Windows WAV File Bug & Compiled File Routines
- To: mathgroup at smc.vnet.net
- Subject: [mg5088] Windows WAV File Bug & Compiled File Routines
- From: Mark Evans <evans at gte.net>
- Date: Wed, 30 Oct 1996 22:03:36 -0500
- Organization: None
- Sender: owner-wri-mathgroup at wolfram.com
I'm very impressed by 3.0, but Mathematica is still a real bear when it comes
to working with data files. I think WRI should implement some compiled C code
to read and write the most common file formats that exist on PCs and Macs,
instead of forcing everyone to rely on Read and its family of functions.
Will anyone second the motion?
Here is the latest file reading bug: The package Miscellaneous`Audio` does not
read all Windows .WAV files correctly. It reads 8-bit files, albeit at a
snail's pace, but has problems reading 16-bit files. It will interpret the
header correctly, but then fail to read the actual data.
I had to truncate my 12.5 second, 44100 Hz, 16-bit mono file to 8 bits, and
then wait a long time, to get it into Mathematica. It took at least 60 seconds
on a P166 machine. By contrast, some of the freeware sound utilities that I
downloaded from the Internet take about a tenth of a second to read in this
Of course, the package does not offer a way to write .WAV files back to disk.
This omission is in itself a great deficiency.
If you look at the file-reading code in Audio.m you begin to understand why (1)
reading files into Mathematica is slow, and (2) error-prone. There are all
kinds of flips and flops relating to byte ordering, scaling and the like that
cry out for compiled routines instead of interpreted execution.
I love Mathematica, and yes it can do everything, but in cases like these I
request compiled code. I respect the work that has gone into many of these
file-reading utilities, and I am thankful for what I have; but it seems to me
that if the freebies I pull down from ftp sites can read and write .WAV files,
then a mammoth like Mathematica should be able to pull it off with ease.
evans at gte.net
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