Hi Brian, On Sat, Jun 11, 2005 at 01:29:15PM -0700, Brian Kuschak wrote: > > Examples? Remember that most tuner modules use i2c > for all control (tuning, checking lock status, LNB > control, Diseqc, etc). Considering the time required > for 100khz I2C messaging, the additional time > contributed by transport over 100mbps Ethernet on a > LAN is negligible. I think it is quite different depending on which tuner and modulation scheme you use. (Older) DVB-S frontends required a continuous zig-zag-scan to keep the lock, while some more modern (DVB-T) frontends require firmware to be uploaded before they do work. Of course, all these are I2C transfers, and so it can be done like you say, the only thing is that I would feel more comfortable with this being handled locally. ;-) > What kind of timestamp would you like to see? IIRC, > RTP uses the 27mhz clock from the STC. We could > append a local 32-bit timestamp as well to each packet > as it arrives. Would this suffice? Sorry for bringing this up. :-) Actually, it is not a different time stamp (the 27MHZ STC in the RTP header is perfect), but if you want to synchronize at the other end of the LAN you have varying packet delays, making "locking" a software-PLL to this difficult. What we did was implement another header field carrying the accumulated delay of a previous packet, which of course had to be updated on each routing hop in between. First we should try to get anything over the net, then we can improve it. ;-) > Regards, > Brian Regards, Wolfgang
