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. If some driver states that it is simply due to lack of knowledge at the coding side. ISDB-T uses hierarchial modulation, just like DVB-S2 or DVB-T2 Once the Outer code is decoded, the OFDM segments are separated using Hierarchial separation. This is well described by NHK. "To improve mobile reception and robustness to multipath interference, the system performs, in symbol units, time interleaving plus frequency interleaving according to the arrangement of OFDM segments. Pilot signals for demodulation and control symbols consisting of TMCC information are combined with information symbols to an OFDM frame. Here, information symbols are modulated by Differential Binary Phase Shift Keying (DBPSK) and guard intervals are added at the IFFT output. [3] Hierarchical transmission A mixture of fixed-reception programs and mobile reception programs in the transmission system is made possible through the application of hierarchical transmission achieved by band division within a channel. "Hierarchical transmission" means that the three elements of channel coding, namely, the modulation system, the coding rate of convolutional correction code, and the time interleave length, can be independently set. Time and frequency interleaving are each performed in their respective hierarchical data segment. As described earlier, the smallest hierarchical unit in a frequency spectrum is one OFDM segment." Please don't muck up existing working things with uber crap. 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
