Comments on the new Audio FAQ

[KpeX]

If anyone has any thoughts or suggestions on the new Audio FAQ please post them here. I don't have time to research it right now but I couldn't figure out how to get post linking working so for now there are no links in the first post.

The Audio FAQ now features the original Audio FAQ merged with the AC3 and AAC FAQs, and the questions have been more organized. Hopefully this will be helpful to all.

[Wilbert]

Very cool!

About DTS faq:

Yes, a few ripping tools such as VOBrator, VobEdit,vStrip and DVD2AVI can demux DTS streams.

It is recommended to not use vStrip to demux your DTS streams. It cripples the DTS streams (it adds some bytes to the stream/header, while it shouldn't, or something like that). The relevant thread can be found in the dev. forum.

[KpeX]

Thanks for that info, Wilbert. I'd appreciate any DTS corrections by you or anyone else, DTS is not an area that I have any expertise in or use much. Would you like a link to your DTS guide added to the FAQ?

[bond]

great idea!

tough i still miss the aac faq, hope you didnt forget it ;)


btw about direct post linking, it works like this:
http://forum.doom9.org/showthread.php?s=&postid=424234#post424234

to find out the postid value simply move with the mouse over the "edit" or the "quote" button, this will display the id of each post

[Wilbert]

Would you like a link to your DTS guide added to the FAQ?
Sure!

to find out the postid value simply move with the mouse over the "edit" or the "quote" button, this will display the id of each post
Damn, why didn't anyone tell me this before :)

[KpeX]

@Wilbert

Done.

@bond

AAC FAQ is integrated now.

to find out the postid value simply move with the mouse over the "edit" or the "quote" button, this will display the id of each post

I know how to post-link like that, what I wanted to do is just link to the #post'whatever' so that it jumps to the post without reloading the page and opening in a new window. If it was html I'd just use <a href=#post424070> but I can't find a way to do that with vB code; vB wants to put a http:// in front of the link.

[Wilbert]

4. Is it possible to encode DTS with BeSweet?

Yes, but you'll also need Surcode CD/DVD Pro. Please see Q32 of the Besweet FAQ.

I'm sure you know it, but Surcode produces dtswav and not dts. It can be converted to normal dts with besplit/bespliced, but you put that already in the faq :)

In order to use the dtswav directshow filter (by Hypercube), you have to rename the extension from wav (what surcode produces) to dtswav (and of course register the filter).

[Jukke]

Hi,
In the second post "General Audio Procedures FAQ", at question 16 Please post a list of the most recommended winamp plugins, the third link (http://www.blorp.com/~peter/zips/in_vorbis.exe) returns a 403 Forbidden to me.
Perhaps it is just on my machine it happens, but you might check the link to see if it works for you.

[bond]

Originally posted by KpeX
AAC FAQ is integrated now. i rewrote the first part of question 3 as it is a little bit confusing i guess, it should be clearly seperated what is a codec and what are apps using this codec

feel free to use my proposal:


FAAC (http://sourceforge.net/projects/faac) (Free Advanced Audio Coder) free and open source LC-AAC [Commandline (http://rarewares.hydrogenaudio.org/aac.html), DirectShow (http://www.3ivx.com/) (3ivx), foobar (http://www.saunalahti.fi/cse/html/foobar.html), CoolEdit (http://www.saunalahti.fi/~cse/files/cool_faac.zip)]
Apple's AAC: only CBR atm, doesnt handle multichannel [Quicktime Pro (http://www.apple.com/quicktime/download/), iTunes (http://www.apple.com/itunes/download/)] iTunes uses the same codec but is freely available
PsyTEL's AACENC, dont use it for multichannel as it produces wrong channel mapped files! [Commandline (http://www.doom9.org/Soft21/Audio/aacenc_v215.zip), AACMachine (http://www.doom9.org/AacMachine.htm) (GUI using BeSweet) ]
Dicas' Compaact (http://www.compaact.com/) AAC encoder
Sorenson (http://www.sorenson.com/)'s AAC Encoder

The results of the public listening test conducted by rjamorim, comparing these AAC codecs at 128kbps are available here (http://audio.samharris.us/test/aac128test/results.html)


maybe you also want to add again that it is possible to join *.aac files with dos commandline but not *.mp4 files

I know how to post-link like that, what I wanted to do is just link to the #post'whatever' so that it jumps to the post without reloading the page and opening in a new window. If it was html I'd just use <a href=#post424070> but I can't find a way to do that with vB code; vB wants to put a http:// in front of the link.ic, yes this would be great!
perhaps ask doom9 or swede about if this is possible, if not i would use the linking way i proposed as it is better than nothing and it makes it easier if someone wants to link to a specific faq (via copy paste)

Originally posted by Jukke
Please post a list of the most recommended winamp plugins[/I], the third link (http://www.blorp.com/~peter/zips/in_vorbis.exe) returns a 403 Forbidden to me.you dont have to download this anymore, in_vorbis is available in winamp already by default

[Jukke]

Originally posted by bond
you dont have to download this anymore, in_vorbis is available in winamp already by default
Then the link to in_vorbis could be removed from the FAQ, don't you think?

[KpeX]

@Wilbert

DTS Q4 and Q6 updated, thanks again :).

@Juke

Thanks for noting that. Vorbis is supported now, so the link has been removed.

@bond

feel free to use my proposalI did, and listed it. Thanks.
maybe you also want to add again that it is possible to join *.aac files with dos commandline but not *.mp4 filesI felt it would be simpler and better for newbs to leave this out, especially since BeSplit will do the job quite well.

[bond]

Originally posted by KpeX
I felt it would be simpler and better for newbs to leave this out, especially since BeSplit will do the job quite well.hm i wonder if its easier cause in both ways you will need dos commandline, but in the mentioned way you also need additionally the besplit tool...

[KpeX]

Originally posted by bond
hm i wonder if its easier cause in both ways you will need dos commandline, but in the mentioned way you also need additionally the besplit tool... True. Are there any limitations of the copy /b method? Does it work for VBR or HE or any other kind of weird AAC file you can come up with?

[bond]

according to menno there are no troubles when muxing raw aac, aac with adts header, plain he-aac (of course also not with vbr) files with dos commandline

[KpeX]

Originally posted by bond
according to menno there are no troubles when muxing raw aac, aac with adts header, plain he-aac (of course also not with vbr) files with dos commandline Thanks again bond, it's back in the AAC FAQ Q10.

[Stux]

I would expect you'd want the two files to be of the same type

for example, same channel layout, same samplerate and same profile

[Eye of Horus]

Originally posted by KpeX
Thanks for that info, Wilbert. I'd appreciate any DTS corrections by you or anyone else, DTS is not an area that I have any expertise in or use much. Would you like a link to your DTS guide added to the FAQ?

Addition : Smartripper also demuxes DTS.

And this sentence can lead to wrong conclusions :
"Also imagine transcoding a DTS file to lower bitrates (eg. 1536kbps -> 448kbps) in order to conserve space but maintain the DTS format and quality"

Lowering to 448kbps will never maintain the quality !!

grtz,

Eye of Horus

[KpeX]

Question edited. Most of the DTS section is from Matter's old AC3 FAQ, and as you can tell by quotes like that, there is definitely some DTS zealotry going on.

I think what he meant is that when transcoding to a different format the quality will be better than an AC3 source, but the statement was misleading, and may not even be accurate.

IMO the DTS is superior to AC3 phenomenon is one of the major misconceptions of multichannel audio. For example, you don't hear many users insisting that VCD MP2 audio is higher quality than MP3 audio just because it uses twice the bitrate.

Thanks for that correction, EoH.

[bond]

the links to some faac plugins changed:
the cool edit plugin is now available here (http://www.rarewares.org/files/case/cool_faac.zip)
the foobar plugin here (http://koti.mbnet.fi/chastity/foo_faac.zip)

also you maybe want to add to the quicktime encoder "Qutibacoas" as a Commandline (http://efenstor.stratopoint.com/qutibacoas.htm), (which uses the quicktime encoder dlls, like nencoder does with nero)

also maybe important to mention is that to encode to he-aac with real you have to dl the aac addon package from here (https://helix-producer.helixcommunity.org/downloads.htm), by default real doesnt support he-aac

and winamp5 (http://www.winamp.com/) has joined the list of available aac encoders

and last but not least you maybe want to merge question 9 and 23, or at least place 23 after 9 to keep the extension questions together
also its important to mention that winamp5 and realplayer gold now encode to .m4a by default

[alexnoe]

AAC files are raw AAC data streams, whereas MP4 is a container format of the MPEG4 standard which can contain AAC streams and many other thingsAAC files usually use ADTS packing.
RAW aac files cannot be processed without decoding them...

[KpeX]

@bond and alexnoe:

Q23 merged to Q9, Q9 updated, Q3 updated, thanks. Let me know any more changes.

[P0l1m0rph1c]

About DTS FAQ:

Surcode DVD Pro can create both .DTS, .CPT, and .WAV dts files, not only dtswav.

And, would it be useful to include the OSS dtsdec in the DTS decoding options?

[KpeX]

Originally posted by P0l1m0rph1c
About DTS FAQ:

Surcode DVD Pro can create both .DTS, .CPT, and .WAV dts files, not only dtswav. DTS Q4 Clarified.Originally posted by P0l1m0rph1c
And, would it be useful to include the OSS dtsdec in the DTS decoding options? When it becomes more stable, yes. I haven't tested it yet personally but the development appears to be coming along well.

[bond]

i just saw that the new realplayer gold (which encodes directly to aac in m4a) is the free version and not some payware
(great stuff real!)

maybe realplayer should be added as aac encoder (next to realproducer) as most people will possibly have realplayer already installed and therefore dont need to mess around with realproducer, if they want to encode with aac

[SeeMoreDigital]

Originally posted by bond
i just saw that the new realplayer gold (which encodes directly to aac in m4a) is the free version and not some payware
(great stuff real!)

maybe realplayer should be added as aac encoder (next to realproducer) as most people will possibly have realplayer already installed and therefore dont need to mess around with realproducer, if they want to encode with aac Agreed!

This addition to RealPlayer is very welcome and was quite unexpected (I was expecting AAC in .ram/.rm only). I've been bombarding MusicMatch with emails requesting something similar but nothing positive has happened so far!

Anyways, it nice to see you guys in the Audio Encoding forum discussing future plans... I'm sorry to say that I wish the DivX section of the forum would be as positive :(

Cheers

[KpeX]

Originally posted by bond
i just saw that the new realplayer gold (which encodes directly to aac in m4a) is the free version and not some payware
(great stuff real!)

maybe realplayer should be added as aac encoder (next to realproducer) as most people will possibly have realplayer already installed and therefore dont need to mess around with realproducer, if they want to encode with aac Done, sorry for the late reply, I was away for the holiday. I'm surprised this isn't getting more attention. Unfortunately I don't have time to test RP10 at the moment, does this mean that we now have a fully free LC/HE AAC encoder that outputs MP4 container by default?

[bond]

Originally posted by KpeX
Done, sorry for the late reply, I was away for the holiday. I'm surprised this isn't getting more attention. Unfortunately I don't have time to test RP10 at the moment, does this mean that we now have a fully free LC/HE AAC encoder that outputs MP4 container by default? maybe, i dunno if the realplayer is able to encode with he-aac or only the real/helixproducer...
note that real is not offering officially he-aac! so i dont know if/how they support it, if its bug free, if the care about bugs, support multichannel aso...

[hans-jürgen]

Some updates concerning Audiocoding.com and FAAC:

* The usual website link http://www.audiocoding.com/ is not available at the moment, because the updated site is moved to a new and faster server. But the old link http://faac.sourceforge.net/ still works, also with the new website content (new design, weekly snapshots of the FAAC/FAAD2 CVS source code etc.). So it might be a good idea to add this link to the FAQ, too.

* All links related to different sections of the new website are outdated if they don't contain the /modules/ directory, e.g. http://www.audiocoding.com/modules/wiki/ would be the correct one for the Wiki/Knowledge Base or http://faac.sourceforge.net/modules/wiki/ at the moment. This also affects the forum, the download section and so on.

* Linking to the SourceForge project page doesn't make sense, because there isn't much "newbie" information to be found there, and it's hardly ever updated. So it's better to link directly to the Wiki page for FAAC which I update regularly, e.g. with recommendations due to new software using FAAC etc.:

http://www.audiocoding.com/modules/wiki/?page=FAAC
http://faac.sourceforge.net/modules/wiki/?page=FAAC

* There are other FAAC plugins than the ones for foobar2000 or CoolEdit, e.g. for Winamp (allows transcoding to AAC/MP4 from any input format, e.g. with Xvalex's AC-3 input plugin, unlike the original Nullsoft codec that only works for CD ripping), dbpowerAMP, winLAME, HeadAC3he and CD rippers like CDex, BonkEnc (new version coming soon), Easy CD-DA Extractor or AudioCrusher. The command line version is able to write MP4 files and tag them with iTunes-compatible tags, so EAC, Audiograbber, GX::Transcoder and others are able to use FAAC for this on-the-fly.

* FAAC/FAAD2 are the only available open source cross-platform AAC codecs (Windows, Linux, other *nix version, Mac OS X) so this should be mentioned in the FAQ, too. It means that plugins for well-known Linux apps like XMMS or xmcd are available, too, and development for new ones is possible, e.g. the new gstreamer plugins based on FAAC and FAAD2 which enable AAC/MP4 support for apps like Rhythmbox. This only relates to audio software, but multimedia applications like Mplayer, VLC (new v0.8 with full transcoding capabilities) and Xine are using FAAC and/or FAAD2 for quite some time already, and FAAC has been added to the ffmpeg library lately, too.

* The download links in the FAQ for FAAC versions are outdated most of the time, because at the moment RareWares has the latest binaries of the plugins mentioned above, also for the Linux versions on its Debian page:

http://www.rarewares.org/debian.html

Other *nix binaries for different distributions can be found with search engines like http://www.rpmseek.com/, http://rpm.pbone.net/ or http://www.rpmfind.net/

* Most of this information is provided on the Wiki page for FAAC, but there are other Wiki pages that could be added to the FAQ as well:

http://www.audiocoding.com/modules/wiki/?page=MPEG-4+Players
http://www.audiocoding.com/modules/wiki/?page=Software+Audio+Players+for+Windows
http://www.audiocoding.com/modules/wiki/?page=view/Software+Audio+Players+for+Linux%2FBSD
http://www.audiocoding.com/modules/wiki/?page=Software+Audio+Players+for+other+OS

[KpeX]

Thanks for the info hans-jürgen. I implemented most of your suggestions, and updated the links to point to faac.sf.net. I added the winampl encoding plugin to the FAAC download links section, but in the interest of keeping the FAQ focused on A/V needs, I left out some of the CD-audio related plugins and information.

I also added a question about building/installing FAAC under *nix, and a question about FAAC encoding information that links to the wiki as well as our 5.1 discussion in this forum.

[hans-jürgen]

Originally posted by KpeX
I also added a question about building/installing FAAC under *nix, and a question about FAAC encoding information that links to the wiki as well as our 5.1 discussion in this forum. Right, forgot to mention that... thanks!

[KpeX]

To all linux users / experts / critics ;):

I added some linux information about encoding / playback to the MP3, Vorbis, AC3, DTS, and AAC FAQs. Any criticisms / additions /suggestions are very welcome.

[hans-jürgen]

Originally posted by KpeX
I added some linux information about encoding / playback to the MP3, Vorbis, AC3, DTS, and AAC FAQs. Any criticisms / additions /suggestions are very welcome. The compiling help for FAAC is slightly outdated, because libmp4v2 is now located in the FAAC CVS folder, since FAAD2 doesn't use it anymore.

In my opinion the AAC FAQ in general sounds as if Nero AAC was the only possibility to encode (multichannel) AAC/MP4 files with foobar2000, although using either faac.exe with the command line interface or the foo_faac plugin is easier and more flexible (e.g. supporting the audiobook file extension *.m4b), because it doesn't afford to download, install and register the Nero 6 package.

Furthermore I think mentioning at least HeadAC3he and winLAME as possible transcoder GUIs for FAAC (links on the Wiki page) is interesting for the Doom9.org community (e.g. DeXT announced his winLAME version here).

The usual homepage URL http://www.audiocoding.com/ works again, and Menno thinks it's faster, too. ;) He also disabled the old URL http://faac.sourceforge.net/ yesterday.

[KpeX]

Originally posted by hans-jürgen
The compiling help for FAAC is slightly outdated, because libmp4v2 is now located in the FAAC CVS folder, since FAAD2 doesn't use it anymore.

In my opinion the AAC FAQ in general sounds as if Nero AAC was the only possibility to encode (multichannel) AAC/MP4 files with foobar2000, although using either faac.exe with the command line interface or the foo_faac plugin is easier and more flexible (e.g. supporting the audiobook file extension *.m4b), because it doesn't afford to download, install and register the Nero 6 package.

Furthermore I think mentioning at least HeadAC3he and winLAME as possible transcoder GUIs for FAAC (links on the Wiki page) is interesting for the Doom9.org community (e.g. DeXT announced his winLAME version here).

The usual homepage URL http://www.audiocoding.com/ works again, and Menno thinks it's faster, too. ;) He also disabled the old URL http://faac.sourceforge.net/ yesterday. Okay, libmp4v2 info updated, FAAC links have beeh changed back to audiocoding.com, foo_faac, winlame, and headac3he are in the frontends section. Hopefully that brings the AAC section up todate.

[hans-jürgen]

Originally posted by KpeX
Hopefully that brings the AAC section up todate. Great. :)

[Schnoodledorfer]

In the General Audio Procedures FAQ, Question 13:
13. How can I extract an audio stream (AC3/MP3/OGG/WAV) from an AVI file?

Download VirtualDubmod and open your AVI file. Click streams -> stream list. Click on the audio stream you want to extract; then click demux to remove the stream losslessly, or click decode to decompress the audio to a .wav file. This will work for any audio stream in an .avi file (first/second etc.)


The issue is that there is no "decode" to click on. Instead, there is a "Save WAV" button, but I think that just adds a WAV RIFF header -- the output is still compressed. I've double-checked (with MP3 only) that the resulting file size is the same whether "Save WAV" or "Demux" are clicked. Other posts, for example this one say the same thing. vDubMod's FAQ (http://virtualdubmod.sourceforge.net/?page=faq) implies this as well.

Of course, you can do a full processing mode, select PCM as the compression, and save as a WAV.

[SeeMoreDigital]

By-the-way, AVI-Mux GUI can also de-mux audio streams from .AVI and .MKV contained files ;)

[shon3i]

I think is time to update FAQ

[Schnoodledorfer]

By-the-way, AVI-Mux GUI can also de-mux audio streams from .AVI and .MKV contained files ;)

Also, AVI-Mux GUI reports any delay in the audio (but doesn't report the length of the audio - at least not where I could find it). vDubMod (misleadingly, in my opinion) hides the fact that there is a delay and reports the sum of the delay and length as the audio length. You need to know the delay if you are going to mux again, and winding up with an audio file with a different duration than vDubMod indicated is confusing. Also, someone is still working on AVI-Mux GUI, while vDubMod has fallen well behind vDub. So it might be better to recommend AVI-Mux GUI for demuxing now.

I just wasted several hours trying to figure out how to keep synch while transmuxing an AVI (with no audio at the beginning or end) into an MP4. vDubMod reported one length for the audio (and the WAVs it created matched that length), but the demuxed mp3s were a different length, and the video was a third length. It didn't help that it appeared that the audio might have had some minor corruption, so I spent hours chasing that red herring. :mad:

The morals are: trust the demuxed MP3s, watch for audio delays, and don't believe everything that vDubMod tells you. It's still great that we have vDubMod, though.

[SeeMoreDigital]

I forgot to mention...

It's also possible to extract various types of audio (even AC3) and video streams from out of the .AVI container using MP4Box (with YAMB).... Whoda-thought it ;)