Delay in audio output over HDMI (3 Viewers)

[Ronald Robertson]

Thanks for all the feedback - much appreciated. After quite a bit of independent research I've learned that the Silent Stream bug is apparently a Windows issue so maybe W10 was the fix for Joecrow; not sure. As far as turning off the effects, the real issue is that I have a lot of custom automation running my theater and much of it verbally speaks things its doing such as "turning on projector" and so on since if you have no picture, you would't know if the remote key press was actually acknowledged... The fact that the first second or so of all those annunciations getting cut off is really why I want to fix the problem more than just the clicks.

I have in the mean time also installed a new sound card and connected over digital co-ax and of course the problem goes away but digital co-ax (or toslink) do not support multi-channel uncompressed native HD audio so I'm back to HDMI again.

Among this research, I have also found a host of other s/w solutions that keep the audio channel alive and I'm going to try those this weekend. I can post the results if anyone is interested.

Thanks

 

[joecrow]

After quite a bit of independent research I've learned that the Silent Stream bug is apparently a Windows issue so maybe W10 was the fix for Joecrow; not sure.

Just wanted to clarify this, or perhaps muddy the waters further, but I cannot be sure if I ever ran my AVR with Win 7. Before I bought the AVR I had the HTPCs audio line out connected to an old stereo amp and I got the AVR in Nov. 2015. The Win 7-10 free upgrade was available from the Summer of 2015 and I know I did not switch the HTPC to Win 10 straight away but I am really not sure when.
The bottom line is that the Silent Stream bug I experienced. may have been fixed with the Win 7-10 upgrade or perhaps a subsequent Win 10 update (I'm currently on 1803) or some other update , sorry I really can't be sure.

 

[lapo]

Hi,

this issue is widely known as the "HDMI Audio Handshake Delay" or "Silent Stream Issue".
It occurs because when the PC stops outputting audio, the AV receiver (AVR) drops the audio connection to enter a standby/power-saving state or to prevent pops/clicks.

When the PC sends a new sound (like a UI navigation click), the AVR takes about 0.5 to 1.5 seconds to detect the stream, perform the HDMI handshake, and lock onto the signal, causing the first second of audio to be clipped.

Since the root cause is the lack of a continuous signal, the definitive solution is to force your PC to send a constant, invisible stream of silence to keep the HDMI audio pipeline active at all times.

Here is how you can resolve this across Windows, MediaPortal, and LAV Filters:

1. System-Wide Fix for Windows (Recommended)

Use a background utility that maintains an active HDMI audio stream:

• SoundKeeper (Free, lightweight): A portable utility that runs seamlessly in the background. It generates an imperceptible, silent audio signal that prevents the receiver from dropping the HDMI audio connection, completely eliminating the delay for UI sounds. You can set it to run on Windows startup.
• HDMI Audio Keep Alive (HAKA) or AVR-KeepAlive: Good alternative open-source tools that achieve the exact same result.

2. MediaPortal Settings

To handle this directly inside MediaPortal:

• Open MediaPortal Configuration -> Audio Settings.
• Ensure the GUI/system sound output uses a renderer configured to keep the audio endpoint active. Look for settings or audio renderer options such as "Keep audio device alive" or continuous PCM streaming in background settings (depending on the audio plugin or custom renderer installed).

3. LAV Audio Decoder Tweaks

For movie playback transitions:

• Open LAV Audio Configuration.
• Navigate to the Audio Settings tab.
• If you are using Bitstreaming (sending raw Dolby Digital/DTS/TrueHD to the receiver), the AVR is forced to re-lock its DSP decoder every time a file starts or audio changes. If you experience delay at the start of videos, uncheck bitstreaming for standard formats and let LAV decode to Uncompressed LPCM. Sending a continuous PCM stream eliminates the decoding mode-switch delay on the AVR side.