lame(1) LAME audio compressor lame(1)
NAME
lame - create mp3 audio files
SYNOPSIS
lame [options] <infile> <outfile>
DESCRIPTION
LAME is a program which can be used to create compressed audio files.
(Lame ain't an MP3 encoder). These audio files can be played back by
popular MP3 players such as mpg123 or madplay. To read from stdin, use
"-" for <infile>. To write to stdout, use a "-" for <outfile>.
OPTIONS
Input options:
-r Assume the input file is raw pcm. Sampling rate and
mono/stereo/jstereo must be specified on the command line. For
each stereo sample, LAME expects the input data to be ordered
left channel first, then right channel. By default, LAME expects
them to be signed integers with a bitwidth of 16. Without -r,
LAME will perform several fseek()'s on the input file looking
for WAV and AIFF headers.
Might not be available on your release.
-x Swap bytes in the input file or output file when using --decode.
For sorting out little endian/big endian type problems. If your
encodings sounds like static, try this first.
Without using -x, LAME will treat input file as native endian.
-s sfreq
sfreq = 8/11.025/12/16/22.05/24/32/44.1/48
Required only for raw PCM input files. Otherwise it will be
determined from the header of the input file.
LAME will automatically resample the input file to one of the
supported MP3 samplerates if necessary.
--bitwidth n
Input bit width per sample.
n = 8, 16, 24, 32 (default 16)
Required only for raw PCM input files. Otherwise it will be
determined from the header of the input file.
--signed
Instructs LAME that the samples from the input are signed (the
default for 16, 24 and 32 bits raw pcm data).
Required only for raw PCM input files.
--unsigned
Instructs LAME that the samples from the input are unsigned (the
default for 8 bits raw pcm data, where 0x80 is zero).
Required only for raw PCM input files and only available at
bitwidth 8.
--little-endian
Instructs LAME that the samples from the input are in little-
endian form.
Required only for raw PCM input files.
--big-endian
Instructs LAME that the samples from the input are in big-endian
form.
Required only for raw PCM input files.
--mp2input
Assume the input file is a MPEG Layer II (ie MP2) file.
If the filename ends in ".mp2" LAME will assume it is a MPEG
Layer II file. For stdin or Layer II files which do not end in
.mp2 you need to use this switch.
--mp3input
Assume the input file is a MP3 file.
Useful for downsampling from one mp3 to another. As an example,
it can be useful for streaming through an IceCast server.
If the filename ends in ".mp3" LAME will assume it is an MP3.
For stdin or MP3 files which do not end in .mp3 you need to use
this switch.
--nogap file1 file2 ...
gapless encoding for a set of contiguous files
--nogapout dir
output dir for gapless encoding (must precede --nogap)
Operational options:
-m mode
mode = s, j, f, d, m
Joint-stereo is the default mode for stereo files with VBR when
-V is more than 4 or fixed bitrates of 160kbs or less. At
higher fixed bitrates or higher VBR settings, the default is
stereo.
(s)imple stereo
In this mode, the encoder makes no use of potentially existing
correlations between the two input channels. It can, however,
negotiate the bit demand between both channel, i.e. give one
channel more bits if the other contains silence or needs less
bits because of a lower complexity.
(j)oint stereo
In this mode, the encoder will make use of a correlation between
both channels. The signal will be matrixed into a sum ("mid"),
computed by L+R, and difference ("side") signal, computed by
L-R, and more bits are allocated to the mid channel. This will
effectively increase the bandwidth if the signal does not have
too much stereo separation, thus giving a significant gain in
encoding quality.
Using mid/side stereo inappropriately can result in audible com-
pression artifacts. To much switching between mid/side and reg-
ular stereo can also sound bad. To determine when to switch to
mid/side stereo, LAME uses a much more sophisticated algorithm
than that described in the ISO documentation, and thus is safe
to use in joint stereo mode.
(f)orced MS stereo
This mode will force MS stereo on all frames. It is slightly
faster than joint stereo, but it should be used only if you are
sure that every frame of the input file has very little stereo
separation.
(d)ual mono
In this mode, the 2 channels will be totally independently
encoded. Each channel will have exactly half of the bitrate.
This mode is designed for applications like dual languages
encoding (for example: English in one channel and French in the
other). Using this encoding mode for regular stereo files will
result in a lower quality encoding.
(m)ono
The input will be encoded as a mono signal. If it was a stereo
signal, it will be downsampled to mono. The downmix is calcu-
lated as the sum of the left and right channel, attenuated by 6
dB.
-a Mix the stereo input file to mono and encode as mono.
The downmix is calculated as the sum of the left and right chan-
nel, attenuated by 6 dB.
This option is only needed in the case of raw PCM stereo input
(because LAME cannot determine the number of channels in the
input file). To encode a stereo PCM input file as mono, use
lame -m s -a.
For WAV and AIFF input files, using -m will always produce a
mono .mp3 file from both mono and stereo input.
-d Allows the left and right channels to use different block size
types.
--freeformat
Produces a free format bitstream. With this option, you can use
-b with any bitrate higher than 8 kbps.
However, even if an mp3 decoder is required to support free
bitrates at least up to 320 kbps, many players are unable to
deal with it.
Tests have shown that the following decoders support free for-
mat:
FreeAmp up to 440 kbps
in_mpg123 up to 560 kbps
l3dec up to 310 kbps
LAME up to 560 kbps
MAD up to 640 kbps
--decode
Uses LAME for decoding to a wav file. The input file can be any
input type supported by encoding, including layer II files.
LAME uses a bugfixed version of mpglib for decoding.
If -t is used (disable wav header), LAME will output raw pcm in
native endian format. You can use -x to swap bytes order.
This option is not usable if the MP3 decoder was explicitly dis-
abled in the build of LAME.
-t Disable writing of the INFO Tag on encoding.
This tag in embedded in frame 0 of the MP3 file. It includes
some information about the encoding options of the file, and in
VBR it lets VBR aware players correctly seek and compute playing
times of VBR files.
When --decode is specified (decode to WAV), this flag will dis-
able writing of the WAV header. The output will be raw pcm,
native endian format. Use -x to swap bytes.
--comp arg
Instead of choosing bitrate, using this option, user can choose
compression ratio to achieve.
--scale n
--scale-l n
--scale-r n
Scales input (every channel, only left channel or only right
channel) by n. This just multiplies the PCM data (after it has
been converted to floating point) by n.
n > 1: increase volume
n = 1: no effect
n < 1: reduce volume
Use with care, since most MP3 decoders will truncate data which
decodes to values greater than 32768.
--replaygain-fast
Compute ReplayGain fast but slightly inaccurately.
This computes "Radio" ReplayGain on the input data stream after
user-specified volume-scaling and/or resampling.
The ReplayGain analysis does not affect the content of a com-
pressed data stream itself, it is a value stored in the header
of a sound file. Information on the purpose of ReplayGain and
the algorithms used is available from http://www.replay-
gain.org/.
Only the "RadioGain" Replaygain value is computed, it is stored
in the LAME tag. The analysis is performed with the reference
volume equal to 89dB. Note: the reference volume has been
changed from 83dB on transition from version 3.95 to 3.95.1.
This switch is enabled by default.
See also: --replaygain-accurate, --noreplaygain
--replaygain-accurate
Compute ReplayGain more accurately and find the peak sample.
This enables decoding on the fly, computes "Radio" ReplayGain on
the decoded data stream, finds the peak sample of the decoded
data stream and stores it in the file.
The ReplayGain analysis does not affect the content of a com-
pressed data stream itself, it is a value stored in the header
of a sound file. Information on the purpose of ReplayGain and
the algorithms used is available from http://www.replay-
gain.org/.
By default, LAME performs ReplayGain analysis on the input data
(after the user-specified volume scaling). This behavior might
give slightly inaccurate results because the data on the output
of a lossy compression/decompression sequence differs from the
initial input data. When --replaygain-accurate is specified the
mp3 stream gets decoded on the fly and the analysis is performed
on the decoded data stream. Although theoretically this method
gives more accurate results, it has several disadvantages:
* tests have shown that the difference between the ReplayGain
values computed on the input data and decoded data is usu-
ally not greater than 0.5dB, although the minimum volume
difference the human ear can perceive is about 1.0dB
* decoding on the fly significantly slows down the encoding
process
The apparent advantage is that:
* with --replaygain-accurate the real peak sample is deter-
mined and stored in the file. The knowledge of the peak
sample can be useful to decoders (players) to prevent a
negative effect called 'clipping' that introduces distor-
tion into the sound.
Only the "RadioGain" ReplayGain value is computed, it is stored
in the LAME tag. The analysis is performed with the reference
volume equal to 89dB. Note: the reference volume has been
changed from 83dB on transition from version 3.95 to 3.95.1.
This option is not usable if the MP3 decoder was explicitly dis-
abled in the build of LAME. (Note: if LAME is compiled without
the MP3 decoder, ReplayGain analysis is performed on the input
data after user-specified volume scaling).
See also: --replaygain-fast, --noreplaygain --clipdetect
--noreplaygain
Disable ReplayGain analysis.
By default ReplayGain analysis is enabled. This switch disables
it.
See also: --replaygain-fast, --replaygain-accurate
--clipdetect
Clipping detection.
Enable --replaygain-accurate and print a message whether clip-
ping occurs and how far in dB the waveform is from full scale.
This option is not usable if the MP3 decoder was explicitly dis-
abled in the build of LAME.
See also: --replaygain-accurate
--preset [fast] type | [cbr] kbps
Use one of the built-in presets.
Have a look at the PRESETS section below.
--preset help gives more infos about the the used options in
these presets.
--preset [fast] type | [cbr] kbps
Use one of the built-in presets.
--noasm type
Disable specific assembly optimizations ( mmx / 3dnow / sse ).
Quality will not increase, only speed will be reduced. If you
have problems running Lame on a Cyrix/Via processor, disabling
mmx optimizations might solve your problem.
Verbosity:
--disptime n
Set the delay in seconds between two display updates.
--nohist
By default, LAME will display a bitrate histogram while produc-
ing VBR mp3 files. This will disable that feature.
Histogram display might not be available on your release.
-S
--silent
--quiet
Do not print anything on the screen.
--verbose
Print a lot of information on the screen.
--help Display a list of available options.
Noise shaping & psycho acoustic algorithms:
-q qual
0 <= qual <= 9
Bitrate is of course the main influence on quality. The higher
the bitrate, the higher the quality. But for a given bitrate,
we have a choice of algorithms to determine the best scalefac-
tors and Huffman encoding (noise shaping).
-q 0:
use slowest & best possible version of all algorithms. -q 0 and
-q 1 are slow and may not produce significantly higher quality.
-q 2:
recommended. Same as -h.
-q 5:
default value. Good speed, reasonable quality.
-q 7:
same as -f. Very fast, ok quality. Psycho acoustics are used
for pre-echo & M/S, but no noise shaping is done.
-q 9:
disables almost all algorithms including psy-model. Poor qual-
ity.
-h Use some quality improvements. Encoding will be slower, but the
result will be of higher quality. The behavior is the same as
the -q 2 switch.
This switch is always enabled when using VBR.
-f This switch forces the encoder to use a faster encoding mode,
but with a lower quality. The behavior is the same as the -q 7
switch.
Noise shaping will be disabled, but psycho acoustics will still
be computed for bit allocation and pre-echo detection.
CBR (constant bitrate, the default) options:
-b n For MPEG-1 (sampling frequencies of 32, 44.1 and 48 kHz)
n = 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256,
320
For MPEG-2 (sampling frequencies of 16, 22.05 and 24 kHz)
n = 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160
For MPEG-2.5 (sampling frequencies of 8, 11.025 and 12 kHz)
n = 8, 16, 24, 32, 40, 48, 56, 64
Default is 128 for MPEG1 and 64 for MPEG2.
--cbr enforce use of constant bitrate
ABR (average bitrate) options:
--abr n
Turns on encoding with a targeted average bitrate of n kbits,
allowing to use frames of different sizes. The allowed range of
n is 8 - 310, you can use any integer value within that range.
It can be combined with the -b and -B switches like: lame --abr
123 -b 64 -B 192 a.wav a.mp3 which would limit the allowed frame
sizes between 64 and 192 kbits.
The use of -B is NOT RECOMMENDED. A 128 kbps CBR bitstream,
because of the bit reservoir, can actually have frames which use
as many bits as a 320 kbps frame. VBR modes minimize the use of
the bit reservoir, and thus need to allow 320 kbps frames to get
the same flexibility as CBR streams.
VBR (variable bitrate) options:
-v use variable bitrate (--vbr-new)
--vbr-old
Invokes the oldest, most tested VBR algorithm. It produces very
good quality files, though is not very fast. This has, up
through v3.89, been considered the "workhorse" VBR algorithm.
--vbr-new
Invokes the newest VBR algorithm. During the development of
version 3.90, considerable tuning was done on this algorithm,
and it is now considered to be on par with the original --vbr-
old. It has the added advantage of being very fast (over twice
as fast as --vbr-old).
-V n 0 <= n <= 9
Enable VBR (Variable BitRate) and specifies the value of VBR
quality (default = 4). 0 = highest quality.
ABR and VBR options:
-b bitrate
For MPEG-1 (sampling frequencies of 32, 44.1 and 48 kHz)
n = 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256,
320
For MPEG-2 (sampling frequencies of 16, 22.05 and 24 kHz)
n = 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160
For MPEG-2.5 (sampling frequencies of 8, 11.025 and 12 kHz)
n = 8, 16, 24, 32, 40, 48, 56, 64
Specifies the minimum bitrate to be used. However, in order to
avoid wasted space, the smallest frame size available will be
used during silences.
-B bitrate
For MPEG-1 (sampling frequencies of 32, 44.1 and 48 kHz)
n = 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256,
320
For MPEG-2 (sampling frequencies of 16, 22.05 and 24 kHz)
n = 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160
For MPEG-2.5 (sampling frequencies of 8, 11.025 and 12 kHz)
n = 8, 16, 24, 32, 40, 48, 56, 64
Specifies the maximum allowed bitrate.
Note: If you own an mp3 hardware player build upon a MAS 3503
chip, you must set maximum bitrate to no more than 224 kpbs.
-F Strictly enforce the -b option.
This is mainly for use with hardware players that do not support
low bitrate mp3.
Without this option, the minimum bitrate will be ignored for
passages of analog silence, i.e. when the music level is below
the absolute threshold of human hearing (ATH).
PSY related:
--nssafejoint
M/S switching criterion
--nsmsfix arg
M/S switching tuning [effective 0-3.5]
--ns-bass x
Adjust masking for sfbs 0 - 6 (long) 0 - 5 (short)
--ns-alto x
Adjust masking for sfbs 7 - 13 (long) 6 - 10 (short)
--ns-treble x
Adjust masking for sfbs 14 - 21 (long) 11 - 12 (short)
--ns-sfb21 x
Change ns-treble by x dB for sfb21
Experimental options:
-X n 0 <= n <= 7
When LAME searches for a "good" quantization, it has to compare
the actual one with the best one found so far. The comparison
says which one is better, the best so far or the actual. The -X
parameter selects between different approaches to make this
decision, -X0 being the default mode:
-X0
The criterions are (in order of importance):
* less distorted scalefactor bands
* the sum of noise over the thresholds is lower
* the total noise is lower
-X1
The actual is better if the maximum noise over all scalefactor
bands is less than the best so far.
-X2
The actual is better if the total sum of noise is lower than the
best so far.
-X3
The actual is better if the total sum of noise is lower than the
best so far and the maximum noise over all scalefactor bands is
less than the best so far plus 2dB.
-X4
Not yet documented.
-X5
The criterions are (in order of importance):
* the sum of noise over the thresholds is lower
* the total sum of noise is lower
-X6
The criterions are (in order of importance):
* the sum of noise over the thresholds is lower
* the maximum noise over all scalefactor bands is lower
* the total sum of noise is lower
-X7
The criterions are:
* less distorted scalefactor bands
or
* the sum of noise over the thresholds is lower
-Y lets LAME ignore noise in sfb21, like in CBR
MP3 header/stream options:
-e emp emp = n, 5, c
n = (none, default)
5 = 0/15 microseconds
c = citt j.17
All this does is set a flag in the bitstream. If you have a PCM
input file where one of the above types of (obsolete) emphasis
has been applied, you can set this flag in LAME. Then the mp3
decoder should de-emphasize the output during playback, although
most decoders ignore this flag.
A better solution would be to apply the de-emphasis with a
standalone utility before encoding, and then encode without -e.
-c Mark the encoded file as being copyrighted.
-o Mark the encoded file as being a copy.
-p Turn on CRC error protection.
It will add a cyclic redundancy check (CRC) code in each frame,
allowing to detect transmission errors that could occur on the
MP3 stream. However, it takes 16 bits per frame that would oth-
erwise be used for encoding, and then will slightly reduce the
sound quality.
--nores
Disable the bit reservoir. Each frame will then become indepen-
dent from previous ones, but the quality will be lower.
--strictly-enforce-ISO
With this option, LAME will enforce the 7680 bit limitation on
total frame size.
This results in many wasted bits for high bitrate encodings but
will ensure strict ISO compatibility. This compatibility might
be important for hardware players.
Filter options:
--lowpass freq
Set a lowpass filtering frequency in kHz. Frequencies above the
specified one will be cutoff.
--lowpass-width freq
Set the width of the lowpass filter. The default value is 15%
of the lowpass frequency.
--highpass freq
Set an highpass filtering frequency in kHz. Frequencies below
the specified one will be cutoff.
--highpass-width freq
Set the width of the highpass filter in kHz. The default value
is 15% of the highpass frequency.
--resample sfreq
sfreq = 8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48
Select output sampling frequency (only supported for encoding).
If not specified, LAME will automatically resample the input
when using high compression ratios.
ID3 tag options:
--tt title
audio/song title (max 30 chars for version 1 tag)
--ta artist
audio/song artist (max 30 chars for version 1 tag)
--tl album
audio/song album (max 30 chars for version 1 tag)
--ty year
audio/song year of issue (1 to 9999)
--tc comment
user-defined text (max 30 chars for v1 tag, 28 for v1.1)
--tn track[/total]
audio/song track number and (optionally) the total number of
tracks on the original recording. (track and total each 1 to
255. Providing just the track number creates v1.1 tag, providing
a total forces v2.0).
--tg genre
audio/song genre (name or number in list)
--add-id3v2
force addition of version 2 tag
--id3v1-only
add only a version 1 tag
--id3v2-only
add only a version 2 tag
--space-id3v1
pad version 1 tag with spaces instead of nulls
--pad-id3v2
same as --pad-id3v2-size 128
--pad-id3v2-size num
adds version 2 tag, pad with extra "num" bytes
--genre-list
print alphabetically sorted ID3 genre list and exit
--ignore-tag-errors
ignore errors in values passed for tags, use defaults in case an
error occurs
Analysis options:
-g run graphical analysis on <infile>. <infile> can also be a .mp3
file. (This feature is a compile time option. Your binary may
for speed reasons be compiled without this.)
ID3 TAGS
LAME is able to embed ID3 v1, v1.1 or v2 tags inside the encoded MP3
file. This allows to have some useful information about the music
track included inside the file. Those data can be read by most MP3
players.
Lame will smartly choose which tags to use. It will add ID3 v2 tags
only if the input comments won't fit in v1 or v1.1 tags, i.e. if they
are more than 30 characters. In this case, both v1 and v2 tags will be
added, to ensure reading of tags by MP3 players which are unable to
read ID3 v2 tags.
ENCODING MODES
LAME is able to encode your music using one of its 3 encoding modes:
constant bitrate (CBR), average bitrate (ABR) and variable bitrate
(VBR).
Constant Bitrate (CBR)
This is the default encoding mode, and also the most basic. In
this mode, the bitrate will be the same for the whole file. It
means that each part of your mp3 file will be using the same
number of bits. The musical passage being a difficult one to
encode or an easy one, the encoder will use the same bitrate, so
the quality of your mp3 is variable. Complex parts will be of a
lower quality than the easiest ones. The main advantage is that
the final files size won't change and can be accurately pre-
dicted.
Average Bitrate (ABR)
In this mode, you choose the encoder will maintain an average
bitrate while using higher bitrates for the parts of your music
that need more bits. The result will be of higher quality than
CBR encoding but the average file size will remain predictable,
so this mode is highly recommended over CBR. This encoding mode
is similar to what is referred as vbr in AAC or Liquid Audio (2
other compression technologies).
Variable bitrate (VBR)
In this mode, you choose the desired quality on a scale from 9
(lowest quality/biggest distortion) to 0 (highest quality/lowest
distortion). Then encoder tries to maintain the given quality
in the whole file by choosing the optimal number of bits to
spend for each part of your music. The main advantage is that
you are able to specify the quality level that you want to
reach, but the inconvenient is that the final file size is
totally unpredictable.
PRESETS
The --preset switches are aliases over LAME settings.
To activate these presets:
For VBR modes (generally highest quality):
--preset medium
This preset should provide near transparency to most people on
most music.
--preset standard
This preset should generally be transparent to most people on
most music and is already quite high in quality.
--preset extreme
If you have extremely good hearing and similar equipment, this
preset will generally provide slightly higher quality than the
standard mode.
For CBR 320kbps (highest quality possible from the --preset switches):
--preset insane
This preset will usually be overkill for most people and most
situations, but if you must have the absolute highest quality
with no regard to filesize, this is the way to go.
For ABR modes (high quality per given bitrate but not as high as VBR):
--preset kbps
Using this preset will usually give you good quality at a speci-
fied bitrate. Depending on the bitrate entered, this preset
will determine the optimal settings for that particular situa-
tion. While this approach works, it is not nearly as flexible
as VBR, and usually will not attain the same level of quality as
VBR at higher bitrates.
The following options are also available for the corresponding pro-
files:
fast standard|extreme
cbr kbps
fast Enables the new fast VBR for a particular profile.
cbr If you use the ABR mode (read above) with a significant bitrate
such as 80, 96, 112, 128, 160, 192, 224, 256, 320, you can use
the cbr option to force CBR mode encoding instead of the stan-
dard ABR mode. ABR does provide higher quality but CBR may be
useful in situations such as when streaming an MP3 over the
Internet may be important.
EXAMPLES
Fixed bit rate jstereo 128kbs encoding:
lame sample.wav sample.mp3
Fixed bit rate jstereo 128 kbps encoding, highest quality (recom-
mended):
lame -h sample.wav sample.mp3
Fixed bit rate jstereo 112 kbps encoding:
lame -b 112 sample.wav sample.mp3
To disable joint stereo encoding (slightly faster, but less quality at
bitrates <= 128 kbps):
lame -m s sample.wav sample.mp3
Fast encode, low quality (no psycho-acoustics):
lame -f sample.wav sample.mp3
Variable bitrate (use -V n to adjust quality/filesize):
lame -h -V 6 sample.wav sample.mp3
Streaming mono 22.05 kHz raw pcm, 24 kbps output:
cat inputfile | lame -r -m m -b 24 -s 22.05 - - > output
Streaming mono 44.1 kHz raw pcm, with downsampling to 22.05 kHz:
cat inputfile | lame -r -m m -b 24 --resample 22.05 - - > output
Encode with the fast standard preset:
lame --preset fast standard sample.wav sample.mp3
BUGS
Probably there are some.
SEE ALSO
mpg123(1), madplay(1), sox(1)
AUTHORS
LAME originally developed by Mike Cheng and now maintained by
Mark Taylor, and the LAME team.
GPSYCHO psycho-acoustic model by Mark Taylor.
(See http://www.mp3dev.org/).
mpglib by Michael Hipp
Manual page by William Schelter, Nils Faerber, Alexander Leidinger,
and Rogerio Brito.
LAME 3.98 July 08, 2008 lame(1)
lame 3.98.4 - Generated Sat Nov 6 06:39:10 CDT 2010