Hydrogenaudio Knowledgebase - User contributions [en]

Blade

2005-04-17T08:33:10Z

222.98.194.47: Blade is gapless?

BladeEnc is a freeware MP3 encoder. It is based on the same ISO compression routines as mpegEnc, so you can expect roughly the same, or better, quality . The main difference is the appearance and speed. BladeEnc doesn't have a nice, user-friendly interface like mpegEnc, but it is more than three times faster, and it works with several popular front-end graphical user interfaces .

==Features==
* Sourcecode available under the LGPL-license!
* Stereo or Mono output. Can downmix to Mono on the fly.
* Supports the following bitrates: 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256 and 320 kBit/s. However, for bitrates lower than 128 kBit we seriously recommend you to use another encoder.
* Flags like Private, Original and Copyright can be set.
* Input samples can be in either 32, 44.1 or 48 kHz.
* Both 8 and 16-bit samples are supported.
* Working CRC checksum generation (since 0.80). The ISO reference code had broken CRC calculations, which has been inherited into every ISO based encoder that haven't added a fix for it.
* Can be compiled for nearly any operating system still in use.
* Commandline based, makes it easy to include BladeEnc into BAT files and shell scripts.


* Reads standard uncompressed WAV- and AIFF-files as well as well as RAW PCM-data.
* Batch encoding. Can encode any number of samples in a row.
* Wildcards supported. You can for example encode all WAV-files in a directory by typing "*.WAV".
* Input samples can be automatically deleted after encoding.
* Large selection of graphical frontends available.
* Task priority can be set from the commandline and is by default set to LOWEST so that you still can use your computer effectively while encoding (Windows & OS/2 only).
* Full support for pipes and redirection (stdin and stdout).
* Textbased configuration file where you can change default settings.

==Screenshot==
<center>[[Image:BladeEnc.png|frame|center|Blade Mp3 Encoder]]</center>

==Addtional Reading==
* [http://bladeenc.mp3.no/ Blade Encoder Homepage]
* [[MP3]]

Advanced Audio Coding

2005-04-17T08:31:15Z

222.98.194.47: /* Do AAC encoded files play back gaplessly? */

=Introduction=
'''AAC''' or 'Advanced Audio Coding' forms part of the latest specifications from the MPEG committee, and is their official successor to the popular [[MP3]] format. As with [[MP3]], the '''AAC''' format is an international standard, and is backed by several big-name companies, including Dolby, Sony and Nokia.

With the 8 <small>(this is just a guess)</small> years that had passed since the creation of the [[MP3]] format, many improvements had been realised leading to a seemingly complex specification with several flavours of '''AAC''' available. To potentially add to the confusion, '''AAC''' is usually wrapped inside an [[MP4]] container to provide tagging, seeking and possibly other benefits?? For this reason, '''AAC''' can also be referred to as [[MP4]] audio..

There are several '''AAC''' encoders to choose from, coming from large names such as Apple and Ahead (Creators of Nero - Burning Rom), or the open source F'''AAC''' which is analogous to the [[LAME]] encoder. '''AAC''' is supported on many hardware players, and is available in online stores..

In terms of quality, it outperforms [[MP3]] by a nice margin, being on par with OGG and other great codecs, and with '''AAC-HE''' provide the best low bitrate quality.

==Pros==

* An international standard approved by the [http://www.iso.ch ISO]
* Flexible: supports several [[sampling rate]]s (8000-96000 Hz), bit depths, and [[multichannel]] (up to 48 channels)
* Several implementations, including a free and high quality one ([http://www.itunes.com iTunes])
* Reaches transparency in most samples and for most users at around 150kbps
* Part of MPEG4 specs
* Anyone can create it's own implementation (Specifications and demo sources available)
* Some portable players support it (Philips Expanium, iPod, cell phones from Nokia)

==Cons==

* Problem cases that trip out all transform codecs
* Relatively slow encoding
* Heavily patented
* Increased complexity
* '''AAC''' comes in different "flavors" (object types: '''AAC LC''', '''AAC HE''', '''AAC PS''' etc.). Many (especially portable) players only support LC (at the moment) so you can have files that are valid but your player won't play them.

=Technical Information=
'''AAC''' stands for 'Advanced Audio Coding' and is part of the MPEG-4 Systems Standard. Originally known as MPEG-2 Non-Backwards Compatible (As apposed to MPEG-2 Backwards Compatible) it is the succesor to MPEG-1/2 Layer III ([[MP3]]). It uses the [[MP4]] [[container]] (which is based on Apple's MOV [[container]]) to store metadata (i.e. tag information).

As part of the MPEG-4 Systems Standard, an '''AAC''' encoded file can include up to 48 full-bandwith audio
channels (up to 96 kHz) and 15 Low Frequency Enhancement channels (limited to 120 Hz) plus 15 data streams.

'''AAC''' encoding methods are organised into Profiles (MPEG-2) or Object Types (MPEG-4). These different Object Types are not necessarily compatible with each other and may not be playable with various decoders. The various Object Types are:

* MPEG-2 AAC LC / Low Complexity
* MPEG-2 AAC Main
* MPEG-2 AAC SSR / Scalable Sampling Rate
* MPEG-4 AAC LC / Low Complexity
* MPEG-4 AAC Main
* MPEG-4 AAC SSR / Scalable Sampling Rate
* MPEG-4 AAC LTP / Long Term Prediction
* MPEG-4 AAC HE / High Efficiency
* MPEG-4 AAC LD / Low Delay

Different Object Types vary in complexity. Some take longer to encode/decode as a result of the different complexities. Furthermore, the benefits of the more complex profiles are often not worth the CPU power required to encode/decode them. As a result the Low Complexity/LC Object Type has become the profile used by most encoders. However, the High Efficiency Object Type has become more popular recently with its addition to the Nero '''AAC''' encoder which now supports HE '''AAC''' encoding.

Currently all players support the LC Object Type. Players based on the FAAD2 decoder (eg. foobar2000,
Winamp Plugins) support almost all Object Types including HE '''AAC'''. 3ivX also supports all Object Types
except SSR.

==Technologies used for compression==

* [[Huffman coding]]
* [[Quantization]] and scaling
* [[Joint stereo|M/S matrixing]]
* [[Intensity stereo]]
* Channel coupling
* Backward adaptive prediction
* Temporal Noise Shaping (TNS)
* Modified Discrete Cosine Transform (I[[MDCT]])
* Gain control and hybrid filter bank (polyphase quadrature filter (IPQF)+IMDCT)
* Long Term Predictor (LTP) - MPEG4 '''AAC''' only
* Perceptual Noise Substitution (PNS) - MPEG4 '''AAC''' only
* Spectral Band Replication ([[SBR]]) - HE '''AAC'''
* Parametric Stereo (PS) - HE '''AAC'''

=Encoders / Decoders (Supported Platforms)=

* [[Nero AAC]] (Win32)
* [[QuickTime AAC]] (Win32/MacOS X)
* [[FAAC]] [[FAAD]] (Multiplatform)
* HHI/zPlane [[Compaact!]] (Win32)
* [[PsyTEL]] (Win32)

=FAQ=

==Great, so you've given me all the technical stuff, but what is AAC really?==
AAC is the culmination of the current state of the art audio encoding techniques. It is designed
to improve upon and replace [[MP3]] as the defacto Audio Encoding standard. It usually offers (depending on
the codec) equivalent quality to [[MP3]] at a lower bitrate.

==What is the difference between *.[[MP4]] and *.M4A?==
Besides the extension, absolutely nothing. Apple came up with extension to distiguish between files with
Video and Audio (the [[MP4]] extension) and files with Audio only (the M4A extension). As far as the internal
structure of the file, nothing is different.

==What MPEG 4 extensions does the Apple iPod Accept?==
The iPod accepts files with the [[MP4]] extension, the M4A extension, the M4P extension (a [[Protected AAC]] file), and the M4B extension for audiobook files (which can be either protected or unprotected). It will not accept unwrapped AAC files (files with the .AAC extension).

==What is the difference between LC (Low Complexity) and HE (High Efficiency)?==
These are two of the various Object Types in the MPEG4 Systems Standard. LC is the most popular Object Type
with all encoders/decoders supporting it. Currently, Nero, Coding Technolgies, and Panasonic have incorporated
the HE '''AAC''' standard into their encoders, which allows for higher quality sound at lower bitrates then the LC
Object Type does (at the same bitrate). The HE Object Type is only used for music with a bitrate of less than
~80kbps.

==What's the best AAC encoder?==
There is no best '''AAC''' encoder as such. It can be said with reasonable confidence (based on guruboolez's last test,
[http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 hear]) that [http://www.nero.com/en/ Nero AAC] is the best '''AAC''' encoder at 128kbps. However, the quality of any encoder is not linear and therefore these results can not be extrapolated to other bitrates. It can also be said with reasonable confidence that both the iTunes encoder and the [http://www.nero.com/en/ Nero '''AAC''' encoder] are 'mature' and should not fail badly on any particular sample at an average bitrate of 128kbps (i.e. Internet Profile for Nero '''AAC''') or above (based on Roberto's listening tests, see bottom). Beyond that, only you can decide through [[ABX]] testing. See the [[Audio format guide]]
for more information. However, that being said, QuickTime/iTunes and Nero '''AAC''' are considered to be the "safe"
encoders if you wish to archive your music collection on your computer.

==Do AAC encoded files play back gaplessly?==
[[Gapless]] playback is not part of the '''AAC''' standard and as such is not mandatory. However, certain companies can
choose to add gapless encoding/decoding if they desire, providing it doesn't break compatibility with previous
decoders. This is what Ahead have done with their Nero '''AAC''' codec. The files get encoded with information that
allows the gap heard between files to be removed. This however is only possible with supported players (currently
these include foobar2000 and Nero ShowTime). Currently Nero '''AAC''' is the only '''AAC''' codec to have gapless encoding/decoding
support.

==What software players can play back AAC music?==
There are now a number of software players that can play back this new format. [http://www.foobar2000.org/ foobar2000]
is considered by many to be the most powerful audio player in existence, and it is certainly capable of playing back
'''AAC''' encoded files. Other players include the [http://www.itunes.com/ iTunes Digital Jukebox], [http://www.winamp.com/
Winamp], [http://www.real.com/ Real Player] and [http://www.microsoft.com/windows/windowsmedia/default.aspx Windows Media Player] using the [http://corecodec.org/projects/coreaac CoreAAC filter] and [http://www.elecard.com/download/ Moonlight MP4 Demultiplexer]. Also for Directshow-based applications playback and encoding is possible using the commercial [http://www.3ivx.com/ 3ivx filter suite].

==What hardware players can play back AAC music?==
There are also a number of hardware players that can play back AAC audio. The most famous of these is the [http://www.apple.com/ipod/ Apple iPod] series of products, all of which feature AAC playback. A number of mobile (cell) phones also support unwrapped AAC (AAC not contained in the MP4 container).

= External References =
Known [[AAC implementations]].

Read the [[AAC guide]] to learn how to obtain '''AAC'''/[[MP4]] files out of WAV files and CDs.

Detailed '''AAC''' comparisons can be found at [http://www.rjamorim.com/test/ Roberto's listening tests page].

LAME

2005-04-16T03:30:57Z

222.98.194.47:

LAME (LAME Ain't an [[MP3]] Encoder) is the recommended encoder. It has been developed by the open-source community since 1998, and has become the highest quality encoder for most purposes.

Some benefits for using LAME
* highly optimised presets
* [[Exact Audio Copy]] support
* [[CBR]], [[VBR]] and [[ABR]] encoding methods
* [[CDex]] Support
* [[Gapless]] playback with LAME-header compliant decoders

'''Note: These settings require Lame 3.90 or later. Lame 3.90.3 found on this website is the recommended version''' ([[Lame Compiles|Check here to download]])

''Note: At a given bitrate range, the quality scale usually works to where VBR is higher quality than ABR which is higher quality than CBR (CBR < ABR < VBR in terms of quality). The exception to this is when you choose the highest possible CBR bitrate which is 320kbps. In the case of the named VBR profiles "standard" and "extreme" they are usually "effectively" equal in quality to high bitrate cbr, in the range of around 256 kbps due to their ability to scale down the bitrate when necessary but increase the bitrate beyond 256 kbps on a frame by frame basis also, when that is necessary.''

=Encoder Presets=

'''Recommended Preset'''
* '''--alt-preset standard''' (~190 kbit/s, typical 180 ... 220. '''Best quality / size ratio''')

'''Other Presets'''
* '''--alt-preset fast standard''' (~190 kbit/s, faster but potentially lower quality)

* '''--alt-preset extreme''' (~250 kbit/s, typical 220 ... 270. Quality can be a little better than standard)

* '''--alt-preset fast extreme''' (~250 kbit/s, faster but potentially lower quality)

* '''--alt-preset insane''' (320 kbit/s CBR, highest possible quality, that can be a little higher than extreme)

'''Note:''' ''Lame version 3.95.1 and above use a different naming scheme for the presets, e.g. '''--alt-preset standard''' becomes '''--preset standard''' so if you remove '''alt-''' from the above presets, they will work with newer versions of Lame.''

==VBR (Variable bitrate) settings==
*[[VBR]] can be useful to get good quality from a specific quality level. Size is less predictable than with [[ABR]], but the quality is usually better.

-V(number) where number is 0-9, 0 being highest quality, 9 being the lowest.

{| align=center border="1" cellpadding="5" cellspacing="0"
|+'''Lame 3.96.1 -V n, Presets, bitrates and lowpass of V values'''
| '''Switch''' || '''Preset''' || '''Target Kbps''' || '''Y Switch''' || '''-b''' || '''Lowpass''' || '''Resample'''
|-
| -V 0 || --preset extreme || 240 || || 128 || 19383 Hz - 19916 Hz ||
|-
| -V 0 --vbr-new || --preset fast extreme || 240 || || 128 || 19383 Hz - 19916 Hz ||
|-
| -V 1 || || 210 || || 128 || 18671 Hz - 19205 Hz ||
|-
| -V 1 --vbr-new || ||210 || || 128 || 18671 Hz - 19205 Hz ||
|-
| -V 2 || --preset standard || 190 || || 128 || 18671 Hz - 19205 Hz ||
|-
| -V 2 --vbr-new || --preset fast standard || 190 || || 128 || 18671 Hz - 19205 Hz ||
|-
| -V 3 || || 175 || Y || || 17960 Hz - 18494 Hz ||
|-
| -V 3 --vbr-new || || 175 || Y || || 17960 Hz - 18494 Hz ||
|-
| -V 4 || --preset medium || 165 || Y || || 17960 Hz - 18494 Hz ||
|-
| -V 4 --vbr-new || --preset fast medium || 165 || Y || || 17960 Hz - 18494 Hz ||
|-
| -V 5 || || 130 || Y || || 16538 Hz - 17071 Hz ||
|-
| -V 5 --vbr-new || || 130 || Y || || 16538 Hz - 17071 Hz ||
|-
| -V 6 || || 115 || Y || || 15826 Hz - 16360 Hz ||
|-
| -V 6 --vbr-new || || 115 || Y || || 15826 Hz - 16360 Hz ||
|-
| -V 7 || || 100 || Y || || 14581 Hz - 14968 Hz || 32000 Hz
|-
| -V 7 --vbr-new || || 100 || Y || || 14581 Hz - 14968 Hz || 32000 Hz
|-
| -V 8 || || 85 || Y || || 12516 Hz - 12903 Hz || 32000 Hz
|-
| -V 8 --vbr-new || || 85 || Y || || 12516 Hz - 12903 Hz || 32000 Hz
|-
| -V 9 || || 65 || Y || || 9774 Hz - 10065 Hz || 24000 Hz
|-
| -V 9 --vbr-new || || 65 || Y || || 9774 Hz - 10065 Hz || 24000 Hz
|}

==ABR (average bitrate) settings==
''(128 kbit/s ABR: roughly the same filesize as 128 kbit/s CBR)''

* '''[[ABR]] Setting tuned from 320 kbit/s down to 80 kbit/s'''
** --alt-preset <bitrate>
:: Example: --alt-preset 200

* '''128 kbit/s ABR'''
** -V5 --athaa-sensitivity 1 (when using >= LAME 3.96.1, for best results at 128kbps)
** --alt-preset 128

:: or (ff123's and Hans' suggestion: http://www.ff123.net/cbr128.html ):
:: --abr 128 -h --nspsytune --athtype 2 --lowpass 16 --ns-bass -8 --scale 0.93

==CBR (constant bitrate) settings==

*'''[[CBR]] Setting tuned from 320 kbit/s down to 80 kbit/s'''
** --alt-preset cbr <bitrate>
:: Example: --alt-preset cbr 96

* '''128 kbit/s CBR'''
** --alt-preset cbr 128

:: or (ff123's and Hans' suggestion: http://www.ff123.net/cbr128.html ):
:: -h --nspsytune --athtype 2 --lowpass 16 --ns-bass -8 --scale 0.93

: note: --alt-preset cbr 320 is the exact same thing as --alt-preset insane

==Additional reading==

* [http://www.hydrogenaudio.org/forums/index.php?showtopic=28124 List of recommended LAME settings] @ HydrogenAudio forum
* [http://www.mp3dev.org LAME homepage]
* [http://www.hydrogenaudio.org/forums/index.php?showtopic=18091 -V n (in 3.95.1), Presets, bitrates and lowpass of V value] created by Vietwoojagig
* [[EAC_and_Lame | Configuring EAC and LAME]]

Vorbis

2005-04-16T03:30:20Z

222.98.194.47: /* Pros */

=Introduction=
'''Ogg Vorbis''' ([http://www.vorbis.com www.vorbis.com]) is a fully open, non-proprietary, patent-free <small>(subject to [http://www.hydrogenaudio.org/forums/index.php?showtopic=13531 speculation])</small>, and royalty-free, general-purpose compressed audio format for mid to high quality (8khz-48.0kHz, 16+ bit, polyphonic) audio and music at fixed and variable bitrates from 16 to >256 kbps/channel. This places vorbis in the same competitive class as audio representations such as mpeg-4 ([[AAC]]), and similar to, but higher performance [[MP3]], twinvq ([[VQF]]), [[WMA]] and [[PAC]].

Vorbis is the first of a planned family of Ogg multimedia coding formats being developed as part of Xiph.org's ogg multimedia project.

Informal listening test suggest Vorbis to be comparable to mpeg-4 [[AAC]] at most bitrates and [[MPC]] at 128kbs. Transparency is generally reached at about 150-170kbps (with some exceptions). The encoder is reasonably young and unoptimized, so further improvements can be expected.

Unfortunately, Xiph.org has failed to improve Vorbis at a steady rate since its initial 1.0 release in July 2002. Since then development has been lead by other coders such as Garf and Aoyumi. Aoyumi's AoTuV series of encoders was incorporated into the September 2004 release of 1.1, which brought about the first quality improvements across the board for 2 years.

==Pros==
* Free (as in speech), Open Source and claimed to be patent free
* Good all-round performance (>48kbs - a leading codec at 128kbs)
* Well written [http://www.xiph.org/ogg/vorbis/docs.html specs]
* Several portable hardware players
* Suitable for internet-streaming (via Icecast)
* Fully [[gapless]] playback

==Cons==
* Limited official development
* Current implementations are more computationally intensive to encode and decode than MP3
* Quality at high bitrates could benefit from further tuning

=Techniques used in compression=
* Advanced psymodel
* Coupled stereo modes (Point/Phase Stereo and [[lossless]])
* [[Huffman coding]]
* Vector quantization
* Modified discrete cosine transform ([[MDCT]])
* Multiple block sizes for window switching

=Software=
'''Encoders'''
* [[oggenc]]

'''Decoders'''

* [http://qtcomponents.sourceforge.net/ QuickTime Component] (Allows playback in [[QuickTime]]/[[iTunes]])
* [http://corevorbis.corecodec.org/ CoreVorbis] (DirectShow)
* [http://www.illiminable.com/ogg/ illiminable Ogg Directshow Filters] (Also plays Speex, Theora and FLAC)

=Hardware=
The following list contains some players that support Vorbis playback.
* [[iRiver H-Series]]
* [[Rio Karma]]
* [[IAudio M3]]
* [[Neuros]]

=Additional reading=
* [[Ogg]] (Container)
* [http://www.audiocoding.com/modules/wiki/?page=Ogg+Vorbis Ogg Vorbis at AudioCoding]
* [http://www.hydrogenaudio.org/show.php/showtopic/13531 Discussion of Vorbis' legal status]
* [http://www.xiph.org Xiph.org Foundation]

Foobar2000:Foobar2000

2005-04-14T04:58:07Z

222.98.194.47:

[http://www.foobar2000.org/ '''foobar2000'''] is a free music player for Windows. It features multiple playlists, a music database, streaming, [[ReplayGain]] support, [[gapless]] playback, extensive plug-ins support and more.

= Support =

* [[MP3]], [[Ogg Vorbis]], [[MP2]], [[AAC]], [[WAV]], [[AIFF]], [[Musepack]], [[VOC]], [[SND]]

Supported through plug-ins:
* [[TTA]], [[FLAC]], [[Monkey's Audio]], [[WavPack]], [[Speex]], [[Mod]], [[SPC]], [[TFMX]], [[Shorten]], [[OptimFROG]], [[LPAC]], [[WMA]], [[AC3]], [[PSF]], [[NSF]], [[XID]], [[XA]], [[Matroska]]

In addition, foobar2000 can also play music directly from compressed RAR, ZIP and 7-Zip archives without requiring the user to extract the files prior to playing.

foobar2000 is an English program and the author has stated that he does not plan to make translations possible.

foobar2000 is a Windows only program.
No known plans exists to port it to other platforms, but attempts have been made, with varying degrees of success, to run foobar2000 on x86 Linux systems by using [http://www.winehq.org/ Wine].

= User Interface =

By default foobar2000 uses the standard interface, foo_ui_std. This interface is based around a tabbed list of playlists. Playlists are then formatted according to the title formatting strings entered by the user. These allow access to tag data, as well as information about the state of the program in the playlist display.
For more information go to the [[foobar2000:Interface|Interface]] page.

= User Guides =

* [[foobar2000:Newbie User Guide|Newbie User Guide]]
* [[foobar2000:Novice User Guide|Novice User Guide]]
* [[foobar2000:Advanced User Guide|Advanced User Guide]]
* [http://foobar2000.net/ French-language guide; external]

=Other pages at the foobar2000 section =

* [[foobar2000:Tips & Tricks|Tips & Tricks for foobar2000]]
* Find components for foobar2000 at the [[foobar2000:components|components page]]
* [[foobar2000:FAQ|foobar2000 FAQ]]
* [[foobar2000:Encouraged Tag Standards|foobar2000 Encouraged Tag Standards]]

= Important Links =

== Official Site ==

* [http://www.foobar2000.org foobar2000.org: Homepage]

* [http://www.foobar2000.org/download.html foobar2000.org: Download]

* [http://www.foobar2000.org/requirements.html foobar2000.org: Requirements]

== Community ==

* [http://www.hydrogenaudio.org/forums/index.php?showforum=28 Official foobar2000 forum]

* [http://www.fforum.ru/index.php?showforum=59 Russian-language forum]

* [http://www.foobar.prv.pl/ Polish-language forum]

== Appearance ==

* [http://www.hydrogenaudio.org/forums/index.php?showtopic=30988 Foobar Gallery]: screenshot thread

* [http://pelit.koillismaa.fi/fb2k/index.php Default UI formatting strings]: cut-n-paste ready

* [http://foobar.nub4life.net/columns/ Columns UI configs]: .fcs file format

* [http://www.hydrogenaudio.org/forums/index.php?showtopic=30281 foo_ui_gfx (alpha)]: skin support for foobar

= Thanks =

picmixer: ReplayGain tutorial

Gapless playback

2005-04-14T04:52:45Z

222.98.194.47: My own rewrite. Duplicated from Wikipedia

'''Gapless playback''' is the seamless playback of digital audio formats. It allows live music or consecutive tracks to be heard exactly as they are mastered, without gaps between tracks.

==Why gaps occur==
Most lossy audio compression schemes involve a frequency/time domain transform. The playtime of the audio data may not be equal before and after the compression.

Most audio playback software also closes the audio output streamed to the soundcard when switching tracks. This can introduce gaps also.

==Optimal solution==
It is possible to store metadata in the audio to explicitly declare the playtime, and/or the delays introduced in the encoding process. This information can be used to ensure that playtime will remain constant after decoding.

The audio playback software must be able to recognize the metadata, and trim the decoded audio as necessary.

The software can then take care to keep the output stream open between tracks.

==Alternative solutions==
DSP plugins can be used to detect silence between tracks and trim the audio as necessary on playback. This is not immune to error however, and is not optimal.

DSP plugins can also be used to crossfade between tracks, but this is not always desirable.

==Gapless solutions==
* [[foobar2000]]: Optimal gapless playback
* [http://www.hydrogenaudio.org/forums/index.php?showtopic=18530 Otachan's in_mpg123]: A gapless [[MP3]] decoder for [[Winamp]]

==See also==
* [[Ogg]] [[Vorbis]]