dvb/descriptors: improve ISDB-T verbosity

On ISDB-T, most of the network parameters are decoded via the TMCC
carrier, modulated on all segments using DBPSK. It is up to the
ISDB-T demod to parse the TMCC registers and pass their contents via
get_frontend().

Yet, the NIT table provides a few data:
	ISDB-T mode (1, 2 or 3);
	Guard interval.

The ISDB-T mode is directly related to the number of OFDM carriers,
and the IFFT size:
	Mode 1 corresponds to an IFFT size of 2K;
	Mode 2 corresponds to an IFFT size of 4K;
	Mode 3 corresponds to an IFFT size of 8K.

Provide a better output of those data, if verbose mode is enabled.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/utils/dvb/descriptors.c b/utils/dvb/descriptors.c
index 88d4677..64e3b1a 100644 (file)
--- a/utils/dvb/descriptors.c
+++ b/utils/dvb/descriptors.c
@@ -232,23 +232,39 @@ static void parse_NIT_ISDBT(struct nit_table *nit_table,
                [2] = GUARD_INTERVAL_1_8,
                [3] = GUARD_INTERVAL_1_4,
        };
+       static const char *interval_name[] = {
+               [GUARD_INTERVAL_1_4] =    "1/4",
+               [GUARD_INTERVAL_1_8] =    "1/8",
+               [GUARD_INTERVAL_1_16] =   "1/16",
+               [GUARD_INTERVAL_1_32] =   "1/32",
+       };
        static const uint32_t mode[] = {
                [0] = TRANSMISSION_MODE_2K,     /* Mode 1 */
                [1] = TRANSMISSION_MODE_4K,     /* Mode 2 */
                [2] = TRANSMISSION_MODE_8K,     /* Mode 3 */
                [3] = TRANSMISSION_MODE_AUTO    /* Reserved */
        };
-       unsigned tmp = buf[3] >> 4 & 0x3;
-       int i;
+       static const char *tm_name[] = {
+               [TRANSMISSION_MODE_2K] =   "2K",
+               [TRANSMISSION_MODE_4K] =   "4K",
+               [TRANSMISSION_MODE_8K] =   "8K",
+               [TRANSMISSION_MODE_AUTO] = "AUTO",
+       };
+       int i, isdbt_mode, guard;
 
        nit_table->delivery_system = SYS_ISDBT;
+       isdbt_mode = buf[3] >> 6;
+       guard = buf[3] >> 4 & 0x3;
        nit_table->area_code = (buf[3] & 0x0f) << 8 | buf[2];
-       nit_table->guard_interval = interval[tmp];
-       nit_table->transmission_mode = mode[buf[3] >> 6];
+       nit_table->guard_interval = interval[guard];
+       nit_table->transmission_mode = mode[isdbt_mode];
+
        if (verbose)
-               printf("Area code: %d, guard interval: %d, mode: %d\n",
+               printf("Area code: %d, mode %d (%s), guard interval: %s\n",
                        nit_table->area_code,
-                       tmp, 1 + (buf[3] >> 6));
+                       isdbt_mode + 1,
+                       tm_name[nit_table->transmission_mode],
+                       interval_name[nit_table->guard_interval]);
        buf += 4;
        for (i = 4; i < dlen; i += 2) {
                freq = buf[i] << 8 | buf[i + 1];