[dvblast-devel] SAA7146 driver fix for better PCR accuracy and finer IP granularity

[Christophe Massiot]

Dear Marian,

Le 9 juin 2010 à 09:56, Marian Ďurkovič a écrit :

>  Fortunately, the DMA block size for SAA7146 is easily tunable by a specific
> HW register. After some experimentation, it looks like 8 kB is much better
> value here, resulting in ~44 TS packets being output once per 1.75 msec. 
> With a typical DVB-S transponder, it basically means that one IP packet
> per TV station is sent per DMA cycle. It also nicely corresponds to the
> dvblast's default processing of upto 50 TS packets per demux cycle.

You have done what I have been dreaming of for the past couple of months !

Do you think it would be possible to tune this value depending on the symbol rate (or best, multiplex rate) of the transponder ? Because 27500 transponders do not behave the same way as 1995 transponders...