hello All, the issue in question is that in case full TS is captured immediately after lock ( without some delay ) then garbage data ( that don't belong to the TS ) are introduced in the stream. initially Michael Repplinger noticed the problem and told me about it. also, he made test script ( 'run_szap-s2_adapter0_record_dvbsnoop.sh' ) for reproducing the problem easily ( you can find it in the attachment, i made some very small changed to it compared to the original script).
so, basically, the test script 'szap-s2' to first transponder in your 'channel.conf' file, use 'dvbsnoop' to dump the full TS from that transponder to a file for 30 seconds, then 'szap-s2' to second transponder in your 'channel.conf' file, use 'dvbsnoop' again to dump the full TS to another file for 30 seconds and repeats this in endless loop. if there is no delay ( 'sleep 0' ) or delay is less than 5 seconds ( at least on my setup those are delays i measured ) between executing 'szap-s2' and 'dvbsnoop' then captured stream contains some additional data that don't belong there, i.e. garbage and you can confirmed it with any TS analyzer tool or just use the attached 'test_file_with_dvbsnoop.sh' that Michael Repplinger prepared. i've already tested about 10 DVB devices from different manufacturers using completely different chips and PCI or PCIe interface and even USB interface, just for completeness here is what i've already tested: - Philips/NXP SAA7146 bridge driver - B2C2 Flexcop IIb PCI bridge driver (put in full TS mode with 'options b2c2_flexcop_pci enable_pid_filtering=0') - Booktree bt8xx bridge driver - Conexant cx88 bridge driver - Conexant cx23885 bridge driver - all USB DVB devices i have (all of them use Cypress USB controller) and with all of the above i can reproduce the problem using 'run_szap-s2_adapter0_record_dvbsnoop.sh' script. however, it seems SAA7146 is somehow better than the others, because sometimes it works good, i.e. captures correct data even without any delay between executing 'szap-s2' and 'dvbsnoop'. so, any ideas, please, either for what could be the root cause for the problem or for acceptable workaround? it seems to me at least at the moment it's a general problem with Linux DVB, but maybe it's known issue and someone knows more about it. many thanks, konstantin
test_file_with_dvbsnoop.sh
Description: Bourne shell script
run_szap-s2_adapter0_record_dvbsnoop.sh
Description: Bourne shell script
