Theo Verelst Local Diary Page 106

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Oct 8, 19:00, 2011

Click on the image above for one of the youtube hosted recordings made like indicated. The videos were converted to 10mb/s h264 using ffmpeg with vdpau decoding. Audio is from analog output of the Kurzweil straigt into the peamp of my big audio system recorded by the HD cam, no processing or editing.

192 Kilo Sample per second converted Blu Ray sound tracks

Latest rented ones, 7 for 10 a week, including the Tarantino "Inglorious Basterds"

I also tried decoding uncompressed digitied TV sound in 192kHz sample format, which is pretty nice most of the time, of course depending on channel properties. Adding Lexicon surround reverb to that (the 4 channel in 4 channel out variation from the MX400) is getting there where it is acceptable to listen to it a whole movie from various seats and can actually start to get nicely adjusted, starting with low values for spread and shape.

Fully wireless High Definition Satellite

Essentially I used the fat wireless connection of the I7 notebook on Linux (Fedora 16-alpha, 64 bit) with the new internet modem wireless connection (which I put only "on" when I use it) and connect over the ethernet to the sat receiver media machine connected with the dish in the picture above. A linux kernel program receives the ITV-HD 12megabit/sec signal, sends it too the notebook over the wireless using two tcl scripts and the notebook decodes the signal and displays it in full HD, which looks neat. Also I can now log in the media machine, and run a signal analizer program which is now visible as a transparent window (I use KDE) when I bring the notebook outside to adjust the antenna. Works cool, batteries last I think an hour and a half while viewing, without getting too hot.

Still the VDPAU cannot be used, just like the NVIDIA GT540m (very fast) graphics acceleration. I tried running bublebee, the nvidia driver and some of the nvidia kmod libraries, but none of that gets the graphics cards picture switched to the built in lcd. I can even make the sandybridge I7 put a simultaneous HD picture over the HDMI but the best I had with nvidia card is that the startup sequence from X windows indicates succes and that there is some screen attached (but not that it is HD like it is) but the screen remains black and there is no furter succes and some 640x480 minimum size. I put the nvidia driver (the most recent) of and went back to the standard X startup, which gives nice sandybridge graphics at HD size. But now deinterlacing and 420p too rgb processing needs to be done by the I7 processor, which it does nicely with some of the -vf mplayer (ffmpeg based) filters with -vo x11, but temporal averaging and elaborate colorspace corrections are much stronger with VDPAU and don't always work fast enough for HD.

Like with the phone+notebook+ipad example, the wireless signal from the notebook didn't interfere noticably with the sat reception, and neither did the nearby wireless 3.5G phone, all worked simultaneously with no problems within a meter from eachother...

This is the same machine with KDE with wireless network, showing an X window based TV channel coming over the gigaether link without compression, from two different sources (put on the same screen):

Signal Processing Galore ?

The I7 notebook  runs some good number of jack plugins and also connects correctly to the other machine over ethernet, for instance to share the load of running all the processing or to get a 192kHz 32 bit feed from the server disc with 4500+ CD songs:

KDE still has the nice transparent windows.

Aes Lecture

about switching amps

(Tcl script used for creating 2/3 size screendumps with click to original:)
set s Ldi106/Scr
foreach i [glob $s/*.png] {
puts "<a href=\"$i\"> <img src=\"[file rootname $i].jpg\"> </a><br>\n"
# exec pngtopnm $i | pamscale -filter=sinc 0.666 | cjpeg -q 85 -pro -dct float -outfile [file rootname $i].jpg