Devin Heitmueller wrote:
On Tue, Mar 24, 2009 at 12:35 PM, wk <handygewinnspiel@xxxxxx> wrote:
While trying to update an application to API v5 some question arised.
Which type of "delivery_system" should be set for ATSC?
<frontend.h> says...
SYS_DVBC_ANNEX_AC, <- european DVB-C
SYS_DVBC_ANNEX_B, <- american ATSC QAM
..
SYS_ATSC, <- oops, here we have ATSC again, cable and terrestrial not
named? Is this VSB *only*?
Which one should i choose, "SYS_ATSC" for both (VSB and QAM),
or should i choose SYS_DVBC_ANNEX_B for ATSC cable and SYS_ATSC for VSB?
thanks,
Winfried
I'm pretty sure it's SYS_ATSC for both VSB and QAM.
Devin
Meanwhile i think this is the answer..
dvb-core/dvb_frontend.c line 1076
/* Synchronise the legacy tuning parameters into the cache, so that
demodulator
* drivers can use a single set_frontend tuning function, regardless of
whether
* it's being used for the legacy or new API, reducing code and complexity.
*/
static void dtv_property_cache_sync(struct dvb_frontend *fe,
struct dvb_frontend_parameters *p)
{
.....
switch (fe->ops.info.type) {
......
case FE_ATSC:
c->modulation = p->u.vsb.modulation;
if ((c->modulation == VSB_8) || (c->modulation == VSB_16))
c->delivery_system = SYS_ATSC;
else
c->delivery_system = SYS_DVBC_ANNEX_B; <- QAM_64
and QAM_256 here
break;
That means the naming is completely misleading here.
I have to choose SYS_DVBC_ANNEX_B for ATSC QAM, but ATSC VSB needs SYS_ATSC.
Winfried
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