pcm uncompressed

[admin_exported]

Hi all,

today I rented the "Train" blu ray.

I noticed that you can choose 2 audio options.One was dolby digital and the other pcm uncompressed;

What's the difference between those 2?

Somethimes pcm also appears on my amp's display(yamaha rx-v1065)and I always wonder what it means.

Sorry if it's a stupid question but I really an amateur.-)

 

[nads]

the DD is a compressed sound track and the PCM is not compressed.

 

[Anonymous]

Can anyone give a little more information please?

 

[Anonymous]

PCM is the standard format for encoding audio digitally on CD/DVD/BD.

Dolby and DTS soundtracks have taken the original PCM tracks and compressed them to save space.

Decoding of Dolby/DTS soundtracks 'unpacks' these PCM tracks and reassembles them (sometimes data is lost as part of the space saving process (lossy encoding such as standard Dolby digital 5.1 and DTS 5.1; sometimes lossless as with the high-def soundtracks on bluray).

Uncompressed PCM is where no encoding (compression) is utilised and therefore no decoding and extra processing is necessary. This takes up more storage though as a downside.

Although hi-def formats unpack the orginal PCM tracks bit-for-bit, you could argue that bypassing the entire encoding/decoding processes may potentially produce a superior sound. Some argue that the digital processes of encoding decoding result in a perfect copy of the original and that it is therefore nonsense to suggest there will be any loss of quality.

 

[Anonymous]

the pcm soundtrack on the casino royale blu-ray sounds better than the dolby digital one ...

 

[aliEnRIK]

I can set my amp to decode or my sony S370 or my PS3

My amp definitely sounds best when its doing the decoding, so on that basis id say that uncompressed PCM would be the best option (No decoding, theoretically no loss)

That said, uncompressed PCM also has a higher bitrate, so if your HDMI cables a poor quality one and cant quite handle the higher bitrate, then the compressed soundtrack may be better

 

[Anonymous]

Ok thx guys!