diff --git a/apps/README.modulator b/apps/README.modulator new file mode 100644 index 0000000..84a86e8 --- /dev/null +++ b/apps/README.modulator @@ -0,0 +1,18 @@ +Here are some tips on how to use the modulator +cards. + +After you set the tuning parameter of the modulator you open the +/dev/adaptor/mod of your modulator and write into it. +You should write a steady stream of transport packets with the +rate given by the modulation. The easiest way to keep a steady rate +is to write as much as the device will receive until it blocks. In that +way you ensure that the device will not get an underrun of data and +you can use the acceptance rate as a guide for you input rate. +All you should do is to correct the PTS of your transport stream according +to the calculated packet rate and use a buffer that assures that you are +always ready to write as sson as the modulator device allows it. +E.g you have a circular output buffer that you fill to say 50% and than start +writing into the device in a seperate thread. You feed the output buffer +with you input TS and see that it does not underrun, you may need to insert +empty packets to do that. The output thread should always have enough data +to write to the device as soon as it no longer blocks. \ No newline at end of file