Re: [kidsgames] Word database

[Erik <br0ke@math.smsu.edu>]

On 19-Feb-2000 Steve Baker wrote:
> Kidsgames Project Coordinator - Jeff Waddell wrote:
> 
>> -->I think there are a few things I'm really going to need help with are: a
>> -->recording mechanism, maybe one that can be used from inside of forms for
>> -->enter the data, what is a good format, mp3 wav...
>> 
>> I personally like .au (Sun audio format, but I'm not sure the status of
>> that format)
>> 
>> I can't recommend (even though I'd like to) .mp3 or .wav because they have
>> patent issues.
> 
> MP3 is very costly (in time and code complexity) to decode - it's compression
> is also optimised for music, not voice.  I don't recommend it.
> 

mp3 is expensive to decode and extremely expensive to encode, but the
optimization if for general sound, not just music. It's highly effective for
voice, and if you use low bitrates and mono, it's incredibly small and fairly
cheap to decode. decoding into persistant buffers would probably be a good move
to low powered computers (IE, store them in mp3 on the hdd, but cache them
uncompressed in ram or tmp files). For a small low quality mp3, the time to
decode would probably be a fraction of a second on even a 486. 

the MP3 format itself is an iso standard and is free for use, the patent issues
are with a specific algorithm that Fraunhofer-IIS patented for encoding, but
the format is open, and there are free implementations available. I've read
about some upset with patents and iso standards, so I'm not 100% sure :/

> WAV is nasty to decode and being a Mircosoft product is liable to change
> with every new release of Windoze.  I don't like it - but it is a pretty
> universal standard - and you should probably support it.
> 

modern wav only has one small header difference from RIFF format and hasn't
changed in the real format for a long long time. I'm not quite sure what the
difference between AIFF and RIFF are, but they're very old formats. MP3's are
actually compressed RIFF/wav audio files

> AU is OK too.
> 

au has some quality deficiencies, but is probably good enough for plain voice. 

>> --> Another thing is the
>> -->image files format? pcx png gif????
>> 
>> I recommend AGAINST gif due to the Unisys patent fiasco.  PNG should be
>> great, and if somebody submits a gif, it can't be too hard to pull it into
>> the gimp and resave it as .png before it is made globally avabilable can
>> it?
> 
> Choosing GIF could be very bad news. If a GIF is generated from a
> non-licensed
> program (eg GIMP) then if you have that file on your web page - you could
> be liable for a $25,000 license fee to UniSys...don't go there!
> 
> PNG is an excellent choice.  There is a convenient portable library for
> reading and writing them, they are suitable for the WWW and are nicely
> compressed with a LOSSLESS compression scheme.  You might also consider
> 'MNG' - which allows simple animations to be stored in the file just as
> GIF does - and which is based on PNG.  Both PNG and MNG come from the
> OpenSource community and are FREE in every sense.
> 
> JPEG is another obvious standard - but beware because JPEG is a LOSSY
> compression scheme - the image you get out is not as good quality as
> the one you put in.  This isn't too noticable for photos - but for simple
> 'cartoonish' images (such as this project is most likely to use), JPEG
> produces nasty 'ringing' artifacts around sharp colour transitions.
> JPEG also doesn't allow an 'alpha' channel - so no transparency - also
> no GIF-style animation.
> 
> PCX is obsolete....let's not go there.
> 
> Another format I like is '.rgb' - or 'SGI' format.  It's VERY easy to
> read and write - allows for monochrome images and images with transparency.
> No animation features though.
>  
> TIFF may be worthy of investigation - it has a lot of obscure varients
> though and some 'extensions' make it hard to read well.
> 
> There are a variety of X-windows formats - but they are not well used
> or supported under Windoze...so let's not go there.
> 
> BMP is the commonest Windoze format - but just like WAV, it changes with
> every new version of Windoze and is not too well documented.
> 

GIF is evil, pcx and tiff are prehistoric and so de-standardized they're almost
worthless, there are a few differnet rgb/sgi formats (I've seen some with
headers and some without... I beleive imagemagick produces rgb and rgba without
which means very easy parsing, but absolutely no compression). JPG and PNG are
the two best ones, and libraries exist to handle them easily (the libraries
even exist on windows, crystal space uses 'em). 

> As for the format of the database itself, I'd STRONGLY recommend
> that we go with XML - which is a spin-off of HTML and which is going
> to become a big-time standard for web-based databases.  Hopefully,
> most database engines will ultimately support it.
> 

Tools to convert between dbms formats are pretty trivial to write, and mysql
can 'export' files into a script of sql commands. SQL is a well defined and
common dbms language, and it's here right now. I don't know of any mature
dbms's for XML, it'd be nice if they went that way, but it's not a certainty.
If you want to implement one then switch to the other, it'd be trivial to write
conversion utilities. The actual dbms chosen is actually fairly moot, the more
important thing is the schema used.

> While you are thinking about standards for things like images and
> sounds, why not also consider a format for 3D models.  Allowing people
> to attach a 3D model to a word is going to be very important for the
> future.  2D is dead!
> 
> There is one clear format for 3D in a situation like this - and it's
> VRML.  This allows for animations and even simple 'behaviours' to
> be attached to a model.
> 

that would be cool

> Conclusions:
> ~~~~~~~~~~~~
> 
> I would recommend:
> 
> * WAV or AU for sounds.
If a lot of sounds are present, a more compressed format, like mp3, would be
better.
> * PNG or MNG for pictures and 2D animations.
png/mng and jpg/mpeg both are good choices
> * VRML for 3D models and animations.
> * XML for the overall database structure.
moot and pointless, it's an implementation detail, how the tables are built is
far more important than if they use xml or sql or dbase or whatever

> 
> -- 
> Steve Baker                  http://web2.airmail.net/sjbaker1
> sjbaker1@airmail.net (home)  http://www.woodsoup.org/~sbaker
> sjbaker@hti.com      (work)
> 
> 
> -
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        -Erik <erik@smluc.org> [http://math.smsu.edu/~br0ke]

The opinions expressed by me are not necessarily opinions. In all
probability, they are random rambling, and to be ignored. Failure to ignore
may result in severe boredom or confusion. Shake well before opening. Keep
Refrigerated.
        
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