On Sat, Dec 27, 2003 at 04:47:05PM -0800, T. Joseph Carter wrote:
> On Sat, Dec 27, 2003 at 01:06:44PM -0800, Ben Barrett wrote:
> > I can suggest ncftp for a very good CLI FTP client.
>
> lftp is also rather nice, but it is not always perfect (it doesn't show
> the MOTD for example..)
>
>
> > AVI is a wrapper, AFAIK, for a wide variety of stuff. Even for divx, there
> > are multiple versions. There are some alternative media players for 'bloze
> > on sites such as cnet's download.com ... best wishes for a media-filled new
> > year!
>
> AVI files are actually RIFF files given the AVI extension so you know that
> they contain video. RIFF is also used by WAV files, with the WAV
> extension meaning that the files contain PCM sound data with no or
> lossless compression.
>
> Apple's equivalent to RIFF is called moov. The name of moov is taken from
> its first tag which holds the header information which identifies the
> file's contents. Both come from the Amiga IFF file format, which is
> described by many Amiga fans as "binary XML". I do not know what the R
> stands for in RIFF, but RIFF is a little-endian format. The Amiga and mac
> both are big-endian. The structure of the file, regardless of whose
> version you're using, is as sequential blocks prefixed by a block size and
> type. I believe the size is a 32 bit number. The type is four bytes and
> is intended to be ASCII for some measure of sanity when viewed in a hex
> editor. ie, moov being the QuickTime format used originally for QT movies
> only, the identifier makes perfect sense.
>
> A little more useless/random information, file(1) indicates that WAV files
> are RIFF WAVE. You guessed it, WAVE is the name of the block which
> contains the header information telling you that the file is PCM data,
> what rate, how many channels, etc.
>
>
> Caveat 1: Whether the block name or size comes first, I can't remember off
> the top of my head.
>
> Caveat 2: Given how much uses the moov format these days, I have to
> wonder if I'm not mistaken about its origins with QuickTime.
>
> Caveat 3: I'm not sure if moov is in fact just Amiga IFF and the only
> thing special about it is the signature tag.
>
> Caveat 4: In order for IFF to be binary XML, one must see nesting.
> Indeed, there is nesting, but not as much as you find with XML. At some
> point in the file, you wind up with one or more huge bloxks of data in
> some format specified either by the header or the name of the tag itself.
>
> Vaveat 5: There are too many caveats in this bit of useless information.
<@Knghtbrd> LordHavoc: moov is basically IFF isn't it?
<@LordHavoc> Knghtbrd: similar overall but not quite
<@LordHavoc> Knghtbrd: 4 byte size, 8 byte name, then the data
<@LordHavoc> Knghtbrd: IFF is 4 byte name, then 4 byte size, then the data
<@LordHavoc> Knghtbrd: (same as RIFF and AIFF)
<@LordHavoc> Knghtbrd: differences between IFF, RIFF, and AIFF are in name
restrictions (IFF requires all names be uppercase, for
example, RIFF and AIFF do not impose that restriction, and
RIFF is little endian where as the other two are big endian)
<@LordHavoc> Knghtbrd: and in completeness (IFF is a larger spec than RIFF
and AIFF which do not support things like archives, catalogs,
and certain other special constructs)
<@LordHavoc> Knghtbrd: and of course in who runs the registration body
<@LordHavoc> Knghtbrd: (all formats are supposed to be registered)
moov begins with those four letters. After that is a Uint32 size, char
name[8], and data. Nesting of tags is doable only because Apple has
decided that it wants to do that - the data is a binary black box as far
as the format is concerned. Interesting is that AIFC files on the mac are
not in AIFF format, but actually moov format.
That's enough useless information for one day. ;)
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