OK, then what? Is the S2API behavior (returning cached - but incorrect - tuning parameter values) satisfactory for everyone or shall we adapt S2API to mimic the API V3 behavior (return the actual tuning parameter values as automatically adjusted by the driver)? -Thierry > -----Original Message----- > From: linux-media-owner@xxxxxxxxxxxxxxx [mailto:linux-media-owner@xxxxxxxxxxxxxxx] On > Behalf Of Thierry LELEGARD > Sent: Friday, January 14, 2011 5:44 PM > To: linux-media@xxxxxxxxxxxxxxx > Cc: Devin Heitmueller; Andreas Oberritter > Subject: RE: [linux-media] API V3 vs SAPI behavior difference in reading tuning > parameters > > > -----Original Message----- > > From: Andreas Oberritter [mailto:obi@xxxxxxxxxxx] > > Sent: Friday, January 14, 2011 5:32 PM > > > > Albeit, DVB-SI data isn't perfect and misconfiguration at the > > transmitter happens (e.g. wrong FEC values), especially where most of > > the parameters are signaled in-band (e.g. TPS for DVB-T). It's a better > > user experience if the reception continues to work, even if the user > > didn't specify AUTO. > > Exactly. In the French DVB-T network, there is no regional NIT, only one > common national NIT. As a consequence, all tuning parameters (frequency > but also FEC, guard interval, etc) are wrong in the terrestrial delivery > descriptors because for a given TS they are obviously not identical on all > transmitters. Moreover, these parameters change over time (many transmitters > recently moved from 2/3 - 1/32 to 3/4 - 1/8). > > In such networks, nobody "knows" for sure the modulation parameters. This is > why it is a good thing that the tuners can 1) find the actual parameters and > 2) report them to the application whenever it requests them. > > > I'd rather understand non-AUTO parameters that way: "Try these first, > > but if you want and if you can, you're free to try other parameters." > > Exactly, for the same reasons as above. > > This is why the new behavior of S2API (compared to API V3) is quite unfortunate. > On a pragmatic standpoint, this is really a major step backward. > > -Thierry > > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
