Hi Antti, On Thu, Jan 3, 2013 at 9:04 PM, Antti Palosaari <crope@xxxxxx> wrote: > On 01/01/2013 06:48 PM, Manu Abraham wrote: >> >> 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 > > > Manu, you confused now two concept (which are aimed to resolve same real > life problem) - hierarchical coding and multiple transport stream. Both are > quite similar on lower level of radio channel, but differs on upper levels. > > Hierarchical is a little bit weird baby as it remuxes those lower lever > radio channels (called layers in case of ISDB-T) to one single mux! That is not really correct. There is one single OFDM channel, the layers are processed via hierarchial separation. Stuffing exists, to maintain constant rate. http://farm9.staticflickr.com/8077/8343296328_e1e375b519_b_d.jpg When rate is constant within the same channel.. (The only case what I can think parameters could be different with a constant rate, is that stuffing frames are unaccounted for. Most likely a bug ?) 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
