On Thu, Jan 3, 2013 at 6:50 PM, Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> wrote: > Em Wed, 2 Jan 2013 00:38:50 +0530 > Manu Abraham <abraham.manu@xxxxxxxxx> escreveu: > >> On Tue, Jan 1, 2013 at 10:59 PM, Mauro Carvalho Chehab >> <mchehab@xxxxxxxxxx> wrote: >> > Em Tue, 1 Jan 2013 22:18:49 +0530 >> > Manu Abraham <abraham.manu@xxxxxxxxx> escreveu: >> > >> >> On Tue, Jan 1, 2013 at 8:30 PM, Mauro Carvalho Chehab >> >> <mchehab@xxxxxxxxxx> wrote: >> >> >> >> > [RFCv4] dvb: Add DVBv5 properties for quality parameters >> >> > >> >> > The DVBv3 quality parameters are limited on several ways: >> >> > - Doesn't provide any way to indicate the used measure; >> >> > - Userspace need to guess how to calculate the measure; >> >> > - Only a limited set of stats are supported; >> >> > - Doesn't provide QoS measure for the OFDM TPS/TMCC >> >> > carriers, used to detect the network parameters for >> >> > DVB-T/ISDB-T; >> >> > - Can't be called in a way to require them to be filled >> >> > all at once (atomic reads from the hardware), with may >> >> > cause troubles on interpreting them on userspace; >> >> > - On some OFDM delivery systems, the carriers can be >> >> > independently modulated, having different properties. >> >> > Currently, there's no way to report per-layer stats; >> >> >> >> per layer stats is a mythical bird, nothing of that sort does exist. >> > >> > Had you ever read or tried to get stats from an ISDB-T demod? If you >> > had, you would see that it only provides per-layer stats. Btw, this is >> > a requirement to follow the ARIB and ABNT ISDB specs. >> >> I understand you keep writing junk for ages, but nevertheless: >> >> Do you have any idea what's a BBHEADER (DVB-S2) or >> PLHEADER (DVB-T2) ? The headers do indicate what MODCOD >> (aka Modulation/Coding Standard follows, whatever mode ACM, >> VCM or CCM) follows. These MODCOD foolows a TDM approach >> with a hierarchial modulation principle. This is exactly what ISDB >> does too. > > No, I didn't check DVB-S2/T2 specs deeply enough to understand > if they're doing the same thing as ISDB. > > Yet, ISDB-T doesn't use a TDM approach for hierarchical modulation. > It uses a FDM (OFDM is a type of Frequency Division Multiplexing). • ISDB‐T uses a modulation method referred to as Band Segmented OFDM Transmission with Time Interleave. Definition: Time Division Multiplexing (TDM) is the time interleaving of samples from several sources so that the information from these sources can be transmitted serially over a single communication channel. Manu -- 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
