Slackware and Slackware derivatives on fit-pc2

vtailor
Posts: 229
Joined: Mon Sep 24, 2012 6:54 pm

Re: Slackware and Slackware derivatives on fit-pc2

Post by vtailor »

OK, here's the scoop for a base fit-pc2 with SPDIF to analog converter tied in to the SPDIF output: alsamixer won't come up without some help in the form of an /etc/asound.conf file. There is a script in alsaland somewhere that makes this asound.conf file "automatically". I think I managed to attach the script to this post. Run the script, and alsamixer starts to work. I'm not sure what does what here, but un-muting both SPDIF buttons in alsamixer actually gets digital sound going into the SPDIF to analong converter on my fit-pc2. The converted analog sound, so you can check on me, has some kind of a ground-loop hum in it, that diminishes when the sound reaches a reasonable room volume. I'm pretty sure the ground loop is in the fit-pc2.

So, in two versions of Linux, using the SPDIF to analog converter, I get reasonable lipsync and similar to Windows 7 streaming flash quality.

vtailor
Posts: 229
Joined: Mon Sep 24, 2012 6:54 pm

Re: Slackware and Slackware derivatives on fit-pc2

Post by vtailor »

OK, take the fit-pc2 away from my HDMI television set and connect it to my desktop apparatus with the dvi-d monitor and computer speakers. When I connect the SPDIF to analog gadget between the fit-pc2 and the computer speakers, I no longer get the HDMI noise, because the HDMI is to a DVI-D device, and I do get lipsync and continuous motion, under very particular circumstances: Lowest available bandwidth (240p for youtube) and small or medium, but not full screen.

vtailor
Posts: 229
Joined: Mon Sep 24, 2012 6:54 pm

Re: Slackware and Slackware derivatives on fit-pc2

Post by vtailor »

One more thought: Suppose you find exactly the right /etc/asound.conf file that makes the fit-pc2 not do analog sound, but only SPDIF sound. That way, in theory, there is less going on in the CPU and more available for displaying video. So, here is a minimal audio asound.conf file:

pcm.!default {
type hw
card 0
device 1
}

Supposedly, that specializes the fit-pc2 to do only SPDIF sound going to my SPDIF to analog converter and desktop speakers. The screen capture of this in operation shows, depending on the streaming flash source, excellent part-screen video and gorgeous sound.

vtailor
Posts: 229
Joined: Mon Sep 24, 2012 6:54 pm

Re: Slackware and Slackware derivatives on fit-pc2

Post by vtailor »

To anyone worried about "ground loop hum" in an HDMI television set: According to one of the internet blogs, there is a "handshaking" that goes on to acquire HDMI audio. So, if your HDMI cable into the HDMI input only has DVI-D video, you will get the video on the television, but connecting analog cable to the rear component analog connector leaves the HDMI input volume turned up full (but no signal, therefore the hum), and, yes, your SPDIF to analog converter is also heard above the hum.

In other words, the ground loop hum is in the HDMI television set, not the fit-pc2. No ground loop hum when the DVI-D output is used on a desktop with the SPDIF to analog converter going to the desktop speakers.

Post Reply

Return to “Linux on fit-PC2”