1141 lines
27 KiB
Groff
1141 lines
27 KiB
Groff
.TH lame 1 "July 08, 2008" "LAME 3.99" "LAME audio compressor"
|
|
.SH NAME
|
|
lame \- create mp3 audio files
|
|
.SH SYNOPSIS
|
|
lame [options] <infile> <outfile>
|
|
.SH DESCRIPTION
|
|
.PP
|
|
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 "\-" for <outfile>.
|
|
.SH OPTIONS
|
|
Input options:
|
|
.TP
|
|
.B \-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
|
|
.B \-r,
|
|
LAME will perform several
|
|
.I fseek()'s
|
|
on the input file looking for WAV and AIFF headers.
|
|
.br
|
|
Might not be available on your release.
|
|
.TP
|
|
.B \-x
|
|
Swap bytes in the input file or output file when using
|
|
.B \-\-decode.
|
|
.br
|
|
For sorting out little endian/big endian type problems.
|
|
If your encodings sounds like static,
|
|
try this first.
|
|
.br
|
|
Without using
|
|
.B \-x,
|
|
LAME will treat input file as native endian.
|
|
.TP
|
|
.BI \-s " sfreq"
|
|
.I 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.
|
|
.TP
|
|
.BI \-\-bitwidth " n"
|
|
Input bit width per sample.
|
|
.br
|
|
.I 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.
|
|
.TP
|
|
.BI \-\-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.
|
|
.TP
|
|
.BI \-\-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.
|
|
.TP
|
|
.BI \-\-little-endian
|
|
Instructs LAME that the samples from the input are in little-endian form.
|
|
|
|
Required only for raw PCM input files.
|
|
.TP
|
|
.BI \-\-big-endian
|
|
Instructs LAME that the samples from the input are in big-endian form.
|
|
|
|
Required only for raw PCM input files.
|
|
.TP
|
|
.B \-\-mp2input
|
|
Assume the input file is a MPEG Layer II (ie MP2) file.
|
|
.br
|
|
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.
|
|
.TP
|
|
.B \-\-mp3input
|
|
Assume the input file is a MP3 file.
|
|
.br
|
|
Useful for downsampling from one mp3 to another.
|
|
As an example,
|
|
it can be useful for streaming through an IceCast server.
|
|
.br
|
|
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.
|
|
.TP
|
|
.BI \-\-nogap " file1 file2 ..."
|
|
gapless encoding for a set of contiguous files
|
|
.TP
|
|
.BI \-\-nogapout " dir"
|
|
output dir for gapless encoding (must precede \-\-nogap)
|
|
|
|
.PP
|
|
Operational options:
|
|
.TP
|
|
.BI \-m " mode"
|
|
.I mode
|
|
= s, j, f, d, m, l, r
|
|
|
|
Joint-stereo is the default mode for stereo files with VBR when
|
|
.B \-V
|
|
is more than 4 or fixed bitrates of 160kbs or less.
|
|
At higher fixed bitrates or higher VBR settings,
|
|
the default is stereo.
|
|
|
|
.B (s)imple stereo
|
|
.br
|
|
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.
|
|
|
|
.B (j)oint stereo
|
|
.br
|
|
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
|
|
compression artifacts.
|
|
To much switching between mid/side and regular 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.
|
|
|
|
.B (f)orced MS stereo
|
|
.br
|
|
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.
|
|
|
|
.B (d)ual mono
|
|
.br
|
|
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.
|
|
|
|
.B (m)ono
|
|
.br
|
|
The input will be encoded as a mono signal.
|
|
If it was a stereo signal,
|
|
it will be downsampled to mono.
|
|
The downmix is calculated as the sum of the left and right channel,
|
|
attenuated by 6 dB.
|
|
|
|
.B (l)eft channel only
|
|
.br
|
|
The input will be encoded as a mono signal.
|
|
If it was a stereo signal,
|
|
the left channel will be encoded only.
|
|
|
|
.B (r)ight channel only
|
|
.br
|
|
The input will be encoded as a mono signal.
|
|
If it was a stereo signal,
|
|
the right channel will be encoded only.
|
|
|
|
.TP
|
|
.B \-a
|
|
Mix the stereo input file to mono and encode as mono.
|
|
.br
|
|
The downmix is calculated as the sum of the left and right channel,
|
|
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
|
|
.B lame \-m
|
|
.I s
|
|
.B \-a.
|
|
|
|
For WAV and AIFF input files,
|
|
using
|
|
.B \-m
|
|
will always produce a mono .mp3 file from both mono and stereo input.
|
|
.TP
|
|
.B \-d
|
|
Allows the left and right channels to use different block size types.
|
|
.TP
|
|
.B \-\-freeformat
|
|
Produces a free format bitstream.
|
|
With this option,
|
|
you can use
|
|
.B \-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 format:
|
|
.br
|
|
.B FreeAmp
|
|
up to 440 kbps
|
|
.br
|
|
.B in_mpg123
|
|
up to 560 kbps
|
|
.br
|
|
.B l3dec
|
|
up to 310 kbps
|
|
.br
|
|
.B LAME
|
|
up to 560 kbps
|
|
.br
|
|
.B MAD
|
|
up to 640 kbps
|
|
.TP
|
|
.B \-\-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
|
|
.B \-t
|
|
is used (disable wav header),
|
|
LAME will output raw pcm in native endian format.
|
|
You can use
|
|
.B \-x
|
|
to swap bytes order.
|
|
|
|
This option is not usable if the MP3 decoder was
|
|
.B explicitly
|
|
disabled in the build of LAME.
|
|
.TP
|
|
.BI \-t
|
|
Disable writing of the INFO Tag on encoding.
|
|
.br
|
|
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
|
|
.B \-\-decode
|
|
is specified (decode to WAV),
|
|
this flag will disable writing of the WAV header.
|
|
The output will be raw pcm,
|
|
native endian format.
|
|
Use
|
|
.B \-x
|
|
to swap bytes.
|
|
.TP
|
|
.BI \-\-comp " arg"
|
|
Instead of choosing bitrate,
|
|
using this option,
|
|
user can choose compression ratio to achieve.
|
|
.TP
|
|
.BI \-\-scale " n"
|
|
.PD 0
|
|
.TP
|
|
.BI \-\-scale\-l " n"
|
|
.TP
|
|
.BI \-\-scale\-r " n"
|
|
Scales input (every channel, only left channel or only right channel) by
|
|
.I n.
|
|
This just multiplies the PCM data (after it has been converted to floating
|
|
point) by
|
|
.I n.
|
|
|
|
.I n
|
|
> 1: increase volume
|
|
.br
|
|
.I n
|
|
= 1: no effect
|
|
.br
|
|
.I n
|
|
< 1: reduce volume
|
|
|
|
Use with care,
|
|
since most MP3 decoders will truncate data which decodes to values
|
|
greater than 32768.
|
|
.PD
|
|
.TP
|
|
.B \-\-replaygain\-fast
|
|
Compute ReplayGain fast but slightly inaccurately.
|
|
|
|
This computes "Radio" ReplayGain on the input data stream after
|
|
user\(hyspecified volume\(hyscaling and/or resampling.
|
|
|
|
The ReplayGain analysis does
|
|
.I not
|
|
affect the content of a compressed 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
|
|
.B http://www.replaygain.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:
|
|
.B \-\-replaygain\-accurate, \-\-noreplaygain
|
|
.TP
|
|
.B \-\-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
|
|
.I not
|
|
affect the content of a compressed 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
|
|
.B http://www.replaygain.org/.
|
|
|
|
|
|
By default, LAME performs ReplayGain analysis on the input data
|
|
(after the user\(hyspecified 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
|
|
.B \-\-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:
|
|
.RS 8
|
|
.IP "*" 4
|
|
tests have shown that the difference between the ReplayGain values computed
|
|
on the input data and decoded data is usually not greater than 0.5dB,
|
|
although the minimum volume difference the human ear can perceive is
|
|
about 1.0dB
|
|
.IP "*" 4
|
|
decoding on the fly significantly slows down the encoding process
|
|
.RE
|
|
.RS 7
|
|
|
|
The apparent advantage is that:
|
|
.RE
|
|
.RS 8
|
|
.IP "*" 4
|
|
with
|
|
.B \-\-replaygain-accurate
|
|
the real peak sample is determined 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 distortion
|
|
into the sound.
|
|
.RE
|
|
.RS 7
|
|
|
|
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
|
|
.B explicitly
|
|
disabled 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:
|
|
.B \-\-replaygain-fast, \-\-noreplaygain \-\-clipdetect
|
|
.RE
|
|
.TP
|
|
.B \-\-noreplaygain
|
|
Disable ReplayGain analysis.
|
|
|
|
By default ReplayGain analysis is enabled. This switch disables it.
|
|
|
|
See also:
|
|
.B \-\-replaygain-fast, \-\-replaygain-accurate
|
|
.TP
|
|
.B \-\-clipdetect
|
|
Clipping detection.
|
|
|
|
Enable
|
|
.B \-\-replaygain-accurate
|
|
and print a message whether clipping occurs and how far in dB the waveform
|
|
is from full scale.
|
|
|
|
This option is not usable if the MP3 decoder was
|
|
.B explicitly
|
|
disabled in the build of LAME.
|
|
|
|
See also:
|
|
.B \-\-replaygain-accurate
|
|
.TP
|
|
.B \-\-preset " type | [cbr] kbps"
|
|
Use one of the built-in presets.
|
|
|
|
Have a look at the PRESETS section below.
|
|
|
|
.B \-\-preset help
|
|
gives more infos about the the used options in these presets.
|
|
.TP
|
|
.B \-\-preset " type | [cbr] kbps"
|
|
Use one of the built-in presets.
|
|
.TP
|
|
.B \-\-noasm " type"
|
|
Disable specific assembly optimizations (
|
|
.B mmx
|
|
/
|
|
.B 3dnow
|
|
/
|
|
.B 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.
|
|
|
|
.PP
|
|
Verbosity:
|
|
.TP
|
|
.BI \-\-disptime " n"
|
|
Set the delay in seconds between two display updates.
|
|
.TP
|
|
.B \-\-nohist
|
|
By default,
|
|
LAME will display a bitrate histogram while producing VBR mp3 files.
|
|
This will disable that feature.
|
|
.br
|
|
Histogram display might not be available on your release.
|
|
.TP
|
|
.B -S
|
|
.PD 0
|
|
.TP
|
|
.B \-\-silent
|
|
.TP
|
|
.B \-\-quiet
|
|
Do not print anything on the screen.
|
|
.PD
|
|
.TP
|
|
.B \-\-verbose
|
|
Print a lot of information on the screen.
|
|
.TP
|
|
.B \-\-help
|
|
Display a list of available options.
|
|
|
|
.PP
|
|
Noise shaping & psycho acoustic algorithms:
|
|
.TP
|
|
.BI -q " qual"
|
|
0 <=
|
|
.I 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 scalefactors
|
|
and Huffman encoding (noise shaping).
|
|
|
|
.B -q 0:
|
|
.br
|
|
use slowest & best possible version of all algorithms.
|
|
.B -q 0
|
|
and
|
|
.B -q 1
|
|
are slow and may not produce significantly higher quality.
|
|
|
|
.B -q 2:
|
|
.br
|
|
recommended.
|
|
Same as
|
|
.B -h.
|
|
|
|
.B -q 5:
|
|
.br
|
|
default value.
|
|
Good speed,
|
|
reasonable quality.
|
|
|
|
.B -q 7:
|
|
.br
|
|
same as
|
|
.B -f.
|
|
Very fast,
|
|
ok quality.
|
|
Psycho acoustics are used for pre-echo & M/S,
|
|
but no noise shaping is done.
|
|
|
|
.B -q 9:
|
|
.br
|
|
disables almost all algorithms including psy-model.
|
|
Poor quality.
|
|
.TP
|
|
.B -h
|
|
Use some quality improvements.
|
|
Encoding will be slower,
|
|
but the result will be of higher quality.
|
|
The behavior is the same as the
|
|
.B -q 2
|
|
switch.
|
|
.br
|
|
This switch is always enabled when using VBR.
|
|
.TP
|
|
.B -f
|
|
This switch forces the encoder to use a faster encoding mode,
|
|
but with a lower quality.
|
|
The behavior is the same as the
|
|
.B -q 7
|
|
switch.
|
|
|
|
Noise shaping will be disabled,
|
|
but psycho acoustics will still be computed for bit allocation
|
|
and pre-echo detection.
|
|
|
|
.PP
|
|
CBR (constant bitrate, the default) options:
|
|
.TP
|
|
.BI -b " n"
|
|
For MPEG-1 (sampling frequencies of 32, 44.1 and 48 kHz)
|
|
.br
|
|
.I 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)
|
|
.br
|
|
.I 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)
|
|
.br
|
|
.I n
|
|
= 8, 16, 24, 32, 40, 48, 56, 64
|
|
|
|
Default is 128 for MPEG1 and 64 for MPEG2.
|
|
.TP
|
|
.BI \-\-cbr
|
|
enforce use of constant bitrate
|
|
|
|
.PP
|
|
ABR (average bitrate) options:
|
|
.TP
|
|
.BI \-\-abr " n"
|
|
Turns on encoding with a targeted average bitrate of n kbits,
|
|
allowing to use frames of different sizes.
|
|
The allowed range of
|
|
.I n
|
|
is 8 - 310,
|
|
you can use any integer value within that range.
|
|
|
|
It can be combined with the
|
|
.B -b
|
|
and
|
|
.B -B
|
|
switches like:
|
|
.B lame \-\-abr
|
|
.I 123
|
|
.B -b
|
|
.I 64
|
|
.B -B
|
|
.I 192 a.wav a.mp3
|
|
which would limit the allowed frame sizes between 64 and 192 kbits.
|
|
|
|
The use of
|
|
.B -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.
|
|
|
|
.PP
|
|
VBR (variable bitrate) options:
|
|
.TP
|
|
.B -v
|
|
use variable bitrate
|
|
.B (\-\-vbr-new)
|
|
.TP
|
|
.B \-\-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.
|
|
.TP
|
|
.B \-\-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
|
|
.B \-\-vbr-old.
|
|
It has the added advantage of being very fast (over twice as fast as
|
|
.B \-\-vbr-old).
|
|
.TP
|
|
.BI -V " n"
|
|
0 <=
|
|
.I n
|
|
<= 9
|
|
.br
|
|
Enable VBR (Variable BitRate) and specifies the value of VBR quality
|
|
(default = 4).
|
|
0 = highest quality.
|
|
|
|
.PP
|
|
ABR and VBR options:
|
|
.TP
|
|
.BI -b " bitrate"
|
|
For MPEG-1 (sampling frequencies of 32, 44.1 and 48 kHz)
|
|
.br
|
|
.I 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)
|
|
.br
|
|
.I 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)
|
|
.br
|
|
.I 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.
|
|
.TP
|
|
.BI -B " bitrate"
|
|
For MPEG-1 (sampling frequencies of 32, 44.1 and 48 kHz)
|
|
.br
|
|
.I 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)
|
|
.br
|
|
.I 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)
|
|
.br
|
|
.I 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.
|
|
.TP
|
|
.B -F
|
|
Strictly enforce the
|
|
.B -b
|
|
option.
|
|
.br
|
|
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).
|
|
|
|
.PP
|
|
Experimental options:
|
|
.TP
|
|
.BI -X " n"
|
|
0 <=
|
|
.I 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
|
|
.B -X
|
|
parameter selects between different approaches to make this decision,
|
|
.B -X0
|
|
being the default mode:
|
|
|
|
.B -X0
|
|
.br
|
|
The criteria are (in order of importance):
|
|
.br
|
|
* less distorted scalefactor bands
|
|
.br
|
|
* the sum of noise over the thresholds is lower
|
|
.br
|
|
* the total noise is lower
|
|
|
|
.B -X1
|
|
.br
|
|
The actual is better if the maximum noise over all scalefactor bands is
|
|
less than the best so far.
|
|
|
|
.B -X2
|
|
.br
|
|
The actual is better if the total sum of noise is lower than the best so
|
|
far.
|
|
|
|
.B -X3
|
|
.br
|
|
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.
|
|
|
|
.B -X4
|
|
.br
|
|
Not yet documented.
|
|
|
|
.B -X5
|
|
.br
|
|
The criteria are (in order of importance):
|
|
.br
|
|
* the sum of noise over the thresholds is lower
|
|
.br
|
|
* the total sum of noise is lower
|
|
|
|
.B -X6
|
|
.br
|
|
The criteria are (in order of importance):
|
|
.br
|
|
* the sum of noise over the thresholds is lower
|
|
.br
|
|
* the maximum noise over all scalefactor bands is lower
|
|
.br
|
|
* the total sum of noise is lower
|
|
|
|
.B -X7
|
|
.br
|
|
The criteria are:
|
|
.br
|
|
* less distorted scalefactor bands
|
|
.br
|
|
or
|
|
.br
|
|
* the sum of noise over the thresholds is lower
|
|
.TP
|
|
.B -Y
|
|
lets LAME ignore noise in sfb21, like in CBR
|
|
|
|
.PP
|
|
MP3 header/stream options:
|
|
.TP
|
|
.BI -e " emp"
|
|
.I emp
|
|
= n, 5, c
|
|
|
|
n = (none, default)
|
|
.br
|
|
5 = 0/15 microseconds
|
|
.br
|
|
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
|
|
.B -e.
|
|
.TP
|
|
.B -c
|
|
Mark the encoded file as being copyrighted.
|
|
.TP
|
|
.B -o
|
|
Mark the encoded file as being a copy.
|
|
.TP
|
|
.B -p
|
|
Turn on CRC error protection.
|
|
.br
|
|
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 otherwise be used for encoding,
|
|
and then will slightly reduce the sound quality.
|
|
.TP
|
|
.B \-\-nores
|
|
Disable the bit reservoir.
|
|
Each frame will then become independent from previous ones,
|
|
but the quality will be lower.
|
|
.TP
|
|
.B \-\-strictly-enforce-ISO
|
|
With this option,
|
|
LAME will enforce the 7680 bit limitation on total frame size.
|
|
.br
|
|
This results in many wasted bits for high bitrate encodings but will
|
|
ensure strict ISO compatibility.
|
|
This compatibility might be important for hardware players.
|
|
|
|
.PP
|
|
Filter options:
|
|
.TP
|
|
.BI \-\-lowpass " freq"
|
|
Set a lowpass filtering frequency in kHz.
|
|
Frequencies above the specified one will be cutoff.
|
|
.TP
|
|
.BI \-\-lowpass-width " freq"
|
|
Set the width of the lowpass filter.
|
|
The default value is 15% of the lowpass frequency.
|
|
.TP
|
|
.BI \-\-highpass " freq"
|
|
Set an highpass filtering frequency in kHz.
|
|
Frequencies below the specified one will be cutoff.
|
|
.TP
|
|
.BI \-\-highpass-width " freq"
|
|
Set the width of the highpass filter in kHz.
|
|
The default value is 15% of the highpass frequency.
|
|
.TP
|
|
.BI \-\-resample " sfreq"
|
|
.I sfreq
|
|
= 8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48
|
|
.br
|
|
Select output sampling frequency (only supported for encoding).
|
|
.br
|
|
If not specified,
|
|
LAME will automatically resample the input when using high compression ratios.
|
|
|
|
.PP
|
|
ID3 tag options:
|
|
.TP
|
|
.BI \-\-tt " title"
|
|
audio/song title (max 30 chars for version 1 tag)
|
|
.TP
|
|
.BI \-\-ta " artist"
|
|
audio/song artist (max 30 chars for version 1 tag)
|
|
.TP
|
|
.BI \-\-tl " album"
|
|
audio/song album (max 30 chars for version 1 tag)
|
|
.TP
|
|
.BI \-\-ty " year"
|
|
audio/song year of issue (1 to 9999)
|
|
.TP
|
|
.BI \-\-tc " comment"
|
|
user-defined text (max 30 chars for v1 tag, 28 for v1.1)
|
|
.TP
|
|
.BI \-\-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).
|
|
.TP
|
|
.BI \-\-tg " genre"
|
|
audio/song genre (name or number in list)
|
|
.TP
|
|
.B \-\-add-id3v2
|
|
force addition of version 2 tag
|
|
.TP
|
|
.B \-\-id3v1-only
|
|
add only a version 1 tag
|
|
.TP
|
|
.B \-\-id3v2-only
|
|
add only a version 2 tag
|
|
.TP
|
|
.B \-\-id3v2-latin1
|
|
add following options in ISO-8859-1 text encoding.
|
|
.TP
|
|
.B \-\-id3v2-utf16
|
|
add following options in unicode text encoding.
|
|
.TP
|
|
.B \-\-space-id3v1
|
|
pad version 1 tag with spaces instead of nulls
|
|
.TP
|
|
.B \-\-pad-id3v2
|
|
same as \-\-pad-id3v2-size 128
|
|
.TP
|
|
.B \-\-pad-id3v2-size "num"
|
|
adds version 2 tag, pad with extra "num" bytes
|
|
.TP
|
|
.B \-\-genre-list
|
|
print alphabetically sorted ID3 genre list and exit
|
|
.TP
|
|
.B \-\-ignore-tag-errors
|
|
ignore errors in values passed for tags, use defaults in case an error occurs
|
|
|
|
.PP
|
|
Analysis options:
|
|
.TP
|
|
.B \-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.)
|
|
|
|
.SH 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.
|
|
|
|
.SH 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).
|
|
.TP
|
|
.B 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 predicted.
|
|
.TP
|
|
.B 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).
|
|
.TP
|
|
.B 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.
|
|
|
|
.SH PRESETS
|
|
The
|
|
.B \-\-preset
|
|
switches are aliases over LAME settings.
|
|
|
|
To activate these presets:
|
|
.PP
|
|
For VBR modes (generally highest quality):
|
|
.TP
|
|
.B \-\-preset medium
|
|
This preset should provide near transparency to most people on most music.
|
|
.TP
|
|
.B \-\-preset standard
|
|
This preset should generally be transparent to most people on most music and
|
|
is already quite high in quality.
|
|
.TP
|
|
.B \-\-preset extreme
|
|
If you have extremely good hearing and similar equipment,
|
|
this preset will generally provide slightly higher quality than the
|
|
.B standard
|
|
mode.
|
|
.PP
|
|
For CBR 320kbps (highest quality possible from the
|
|
.B \-\-preset
|
|
switches):
|
|
.TP
|
|
.B \-\-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.
|
|
.PP
|
|
For ABR modes (high quality per given bitrate but not as high as VBR):
|
|
.TP
|
|
.B \-\-preset " kbps"
|
|
Using this preset will usually give you good quality at a specified bitrate.
|
|
Depending on the bitrate entered,
|
|
this preset will determine the optimal settings for that particular situation.
|
|
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.
|
|
.PP
|
|
The following options are also available for the corresponding profiles:
|
|
.PP
|
|
.B standard|extreme
|
|
.br
|
|
.B cbr " kbps"
|
|
.PP
|
|
.TP
|
|
.B 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
|
|
.B cbr
|
|
option to force CBR mode encoding instead of the standard 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.
|
|
|
|
|
|
.SH EXAMPLES
|
|
.LP
|
|
Fixed bit rate jstereo 128kbs encoding:
|
|
.IP
|
|
.B lame
|
|
.I sample.wav sample.mp3
|
|
|
|
.LP
|
|
Fixed bit rate jstereo 128 kbps encoding, highest quality (recommended):
|
|
.IP
|
|
.B lame \-h
|
|
.I sample.wav sample.mp3
|
|
|
|
.LP
|
|
Fixed bit rate jstereo 112 kbps encoding:
|
|
.IP
|
|
.B lame \-b
|
|
.I 112 sample.wav sample.mp3
|
|
|
|
.LP
|
|
To disable joint stereo encoding (slightly faster,
|
|
but less quality at bitrates <= 128 kbps):
|
|
.IP
|
|
.B lame \-m
|
|
.I s sample.wav sample.mp3
|
|
|
|
.LP
|
|
Fast encode,
|
|
low quality (no psycho-acoustics):
|
|
.IP
|
|
.B lame \-f
|
|
.I sample.wav sample.mp3
|
|
|
|
.LP
|
|
Variable bitrate (use \-V n to adjust quality/filesize):
|
|
.IP
|
|
.B lame \-h \-V
|
|
.I 6 sample.wav sample.mp3
|
|
|
|
.LP
|
|
Streaming mono 22.05 kHz raw pcm, 24 kbps output:
|
|
.IP
|
|
.B cat
|
|
.I inputfile
|
|
.B | lame \-r \-m
|
|
.I m
|
|
.B \-b
|
|
.I 24
|
|
.B \-s
|
|
.I 22.05 \- \-
|
|
.B >
|
|
.I output
|
|
|
|
.LP
|
|
Streaming mono 44.1 kHz raw pcm,
|
|
with downsampling to 22.05 kHz:
|
|
.IP
|
|
.B cat
|
|
.I inputfile
|
|
.B | lame \-r \-m
|
|
.I m
|
|
.B \-b
|
|
.I 24
|
|
.B \-\-resample
|
|
.I 22.05 \- \-
|
|
.B >
|
|
.I output
|
|
|
|
.LP
|
|
Encode with the
|
|
.B standard
|
|
preset:
|
|
.IP
|
|
.B lame \-\-preset standard
|
|
.I sample.wav sample.mp3
|
|
|
|
.SH BUGS
|
|
.PP
|
|
Probably there are some.
|
|
.SH SEE ALSO
|
|
.BR mpg123 (1) ,
|
|
.BR madplay (1) ,
|
|
.BR sox (1)
|
|
.SH AUTHORS
|
|
.nf
|
|
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 Rog\['e]rio Brito.
|
|
.\" Local Variables:
|
|
.\" mode: nroff
|
|
.\" End:
|