[mythtv] DVB, HD-2000, and CRCs

[Doug Larrick]

Taylor Jacob wrote:
> If you look at the dvb driver API and the code in question, you will see that
> the demux driver does section reassembly in software and or hardware (depending
> on if your transport ic can do it in hardware or not).  It is ONLY for section
> data the dvb driver does CRC validation.. This is a reasonable thing so CRC
> checking does not need to be implimented in every application..

Looking at the driver source, I concur... it should be checking CRC for
section data (metadata, not video/audio streams).  Nevertheless, with
the HD-2000 DVB driver at least, it is not.  I've verified that the
DMX_CHECK_CRC flag is being set on the filter.

I hacked in a call to mpegts_crc32 for EIT and ETT PIDs, and am now not
seeing the errors I was seeing before.  A quick inspection of the
HD-2000 driver did not reveal a bug in this area, but I suspect that's
where it is.

-Doug
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 256 bytes
Desc: OpenPGP digital signature
Url : http://mythtv.org/pipermail/mythtv-dev/attachments/20050321/b30cc21f/signature.pgp