Screen recording playback shows a black screen with audio only. The recording captured audio fine but the video is completely black.
This affects approximately 30% of our screen recordings. The other 70% play back normally.
The black screen is typically caused by a codec incompatibility between the recording encoder and the playback decoder.
GC screen recordings use VP8 or VP9 codec. If the agent’s GPU doesn’t support hardware-accelerated VP8 encoding (common on older Intel HD Graphics), the encoder fails silently and writes black frames. Check chrome://gpu on the affected agents’ machines for ‘Video Encode: Software only’.
We resolved this by enabling Chrome’s software VP8 encoder fallback.
Set chrome://flags/#disable-accelerated-video-encode to ‘Enabled’ (which counterintuitively disables hardware and forces software encoding). Software encoding uses more CPU but produces valid video. Monitor CPU usage - software encoding adds approximately 5% CPU load.