HDMI connects digital audio/video sources to audio/video receivers.
Realtek digital output shown in Windows 7 audio playback devices should, I believe, be the HDMI output.
You should be getting digital audio output through HDMI. What settings are you using on your AV receiver/TV?
No, when I connect HDMI I get another audio output device as "Realtek HDMI output" in Windows 7 audio playback devices.
Then what is Realtek digital output over there?
I do not remember all the settings in the TV, but I did set it to HDMI input mode. when I did that I got the video through HDMI but no audio.