Subject: Re: [ecasound] Pitch shifter (-ei) broken with JACK output?
From: Mario Lang (mlang_AT_delysid.org)
Date: Tue Jun 22 2004 - 21:53:50 EEST
janne halttunen <janne_AT_fbn.homeip.net> writes:
> On Thu, 17 Jun 2004 20:58:51 +0300 (EEST)
> Kai Vehmanen <kai.vehmanen_AT_wakkanet.fi> wrote:
>
>> On Thu, 17 Jun 2004, Mario Lang wrote:
>>
>> > I just found out about this, and now I am wondering if this is
>> > perhaps a well known problem after all?
>>
>> Yep, this is a known issue. From ecasound/BUGS:
>>
>> --cut--
>> [ Known Bugs and Features ]
>>
>> - pitch shifter (-ei) doesn't work with all real-time audio object
>> types (for instance JACK)
>> --cut--
>>
>> > I guess this is related to the fact that JACK requests a fixed amount
>> > of frames.
>>
>> Yes, this type of effect simply cannot work with JACK. You could try the
>> LADSPA pitchshifter plugins instead (check for example swh-plugins).
>
> Yes, this has been discussed couple of times earlier. It seems that it
> would require quite big changes to the engine to have (-ei)
> pitchshifter to work correctly.
I see, this answers my second question I guess. Since I have the
impression that it should actually be doable if the input
object is not a realtime source. Oh well, so much about using
ecasound as a classical turntable with JACK by starting two
instances of ecasound (since -ei doesnt work with two chains either.)
> However seem to recall that it used to work with alsa audio-object
> at some point?
Maybe with non-rt objects?
> The name is quite misleading, since it's (-ei) not shifting just pitch,
> but speed also.
I agree.
> So to distinguish it with these LADSPA pitchshifters, would renaming
> be appropriate? Maybe timeshifter, time-expander, or pitch..
Well, timeshifter/time-expander would sound a bit confusing to me, since
I am maintaining a little tool to do just that, stretch/compress
time. However, this is done without changing the pitch (to actually
be useful at all). What about speedshifter? :-)
--
CYa,
Mario | Debian Developer <URL:http://debian.org/>
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