[Ffmpeg-devel] Bug in pts computation in compute_pkt_fields() ?

Wolfram Gloger wmglo
Tue Mar 20 15:37:20 CET 2007


Hi,

> > Well, a raw mpeg transport stream, such as obtained on Linux with:
> > cat /dev/dvb/adapter0/demux0
> 
> I don't understand your use of the qualifier "raw".  Either you have MPEG-TS,
> or you have something else.  Reading the device file you mention should
> return the MPEG-TS stream as transmitted by the broadcaster, possibly with
> some PID filters applied.  There is nothing "raw" about it.  What would,
> in your opinion, a non-raw MPEG-TS stream be?

If you prefer, I'll drop the "raw" qualifier..  It surely has no
meaning in standardese.

Non-raw IMO would be a stream which could be processed by mpegts.c
with ts->mpeg2ts_raw==0 and ts->auto_guess==0.  Unfortunately, I have
a hard time getting those out of Linux DVB -- more often than not the
SDT and/or PAT are incomplete or missing (for sure when unmodified
[tsc]zap from Linux dvbutils is used).

> > So what's the 60 doing there?  Should it perhaps be 42?
> 
> Without a closer inspection of the code, that entire line looks dubious
> to me.  The PCR is in 27MHz units, but it is discarded by the demuxer.

Are you sure?  At least it is used for start_time and bit_rate..

Regards,
Wolfram.




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