Is TrueHD the same thing as MLP? I ask this question because I just noticed that for PowerDVD Ultra 7.1 (HD DVD) splash screen, I don't see the Dolby TrueHD logo (it used to be there for 6.5) anymore.

For Batman Begins, when I select TrueHD from the sound menu, it switches from DD+ 640kbps to MLP which fluctuates ~1500kbps-~2300kbps. Is this working as intended? I thought the "lossless" tracks were supposed to be 18mbps? Did I read something wrong? Is it UP TO 18mbps? Could some owners of this movie tell me what numbers they are seeing for this movie?

Thanks

TrueHD is based on MLP.

18mbps is the max bitrate for TrueHD on both BD and HD DVD, since it maxes out at 96 kHz/24-bit over 8 channels for these formats.

Also, the bitrate for lossless encoding is variable. This is why it saves space unlike uncompressed PCM, which has a constant max bitrate.

TrueHD=MLP

You are NEVER going to see 18Mpbs. Thats higher than the video you were watching. And it wouldn't even fit on a HD DVD with the mux limits. That is simply the maximum the audio codec can do. The current TrueHD tracks are 1.5 - 2Mbps average. And they do indeed use a variable bitrate. PowerDVD was showing you accurate information.

Thank you for the quick reply. I wasn't sure if I bought the right software or not. I was mainly curious because for Black Hawk Down on BluRay (PS3 w/optical) had a PCM track that was downsampled to 1500kbps constant. I figured the TrueHD track would be a lot higher. Batman Begins track is amazing though.

Thats because a PCM track can only do 2-channels over optical. To listen to any of the 'advanced' codecs (pcm, truehd, dts-hd) you need to use HDMI or analog outputs. Optical is only for regular AC3 and DTS.

And PCM is much higher bitrate than TrueHD because it is uncompressed. 16-bit 5.1 PCM is 4.6Mbps and 24-bit 5.1 PCM is 6.9Mbps.

My bad, I meant Kingdom of Heaven and I just checked, it was DTS HD Master Audio downsampled to 1.5mbps constant. Everything is making sense now, thanks!

My bad, I meant Kingdom of Heaven and I just checked, it was DTS HD Master Audio downsampled to 1.5mbps constant. Everything is making sense now, thanks!
It should be the same bitrate for a down-sampled PCM track as well. Two-channel 48/16 PCM is also a constant 1.5Mbps.