I'm trying to understand the physical paths of the audio RCA connectors for tv-out on the PVR-350.
My expectation was that the decoded MPEG stream audio from the cx2341x decoder is routed to the msp44xx sound processor. If this is the case then snd-tvmixer [ http://www.gilfillan.org/v3tv/ALSA/ ] might be able to control the volume. No joy yet. I did finally do the obvious 'Watch TV' test and find that snd-tvmixer DOES control the PVR-350's encoder audio. Changes to the volume in alsamixer are delayed by the latency introduced by buffering. I've found reference to using ivtvctl to control volume on the tv-out, but that only affects the encoding stream, not the tv-out. TV-out with X is working well. I'm not using the ivtvdev xdriver yet. There is no sound card, so patching the audio through another mixer device does not enter into the discussion. The system in question is running Gentoo. I've been running with kernel 2.6.14-gentoo-r4 and ivtv-0.4.0-r3. I've just installed gentoo-sources-2.6.16-r7 and ivtv 0.6.2 from svn. The newer versions have the same result that ivtvctl and snd-tvmixer are unable to affect the volume at the tv-out connectors. The question remains, does the audio from the MPEG decoder go through any device on the PVR-350 that would provide volume control before reaching the RCA sockets? I saw nothing in fw-decoder-api.txt about volume. Does the cx23415 MPEG audio decode stage provide any DSP functions? Thanks, Perry _______________________________________________ ivtv-devel mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-devel
