Re: GStreamer: what mean 'preroll'¿

[Tim Müller <t i m zen co uk>]

On Tue, 2008-06-03 at 11:51 +0200, dooteo wrote:

Hi,

> In GStreamer POT file, there are message with 'preroll' word.

In GStreamer terminology this describes the process of preparing a
GStreamer pipeline for playback/recording. What happens is that
audio/video data starts flowing through the pipeline until all elements
have data (so that you could start actually playing/outputting the
video/audio immediately).

I believe this terminology is only used in strings in developer tools
such as gst-launch.


> In Spanish and French languages, they translate as 'prepare'.

That makes sense, I think.


>  But looking in web sites
> 	http://www.gearwire.com/qa-cubasesx-recording.html#Q08
> it looks that 'preroll' (and postroll) are special marks to select the
> begin and end of a timeline, where is going to record a sound.

This doesn't look directly related.


> In other sites they explain (from video view) as:
> http://www.jeroenwijering.com/?thread=6631
> "That's the definition of a preroll, it rolls before the movie." 
> 
> and I guest it could works for sound too... Unfortunatly i don't
> understand 'it rolls before the movie' expression.

It looks to me like they use preroll/postroll for some kind of
intro/outro movie clips.

 Cheers
  -Tim