After 2 full days of audio testing my findings are that there is around 100ms of audio delay when you enable HDMI Audio Format: Bitstream in GAME MODE!!!
Other people seem to be experiencing the same issue:
My Sony BDV-7200W only accepts PCM 2.0 signal over ARC HDMI. Dolby Digital and DTS are 5.1 via bitstream ARC HDMI.
I've gone through every possible combination on PS4, TV and Sony Audio System.
When game mode is disabled no audio lag HDMI
Audio Delay on TV only lengthens the delay not shorten it.
As of now I have a fantastic image, great surround sound albeit 100ms late.
The killer here is the delay is also present through the TV speakers if you turn off the audio system.
The PS4 is hooked straight to the TV.
In Game Mode, TVs are supposed to reduce video lag.
If you deliver audio to an AVR in bitstream mode (assuming input signal is DD,DDP or DTS), TVs usually just passthrough it to AVR through HDMI, without adjusting delay.
In such a case, if audio still lags video, there might be 2 reasons...
1- AVR audio processing time is really high (Which is less likely..)
2- TV cannot reduce video lag significantly in game mode.