Date: Fri, 19 Sep 1997 13:50:07 -0700 From: Buzz Kettles <buzz@macromedia.com> Subject: Re: ShockWave Audio SettingsYES - There is a very IMPORTANT reason ... External files (.swa) have to fit through a modem, so we offered lower stream rates for SWA files ... If everybody had ISDN lines & faster, we wouldn't have offered 8, 16, & 24kbps for .swa files.
The difference in savings is pretty slim - If the original source was imported at 16/22/mono then files = 44k/sec + header Compression yields: 32kbps = 4k + header, 16kbps = 2k/sec + header, & 8kbps = 1k/sec + header
Sure the compression 'rates' increase (11 to 1, 22 to 1, 44 to 1), but the SAVINGS doesn't ...
11 to 1 compression means that about 91% of the sound has been tossed ... (= amount of savings) Similarily 22 to 1 = 95.45% gone & 44 to 1 = 97.7% gone ...
BUT - the change in audio quality going after this last few percent of savings is IMMENSE!
The idea is for authors to be able to use high quality sound within their Director work (Internet & Desktop) for a fraction of the byte cost that funky old 'Multimedia Tone' used (8/11/mono).
Low Quality sound burdens the end user. - It is incredibly tiresome & can turn off those users listening in headphones or using good speakers. I cannot listen to many older titles anymore because the bad sound quality is extremely distracting & unpleasant.
High Quality sound enhances multimedia in a way that is often understated - In my experience, the Best titles almost always have subtle and incredible implementations of Director's sound capabilities.
Bottom Line - & some important facts about using sounds in Director - There is NO reason to use 8bit sounds anymore if the sounds are going to be Shocked (Used in a .DCR or .CCT). After compression, 1 second of 8/11/mono sound = 1 second of 16/44/mono, so there's no savings to using source sounds that have been downsampled into the 8bit space. Beyond this, ALL swa-compressed sounds reconstruct to 16bit, so why use 8bit. EVER ... (& Remember, since internal sounds play back from available RAM, there IS a benefit to downsampling the sample rate from 44kHz to 22kHz - after reconsturction, they will fit in RAM better & the loss in quality is minimal)
If your sounds are sound effects, they're not very big anyway - If you need to shrink your file, make sure all your bitmaps are as small as they can be ... If one of those is wrong, it will overwhelm any savings that audio compression can gain you.