Recommended Ogg Vorbis: Difference between revisions
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(4)'' Most users agree <font style="color:red;">-q 5</font> achieves transparency'' | (4)'' Most users agree <font style="color:red;">-q 5</font> achieves transparency'' | ||
To know what lowpass frequencies are used for each quality level, see ha thread [http://www.hydrogenaudio.org/forums/index.php?showtopic=15049&st=160&p=357461&#entry357461 here]. | To know what '''lowpass frequencies''' are used for each quality level, see ha thread [http://www.hydrogenaudio.org/forums/index.php?showtopic=15049&st=160&p=357461&#entry357461 here]. | ||
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Revision as of 18:36, 27 March 2006
Vorbis, being a continuously developed standard, improves all the time. Plus, being an open (i.e. patent-free) standard, it has many 'third-parties' that contribute, discuss, and work to improve the project.
Here you can find some guidelines on which utilities to use, and what settings will provide you with the best quality.
History
(For a highly detailed description of Vorbis history, check out OggZealot's Ogg Vorbis Historic where Monty also adds a few more details too). Ogg Vorbis reached version 1.0 in July 2002. It is the official Xiph.org encoder (the one you get from vorbis.com). HA codec developer, Garf, did his own tunings, based on version 1.0 to produce GT3b1 and GT3b2. Both encoders showed improved pre echo handling for q values of 5 to 10. It was later judged in an internal listening test that GT3b1 was the better of the two. There was a minor bugfix update earlier that year in March, which only appeared in the CVS at Xiph.org. This consisted of very minor bug fixes, which do more to correct odd problems that may occur rather than improving quality, including (garbled noise output and gaps in streams). This was referred to as Post 1.0 CVS. Quality problems that mainly affected low bitrates were later addressed in a new bugfix (1.0.1) that was released.
Post 1.0.1 CVS was released late December 2003 by Monty at Xiph, and includes a true CBR template. In order to simplify the situation where we had two encoders (1.0.1 and GT3b1), OggDropXPd developer John33 merged the sources to give us GT3b2. Once the 128 kbps multiformat test was completed, Aoyumi's aoTuV Vorbis tuning was determined to be the best Vorbis encoder. After the success of aoTuV beta 2 encoder, Xiph.Org merged their tunings into the official CVS branch to produce the long-awaited Vorbis 1.1. Aoyumi's later release of aoTuV beta 4 encoder as of November 2005 significantly improves Vorbis' quality while enhancing the compression. It is now the recommended encoder by 3rd party developers at Hydrogenaudio. Aoyumi's latest is aoTuV beta 4.5 (later bugfixed with aoTuV beta 4.51) released in December 2005, which improves low bit-rate quality even more. However, it is still undergoing peer review before it becomes the recommended encoder. Near the end of 2005, after aoTuV beta 4.51 was released, Xiph.org released Vorbis 1.1.2. Unfortunatly it only provides bugfixes to Vorbis 1.1.1. Although this is the 'official' version, it is not recommended by HA. If you are not interested in the latest "bleeding edge" improvements, you are welcome to use the latest release from Xiph.org Vorbis 1.1.2 library.
Note: Xiph.org does not maintain the binaries, but rather provides newest updates and releases to libogg and libvorbis, etc.
Recommended Vorbis Encoders
(adapted from Recommended Encoder and Settings post compiled by QuantumKnot)
Windows binaries
John33's oggenc2.8 is a special version of the Ogg Vorbis encoder. "Features include compression from lossless files (Monkeys Audio, LPAC, FLAC, OptimFROG, WavPack and Shorten - requires presence of decoders), and the ability to specify 'padding' in the headers for subsequent insertion of Tags" (from Ogg Vorbis page at rarewares).
- oggenc2.8 aoTuV beta 4.51 (MSVC compile)
- oggenc2.8 aoTuV beta 4.51 (ICL compile for P3/AMD Athlon)
- oggenc2.8 aoTuV beta 4.51 (ICL compile for P4/AMD Sempron, Athlon 64))
If you prefer a nice drag-and-drop interface, then you can try John33's OggDropXPd (Windows only). "Features include compression from lossless files (Monkey's Audio, LPAC, FLAC and OptimFROG), auto-tagging, renaming of encoded files, setting of advanced encoder parameters, use of VorbisGain tags on decode, Playlist (.m3u) creation, and others" (from Ogg Vorbis page at rarewares).
- OggDropXPd v1.8.7 aoTuV beta 4.51 (MSVC compile)
- OggDropXPd v1.8.7 aoTuV beta 4.51 (ICL compile for P3/AMD Athlon)
- OggDropXPd v1.8.7 aoTuV beta 4.51 (ICL compile for P4/AMD Sempron, Athlon 64)
(Work In Progress: Guide will be completed soon. Check here)
OS/X binaries
- Vorbis Tools (oggenc, oggdec, etc.) version 1.1.1 using aoTuVb4.51 for MacOS X.
- These tools were compiled by krmathis for OS/X.
Linux binaries
- oggenc aoTuV beta 4.51 and libogg 1.1.3 (Static GCC 4 compile) with impulse_trigger_profile
- This static GCC 4 binary was compiled by QuantumKnot.
Note: There is no Linux Oggenc2.x that has been compiled with Lancer Optimizations as of yet (third-parties with a access to a unix environment are encouraged to try and compile one themselves if they have access to the sources).
3rd party source code
These are other Ogg Vorbis encoders that were tuned by 3rd party developers (outside of Xiph.Org).
- aoTuV (Aoyumi's Tuned Vorbis) -- contains modified source code written in C and downloads of binaries.
- The source-code contains modifications mostly to the psychoacoustics model and bitrate allocation, i.e psy.c
- aoTuV beta 4 -- Now the recommended encoder
- Developed by Aoyumi and based on libvorbis 1.1.1, many people have reported this encoder to give better quality at low to medium bitrates. It includes a -q -2 option for the lowest bitrate. According to guruboolez' latest listening test on classical music, aoTuV beta 4 performed magnificently well at -q 6!! (see Aoyumi's website above for more information)
- aoTuV beta 4.51 -- The latest encoder
- Many Hydrogenaudio enthusiasts report that this version gives even better quality for low bit-rates. -q 1.5 works for streaming, even good enough. However, more peer review is needed before this version becomes the recommended encoder.
- See Compiling aoTuV for information on how to compile it for Linux.
Optimized binaries
These are highly optimized encoders developed by the Ogg Vorbis Acceleration Project that are much faster than the standard binary builds with negligible to nearly no effects on audio quality, including sped-up routines, i.e mdct.c
- oggenc2.6 aoTuV beta 4 (Lancer 20050709) (Win32 Build)
- oggenc2.6 aoTuV beta 4.51 (Lancer 20051121) (Win32 Build)
- oggenc2.8 aoTuV beta 4.51 (Lancer 20060131) (Win32 Build) -- Latest version
See Lancer Information and downloads page above.
Note: Output of Lancer may be slightly different from output of 'standard' aoTuV. This is due to the difference of floating-point rounding: Lancer uses 64-bit SSE, while standard aoTuV uses 80-bit FP. This difference, however, should not be audible at all. In fact, tests have proven that playback of Lancer's output is indistinguishable from playback of standard aoTuV output.
Released Binaries
How do I know which encoder was used to make this particular Ogg Vorbis file?
Using either the ogginfo program or file info in your player, you can tell from the vendor tag:
If you aren't interested in the latest compiles feel free to use Vorbis 1.1.2 libraries.
| Vendor Tag | Encoder | Note |
|---|---|---|
| Xiphophorus libVorbis I 20000508 | 1.0 Beta 1 or Beta 2 | |
| Xiphophorus libVorbis I 20001031 | 1.0 Beta 3 | |
| Xiphophorus libVorbis I 20010225 | 1.0 Beta 4 | |
| Xiphophorus libVorbis I 20010615 | 1.0 RC1 | |
| Xiphophorus libVorbis I 20010813 | 1.0 RC2 | |
| Xiphophorus libVorbis I 20010816 (gtune 1) | 1.0 RC2 GT1 | |
| Xiphophorus libVorbis I 20011014 (GTune 2) | 1.0 RC2 GT2 | |
| Xiphophorus libVorbis I 20011217 | 1.0 RC3 | |
| Xiphophorus libVorbis I 20011231 | 1.0 RC3 | |
| Xiph.Org libVorbis I 20020717 | 1.0 | |
| Xiph.Org/Sjeng.Org libVorbis I 20020717 (GTune 3, beta 1) | GT3b1 | |
| Xiph.Org libVorbis I 20030308 | Post 1.0 CVS | |
| Xiph.Org libVorbis I 20030909 | 1.0.1 | |
| Xiph.Org/Sjeng.Org libVorbis I 20030909 (GTune 3, beta 2) EXPERIMENTAL | Experimental GT3b2 | |
| Xiph.Org libVorbis I 20031230 (1.0.1) | Post 1.0.1 CVS | |
| Xiph.Org/Sjeng.Org libVorbis I 20031230 (GTune 3, beta 2) | GT3b2 | |
| AO; aoTuV b2 [20040420] (based on Xiph.Org's 1.0.1) | aoTuV Beta 2 | |
| Xiph.Org libVorbis I 20040629 | Xiph.Org Vorbis 1.1 or Xiph.Org Vorbis 1.1 RC1 | |
| Xiph.Org libVorbis I 20040920 | Xiph.Org Vorbis 1.1 with impulse_trigger_profile | |
| AO; aoTuV b3 [20041120] (based on Xiph.Org's libVorbis) | aoTuV Beta 3 | |
| Xiph.Org libVorbis I 20050304 | Xiph.Org Vorbis 1.1.1 or Xiph.Org Vorbis 1.1.2 | |
| AO; aoTuV b4 [20050617] (based on Xiph.Org's libVorbis) | aoTuV Beta 4 | |
| BS; Lancer [20050709] (based on aoTuV b4 [20050617]) | Lancer based on aoTuV Beta 4 | |
| AO; aoTuV b4a [20051105] (based on Xiph.Org's libVorbis) | aoTuV Beta 4.5 | |
| AO; aoTuV b4b [20051117] (based on Xiph.Org's libVorbis) | aoTuV Beta 4.51 | |
| BS; Lancer [20051121] (based on aoTuV b4b [20051117]) | Lancer based on aoTuV Beta 4.51 | |
| AO; aoTuV pre-beta5 [20060321] (based on Xiph.Org's libVorbis) | AoTuV Beta 5 |
Recommended Encoder Settings
Refer to the table below. For best results, start at -q 4 and ABX your way up.
Ultimately, the best -q setting will depend on your specific needs. Feel free to experiment.
General Command Line Usage:
oggenc -q n inputfile.wav
- where n is a number from -1 to 10, fractions accepted (using comma or period, depending on where the tool is compiled)
e.g. oggenc -q 5 inputfile.wav
Notes:
- Most standard oggenc binaries can input lossless FLAC, WavPack, etc files as well (depending upon oggenc version)
- oggenc2.7 and later are the only versions of oggenc that conform to the WAVEFORMATEXTENSIBLE header for outputing and decoding multi-channel Vorbis files (3 to 6 channels) in compliance with the Vorbis I decoding specification. Encoding multi-channel content might still produce sub-optimal files if lossless channel coupling is not used, due to modifications that need to be performed in libvorbis for proper channel coupling. Encoding assumes source material is CD audio content or PCM equivalent.
- The current oggenc and libvorbis API don't support the capabilities of full "bitrate peeling" yet. Experimental peelers exist, but only for testings purposes. i.e (Vinjey Systems)
| Switch | VBR target (kbit/s) |
VBR range (kbit/s) |
Channel Coupling |
Noise Normalization |
Note |
|---|---|---|---|---|---|
| -q -2 | ~32 | ~32 - ~64 | point/lossless | yes | (1) |
| -q -1 | ~48 | ~48 - ~64 | point/lossless | yes | (2) |
| -q 0 | ~64 | ~64 - ~80 | point/lossless | yes | |
| -q 1 | ~80 | ~80 - ~96 | point/lossless | yes | (3) |
| -q 2 | ~96 | ~96 - ~112 | point/lossless | yes | |
| -q 3 | ~112 | ~112 - ~128 | point/lossless | yes | |
| -q 4 | ~128 | ~128 - ~160 | point/lossless | no | |
| -q 5 | ~160 | ~160 - ~192 | point/lossless | no | (4) |
| -q 6 | ~192 | ~192 - ~224 | lossless | no | |
| -q 7 | ~224 | ~224 - ~256 | lossless | no | |
| -q 8 | ~256 | ~256 - ~320 | lossless | no | |
| -q 9 | ~320 | ~320 - ~500 | lossless | no | |
| -q 10 | ~500 | ~500 - ~1000 | lossless | no |
(1) Only supported on aoTuVb3 and newer
(2) Bitrate of 48 kbit/s is only for aoTuVb3 and newer. Earlier versions and Xiph.org versions use a bitrate of 45 kbit/s
(3) Reports seem to indicate that aoTuVb4.51 -q 1 provides good quality for streaming
(4) Most users agree -q 5 achieves transparency
To know what lowpass frequencies are used for each quality level, see ha thread here.
Advanced Encoder Settings
Reducing Pre-echo
This is applicable to Vorbis 1.1; it may or may not be applicable to aoTuVb4 or aoTuVb4.51.
Generally, using the recommended settings above will give the best quality. There may be cases where Vorbis 1.1 will fail to reproduce sharp attacks or transients in your music, causing pre echo. In which case, you can use the impulse_noisetune advanced encode switch:
oggenc -q n --advanced-encode-option impulse_noisetune=p inputfile.wav
- where p is a number from 0 to -15
- e.g. oggenc -q 5 --advanced-encode-option impulse_noisetune=-5 inputfile.wav
Note that the lower the number (toward -15) for impulse_noisetune, the higher the bitrate will fluctuate in passages of music filled with transient attacks (and the final average bitrate may be much higher than the nominal). Therefore, you should try a small value to start off (say -5) and see if you get acceptable quality. If not, tweak it lower.
Reducing noise due to microattacks
This is only valid for some Vorbis encoders that are marked as having impulse_trigger_profile.
There are certain parts of some types of music, called "microattacks", where Vorbis will produce a noise (sort of like a puff of steam), which is due to inaccuracies in the block-switching algorithm (which can't be corrected). Due to the fact the attacks are so fine and close together, Vorbis doesn't switch to impulse short blocks enough, thus "smearing" the reproduction.
By default (with no additional switches), Vorbis selects a different profile for block switching (lower means less switching, higher means more switching) and the default values are shown in the table below:
| Quality | Profile | Quality | Profile | |
|---|---|---|---|---|
| -1 | 0 | 5 | 2.5 | |
| 0 | 1 | 6 | 2.7 | |
| 1 | 1 | 7 | 3 | |
| 2 | 1.5 | 8 | 3.7 | |
| 3 | 2 | 9 | 4 | |
| 4 | 2 | 10 | 4 |
If you encounter this problem on microattacks, you may try the impulse_trigger_profile advanced encode switch, which will change (increase) the profile to your desired value.
oggenc -q n --advanced-encode-option impulse_trigger_profile=r inputfile.wav
- where r is a number from 0 to 4, fractions accepted.
Notes:
- There is the possibility that relaxed block switching (higher profiles) may cause other quality problems and create suboptimal Vorbis files. Please use it sparingly and with caution. If in doubt, leave impulse_trigger_profile on default (that is, don't use it at all)
- Setting the profile too high will make Vorbis switch to impulse short blocks more often, which will lead to higher bitrate fluctuations. So be conservative.
- This settings has no effect on reducing the level of pre-echo. It can be said to only reduce the likelihood of pre echo, but the amount of pre-echo is tuned using the impulse_noisetune switch instead.
- You may try profiles 5 and 6 as substitutes for 3 and 4. Profile 5 and 6 came from 3 and 4 in GT3b2.
You can use both impulse_noisetune and impulse_trigger_profile at the same time, but you will need separate switches, e.g.
oggenc -q n --advanced-encode-option impulse_noisetune=p --advanced-encode-option impulse_trigger_profile=r inputfile.wav