Intensity Pro HDMI embedded audio distortion

Hello everyone,
I am using the following setup to capture old Hi8 tapes:

Hi8 camcorder ---(S-Video + RCA stereo)---> Panasonic DMR-EH495, 576i50 ---(HDMI)---> HDMI Splitter (to remove HDCP) ---(HDMI)---> Intensity Pro, Media Express 3.6 625i50PAL (Linux, Fedora 30, Desktop Video 11.3)

At first everything worked fine except recording embedded HDMI audio. I set the correct capture options with Desktop Video Setup. The audio was severely distorted ( Sample recording of distorted audio, 1MB FLAC file: https://app.nihaocloud.com/f/ca0235fb04a0448bb0a8/?dl=1 ). Next I connected a TV behind the HDMI splitter and could hear distortion-free audio, both with PCM and downsampled PCM options for digital audio of the Panasonic DMR-EH495 recorder. I tried Desktop Video 11.3 and 11.2. I tried three HDMI cables. I tried different audio inputs of the panasonic. I tried hotplugging the HDMI cables, rebooting the Panasonic recorder and my computer. I used my phone as an audio source. I played a DVD. Everything worked with the TV and always getting distorted audio with the Intensity Pro. I gave up for that day.

On the second day, to my surprise, the distortion was simply gone. I could not reproduce the audio glitch – every capture with the Intensity Pro was flawless.

Problem solved? Not yet. On the third day, the distortion was back. I did not change anything since it worked the day before. Honestly, I have no clue why it worked fine on the second day or why the glitch is back now.

Has anyone experienced similar problems or any advice for troubleshooting?

Have a nice and glitch-free day
Tobias

I can confirm this issue. Almost identical setup, Pana Recorder + HDMI Splitter + Intensity Pro.

The distortion doesn't appear while recording, but when switching signals (eg dropped frames because of changing tapes). Also only the embedded HDMI audio is effected, RCA works just fine. In addition I have to shutdown (not only reboot) my computer to fix the issue. I also tried changing every single setting back and forth with Desktop Video Setup in hope of fixing the problem without the need to shutdown my computer, also un- and replugged cables.

Ubuntu 21.04., Desktop Video 12.1

Fully shutting down and reopening your capture software is the only way to fix this problem .It is a glitch with the capture card itself. You have to hope when you reset that it feels like working properly. But if there was any doubt that it was some other piece of hardware, it's the cap card being fussy.