[dvblast-devel] DVR_BUFFER_SIZE issue

[Marian Ďurkovič]

On Thu, Jan 26, 2012 at 10:40:45PM +0100, Christophe Massiot wrote:
> Le 25 janv. 2012 à 09:42, Richard Hemzal a écrit :
> > originaly
> > #define DVR_BUFFER_SIZE 40*188*1024 /* bytes */ 
> > must change into 
> > #define DVR_BUFFER_SIZE 200*188*1024 /* bytes */
> > 
> > I can say that also value 100*188*1024 not enough. 
> > 
> > Should we do this value controllable from command line? 
> 
> Do you know if this value as an influence on the latency ? 
> Actually I thought until now that is was of no use at all (wasn't connected
> to anything behind), but maybe it depends on the driver.

DVR_BUFFER_SIZE is indeed a driver parameter, instucting it how much memory
should the kernel keep for the dvr device. 

It doesn't influence the latency in any way, since poll() will report
immediately if there's any data in the buffer.

However, the original value equals to 1 second of data on 60 Mbps
transponder, which should be pretty fine IMHO. If dvblast gets regularly
locked for more than 1 second, something else is seriously wrong and I'd
suggest to look for the real reason behind this.  


   With kind regards,

       M.