Re: Converting AU transport info to VST time info?
Re: Converting AU transport info to VST time info?
- Subject: Re: Converting AU transport info to VST time info?
- From: William Stewart <email@hidden>
- Date: Fri, 03 Dec 2004 11:05:07 -0800
On 3/12/04 1:50 AM, "Angus F. Hewlett" <email@hidden> wrote:
> Just to clarify,
>
> Howard is looking to get the absolute position, in samples, in the
> sequencer time line (in VstTimeInfo, this is samplePos).
That's what the callback is meant to be providing. If its not, I'd consider
that a bug in the host.
> Previously, in VST-AU, we used the time counter passed to Render(). This
> works fine for most things, but it seems that it's actually a count from
> whenever the audio engine was last started / flushed (usually happens at
> transport start), rather than an absolute position in the song. So, it's
> OK when the song is started from the beginning, but not when it's
> started at some other point, as Howard's plug needs to track the
> absolute song position in samples.
Right - there's no real guarantee about what this sample counter
indicates.... For instance, if you're connected to AUHAL it will be the time
since that AU was last started (it resets its counter to zero when it starts
up)
> outCurrentSampleInTimeLine should be providing that, but is it? Also,
> why is it a Float64, when sample position at the start of a render call
> is always an integer? Simply because it's possible to represent numbers
> 2x10^31 without a special datatype, or some other reason?
We represent all sample counters using Float64 - so its this way for
consistency
> Also, Howard:- bear in mind that CallHostTransportState is a new part of
> the AU API, and isn't supported on all hosts (which is why we check the
> variable transportSafe first). So, code based on this call should work
> fine on Logic 7 and DP4.5, but that code will never be reached if the
> host is older.
Right...
Thanks for the comments Angus
Bill
> Regards,
> Angus.
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Howard Moon wrote:
>
>> Hi all,
>>
>> I'm working on a vst plug-in "wrapped" as an Audio Unit, and am
>> implementing the CallHostTransportState time & transport information
>> in the AUBase class. I've looked at some code from a couple sources
>> (including DestroyFX), but don't see anyone setting the particular
>> information I need. In particular, I need to set the VstTimeInfo
>> member, samplePos. The third parameter of the CallHostTransportState
>> function (outCurrentSampleInTimeLine) seems to be what I need, but I
>> need to know how to convert it to the samplePos that my wrapped vst
>> plug-in needs. Simply assigning it doesn't seem to be working, perhaps
>> because that parameter needs to be converted and/or offset somehow? In
>> any case, if you've got any advice as to how I can compute samplePos
>> from the outCurrentSampleInTimeLine parameter, I'd appreciate hearing it.
>>
>> Thanks much,
>> Howard
>>
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> Do not post admin requests to the list. They will be ignored.
>> Coreaudio-api mailing list (email@hidden)
>> Help/Unsubscribe/Update your Subscription:
>>
>> This email sent to email@hidden
>>
>
--
mailto:email@hidden
tel: +1 408 974 4056
__________________________________________________________________________
Culture Ship Names:
Ravished By The Sheer Implausibility Of That Last Statement [GSV]
I said, I've Got A Big Stick [OU]
Inappropiate Response [OU]
Far Over The Borders Of Insanity And Still Accelerating [Eccentric]
__________________________________________________________________________
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden