Hello here,
I use an acer aspire 5930 laptop htpc conected to the tv via hdmi.
In my setting, I select hdmi audio output but laptop and hdmi sound play simultaneously.
I would like to configure the audio output to :
- option 1: if laptop start with hdmi plugged, just have the sound from the tv, AND
- option 2: if laptop start whit hdmi unplugged, have the sound from the laptop.
my kodi.log
system log:
if someone could help me, I would be grateful. 
What operating system are you running? I'm thinking you are having sound driver issues on the laptop.
When you plug in the HDMI cable and sound still comes from the laptop:
Right Click the Speaker in the Bottom Right-hand corner
Left Click "Playback Devices"
Look to see if there is a second option for HDMI now that it is plugged in and click on that.
Kodi expects the audio hardware configuration to remain static so it will not dynamically switch between two different configs although you could probably detect an HDMI event to run a python script to make changes over the XML API. Also, on most laptop/generic audio chipsets the alsa configuration will just output sound on all devices; and to change that you'd need to dig into the configuration for that specific chipset and come up with a custom audio routing configuration. It's all technically possible but alsa expertise is one of the Linux "dark arts" and you're unlikely to find willing volunteers and a nicely typed-up howto.
Kodi on Windows probably handles this scenario better.
