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* [PATCH 0 of 3] cx88: fix oops on rmmod and implement stereo detection
@ 2008-03-26  2:07 Marton Balint
  2008-03-26  2:07 ` [PATCH 1 of 3] cx88: fix oops on module removal caused by IR worker Marton Balint
                   ` (5 more replies)
  0 siblings, 6 replies; 13+ messages in thread
From: Marton Balint @ 2008-03-26  2:07 UTC (permalink / raw)
  To: video4linux-list

Here are the updated versions of my cx88 patches (I only sent the old versions
to the linux-dvb list, and they did not draw too much attention there) maybe
better luck here...

The first is a simple fix for a possible Oops on the removal of cx88xx module
caused by the IR worker. This patch is independent from the other two.

The second and the third patches are enhachments of the cx88 audio code, I
tried to implement the detection of stereo TV channels for A2 mode. I had no
idea how to detect it, and falling back to EN_A2_AUTO_STEREO instead of
EN_A2_FORCE_MONO1 did not help either. (The card changed the audio mode
periodically on both mono and stereo channels) Forcing STEREO mode also did not
help, because it resulted a loud static noise on mono tv channels.

Testing proved that AUD_NICAM_STATUS1 and AUD_NICAM_STATUS2 registers change
randomly if and only if the second audio channel is missing, so if these
registers are constant (Usually 0x0000 and 0x01), we can assume that the tv
channel has two audio channels, so we can use STEREO mode. This method seems a
bit ugly, but nicam detection works the same way, so to avoid further
msleep()-ing, the A2 stereo detection code is in the nicam detection function.

By the way, the audio thread in the cx88 code is totally useless, in fact, it
occaisonally sets the audio to MONO after starting a TV application, so i think
it should be removed. My patch does NOT fix cx88_get_stereo, and even if it
would, the audio thread would not work as expected, because
core->audiomode_current is not set in cx88_set_tvaudio, and AUTO stereo modes
(EN_BTSC_AUTO_STEREO, EN_NICAM_AUTO_STEREO) would also cause problems, the
autodetected audio mode should be set to core->audiomode_current to make it
work.

Who is now the cx88 maintainer? I should send him a copy of the patches...


Regards,

 Marton Balint


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^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, other threads:[~2008-04-17 21:36 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-03-26  2:07 [PATCH 0 of 3] cx88: fix oops on rmmod and implement stereo detection Marton Balint
2008-03-26  2:07 ` [PATCH 1 of 3] cx88: fix oops on module removal caused by IR worker Marton Balint
2008-03-28 18:38   ` Mauro Carvalho Chehab
2008-03-26  2:07 ` [PATCH 2 of 3] cx88: fix stereo dematrix for A2 sound system Marton Balint
2008-03-26  2:07 ` [PATCH 3 of 3] cx88: detect stereo output instead of mono fallback in " Marton Balint
2008-03-26  7:02 ` [PATCH 0 of 3] cx88: fix oops on rmmod and implement stereo detection Peter Vágner
2008-03-26 14:40   ` Balint Marton
2008-03-26 17:39     ` Peter Vágner
2008-03-26 19:40       ` Balint Marton
2008-03-28  6:59         ` Peter Vágner
2008-03-26 20:39 ` [PATCH 0 of 3] cx88: fix oops on rmmod and implement stereodetection Torsten Seeboth
2008-03-26 22:25   ` Balint Marton
2008-04-17 21:35 ` [PATCH 0 of 3] cx88: fix oops on rmmod and implement stereo detection Marton Balint

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