File: mp3gain.sgml

package info (click to toggle)
mp3gain 1.4.6-1
  • links: PTS
  • area: main
  • in suites: sarge
  • size: 532 kB
  • ctags: 735
  • sloc: ansic: 7,583; makefile: 75
file content (408 lines) | stat: -rw-r--r-- 13,031 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
<!doctype refentry PUBLIC "-//OASIS//DTD DocBook V4.2//EN" [

<!-- Process this file with docbook-to-man to generate an nroff manual
     page: `docbook-to-man manpage.sgml > manpage.1'.  You may view
     the manual page with: `docbook-to-man manpage.sgml | nroff -man |
     less'.  A typical entry in a Makefile or Makefile.am is:

manpage.1: manpage.sgml
	docbook-to-man $< > $@

    
	The docbook-to-man binary is found in the docbook-to-man package.
	Please remember that if you create the nroff version in one of the
	debian/rules file targets (such as build), you will need to include
	docbook-to-man in your Build-Depends control field.

  -->

  <!-- Fill in your name for FIRSTNAME and SURNAME. -->
  <!ENTITY dhfirstname "<firstname>STEFAN</firstname>">
  <!ENTITY dhsurname   "<surname>FRITSCH</surname>">
  <!-- Please adjust the date whenever revising the manpage. -->
  <!ENTITY dhdate      "<date>February  4, 2004</date>">
  <!-- SECTION should be 1-8, maybe w/ subsection other parameters are
       allowed: see man(7), man(1). -->
  <!ENTITY dhsection   "<manvolnum>1</manvolnum>">
  <!ENTITY dhemail     "<email>sf@sfritsch.de</email>">
  <!ENTITY dhusername  "Stefan Fritsch">
  <!ENTITY dhucpackage "<refentrytitle>MP3GAIN</refentrytitle>">
  <!ENTITY dhpackage   "mp3gain">
  <!ENTITY debian      "<productname>Debian</productname>">
  <!ENTITY gnu         "<acronym>GNU</acronym>">
  <!ENTITY lgpl         "&gnu; <acronym>LGPL</acronym>">
]>

<refentry>
  <refentryinfo>
    <address>
      &dhemail;
    </address>
    <author>
      &dhfirstname;
      &dhsurname;
    </author>
    <copyright>
      <year>2004</year>
      <holder>Glen Sawyer and &dhusername;</holder>
    </copyright>
    &dhdate;
  </refentryinfo>
  <refmeta>
    &dhucpackage;

    &dhsection;
  </refmeta>
  <refnamediv>
    <refname>&dhpackage;</refname>

    <refpurpose>lossless mp3 normalizer</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <cmdsynopsis>
      <command>&dhpackage;</command>

      <arg><option>options</option></arg>

      <arg><replaceable>infile</replaceable></arg>
      
      <arg><option><replaceable>infile 2</replaceable> ...</option></arg>
    </cmdsynopsis>
  </refsynopsisdiv>
  
  <refsect1>
    <title>DESCRIPTION</title>

    <para>This manual page documents briefly the
      <command>&dhpackage;</command>
      command.</para>

    <para>This manual page was written for the &debian; distribution
      because the original program does not have a manual page.
     </para>

    <para><command>&dhpackage;</command> analyzes and adjusts mp3 files
    so that they have the same volume.</para>
    
    <para><command>&dhpackage;</command> does not just do peak normalization,
    as many normalizers do. Instead, it does some statistical analysis to
    determine how loud the file actually sounds to the human ear. Also, the
    changes <command>&dhpackage;</command> makes are completely lossless. There
    is no quality lost in the change because the program adjusts the mp3 file
    directly, without decoding and re-encoding. Also, this works with all mp3
    players, i.e. no support for a special tag or something similar is
    required.</para>
    
    <para>The method mp3gain uses to determine the desired volume
    is described at
    <ulink url="http://www.replaygain.org/">www.replaygain.org</ulink>.
    See also <filename>/usr/share/doc/README.method</filename> .</para>
    
  


  </refsect1>
  <refsect1>
    <title>OPTIONS</title>


    <variablelist>
      <varlistentry>
        <term><option>-?</option>
          <option>-h</option>
        </term>
        <listitem>
          <para>Show summary of options.</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-g <replaceable>i</replaceable></option>
        </term>
        <listitem>
          <para>apply gain <replaceable>i</replaceable> to mp3 without
	   doing any analysis</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-l 0 <replaceable>i</replaceable></option>
        </term>
        <listitem>
          <para>apply gain <replaceable>i</replaceable> to channel 0 
	  	(left channel) of mp3
                  without doing any analysis (ONLY works for STEREO mp3s,
                  not Joint Stereo mp3s)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-l 1 <replaceable>i</replaceable></option>
        </term>
        <listitem>
          <para>apply gain <replaceable>i</replaceable> to channel 1
	  	(right channel) of mp3
                  without doing any analysis (ONLY works for STEREO mp3s,
                  not Joint Stereo mp3s)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-r</option>
        </term>
        <listitem>
          <para>apply Track gain automatically (all files set to equal loudness)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-k</option>
        </term>
        <listitem>
          <para>automatically lower Track gain to not clip audio</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-a</option>
        </term>
        <listitem>
          <para>apply Album gain automatically (files are all from the same
                      album: a single gain change is applied to all files, so
                      their loudness relative to each other remains unchanged,
                      but the average album loudness is normalized)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-m <replaceable>i</replaceable></option>
        </term>
        <listitem>
          <para>modify suggested MP3 gain by integer <replaceable>i</replaceable></para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-d <replaceable>n</replaceable></option>
        </term>
        <listitem>
          <para>modify suggested dB gain by floating-point
	  <replaceable>n</replaceable></para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-c</option>
        </term>
        <listitem>
          <para>ignore clipping warning when applying gain</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-o</option>
        </term>
        <listitem>
          <para>output is a database-friendly tab-delimited list</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-t</option>
        </term>
        <listitem>
          <para>mp3gain writes modified mp3 to temp file, then deletes original
             instead of modifying bytes in original file (This is the default in
	     Debian)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-T</option>
        </term>
        <listitem>
          <para>mp3gain modifys bytes in original file instead of
	   writing to temp file.</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-q</option>
        </term>
        <listitem>
          <para>Quiet mode: no status messages</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-p</option>
        </term>
        <listitem>
          <para>Preserve original file timestamp</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-x</option>
        </term>
        <listitem>
          <para>Only find max. amplitude of mp3</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-f</option>
        </term>
        <listitem>
          <para>Force <command>mp3gain</command> to assume input file
	  is an MPEG 2 Layer III file
             (i.e. don't check for mis-named Layer I or Layer II files)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-s c</option>
        </term>
        <listitem>
          <para>only check stored tag info (no other processing)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-s d</option>
        </term>
        <listitem>
          <para>delete stored tag info (no other processing)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-s s</option>
        </term>
        <listitem>
          <para>skip (ignore) stored tag info (do not read or write tags)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-s r</option>
        </term>
        <listitem>
          <para>force re-calculation (do not read tag info)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-u</option>
        </term>
        <listitem>
          <para>undo changes made by mp3gain (based on stored tag info)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-w</option>
        </term>
        <listitem>
          <para>"wrap" gain change if gain+change &gt; 255 or gain+change &lt; 0
              (see below or use <option>-? wrap</option> switch for a complete
	      explanation)</para>
        </listitem>
      </varlistentry>
      
      <varlistentry>
        <term><option>-v</option>
        </term>
        <listitem>
          <para>Show version of program.</para>
        </listitem>
      </varlistentry>
    </variablelist>
    <para>If you specify <option>-r</option> and <option>-a</option>,
    only the second one will work.</para>
    <para>If you do not specify <option>-c</option>, the program will
    stop and ask before
     applying gain change to a file that might clip</para>
   <refsect2><title>The WRAP option</title>
   <para>Here's the problem:
     The "global gain" field that mp3gain adjusts is an 8-bit unsigned integer, so
     the possible values are 0 to 255.
   </para><para>
     MOST mp3 files (in fact, ALL the mp3 files I've examined so far) don't go
     over 230. So there's plenty of headroom on top-- you can increase the gain
     by 37dB (multiplying the amplitude by 76) without a problem.
   </para><para>
     The problem is at the bottom of the range. Some encoders create frames with
     0 as the global gain for silent frames.
     What happens when you _lower_ the global gain by 1?
     Well, in the past, mp3gain always simply wrapped the result up to 255.
     That way, if you lowered the gain by any amount and then raised it by the
     same amount, the mp3 would always be _exactly_ the same.
   </para><para>
     There are a few encoders out there, unfortunately, that create 0-gain frames
     with other audio data in the frame.
     As long as the global gain is 0, you'll never hear the data.
     But if you lower the gain on such a file, the global gain is suddenly _huge_.
     If you play this modified file, there might be a brief, very loud blip.
   </para><para>
     So now the default behavior of mp3gain is to _not_ wrap gain changes.
     In other words,
     <orderedlist>
     <listitem><para>
        If the gain change would make a frame's global gain drop below 0,
	then the global gain is set to 0.
     </para></listitem><listitem><para>
        If the gain change would make a frame's global gain grow above 255,
	then the global gain is set to 255.
     </para></listitem><listitem><para> 
        If a frame's global gain field is already 0, it is not changed, even if
	the gain change is a positive number.
     </para></listitem>
     </orderedlist>
   </para><para>
     To use the original "wrapping" behavior, use the <option>-w</option> switch.
   </para>
   </refsect2>
  </refsect1>
  <refsect1>
    <title>SEE ALSO</title>

    <para>The homepage of mp3gain is located at
     <ulink url="http://mp3gain.sourceforge.net/">http://mp3gain.sourceforge.net/</ulink> .
    </para>
  </refsect1> 
  <refsect1>
    <title>AUTHOR</title>

    <para>This manual page was written by &dhusername; &dhemail; for
      the &debian; system (but may be used by others).  Permission is
      granted to copy, distribute and/or modify this document under
      the terms of the &gnu; Lesser General Public License, Version 2.1 or 
      any later version published by the Free Software Foundation.
    </para>
	<para>
	  On Debian systems, the complete text of the GNU Lesser General Public
	  License can be found in /usr/share/common-licenses/LGPL.
	</para>

  </refsect1>
</refentry>

<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:2
sgml-indent-data:t
sgml-parent-document:nil
sgml-default-dtd-file:nil
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
-->