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* em28xx_isoc_dvb_max_packetsize for EM2884 (Terratec Cinergy HTC Stick)
@ 2011-12-24 21:58 Dennis Sperlich
  2011-12-25 10:52 ` Mauro Carvalho Chehab
  0 siblings, 1 reply; 15+ messages in thread
From: Dennis Sperlich @ 2011-12-24 21:58 UTC (permalink / raw)
  To: linux-media

Hi,

I have a Terratec Cinergy HTC Stick an tried the new support for the 
DVB-C part. It works for SD material (at least for free receivable 
stations, I tried afair only QAM64), but did not for HD stations 
(QAM256). I have only access to unencrypted ARD HD, ZDF HD and arte HD 
(via KabelDeutschland). The HD material was just digital artefacts, as 
far as mplayer could decode it. When I did a dumpstream and looked at 
the resulting file size I got something about 1MB/s which seems a little 
too low, because SD was already about 870kB/s. After looking around I 
found a solution in increasing the isoc_dvb_max_packetsize from 752 to 
940 (multiple of 188). Then an HD stream was about 1.4MB/s and looked 
good. I'm not sure, whether this is the correct fix, but it works for me.

If you need more testing pleas tell.

Regards,
Dennis



index 804a4ab..c518d13 100644
--- a/drivers/media/video/em28xx/em28xx-core.c
+++ b/drivers/media/video/em28xx/em28xx-core.c
@@ -1157,7 +1157,7 @@ int em28xx_isoc_dvb_max_packetsize(struct em28xx *dev)
                  * FIXME: same as em2874. 564 was enough for 22 Mbit DVB-T
                  * but not enough for 44 Mbit DVB-C.
                  */
-               packet_size = 752;
+               packet_size = 940;
         }

         return packet_size;


^ permalink raw reply related	[flat|nested] 15+ messages in thread

end of thread, other threads:[~2011-12-28 22:55 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-12-24 21:58 em28xx_isoc_dvb_max_packetsize for EM2884 (Terratec Cinergy HTC Stick) Dennis Sperlich
2011-12-25 10:52 ` Mauro Carvalho Chehab
2011-12-25 14:04   ` Dennis Sperlich
2011-12-25 14:11     ` Hans Petter Selasky
2011-12-25 14:47       ` Devin Heitmueller
2011-12-25 17:58       ` Mauro Carvalho Chehab
2011-12-25 19:42       ` Malcolm Priestley
2011-12-25 20:12         ` Dennis Sperlich
2011-12-25 18:13     ` Mauro Carvalho Chehab
2011-12-25 20:33       ` Dennis Sperlich
2011-12-26  5:55         ` Holger Nelson
2011-12-26 12:18           ` Mauro Carvalho Chehab
2011-12-28  3:50             ` Holger Nelson
2011-12-28 12:09               ` Mauro Carvalho Chehab
2011-12-28 22:55                 ` [PATCH] em28xx: Reworked probe code to get rid of some hacks (was: Re: em28xx_isoc_dvb_max_packetsize for EM2884 (Terratec Cinergy HTC Stick)) Holger Nelson

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