LameXP - Frequently Asked Questions (FAQ)


What is LameXP ???

LameXP is a graphical user-interface for a number of audio encoders. It was developed to support a huge
number of input formats. File formats are detected reliably using MediaInfo. Compressed audio formats are
decoded to uncompressed Wave files using suitable CLI audio decoders. Furthermore LameXP allows batch
processing of multiple audio files. Multi-threading is implemented by processing several audio files
concurrently. All the third-party tools incorporated in LameXP are listed in the "About" dialog. The Nero AAC
encoder cannot be redistributed due to licensing issues; it is available as a free download from the public
Nero web-site. Note: LameXP does NOT use/need any "external" audio decoders. It neither requires nor supports
any ACM Codecs or DirectShow/DMO filters! And it will NOT install anything of that kind on your system.



What platforms does LameXP run on?

LameXP is currently being developed and tested on the following platforms:

The following platforms should work as well, but aren't tested extensively:

The following platforms are NOT supported any longer:


What output formats (encoders) does LameXP support?

Currently the following output formats are supported by LameXP:


What input formats (decoders) does LameXP support?

Currently the following input formats are supported by LameXP:


My anti-virus program raises an alarm when I try to download/install/launch LameXP. Why is that?

Occasionally your anti-virus program may mistakenly detect "malware" (virus, trojan, worm, etc.) in some of
the files here. This is called a "false-positive" and the files are actually innocent/clean. It's an error in
your specific anti-virus software. In case you encounter such problems, goto http://www.virustotal.com/ and
check the file with multiple anti-virus engines! Moreover take care with results like "suspicious", "generic"
or "packed". Those are *not* real malware detections, they are just wild speculation.

Apparently anti-virus programs tend to suspect installers/uninstaller created with NSIS. Furthermore some
anti-virus programs blindly suspect all UPX'd (packed) executables of being malware. Obviously this is a
stupid generalization, so please ignore those warnings! Last but not least: Always keep in mind that this is
OpenSource software. If you don't trust the people providing the pre-compiled binaries, download the source
code, search the code for "malicious" functions (good luck ^^) and compile your own binary.

DON'T SUBMIT ANY VIRUS REPORTS, UNLESS YOU HAVE VERIFIED THE INFECTION WITH MULTIPLE ANTI-VIRUS ENGINES!



Who created LameXP?

LameXP was written from the scratch by LoRd_MuldeR <MuldeR2@GMX.de>. However it has to be noted that LameXP
uses a number of third-party tools, which have been created by the individual authors. Moreover various
people have contributed LameXP translations. Please see the "About" dialog for details!



What license is LameXP released under?

LameXP is free software. You can redistribute it and/or modify it under the terms of the GNU General Public
License (GPL) as published by the Free Software Foundation; either version 2 of the License, or (at your
option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Please see the GNU General Public License for more details!



Do I have to pay for LameXP? / How can I donate to the authors of LameXP?

LameXP is free software, so you may use it for free and for any purpose. Moreover the authors of LameXP
currently do NOT accept any donations. Therefore you should NOT pay or donate any money in order to obtain
LameXP! However it was brought to our attention that some dubious third-party web-sites offer "payed"
downloads of LameXP and/or include Adware into the LameXP download. We do NOT cooperate with any of these
sites. So if you pay for the LameXP download, the authors of LameXP will not get a single cent! Instead you
should save your money and download LameXP from one of the official mirrors (see below), which is 100% free.

If you want to support the development of LameXP, you can do so by contributing translations and/or code :-)



How do I enable AAC/MP4/M4A output (encoding) in LameXP?

LameXP uses the Nero AAC Encoder for creating AAC/MP4/M4A files. The Nero AAC Encoder is available as a free
download. However the license doesn't allow redistribution! Therefore we can NOT ship the Nero encoder along
with LameXP. Instead you will have to obtain the Nero encoder as a separate download from the official "Nero
Digital" web-site. Currently you'll find the latest Nero AAC Encoder version at this location:

After you have downloaded the Nero AAC Encoder as a ZIP file, you must "install" the encoder binaries, so
LameXP can use them. Simply unzip the files 'neroAacEnc.exe', 'neroAacDec.exe' as well as 'neroAacTag.exe' to
the same directory where your LameXP executable ('LameXP.exe') is located. For unzipping the ZIP file you can
use any suitable archiver, such as WinRAR or 7-Zip. Once the required Nero encoder binaries are located in
the LameXP directory, the AAC encoding option should be "enabled" on the next startup of LameXP.



Is there a way to output ".aac" or ".m4a" files with LameXP?

LameXP uses the Nero AAC Encoder for AAC encoding. And the Nero encoder always puts the AAC streams into an
MP4 (MPEG-4 Part 14) container - in almost any case that is exactly what you want/need! The one and only
"correct" file extension for MP4 files is '.mp4'. However sometimes the "incorrect" file extension '.m4a' is
used to indicate "audio-only" MP4 files. Even worse: There are some buggy (hardware) players that will
recognize MP4 audio file only with the "incorrect" .m4a extension, but NOT with the "correct" .mp4 extension.
Of course LameXP will save your MP4 files with the "correct" .mp4 extension. But if you need your MP4 files
with an .m4a extension for some reason, you can simply rename(!) these files. This isn't more or less
"incorrect" than saving the files with an .m4a directly. After all, an MP4 file remains an MP4 file.

Having said that, you should NOT rename any .mp4 or .m4a files to .aac, because these are MP4 files and NOT
"raw" AAC streams. The Nero AAC encoder has NO option to output "raw" AAC streams and usually you don't need
such streams. Still, if you want to extract the "raw" AAC stream from an MP4 file you can use MP4Box.



How do I enable WMA input (decoding) in LameXP?

WMA input requires the WMA decoder component to be installed on your local computer. Usually LameXP will show
a warning on startup, if the WMA decoder component could not be found. In that case you can simply choose
"Download & Install" in order to install the WMA decoder component on your system. Alternatively you can
also install the WMA decoder component manually by choosing "Install WMA Decoder" from the "Tools" menu. In
any case you must restart LameXP after the WMA decoder component has been installed.

It has to be noted that the WMA decoder component relies on the Windows Media Format Runtime. All supported
versions of Microsoft Windows should have the Windows Media Format Runtime installed out of the box. However
Wine does not! In case you encounter problems with the WMA decoder component, try downloading and installing
the Windows Media Format 11 Runtime manually. This should also work under Linux/Wine.



How can I use LameXP as a "portable" application?

LameXP always is "portable", in the sense that the application works out of the box: LameXP does NOT require
any additional software, such as codecs, encoders, decoders or runtime libraries, and it will NOT install
anything of that kind on your local computer! All the third-party tools used by LameXP are already built-in.
There currently are two notable exceptions: The Nero AAC encoder and the WMA decoder cannot be redistributed
along with LameXP for legal reasons. Therefore these tools have to be obtained as separate downloads.

Having said that, LameXP stores its configuration file in the %LOCALAPPDATA% folder on the local computer.
That's because on a modern multi-user operating this is the only "correct" folder to store user-specific
configuration files. Also it's one of the few folders where an application is guaranteed to get write-access,
even when the application was launched by a "normal" (non-admin) user and did not request elevated rights.
Storing the configuration file in the "install" folder is antiquated and highly error-prone.

Still some users may want to store the configuration file in the same folder as the LameXP executable file,
e.g. when launching LameXP directly from their USB stick on different computers. For this purpose LameXP now
offers a "true" portable mode. You can enable that mode simply by renaming the LameXP executable file to
"LameXP-Portable.exe". But be aware: When running LameXP in the "portable" mode, the user(!) must ensure that
write-access is granted to the directory where the LameXP executable is located.



The LameXP startup (splash screen) takes very long on my system. What can I do?

Starting up LameXP shouldn't take longer than approximately 10 seconds. However it was brought to our
attention that badly optimized anti-virus software can slow down the startup procedure a lot! On our test
system (Windows 7 running on an Intel Core2 Q6600 with 4 GB of RAM) starting up LameXP takes about 3 seconds
without an anti-virus software and about 6 seconds with the "real-time protection" of Microsoft Security
Essentials enabled. With other anti-virus software the startup was delayed up to 20 seconds and more!

So if you think that LameXP is starting up too slow on your system, you should temporarily(!) disable or
uninstall your current anti-virus program and try again. Usually it should be sufficient to disable only the
"real-time protection", "file system protection" or "guard" feature of your anti-virus software. If it turns
out that the startup is significantly(!) faster WITHOUT the anti-virus software, please report the problem to
the developer of the anti-virus software. And, if they don't fix the problem, switch to a better product!



Why does application 'xyz' not open the Wave files created by LameXP?

Some of the decoders used in LameXP will insert an additional 'JUNK' chunk into the Wave/RIFF file, right
before the 'fmt' chunk ("Wave header"). There are technical reasons why this 'JUNK' chunk (placeholder) might
be needed at the beginning of the file. The 'JUNK' type is a standard RIFF type and, by definition of the
RIFF file format specification, any reading application must ignore/skip all 'JUNK' chunks it may encounter!
Evidently most reading applications do so and thus will correctly open the Wave file. Unfortunately it was
brought to our attention that there are a few broken(!) applications, which reject Wave/RIFF files with an
additional 'JUNK' chunk in front of the 'fmt' chunk. It seems that these applications make false assumptions
and expect the 'fmt' chunk to be located at a fixed position, rather than actually parsing the RIFF structure.

While it is evident that applications, which reject the Wave/RIFF file because of the extra 'JUNK' chunk, are
broken with respect to the RIFF specification and should be fixed by the respective author, there is an easy
workaround: Re-saving the Wave/RIFF file with SoX creates a file that even the broken applications seem to
accept, as SoX apparently doesn't insert any 'JUNK' chunks (although it would be free to do so!) Re-saving
your Wave file with SoX does NOT change the actual content at all, as long as no additional filters are used.

You can use a command-line like this:
sox.exe "c:\some path\input.wav" "c:\some path\output.wav"


Why does LameXP run only 'n' parallel instances/threads on my computer?

By default LameXP will detect the number of CPU cores that are available on your system and run as many
encoder/decoder instances in parallel as CPU cores are available. This is done in order to maximize the CPU
usage on modern multi-core processors and thus speed up the overall encoding process. However be aware that
the number of instances that can run in parallel is also limited by the number of files you are converting.
Consequently the number of instances that will run in parallel is the minimum(!) of the number of CPU cores
and the number of files to convert. Moreover the number of parallel instances is currently bounded at four!

Limiting the maximum number of parallel instances to exactly four might seem somewhat arbitrary. But the more
instances are running in parallel, the more instances will be competing for the hard disk. At some point this
will result in "HDD trashing" and actually slow down the encoding process! The limit will prevent this
situation on computers with a lot of CPU cores. If, however, you want to use even more (or fewer) instances,
then you can use LameXP's option to manually overwrite the maximum number of parallel instances/threads.

Also be aware that LameXP only controls the number of instances that will run in parallel, but it does NOT
control how many threads an individual instance will create! Some encoders use "built-in" multi-threading and
thus will create several threads for a single encoder instance.



How can I translate LameXP to my language or improve an existing translation?

Please see the guide for translators at:


Where can I download the latest version of LameXP?

The latest "official" release of LameXP can be found on the following mirrors:


Where can I submit bug reports or feature requests?

The preferred place to report bugs or request new features is the LameXP thread at Doom9's Forum:

Please do NOT send me E-Mail unless you really have to! I receive a LOT of E-Mail and your mail can get lost!



Where can I find the LameXP source code?

LameXP is developed using the Git revision control system. The LameXP Git repository is mirrored at:


What are the prerequisites to build LameXP from the sources?

LameXP is currently being developed using the following build environment:

Also note the following hints:


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