[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: 'Splain please re: mixer, alsa, pulseaudio and tvtime??



On Sun, 26 Jul 2009 04:42:57 -0400, William wrote:

> I have external receptacles on my motherboard at the back of my computer
> box -- one light green for incoming sound, and one light red (pink) for
> a microphone.  Double checked visually and in my motherboard manual.  
> 
> *However* my tv tuner card has no sound output receptacle, did not come
> with a line to use as an external connection line and shows no external
> hookups in its manual.

Yes, it's a known fact by now. Nobody asks you to put a cable where
you *cannot* put a cable. ;-) The remaining problem, however, is that
there must be a theory about how your tv card "produces" audio then?

> > > Simple mixer control 'Capture',0 -err
> > > Simple mixer control 'Capture',1 -err
> > 
> > This is one of the special things about your audio chipset. Two
> > Capture lines, likely one analog and one digital.
> 
> Yes.  Knowing that Canada and the U.S. were going to all-digital at
> least two years apart (or more), I purposefully purchased a TV tuner
> card that could be both analog and digital.  I checked on-line before
> making the purchase (I forget where, but on one of the normal Linux
> device recommendation sites).  My card was listed as working on Linux.

Above is about your onboard audio chipset, not about the tv card.
Analog/digital here refers to audio, not cable tv.
I still think you cannot expect any tv sound when using the analog
input/capture channels of your audio chipset.
Hence there either must be a way to make tv card and onboard
audio talk together digitally (and in turn have something that puts
the audio chipset into the desired mode), or to have the driver supply an
A/V stream on /dev/video1 (which is what some of the success reports
suggest, as they user mplayer to play back that mpeg stream).

> Remember, the original bug #510105 was simply "Description of problem:
> No sound for my tv tuner"
> 
> Someone said that bug #510105 bug was a duplicate of #498167 "I Can't
> get TVTime to output audio."
> 
> You posted to bug #510105
> 
> "Apparently, even with "alsamixer -c0" reporter cannot turn on any
> input channel to make tv card audio output work. That means that internal
> routing from audio between tv card and sound hw doesn't work/isn't enabled.
> tvtime can't do anything about it if no mixer channel controls the tv audio
> output. It's more of another tv card driver problem (also see bug 497750 - same
> reporter, but F10)."
> 
> I agreed with you.
> 
> I posted this thread on the Fedora user list in order to straighten out
> my use of controls before returning to bugzilla. 

Yeah, it's not really a duplicate anymore, but not a PulseAudio bug either
since switching on a silent audio channel [with tvtime] yields silence, of
course. (With F11, almost every tvtime user runs into the problem that the
old OSS audio system is no longer supported and that tvtime cannot use the
ALSA mixers instead. Only the tvtime update changes that. The majority of
users connect tv card and audio card, though, which doesn't apply to you.)

> > And how?
> > ANd what does your tv card driver does related to audio?
> > 
> 
> I have filed a bug about PulseAudio and my tv tuner card #510105 and
> subsequnetly about ALSA + PulseAudio #511178.

It would really be interesting to retest the tvtime+mplayer solution.
Decoding an mpeg a/v stream with mplayer sounds really plausible.

What other capabilities for audio the tv card driver has might be
found out by seeking help from its author (or by examining the kernel
module source code and inline comments).


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]