[gst-devel] v4l2src, tuner frequency unit
Stéphane LOEUILLET
stephane.loeuillet at tiscali.fr
Sat May 29 03:31:02 CEST 2004
hello list,
playing with v4l2src, looking at frequency values for various channels,
i saw that frequencies where strange :
TF1 : 7796 (real freq = 487 250kHz)
FR2 : 8180 (real freq = 511 250kHz)
FR3 : 8564 (real freq = 278 330kHz)
C+ : 3200 (real freq = 200 000kHz)
FR5 : 7540 (real freq = 471 250kHz)
M6 : 12020 (real freq = 751 250kHz)
can't be Hz, kHz or MHz
then i took a look at v4l2 specs, and i saw :
http://v4l2spec.bytesex.org/spec-single/v4l2.html#V4L2-FREQUENCY
Tuning frequency in units of 62.5 kHz, or if the struct v4l2_tuner or
struct v4l2_modulator capabilities flag V4L2_TUNER_CAP_LOW is set, in
units of 62.5 Hz.
so, the unit is 62.5Hz or 62.5kHz, depending on a property that is not
exported by v4l2src plugin.
what is the better thing to do ?
changing get & set functions to get real frequencies ?
exporting other tuner capability flags to let the user app do it ?
i saw some basic channel/frequency management in v4l2 sources.
what are their state ?
any docs around ?
could they be used for channel discovery/frequency scanning ?
++
--
Stéphane LOEUILLET <stephane.loeuillet at tiscali.fr>
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