[vdr] Re: AC3 over Soundcard (live and replay) (Was: AC3 5.1 - can someone "fix" -a i

["Christian Jacobsen" <christian.jacobsen@stageholding.de>]

Hallo Werner, Hallo @ll,

yeepee, it works :)
Live AC3 and recordings :)

I have noticed one problem though. I did a lot of testing with different
versions and plugins so I am not completly sure that it is the bitstreamout
;)
Maybee someone else can confirm this.

Here my system and findings :

Suse Linux 8.0 (minimum install w. KDE + needed packeges added afterwards)
Alsa Driver 0.9.0rc6 (driver/lib/utils/tools) - with alse-patch - see below
for more
Acer Mainboard (i815) w. PIII 933
1 DVB-S Rev. 1.3
1 WinTV Nova model 541 (don't now rev. Drivers says 1.3)
Nightingale 4.1 Soundcard (CMI8738) with Optical Module

I Connected the Optical Out from the Soundcard with the Reciver (Sony
STR-DB870QS) and the Analog Output of DVB-S also with the reciever.
(I am using the same setup with 1.0.4 and that works very well)
Normaly I then hear the analog signal - with AC3 Program/recording the
reciever automatically switches to Optical in :)

I had a little trouble getting the plugin running - but that was sort of a
RTFM ;) - just that no one else has to go through the same problems I'll
describe it here :
When using the bitstreamout plugin VDR quit after a few seconds when
switching to Pro7.
"Unfortunatly" (for me) I had the -t /dev/tty8 in the vdr start line and the
error from bitstreamout came on tty8 while I was searching my vdr.log (thats
where I log messages from vdr) and /var/log/messages and found nothing.
There was a message on tty8 about pcm_hook.c - don't remeber exact message -
something was missing. I had to patch my alsa-lib and compile/install it
again !! That did the trick :)

Question to that : do I have to compile/install the alsa-driver again after
that ? (didn't do that yet)

All recording Replay tests were done with a DD 2.0 recording from Pro7 and
one DD 5.1 also from Pro7.

I tried VDR 1.1.20 and 1.1.22 - both worked. (Both patched with the
according vdr-1.1.2x-audio.dif)
Then I took a already ElichAIO2 patched VDR 1.1.20 and applied the
vdr-1.1.20-audio.dif patch - patch worked :) - and AC3 worked :)
Then I tried also loading the following plugins : DVD 0.2.0, MPlayer/MP3
0.7.8 and VDRC 0.0.8 - worked too.

The most of my tests I did on this last configuration - therfore it might be
that my findings are caused by one of the other plugin or AIO. On the other
hand that configuration without bitstreamout has been runnning stable for
some time now. Next time when I am having time I will start with a vanilla
VDR 1.1.20 (with vdr-1.1.20-audio.dif patch) and bitstream.

I Did not test DVD/Mplayer yet.

I noticed one problem during my tests :

A couple of times I had no Sound at all on non AC3 channels - which is weard
because it should be comming from the DVB-S analog out (and there is no
Soundcard inbetween) !? The reciever was not on Optical Input so that was
not the problem !
One of the times I had to switch to Pro7 so that the Optical sound was
activated (that was a live DD 2.0) - after that Analog sound worked again
when switching to other channels.
A second time that did not work. I restarted VDR 2 times (killall -9 vdr) -
the third time I stopped VDR completely, Stopped alsasound
(/etc/init.d/alsasound stop) and started Sound/VDR again. After that it
worked again - I am not sure what did it.


Very good work :)

Greetings
Christian

> Hi,
>
>      I've done a patch for VDR 1.1.20 and 1.1.22 which is part of
> the tar ball of my bitstreamout plugin for VDR.
>
> The current version of the plugin can be found at
>
>       http://bitstreamout.sourceforge.net/
>
> or
>
>       https://sourceforge.net/projects/bitstreamout/
>
>
> @Klaus:  Please could you apply the patch for 1.1.22 (let's see if this
> can be attached to this mail).  The patch is _required_ for this
> plugin because without that patch the sound card stays open in
> none audio mode after first usage and the audio/video synchrony
> is missed after Pause, FF/FB, and SF/SB.  This patch also speeds up
> the zeroing of unneeded audio data due usage of memset(3).
>
> Short explanation to the plugin:  A sound card supported by ALSA with
> S/P-DIF out is required.  If your sound card has a S/P-DIF in with loop
> through to the S/P-DIF out you may connect the S/P-DIF out of the DVB
> card to it.  If the sound card supports "Slave clock" on this S/P-DIF in
> the activate it to make the sound card audio synchrony with that of
> the DVB card. This avoids under or overruns of the buffer of the
> sound card (whereas the plugin can handle underruns).  If the S/P-DIF out
> of the DVB card is looped through the sound card a mute script can be
> used for muting all audio (see example mute.sh for C-Media PCI CMI8738
> based sound cards).
>
> This plugin doesn't uses the S/P-DIF out of DVB card which reduces the
> load of the ARM ... which should increase the stability of the ARM ;^)
> On the other hand, without the last video PTS the plugin can't not
> guarantee as it will be done with AC3 over DVB.
>
> For more explanation see the manual page vdr-bitstreamout.5 and the
> file PROBLEMS.  E.g. for older ALSA libs a one line change in plugin.c
> of VDR is required due to a bug in the version control of dlopen usage
> of the ALSA lib.
>
>
>      Werner
>



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