Subject: Re: [ecasound] cs-toggle-loop?
From: Kai Vehmanen (k@eca.cx)
Date: Sat Jun 16 2001 - 21:05:03 EEST
On Thu, 14 Jun 2001, janne halttunen wrote:
>> - Use EWF for looping: the bug you found doesn't exist with EWF files, so
>> you could just create an EWF looking like this:
> One thing though is that it doesn't sound *exactly* like the loop you
> get with cs-loop. (haven't done any extensive testing, though)
You're right, it doesn't. While ewf looping has sample-level precision,
-tl looping is block based (ie. -b:sample_frames).
To illustrate, let's say we have short 120ms audio file sampled at
44100kHz. Almost all audio software (including drivers) operate on blocks
of audio (usually in the range of 64 -> 65366 bytes). With ecasound, you
set the block size with -b:x. If we use the default -b:1024, our example
audio file is divided into five 23ms blocks (A, B, D, E) and one block
which is only partly filled (F):
0ms 23ms 46ms 69ms 92ms 115ms
A B C D E F
When we use -t, ecasound checks after each block, whether we have passed
the processing time limit. If we have, we either stop (only -t), or go
back to start (both -t and -tl). Needless to say, looping only happens at
block boundaries (with -b:1024 this means every 23ms).
Ewf on the other hand provides "real", continuous looping. This means that
is can handle situations where the loop start and end points are not
at block boundaries (for instance, take first 234 sample frames from block
F, and the rest of from block C).
As a summary, -tl is more like "repeat play" feature of your cd-player,
while ewf-looping is closer to looping feature of sample editors and
samplers.
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