Digital audio output over HDMI (via DP to HDMI converter) works fine out of the box in Vista on my Latitude E6500. Does not work at all in linux (only the single analog headphone output is listed as available outputs). I've tried a number of things, including different kernel versions, different alsa versions, different nVidia driver versions (I have the nvidia model of this laptop) and manually selecting model options for the alsa driver. Using the display over the DisplayPort works perfectly fine. Anybody have any suggestions or know if it's being worked on?
Please don't reply just to say "works in windows" (i know), "never tried it but it should work fine" (not helpful), "what is a DisplayPort?" (def not helpful), or "HDMI doesn't do audio" (not true).
My guess is that you have already discovered that HDMI is unsupported in Linux due to the copy protection scheme called HDCP. Which yes, has been cracked, and no, won't really lend itself toward HDMI support in Linux. At present, only MacOS and Windows offer HDMI support. You might look into composite or VGA video formats, with some sort of 3/32nd audiojack converter.
I was using a cheap ATI HD 4550 video card and it had sound out the HDMI using kubuntu ( both 10.04 & 10.10, but don't remember if it worked with 9.04 and 9.1) but had trouble getting 5.1 to work, I switched to the EVGA GEForce 220 and now I have 5.1 sound . The proprietary Nvidia drivers from Nvidia work best for me. It has been a while but I seem to remember two things I used:
First - I used the version of smplayer developed by Nvidia which had a special audio out option for the hdmi using the default alsa sound system and later added pulse audio which allowed me to send all sounds to the both the internal nvidia as well as the hdmi. I wish I could be more specific but no longer remember what package I used but it had to do with Pulse Audio, perhaps pavucontrol ( Pulse Audio Volume Control ) the smplayer from nvidia uses the Alsa sound system, both work equally well but the Pulse audio seems to give me more options and works with anything so I can watch Hulu etc. We use a 40' hdmi cable to the computer on the second floor and a little Asus netbook with Peppermint One installed and a program called "quicksynergy" that allows us to use the little netbook keyboard and mouse ( or my wifes Dell 1420N laptop) to control the Dell Inspiron 531 upstairs that actually plays the movies, Hulu, youtube etc on our Plasma TV. You can have both alsa and pulse audio installed and still use the alsa with the smplayer and use pulse audio for everything else like flash.
I am sorry I can't be more specific as I really don't know what the Dell you have has for a video card, but Nvidia is probably the best commercially supported video for linux and they do have 5.1 sound working with HDMI , ATI also has some video cards that do HDMI sound well but as I posted the cheap ($20) HD 4550 did not work as well for me, our Sony receiver would not accept the 5.1, even though the sound tests showed the card was sending multible sound channels, it had sound just not 5.1 sound. The proprietary Nvidia drivers use a program, Nvidia Xserver settings to turn on the hdmi video, I keep mine off unless I am planning to use the HDTV as a monitor. We have a Roku and HD Tivo (transfer our dvds via pyTivo) and get most of our video these days from either of those two sources, on occassion I will use HULU but tried Huli Plus but found Netflix streaming is still better for us.
Sorry, I could not find a way to edit my last post, I forgot to add that for 5.1 sound I use the Nvidia proprietary video drivers which were not the default video drivers installed. In the KDE menu under > applications > system > " addtional drivers" ( technically it may be called jockey-kde ) the program will anaylize your system and determine which proprietary drivers will work best and if available, you can select the nvidia driver so it automatically installs the Nvidia proprietary driver and I think the Nvidia Xserver utultiy program I wrote about. Ubuntu has a similar program in a similar location, but I don't remember more than that without starting up a second X server with gnome. You need the proprietary Nvidia driver for 3D effects.
You can get more help at the Nvidia web site. My wife has a Dell 1420 N preinstalled with ubuntu 8.04 that we also run kubuntu on - at first we had to use the Dell images for all the drivers to work but these days the the regular ubuntu/kubuntu releases seem to work out of the box with both our dell computers we have Maverick on both systems . If I were new to linux and just starting out I would use Linux Mint on the desktop or Peppermint One for a netbook or laptop as it is based on Ubuntu but has most of the things average people want already set up.
good luck, I don't usually visit the Dell site but was checking out the Dell outlet for a newer Dell desktop and wanted see what on these forums. Do a little google searching - you may find the answers you need. The most important thing is 5.1 does work through HDMI on linux systems suing the proper drivers and supported video cards that have hdmi out.
I had the same problem and found the solution on the Ubuntu forum:
"HDMI audio output works. As soon as you plug the HDMI cable in, you
right click the volume button -> Sound Preferences -> Hardware.
Then under Profile at the bottom switch to Digital Stereo (HDMI) Output.
In other words: Just turn it on, in sound preferences -> hardware!
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