@brief Retrieve the quality stats from cache
@ingroup frontend
@param parms struct dvb_v5_fe_parms pointer to the opened device
@param layer DTV layer
Gets a quality measure for a given layer. Layer 0 is
always present. On DTV standards that doesn't have layers, it returns
the same value as dvb_fe_retrieve_stats() for layer = 0.
For DTV standards with multiple layers, like ISDB, layer=1 is layer 'A',
layer=2 is layer 'B' and layer=3 is layer 'C'. Please notice that not all
frontends support per-layer stats. Also, the layer value is only valid if
the layer exists at the original stream.
Also, on such standards, layer 0 is typically a mean value of the layers,
or a sum of events (if FE_SCALE_COUNTER).
For it to be valid, dvb_fe_get_stats() should be called first.
@return returns an enum dvb_quantity, where DVB_QUAL_UNKNOWN means that
the stat isnot available.
@brief Retrieve the quality stats from cache @ingroup frontend
@param parms struct dvb_v5_fe_parms pointer to the opened device @param layer DTV layer
Gets a quality measure for a given layer. Layer 0 is always present. On DTV standards that doesn't have layers, it returns the same value as dvb_fe_retrieve_stats() for layer = 0.
For DTV standards with multiple layers, like ISDB, layer=1 is layer 'A', layer=2 is layer 'B' and layer=3 is layer 'C'. Please notice that not all frontends support per-layer stats. Also, the layer value is only valid if the layer exists at the original stream. Also, on such standards, layer 0 is typically a mean value of the layers, or a sum of events (if FE_SCALE_COUNTER).
For it to be valid, dvb_fe_get_stats() should be called first.
@return returns an enum dvb_quantity, where DVB_QUAL_UNKNOWN means that the stat isnot available.