[an error occurred while processing this directive] [an error occurred while processing this directive][an error occurred while processing this directive] [an error occurred while processing this directive] [an error occurred while processing this directive] [an error occurred while processing this directive] (none) [an error occurred while processing this directive] [an error occurred while processing this directive] [an error occurred while processing this directive] [an error occurred while processing this directive] [an error occurred while processing this directive][an error occurred while processing this directive] [an error occurred while processing this directive][an error occurred while processing this directive] [an error occurred while processing this directive][an error occurred while processing this directive] [an error occurred while processing this directive] [an error occurred while processing this directive] [an error occurred while processing this directive] (none) [an error occurred while processing this directive] [an error occurred while processing this directive] [an error occurred while processing this directive][an error occurred while processing this directive]
 
[an error occurred while processing this directive] [an error occurred while processing this directive]
Skåne Sjælland Linux User Group - http://www.sslug.dk Home   Subscribe   Mail Archive   Forum   Calendar   Search
MhonArc Date: [Date Prev] [Date Index] [Date Next]   Thread: [Date Prev] [Thread Index] [Date Next]   MhonArc
 

Re: [TEKNIK] Jeg forstår ikke dette udsnit af et script, hentet på ffmpegs FAQ



On Sat, 14 Aug 2010 10:42:56 +0200
Doc Nielsen <sslug@sslug> wrote:

> 2010/8/13 Eskild Nielsen <sslug@sslug>:
> > <kode, citeret fra FAQ>
> > mkfifo intermediate1.mpg
> > mkfifo intermediate2.mpg
> > ffmpeg -i input1.avi -sameq -y intermediate1.mpg < /dev/null &
> > ffmpeg -i input2.avi -sameq -y intermediate2.mpg < /dev/null &
> > cat intermediate1.mpg intermediate2.mpg |\
> > ffmpeg -f mpeg -i - -sameq -vcodec mpeg4 -acodec libmp3lame
> > output.avi </kode, citeret fra FAQ>
> >
> > linie 3 og 4: Hvorfor redirect FRA /dev/null tilm standard
> > input, når ffmpeg i dette kald ikke bruger standard in?
> 
> 
> Det ser mig lidt mystisk ud, det vil jeg give dig ret i
> Sansynligvis har forfatteren byttet rundt på < og >
Jeg vil gerne kigge på det senere. Man bruger </dev/null
som en END-OF-FILE til at lukke en fil. Når det drejer
sig om en Pipe, får det betydning - men hvilken betydning,
det er mere avanceret. Named Pipes kan genbruges, men skal
vistnok åbnes hver gang. intermediate*.mpg er named pipes
dannet med mkfifo.

-- 
Donald Axel <sslug@sslug>


 
Home   Subscribe   Mail Archive   Index   Calendar   Search

 
 
Questions about the web-pages to <www_admin>. Last modified 2010-09-01, 02:01 CEST [an error occurred while processing this directive]
This page is maintained by [an error occurred while processing this directive]MHonArc [an error occurred while processing this directive] # [an error occurred while processing this directive] *