Re: [AD] docs: play_audio_stream clarification

[ Thread Index | Date Index | More lists.liballeg.org/allegro-developers Archives ]


On Thursday 12 February 2004 9:19 pm, Eric Botcazou wrote:
> > This function creates a new audio stream and starts playing it. The
> > length is the size of each transfer buffer in sample frames, where a
> > sample frame is a single sample point (i.e. value) for mono data or a
> > pair of sample points for stereo data.
>
> This is better (although I think "sample value" instead of "sample point"
> would be even better) but IMHO not yet crystal clear because...

Go for "a single sample value for mono data" then. I agree, it's more 
intuitive.

> > The length should normally be (but doesn't have to
> > be) a power of two somewhere around 1k in size. Larger buffers are more
> > efficient and require fewer updates, but result in more latency between
> > you providing the data and it actually being played. The bits parameter
> > must be 8 or 16. freq is the sample rate of the data in Hertz. The vol
> > and pan values use the same 0-255 ranges as the regular sample playing
> > functions. The stereo parameter should be set to 1 for stereo streams, or
> > 0 otherwise. If you want to adjust the pitch, volume, or panning of a
> > stream once it is playing, you can use the regular voice_*() functions
> > with stream-&gtvoice as a parameter. The sample data are always in
> > unsigned format. For stereo waveforms, the samples are interleaved, left
> > first.
>
> ...this is confusing.  Above you were talking about "sample frame" and
> "sample point", now you are talking about "sample".

"the sample values are interleaved" then.

I'm surprised this actually confuses you though. Granted it's inconsistent, 
but it's not confusing.

Ben





Mail converted by MHonArc 2.6.19+ http://listengine.tuxfamily.org/