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

[Jakub Paweł Głazik]

2010/6/10 Christophe Massiot <massiot at via.ecp.fr>:
> 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...

This sounds like a fix for out STB lip sync problems discussed on the
list (TT S3200 card) .
Great great news, gonna test this patch ASAP.



-- 
.: Jakub Paweł Głazik,
.: email & jabber: zytek<at>nuxi.pl