[mythtv] a small patch
Michael T. Dean
mtdean at thirdcontact.com
Wed Mar 24 00:03:14 UTC 2010
On 03/23/2010 07:03 PM, Emmanuel Anne wrote:
> I have been struggling for quite some time to get the sound working on
> all channels with my freebox network recorder. The problem seemed easy
> enough, so I took a look at the code...
>
> In fact there are some "low bandwidth" channels which use some 24Khz
> samples (AAC, 2 channels). And a lot of modern sound chips can't play
> directly this sample rate.
> So you have to use the alsa built-in resamping abilities, but for this
> to work you just need to setup the hw parameters before calling
> snd_pcm_hw_params_get_period_size (and not after). I got the solution
> if the source of aplay, the alsa utility.
Please submit patches to http://svn.mythtv.org/ . Thanks.
>
> While I was at it, I also added a test to replace the mixer device by
> "hw:0" when it is set to "/dev/dsp" for alsa (the default
> configuration sets it like that, and alsa can't work with /dev/dsp).
You should almost always use ALSA:default, not hw:0, for the ALSA mixer
device in MythTV (which, BTW, is the other option in the list).
> You might want to put this test elsewhere, but for now it fixes broken
> configs without any manual intervention.
That would be ideal as separate ticket on Trac.
> A few problems I noticed with this setup :
> - the biggest one : the tv guide which uses xmltv stores its programs
> using a unique channel identifier (chanid = integer(10)) in the table
> program. The problem with that is what can you do when you have for
> example 3 channels available which are exactly the same channel but in
> 3 different quality (hd, standard, low bandwidth). With that, you can
> have the guide for only 1 of the 3 channels apparently, which is
> rather bad...
> - the same kind of problem : with these 3 channels, they share the
> same number in the m3u of the network adapter. So only 1 channel
> appears in the channel list in mythtv (the last one). Here again, it's
> too bad...
I'd be happy to explain how to properly configure this on the
mythtv-users mailing list if you want to post a question there about it.
> I hope you find the patch useful, created by using svn diff in the
> mythtv-0-22/mythtv directory.
Thanks, again, for the patch (and thanks, in advance, for putting it in
Trac).
Mike
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