Andreas Oberritter wrote:
> if you have multiple displays and/or Picture-In-Picture decoding, then
> you have to define one PCR per display as master for vcxo control.
>
> Therefore I propose the following simple interface:
>
> struct dmx_stc_mapping {
> unsigned int clock_num;
> unsigned int pcr_num;
> }
>
> #define DMX_SET_STC_MAPPING _IOWR('o', 51, struct dmx_stc_mapping)
I think the naming is a bit misleading, because in your first
sentence you say that this is about setting the "master for
vcxo control". I.e. (if I get it right) you have one 27MHz
crystal, but two PCR/STC. Obviously the vcxo can be synced to
only one of them, so you have to choose (for PiP usually the
one with the bigger picture).
How about:
struct dmx_vcxo_control {
unsigned int vcxo_num; // in case you have more than one vcxo
unsigned int pcr_num; // which PCR to sync the vcxo to
};
#define DMX_VCXO_CONTROL _IOWR('o', 51, struct dmx_vcxo_control)
or maybe DMX_SET_VCXO_SYNC_SOURCE?
Johannes
