Subject: Re: [linux-audio-dev] MIDI routing, FIFO's etc.
From: Paul Barton-Davis (pbd_AT_Op.Net)
Date: ma loka 11 1999 - 15:52:25 EDT
>On a related note, why aren't the advanced features of sound cards (in
>particular, patch dumping) performed through sysex commands rather than
>ioctls? It seems a natural to me to keep everything inband.
speed, partly, but more significantly, it involves creating a sysex
implementation in the device driver. most of the cheap soundcards
don't support actual MIDI data to control them, so the driver has to
parse a MIDI stream and then tweak bits and bytes on the card to get
it to do the right thing. sigh.
but take the example of the nicely designed Turtle Beach Tropez+. This
card has an ICS2115 wavetable synth, which very kindly runs firmware
that allows it to handle an actual MIDI data stream. so, you can, if
you want, do patch loading etc. via the MIDI port. so why not ?
because its about 100 times slower than doing Intel i/o port data
transfers, and when you're downloading a 10MB sample to the synth,
that speed difference matters *a lot*.
given that h/w implementations of MIDI are rate limited, it normally
makes no sense to use it as a communication channel for large amounts
of data *when a massively faster alternative is available*, the MIDI
SDS not withstanding :)
--p
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