unofficial abma/aba faq
Annotated :: Single Page/Plain :: Text :: Notes

1. Preface
2. Introduction
3. Newsgroups
4. Encoding
     a. uu
     b. mime
     c. yEnc
5. Archives
     a. .rar/.r##/.part##.rar
     b. RAR recovery
     c. .ace/.c##
     d. .###
     e. .zip
6. Support Files
     a. .sfv
     b. .par/.p##
     c. .rev
     d. .idx/.sub/.ifo
     e. .smi/.ssa/.srt
     f. .nfo/.txt/.md5
7. Newsreaders
8. Posting
     a. Bad Requests
9. Auto-Posters
10. Hentai
11. Formats/codecs
     a. avi/ogm
     b. mpeg4
     c. mpg
     d. rm
     e. audio
     f. linux
12. News servers
13. Software
14. Appendices
     a. About the FAQ
     b. Mirroring the FAQ

The new home of the FAQ is http://animeusenet.org/wiki/.

This site exists only for historical/archival purposes.

11. What is this media format? How do I play it?

Preface [xo - 2001-07-27]

There is seemingly no end to the type of file formats posted, and each requires at least an understanding of which player can handle the format.

It's also good to understand the limitations formats can impose. Some are "dead end" formats in that there exist no way to convert from it to another. Some are proprietary in that they only work on one platform, so users of other OS's are unable to enjoy files of that format. Some have low CPU requirements, while others will stutter badly without current hardware. And so on.

Most of the information provided is oriented to the Windows platform, with some non-Windows notes intermixed. A Linux-specific FAQ-within-a-FAQ is provided by darkwire.

User Contributed Notes

2001-09-11 05:11am
I had an audio problem recently, thought my eventual solution might save people the headaches I went through. The symptoms: WMP would attempt a download and fail. The video would play properly, but there would be no sound.

Viewing properties for the file would list <code><b>Microsoft ADPCM,</b></code> as the audio codec and VirtualDub would list <code><b>Unknown (tag 0002)</b></code>.

As it turns out, I didn't have the codec "Microsoft ADPCM" installed as indicated in the Multimedia control panel. The tricky part (for me) was figuring out where to get it.

I found this page describes the process of installing it: http://support.microsoft.com/support/kb/articles/Q141/8/01.ASP

In short: Add New Hardware->Next->No, select from list->Audio, video, game controllers->MS audio codecs->ADPCM CODEC

It was sitting on my drive all along :p.

2003-01-29 06:57pm
.ogm is not a 'new multimedia format' precisely. It is merely a hacky way to get Ogg/Vorbis audio mux'd with a video stream and keep it synchronized. Since Ogg/Vorbis audio is variable bitrate and not constant, audio drift would occur when attempting to embed Ogg/Vorbis audio into something like an .avi, even if you bloated the file by trying to syncronize it every 2 video frames or so. The first attempt at a workable solution, then, was to embed the video instead into an Ogg file. Since Vorbis is just carried around in an Ogg file (thus Ogg/Vorbis) you get something analogous to Ogg/Video+Vorbis because Ogg files have a built-in timing mechanism that keeps everything syncronized. Thus .ogm isn't precisely 'new', but instead it's just a new way of combining existing formats. Now to the point... tobias is lazy. It took him months to update his filters to Vorbis 1.0 when it came out; yet the filters remain unique to his site, and demand to have them is growing rapidly. The best pathetic solution I can give lies somewhere along the lines of 'get it from a friend who has managed to get version or so'. I'm aware that Windows users don't care, but my machine chews through .ogm files 'for breakfast' without flinching... but then, support for the 'format' is built-in to my players, under Linux.