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To make the CDs, I extracted the audio tracks off the originals into AIFF format files on my hard drive under the MacOS, then burned the audio CD's with Adaptec Toast. Quite some time was required to save all the audio data, and it is quite large, so rather than throw out the AIFF files after I was done I saved them onto ISO 9660 CD's as data files, in case I want the tracks back to do some further processing.
I was concerned about being able to read the AIFF files on different platforms so I tried out the ISO 9660 CD's on five operating systems: MacOS 8.0, Windows 95, Windows 2000 Server release candidate 1, and BeOS Release 4 and Release 4.5 for Intel processors. QuickTime for both MacOS and Windows was used as well as the standard Windows media software, with the BeOS Media Kit being used on the Be system.
The results show that there is a tremendous difference in the audio capabilities of different platforms, and also show that the CPU speed of a system doesn't have that much effect on the performance for audio, but that the operating system software effects it tremendously.
The audio files were 44.1 kHz 16 bits per channel stereo files, uncompressed, ranging from 26 to 72 megabytes in size.
I found that some audio files that would just fit on one CD in audio format (taking 68 minutes of a 72 minute CD) would not fit on an ISO 9660 CD, so I had to leave one song off my backup. There's two reasons for this - audio CD's are just raw sound samples with no control data interleaved in the tracks, while AIFF files are in "chunks" that contain a certain amount of extra information that's useful to the sound software but that does not make sound itself. Also there is some overhead for the ISO 9660 filesystem.
The ISO 9660 CD's were made with Toast using the CDROM (as opposed to CD-XA) format, and the "Allow Macintosh Names" and "Use Apple Extensions" checked. Using Apple extensions I suppose allows the resource fork to appear as part of a single file when under the MacOS and also saved the type and creator code.
The hardware used was a Macintosh 8500 with a PowerPC 604 at 150 MHz for MacOS 8.0, a homebuilt PC with a Pentium II at 233 MHz for BeOS 4 and 4.5, Windows 95 and Windows 2000, and a Dell with a 500 MHz Pentium III with Windows 2000. Note the tremendous range in raw CPU power used in the tests.
This was the system the CD was mastered on. The files would play fine off the CD and the hard disk. Only one file could be played at a time, if two were opened in MoviePlayer, the frontmost player would be the only one that would play.
The non-preemptive (or cooperative) multitasking of the MacOS had problems here. Basic audio performance was error free, but simple user interface actions like holding down a menu would stop the music.
This was with an old version of the system and QuickTime, I will try the test at a later date with a more recent system and QuickTime version - but note that the 8500 is an "AV" system, presumably made with hardware that optimizes real-time data throughput. Even though this is considered a slow machine nowadays it played the file flawlessly until it was stopped cold by architectural limitations of the MacOS operating system.
Doing a "Properties" on the AIFF files showed that Windows recognized them as "Sound Clips - AIFF file" but Windows could not be made to play them. Double clicking the "*.aif" files off the CD would open an Active Movie control then get an alert that said "Class Not Registered".
Opening the files from the File menu of Media Player would open the file and apparently read through the file - time would elapse on the counter - but no sound was produced.
I think that Windows 95 is built to recognize that AIFF files can contain audio but does not come with the software to actually interpret the files and convert them to sound.
Again Windows would open the file and time would elapse but the files would not play.
Again the software for interpreting AIFF files is not present.
Note that all the server software except the AppleShare server was stopped on this system, and none of the networking was active.
I downloaded QuickTime 4 for Windows from http://www.quicktime.com over a DSL connection at my client's office. The file downloaded with a web browser is actually just a stub installer at 450 kb; after selection the installation options (Full), the stub installer downloads the software itself as a 6 MB file. There does not seem to be any way, however, to take the 6 MB file downloaded by the stub and install it on another machine without re-experiencing the download - a big problem for me with my 28.8 kbaud modem at home.
QuickTime would open the files in its player from the CD and play them. But the sound was corrupting by a fine-grained stutter or crackle, as if the sound was dropped every other instant then started up again.
I copied a file to my C: drive (an IDE disk) and tried again. Now the files would play correctly if left idle as the front application. If put into the background the stutter would start again. Using a 16 bit windows application (the QuickBooks timer from Intuit) was disastrous - sound would be interrupted for large portions of a second and sometimes shut off entirely.
Simply opening the start menu would cause large dropouts in the sound.
Copying a large file while an AIFF file was playing would cause breakups and stutter.
Again, QuickTime would open more than one file but only the frontmost would actually play.
I only tried this out a little bit. Files would play fine with the PlaySound tool, and interestingly you could play two at a time and they'd play correctly if the tracks were recorded physically close to each other on the CD media. Three tracks, or two far-apart tracks would have frequent dropouts.
It's interesting to note that the BeOS Media Kit on R4 running on a 233 MHz Pentium II fared better than either MacOS 8 with an old QuickTime or a 500 MHz Pentium III running the latest QuickTime 4 - the new Media Kit API was incomplete and pretty buggy on R4.
As a little background for those unfamiliar with the BeOS, it is a new operating system from Be, Inc. (NASDAQ: BEOS) that is engineered from the ground up to be applied to multimedia. It features preemptive multitasking with sub-millisecond latency, multithreading, a preemptive, multithreaded kernel, and a multithreaded filesystem. If you have a motherboard with more than one microprocessor (which I don't, sadly), it supports symmetric multiprocessing.
It has a C++ API for native applications plus it has a Posix layer for easy porting of unix applications.
It runs on the now-discontinued dual PowerPC 603 BeBox, certain models of PowerPC 603 and 604 Macintosh and Macs with G3 upgrade cards (but not on currently manufactured Macs, due to animosity from Apple), and Pentium-compatible processors.
Note that I had it running just fine on my PC with 32 MB of memory for routine use (although it wasn't sufficient for development in recent releases), while Windows 95 required 96 MB for routine use, and Windows 2000 Server wouldn't even run at 96 MB and the machine now has a total of 224 MB of physical RAM, thanks to Microsoft.
This release of the BeOS has the full-featured new Media Kit API, but still some bugs - there have been a couple patches released since this that I haven't downloaded yet.
Again, two files would play fine off the CD if close to each other. Or you could play one files while copying several files at a time to the hard disk with no dropouts in the sound.
I hit a bug, though, after a little while sound output stopped entirely and could not be restored, even by restarting Media Services. This has been a frequent complaint with the new media kit all along, although it happens much less in R4.5 than earlier releases. I imagine the patches would help here.
I restarted, then continued copying AIFF files to my hard disks, one an IDE and the other on narrow SCSI. I found that it was significantly faster to copy the files one at a time, letting the previous one complete before starting the next, rather than copying them all at the same time even though the Tracker (the BeOS file browser) would do a multithreaded copy. This may be due to the mechanical limitations of the CD drive. Perhaps the ISO 9660 filesystem add-on is not multithreaded, I don't know.
After copying as many files as I had room for on my hard drives, plus playing some files that were already there, I found I could play 9 files simultanously with no errors in the sound. The sounds were all mixed, though, raising a great cacophony, until one uses the volume controls to emphasize particular songs. The BeOS MediaPlayer can adjust the sound in each window, or you can open the Media preferences application and select the Audio Mixer item to have a master volume control as shown here:
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With most of the sound volumes set low, it had the ambience of a crowded public space, and as I raised and lowered the volumes on the different songs, it was as if people were walking by with radios playing.
The songs used in the test were:
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