Hi smart people.
Listen, I'm looking for a lossless audio codec that is ACM/VFW compatible, for use in archiving video footage. Before you say anything - no, I preffer not to use MP3/Vorbis/MPC/WMA or anything lossy. I want it AS LOSSLESS AS POSSIBLE. Could you help me? All the losslessian-codecs that I found produce strange uncompatible files of their own, with bizzare WinAMP plugins. I would really like to find one that matches my requirements. If you could help me I will be forever thankful.
All the best, and better,
Mister Hatoola.

I am pretty sure that there isn't such a thing. Unfortunately, most of the lossless formats were not designed with this in mind and can't be made to work with ACM. I believe there was somebody working on a ACM version of FLAC (which is streamable) but I don't think this got anywhere. And, of course, even if this was done it still wouldn't be perfect because lossless codecs are VBR by nature, and ACM doesn't work too well with VBR formats.

I seem to recall something about windows media 9 had a lossless audio codec...

I don't know whether it got any farther than this either, but I'd love to believe such is possible. Found this in the flac-dev archives:



This is from the same guy who wrote mpa2wav, ac32wav, and an alternate version of out_lame, but his root site doesn't list anything more about the development of anything ACM-related. Maybe he didn't have any time to continue....

- M.

I believe that WMAv9 supports a lossless compression mode.

Also, now that WavPack sources are available, I believe this may be your best bet at a codec that would be able to be crammed into an ACM/DMO.

NOTE: Edited for clarity.

Just found a more recent post from Steve Lhomme in the archives, regarding the possibility of an ACM codec:



I'd still love to see one though, if anyone else knows how to do this...? An ACM FLAC codec would open up such possibilities as on-the-fly audio CD burning from any FLAC source, opening FLACs directly in a Wave editor, etcetera. (Yes, I am aware much of this is already possible with Monkey's Audio, but I do not use Monkey's Audio.) Or would a UCI codec allow all the same functionality? I'm afraid that's a standard with which I am not - yet! - familiar.

- M.

You could leave the files as original .wav files. I know this would consume more disk space, and probably isn't what you want, etc., however you wouldn't have any plugin's to mess with.

Thankyou all for your replies. You are all good men indeed.
1. I also noticed WMA9 has a lossless codec, but since it isn't exactly (correct me if I'm wrong) ACM/VFW compatible, it doesn't fit to my needs; I preffer not to encapsulate my audio/video in a non-AVI format, since the AVI is the most compatible one, and it would be easiest to use my archived footage in the future this way.
2. Since my footage contains video, keeping my audio in its original WAVe file isn't gonna work - it didn't came from any WAVe file, just a DV/MJPEG AVI.
3. Is WavPack currently able to encode/decode as an ACM? Has it been already implemented that way, or is it just possible to do that in the future?
4. I'm sorry, I am not familier with UCI codecs, could someone please explain what these codecs are? Are they VFW compatible? Are they used in a different file type (aka OGG, MP4)?
5. Although I can leave the audio stream in my AVIs uncompressed, 16-bit stereo 48kHz consume a lot of disk, especially when we're talking about burning the AVIs onto CD-Rs.
Mister Hatoola.

3 - It isn't currently an ACM, put it would be possible to make it one, in theory.
5 - You have to remember, at best, lossless will get you 2:1 compression on a good day.

Do you really need stereo sound? Is this shot from a camcorder or similar mono source? If so, then just convert the files to mono and skip the compression step.

I am sorry to reply that late, somehow i must have missed this thread.

Please allow me to clarify a few things here :

1. Steve 'robux4' LHomme, is 'chief developer' of matroska ( http://matroska.org ), a project fork from MCF. He made Lame ACM codec and wanted to work on FLAC ACM codec when he noticed that the ACM codec API can not support VBR audio codecs correctly ( you have to make hacks, and Steve doesnt like hacks ). As AVI is relying on ACM audio codecs almost completely there is no proper way of putting VBR audio streams into AVI, without breaking specs.


2. When we started to work on MCF ( now matroska for me and Steve ) we soon recognized that creating a new container alone doesnt solve the problem at all, because still all codecs to be used from video file creation/capturing/editing programs like Virtualdub were relying on ACM codecs almost, so we still could not support VBR audio codecs correctly, unless we hardcode support for them into our modified versions of such tools, and into the MCF/matroska parser.

As a result we decided to create a new codec API also, replacing both VfW and ACM. This task was enormous and almost killed the whole project, a first draft of this API is still here : http://matroska.org/transor/ . Fortunately at this time we got in contact with Alex 'Foogod' Stewart, who wanted to create a common codec API for *nix/Linux, as no such thing existed yet. We talked to him and convinced him to extend his work to a x-platform solution, so UCI = Universal Codec Interface ( http://uci.sf.net ) was born. The project was pretty quiet lately as Alex was busy with other stuff, but it definitely is progressing now again ( recent changes were uploaded to CVS 2 days ago ).

We have a working alpha of a mod Virtualdub, developed by Cyrius ( main developer of VirtualdubMod ), with a compiled version of libuci for win32, and some statical linking to it from the VdubMod source code. Cyrius was creating a first UCI 'codec' already ( a YUV --> YUV forwarder ) just to prove the concept, and its working.


3. Steve LHomme was talking to Josh Coalson already about a UCI interface for FLAC, this conversation can be found on the FLAC-devel mailing list ( news://gmane.comp.audio.compression.flac.devel ). I dont know if Josh is still positive towards this interface, now as FLAC is a part of Xiph and Emmett seems to question both matroska and UCI constantly ( sorry, couldnt resist ).


4. A UCI version of HuffYuv for capturing should be a breeze to make, given the simple interface structure of this codec. This would allow to make captures with a modified version of Virtualdub, using lossless video codec and a lossless audio codec ( the dream for capturing ).


And no, i wont give any timelines ( prepared to suffer from more bashing now ... go on guys, keep it coming, its very motivating for all of us to finish what he have started, with the best intentions as a lot of people can testify ).

Best regards

Christian

I'm Steve Lhomme and I fully agree with what Christian said.

As a side note, I got into the MCF/matroska thing especially to do better capturing than in MPEG2 with my TV tuner/video in. AVI is not possible when data loss is involved (because of possible frame loss, then you lose sync between audio and video). And of course lossless cpaturing is the best of all, so you can do a clean 2pass encoding later in better/smaller codecs... Just to say that FLAC in matroska is definitely in my TODO list. Otherwise I don't know of any other existing alternative (so far).

I'm OK with it. FLAC is neutral towards containers. I don't have any plans to personally do anything with UCI right now because I have too much on my plate but I'm not against someone else doing it.

Josh

Hi Steve. All right; supposing matroska and UCI are solutions for lossless video compression, how does that address the need for a lossless audio editing system? Will UCIs be globally accessable from ACM-capable programs (such as Sound Forge, WaveLab, Cool Edit...), or will they always require programs designed to be UCI-compatible?

- M.

@misterhatoola:
what i would do is:

1. demux the audio, pack to flac or ape, keep that as a separate track
2. encode the audio to low-quality mp3 or maybe ogg (cue track)
3. dont know what are your plans for video?
4. mux the video+lowquality cue track (mp3 or ogg)
5. burn the new muxed thingy + flac/ape soundtrack + decoder

that way you will have a way to preview your files; and if you plan to do some editing later on, you can remux the decoded flac/ape with your video...

Well, my main interrest in ACM was to use it in VirtualDub. But since UCI will be natively supported by VirtualDubMod, ACM won't be necessary anymore on that side.

For other ACM compatible, we can't reasonably expect these to switch to UCI right away So yes I think it's possible to use all UCI audio codecs through a special ACM codec (that I could code later). Of course you'll lose a lot of flexibility of a real UCI codec (especially the better VBR handling).

Also please note that ACM is discouraged by Microsoft now, to compile an ACM you need a DDK (Driver Development Kit) and I think the required headers are not in the XP one anymore (W2K still have them). They encourage using DirectShow Filters or DMO (a simpilified API for codec). So these big apps you mention will probably switch to that (superior) API too.

I really cant add more than robux4 had said already, except that there is not only the possiblity to have an ACM wrapper for UCI codecs ( with much reduced capabilities of course ), but also

VfW --> UCI wrappers : To allow using VfW codecs in UCI based apps ( matroska parser for decoding )

ACM --> UCI wrapper : Same as above for ACM codecs

Dshow ---> UCI wrapper : Same as above for any DirectShow based codec


and also

UCI ---> VfW wrapper : UCI based codecs can be used in VfW apps ( Virtualdub )

UCI ---> ACM wrapper : as explained above, reduced functionality only, limited by ACM

UCI --> DShow wrapper : not sure how to do this exactly, but it could be done


But to take the bashing out front : Lets first get UCI to work before thinking about generic wrappers ...

EDIT : In order to not putting oil into the fire i left out some other open source codec APIs ... but of course these could be wrapped also ...