Fwd: [foo-devel] Buff Bugs

[Gerhard E. <ec...@ie...>]

opps, wrong reply

Begin forwarded message:

> From: Gerhard Eckel <ec...@ie...>
> Date: June 28, 2005 10:10:23 GMT+02:00
> To: martin rumori <fo...@ru...>
> Subject: Re: [foo-devel] Buff Bugs
>
>
> Dear Martin, dear Ramon,
>
> yes, I am back to the list, but it took me a while to reply, as the  
> end-of-term-madness has broken out also in Graz. As far as the off/ 
> ref problem goes, I think Martin found the good explanation - it  
> was a bug of mine. I wonder if we all agree now (at least with  
> respect to this aspect :-)?
>
> Best regards,
>
> Gerhard
>
> On Jun 19, 2005, at 12:52, martin rumori wrote:
>
>
>> dear ramon, dear gerhard,
>>
>> o.k., looks to me if gerhard was subscribed again to foo-devel now.
>>
>> On Mon, Jun 13, 2005 at 02:04:25AM +0200, Ramon Gonzalez-Arroyo  
>> wrote:
>>
>>
>>>> ref    A number specifying time in s in the output medium that  
>>>> shall
>>>>     correspond to time origin of the context (time zero).
>>>>
>>>> off    A number specifying the time offset in s from the  
>>>> contexts time
>>>> origin
>>>>     where the execution (with run-task) should start.
>>>>
>>>>
>>>>
>>>
>>> Yes, I agree, the definitions might be confussing. As a matter of  
>>> fact,
>>> you made me doubt at some point, as you know. I talked it over with
>>> Gerhard, and he was agreeing with my interpretation. So, might be  
>>> the
>>> original idea was different, and then it was never done like that. I
>>> cannot say. What I can tell you is that I have used it for years  
>>> as I
>>> told you, and was working.
>>>
>>>
>>
>> o.k.  so gerhard has to enlighten me now...  may be there was another
>> plan in the beginning, but both from the documentation and the
>> implementation, i got the impression of this interpretation.
>>
>> i had a look at the original foo-2.1-code now and compared it to the
>> latest foo in task.m.  as far as i can see, concerning the
>> ref/off-parameters, there is the only difference of my fix.  i  
>> think i
>> now know why you was able to use the "offset" parameter as
>> "reference":  it is related to the bug i fixed.  as i said, offset  
>> was
>> interpreted as samples (instead of seconds), but only in one place.
>> the other place, which moves the rendering time in the sound file
>> according to ref and off, it was interpreted correctly in seconds.
>>
>> that means: offset nearly worked like reference, but it still moved
>> the rendering start inside the context by the few SAMPLES and
>> therefore was not noticeable, unless there wasn't a dirac or  
>> something
>> else for exciting a filter on the first sample.
>>
>> so that's at least an explanation for the fact that you used offset
>> and it apparently worked.  but from the original code, it really  
>> looks
>> like offset sets the time in the context where it starts to render  
>> it.
>>
>> you could just set this line in task.m back to the original:
>>
>>   /* this has to be frame unit instead of seconds
>>    * was wrong first, therefore <offset> didn't work correctly
>>    * rumori 2004-05-03
>>    * orig:  [context setSampleTime:o];
>>    */
>>   [context setSampleTime: rint(o * sr)];
>>
>> and you should have the behavior you are used to.  if you have the
>> spare time for that, please try.  then we at least found out, why it
>> was working for you so many years.
>>
>> o.k., for the rest i think we need gerhards clarification before  
>> going
>> on...
>>
>> all the best,
>>
>> martin
>>
>>
>
>