Haber, Thomas wrote:
> Florian Schirmer wrote:
>
> > When routing/demuxing TS you do that based on:
> >
> > - PID
> > - Section filters
>
> Yes you use
> * packet id for single pes streams (audio,video, ...)
> * packet id [+ table id [+ n bytes section header Filter]] for sections
> * additionally you get the PCR on a PID
>
> > When routing/demuxing PS/AVPES/... you do that based on:
> >
> > - Stream type
> > - camera angle
> > - language
> > - subtitle
> > - ...
>
> No you only use
>
> * streamid for the streams (audio, video ,...) (corresponds to packetid)
> * streamid for program stream map and program stream directory (somehow similar to
> tables)
There is no "section" format for PS, so filtering the PSM and PSD is just the
same as for A/V PES (the PSD even is in PES format). Also, if I'm not
mistaken (plese correct me if I'm wrong), the MPEG-2 PS syntax is the
same as the MPEG-1 System Stream syntax, so there are no additional
requirements for the demux to process MPEG-1.
My hardware manual tells me that it is also possible to filter PS
on the sub_stream_id, which implies that the stream_id is 0xbd
(private_stream_1). I can't find any more documentation on that,
but I guess it's handy for DVD stuff.
So I guess we'd need:
struct dmx_sid_filter_params {
u8 stream_id;
u8 flags;
#define DMX_SFF_NORMAL 0
#define DMX_SFF_SUBSID 1
};
#define DMX_SET_SID_FILTER _IOW('o',99,struct dmx_sid_filter_params)
DMX_SET_SOURCE should also have a stream_type parameter
(TS, PS, AVPES), and DMX_SET_SID_FILTER would only be allowed when the
demux is set to source_type PS and AVPES; DMX_SET_FILTER and DMX_SET_PES_FILTER
would only be allowed for stream_type TS. Other combinations would
return EINVAL (or whatever).
(The nomenclature is confusing here; maybe all three filter types
should be renamed like DMX_SET_PS_FILTER, DMX_SET_TS_PES_FILTER,
DMX_SET_TS_SCT_FILTER?)
> * you additionally get the SCR (like PCR; in case of PS)
For PS the SCR is not associated with any particular stream_id, so
it's not necessary to set a filter. The hardware will do it
automatically, and DMX_GET_STC can be used to retrieve the SCR value
(I guess).
Regards,
Johannes
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