Dolby TrueHD Bitrate Question

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Originally Posted by ClaytonMG

Alright, so upon looking at the bitrate for the Dolby TrueHD track on 300, I noticed it actually drops down to around 1.2mbps in some spots... Which is actually lower than a DTS track and a Dolby Digital-Plus track. How can it do that if it's supposed to be lossless? I'm not saying that it isn't lossless, I just find it interesting and at the same time, it's making me want to stick with PCM's constant 4.6mbps bitrate.

DTS is Constant Bit-rate (CBR). It is always (for example) 1.5Mbps.

It doesn't always have to be. When it is absolutely silent, you could get by with something approaching 0Mbps. Yet, DTS is still using those 1.5Mbps (and LPCM 4.6Mbps).

One way to look at it is that DTS is lossless whenever the TrueHD is below 1.5Mbps. And gets progressively lossy for sound causing TrueHD to go above 1.5Mbps.

Gary