Measuring sound bit rates

[Ridcully]

I have a Pioneer 525 which gives an overall bit rate read out but who can I get specifics on the sound. Just want to be able to check on the different DTS and DD sounds. Will any of the software palyers do this ?

[RoyJones]

The new Power DVD XP does.

It's amazing to see how all LPCM tracks are much higher than Dolby Digital.
I've a couple of DTS tracks that can match the bitrate of LPCM stereo, but generally they are much lower.
The normal seems to be:
LPCM@1600
DTS & DD5.5@550ish
and poor old DD2@190.

Cheers

Roy.

[Tony Keats]

I remember somebody saying their Sony player displayed audio bit-rates too. Just on the off-chance anyone's deeply interested in this topic (unlikely I know), the exact rates are as follows:-

DTS tracks will either be 1509kbps (full-rate), or 754.5kbps (half-rate). In truth though, virtually every title released from this point onwards (save some Jap ones) will have a half-rate track (because 1509kbps takes up far too much disc space). A good example of this fact is the new R1 "superbit" range (which are all 754.5) and if they were to use the full-rate on long films, the picture quality would have to be compromised (which would defeat the object obviously).

Although the existing full-rate discs certainly are jaw-droppingly impressive (Galaxy Quest, Twister etc), there's nothing wrong with the lower efforts either. Saving Private Ryan and Cast Away are both cut-rate, but they're frequently referred to as 'reference quality'. Personally I'd love some more 1509kbps releases TBH, but it's highly unlikely when you consider how difficult it becomes to fit alternate 5.1 tracks onto the discs. DVD's intended for Canada are much more saleable if they have different language choices (The Mummy Returns R1 ditched a DTS track altogether to accomodate a French speaking 5.1 option).

Dolby Digital 5.1 tracks will either be 448kbps or 384kbps, the latter of these can sound a bit 'restrained' on some set-ups IMO though. I remember that my Digitheatre needed a full-rate DD track to really do the film justice and I also remember that some Warner discs were overly tinny/muffled (to my ears anyway). R1 discs are largely 448kbps, but R2 is more of a mixed bag. The big releases usually get encoded generously of course, but back-catalogue titles that are intended for the whole of Europe (and therefore have about 170 languages/subtitles) occasionally get shafted with extra compression.

[Michael Brooke]

<B>It's amazing to see how all LPCM tracks are much higher than Dolby Digital. </B>

Not really, when you consider that PCM tracks are uncompressed, so they pretty much have to have a high bitrate by definition!

DVD-Audio is the other really high bitrate sound format - unlike PCM, it's compressed, but it uses a lossless compression system so that there's no compromise in terms of sound quality. Unfortunately, you need a proper DVD-Audio player to get the full resolution - but the results can be truly staggering (imagine hearing uncompressed PCM-quality sound across all six speakers!)