At Tue, 11 Dec 2007 14:22:49 +0100, Dr. Alexander K. Seewald wrote:
I am trying to output Dolby Digital data via coaxial cable to the Logitech Z-5450 5.1 speaker set. Presumably, a52 is the right plugin for this, taking six channels and combining them into the right format. However, I cannot seem to make the Z-5450 understand the format... it always displays "No digital data" and does not output anything.
Now, the documentation is very sparse on this, but states that Dolby Digital is supported, as well as DTS and DTS with 96kHz sampling rate and 24bit samples. The Z-5450 can play digital PCM stereo data, but this only activates left and right speaker (it is possible to set an effect to distribute sound to the other speakers, but this is insufficient for my purpose). I can play digital DVD 5.1 sound by attaching the coaxial cable to a DVD player.
As of now, speakertest -c 6 tries to play sound on all speakers, but only left and right respond. For all other speakers, "No digital data" is displayed on the Z-5450 console. This is consistent with the Z-5450 not able to play six-channel PCM data. However, using -Dplug:a52 and .asoundrc =
pcm.a52 { type a52 } (with various settings)
always shows "No digital data" and no sound output. I had a sample DTS 96/24 file a while ago which was able to activate all speakers, so the data connection is ok. But sadly I have misplaced it; in any case DTS 96/24 support is not what I'd expect in the near future.
Has anyone successfully output Dolby Digital (A52, AC3, ..) data via coax to the Z-5450 or a similar model? I'm using the newest alsa drivers and plugins on an 2.6.11, and the stereo-PCM output has been working for years... but this one keeps bugging me.
Check first whether "ac3dec -C foo.ac3" work to send AC3 data (not on the fly encoding). Try a52 plugin after confirming this works.
(And, I know there are still some bugs with a52 plugin but no time to play with it right now...)
Takashi