HDMI Normal / Bitstream Audio on HDMI or S/PDIF:
If you select HDMI Normal / Bitstream audio to output audio from your source device (e.g. Blu-ray player, etc.) to your external device (e.g. HDTV, Home Theater, AV Receiver, etc.); the source device will stream compressed audio on HDMI or S/PDIF out without decoding it.
If you, for example, play a Blu-ray disc with audio encoded in Dolby TrueHD and you select Bitstream, the Blu-ray player will simply stream the Dolby TrueHD track from the Blu-ray disc to the AV Receiver to be decoded. i.e. It will not use its on-board Dolby TrueHD decoder.
Note: In some cases, based on EDID information the source device may be forced to decode audio and stream it to the external device as uncompressed PCM / LPCM. e.g. If your TV does not have the capability to decode Dolby TrueHD.
HDMI PCM / LPCM Audio on HDMI or S/PDIF:
If you select HDMI PCM / LPCM audio to output audio from your source device (e.g. Blu-ray player, etc.) to your external device (e.g. HDTV, Home Theater, AV Receiver, etc.); the source device will use its on-board audio decoder to decode audio and then stream uncompressed PCM / LPCM audio to the external device on HDMI or S/PDIF out .
If you play, for example, a Blu-ray disc with audio encoded in Dolby TrueHD and you select HDMI PCM / LPCM, the Blu-ray player will use its on-board decoder to decode the Dolby TrueHD track on the Blu-ray disc and then stream uncompressed PCM / LPCM audio to the external device on HDMI or S/PDIF out.
