[linux-dvb] dvb-apps lib, structs declared with bit fields

DUBOST Brice dubost at crans.ens-cachan.fr
Tue Jul 5 16:14:23 CEST 2005


Oivind wrote:
> I notice that bit fields are used in many of the structs, as for
> example from en50221_hlci.h;
> 
> struct en50221_pmt_object {
>         unsigned ca_pmt_tag: 24;
>         uint8_t *asn_1_length;
>         unsigned ca_pmt_list_mgmt: 8;
>         unsigned program_number: 16;
>         unsigned reserved_1: 2;
> 
>         [...]
> 
> };
> 
> 
> What exactly is the benefit of this? 
> 

Because the object come like this
Dvb objct tries to use less data as possible.

For example
http://www.bc.groteck.ru/pdf-standard-specifications/multiplexing/dvb-vbi/en301775.v1.2.1.pdf


-- 
Brice

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You'll be free, hackers, you'll be free.
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