Hari_Mohan wrote: > > -----Original Message----- > From: Manu Abraham [mailto:manu@xxxxxxxxxxx] > Sent: Wednesday, February 16, 2005 4:37 PM > To: Hari_Mohan > Cc: linux-dvb > Subject: Re: [linux-dvb] [RFC] > > Hari_Mohan wrote: > >>-----Original Message----- >>From: linux-dvb-bounces@xxxxxxxxxxx [mailto:linux-dvb-bounces@xxxxxxxxxxx] >>On Behalf Of Manu Abraham >>Sent: Wednesday, February 16, 2005 3:04 PM >>To: Hari_Mohan >>Cc: linux-dvb >>Subject: Re: [linux-dvb] [RFC] >> >>Hari_Mohan wrote: >> >> >>>-----Original Message----- >>>From: linux-dvb-bounces@xxxxxxxxxxx [mailto:linux-dvb-bounces@xxxxxxxxxxx] >>>On Behalf Of Manu Abraham >>>Sent: Wednesday, February 16, 2005 2:11 PM >>>To: Hari_Mohan >>>Cc: linux-dvb >>>Subject: Re: [linux-dvb] [RFC] >>> >>>Hari_Mohan wrote: >>> >>> >>> >>>>I don't know much about this but I have seen this in a dvb demodulator >>>>output and ASI convertors. These lines were termed DVALID and these used >>> >>>to >>> >>> >>> >>>>stay high whenever there is valid data in the transport stream >>>>bus-8bit/serial. This line stays low when there are some special >>> >>>characters >>> >>> >>> >>>>coming in the bus. I think this flag is related to that. Even error line >>>>also is similar - ie whenever there were some uncorrectable errors this > > is > >>>>supposed to stay low - depends on your configuration >>>> >>> >>>What i was wondering was that, whether this information could help in >>>the upper space DVB API/driver in any manner, in terms of error >>>correction and or other aspects. >>>------------------------ >>>According to my knowledge mpeg decoder chips will clock in the data based >> >>on >> >> >>>the state of these lines. I don't know whether any hardware mechanism is >> >> >>So is this information more reliable than the 13818-1 Discontinuity flag.. > > ? > >>such that this information can be used to identify cases where we have >>problems in the TS.. ? >>since under the Linux DVB API, we don't have an exact solution for >>discontinuity, and TS errors to a 100% effectiveness, would these flags >>be useful for solving that problem ? >> >>For a particular DVB card, i can get these signals out from the frontend >>to the card and the driver.. So, considering that aspect if i get these >>flags out, i was wondering whether it would be possible to have a >>solution for the latter errors.. >> >>That was the query that i had in my mind.. >>******************** >> >>The error bit which I am speaking about is the signal which is given by >>demodulator or a receiver device once it finds that input ts packet is > > Yes, that's the one what i was referring to.. > > >>errored. But the discontinuity indicator which you refered is inside the >>transport stream - so these information which are inside stream are > > inserted > >>from the stream generator (encoder/mux) and I don't think that tuner will > > be > >>reading this data to give the error signal/flag. > > > What i was thinking was that if the demodulator detects a broken stream > and or inconsistencies, this would also result in broken TS's and CRC > failures. > > >>For discontinuity in transport stream you can tweak software or add some >>patches but for errored input signal indication I don't think anything can > > > > Some patches have already gone in regarding broken streams, but that > still doesn't seem to solve all the issues. > That only made me think in this aspect, as well as the availability of > these flags. These cards do not feature a MPEG decoder. > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~ > I don't have much idea about v4l drivers but still if you can tell me the > issues I can try some suggestions. If you are trying to record videos then Broken TS's and CRC failures.. I see them once a while.. I still got to find out where that happens though. > you can avoid the bad vid pes packets. But if you are playing a video > realtime you may face problems. I am not trying to record a video here.. but rather playing it.. > > Hari > ~~~~~~~~~~~~~~~~~~~~~~~~~~ > > >>be done other than making satellite/cable reception proper. > > > So do you mean to say that these falgs can be helpful only for MPEG > decoders and so on ? > When we are doing Software MPEG decoding, rather than Hardware doing it, > would it be possible to make use of these flags ? > > > @@@@@@@@@@@@@@@@@@@@@@ > Do you have APIs which give access to these flags. If you have it then the > possibility can be explored. Which is the video codec s/w used in this? It could be any codec.. Currently for the MPEG2 TS i am using mplayer. > > Hari > @@@@@@@@@@@@@@@@@@@@@@ > >>Hari >>************************** >> >> >>>there to store these values and use for upper layer applications. Because >>>stv299 may have separate APIs to calculate BER and signal quality. >>> >>>Hari >>>--------------------------------- >>> >>> >>> >>> >>> >>> >>>>Hari >>>> >>>>-----Original Message----- >>>>From: linux-dvb-bounces@xxxxxxxxxxx > > [mailto:linux-dvb-bounces@xxxxxxxxxxx] > >>>>On Behalf Of Manu Abraham >>>>Sent: Wednesday, February 16, 2005 12:27 AM >>>>To: linux-dvb >>>>Subject: [linux-dvb] [RFC] >>>> >>>>Hi, >>>> >>>>Is there any advantage in getting the following flags out from the tuner >>>>(STV0299 based).. such that it might be of some help.. ? >>>> >>>>(1) data valid >>>>(2) error >>>> >>>> >>> >>> > Manu
