantgarde'</TD>
718<TD>102</TD>
719<TD>'Chanson'</TD>
720<TD>114</TD>
721<TD>'Samba'</TD>
722<TD>&nbsp;</TD>
723<TD>&nbsp;</TD>
724</TR>
725<TR>
726<TD>91</TD>
727<TD>'Gothic Rock'</TD>
728<TD>103</TD>
729<TD>'Opera'</TD>
730<TD>115</TD>
731<TD>'Folklore'</TD>
732<TD>&nbsp;</TD>
733<TD>&nbsp;</TD>
734</TR>
735<TR>
736<TD COLSPAN=8>Any other value should be considered as 'Unknown'
737</TABLE>
738<P>&nbsp;</P></CENTER>
739
740<P ALIGN="center"><A NAME="MPEG TAG"></A><FONT SIZE="5"><B>MPEG Audio Tag ID3v2</B></FONT>
741<P>This is new proposed TAG format which is different than ID3v1 and ID3v1.1.
742Complete tech specs for it may be found at <A
743HREF="http://www.id3.org/">http://www.id3.org/</A>.
744<P><CENTER>
745<HR>
746<P><FONT SIZE="-1"> Created on September 1998. by <A HREF="http://www.dv.co.yu/broker/">Predrag
747Supurovic</A>.<BR>
748Thanks to <A HREF="http://www.jps.net/kyunghi/">Jean</A> for debugging and polishing
749of this document, <A HREF="http://members.tripod.com/~videoripper/home.htm">Peter
750Luijer</A>, Guwani, Rob Leslie and Franc Zijderveld<BR>
751for valuable comments and corrections.</FONT></P>
752<P>&copy; 1998, 1999 Copyright by DataVoyage</P>
753<P><FONT SIZE="-1">This document may be changed. Check <A
754HREF="http://www.dv.co.yu/mpgscript/mpeghdr.htm">http://www.dv.co.yu/mpgscript/mpeghdr.htm</A>
755for updates.<BR>
756You may use it freely. Distribution is allowed only in unaltered form. If you
757can help me make it more accurate, please do. </FONT></P>
758<P>&nbsp;</P>
759</CENTER>
760
761#include "foot.t"