Getting 5.1 in PCM

[David Faulkner]

About 6 months ago I spent $3,400 on a upgraded 5.1 system, I use my PS4 as the Blu-Ray player. Always noticed the Yamaha Aventage RX-760 showed PCM but it played all movies in 5.1 (and it sounded great) so I never thought twice about it. Today I decided to investigate why this is and it seems the PS4 was set to output in PCM instead of Bitstream. Since making the change the receiver now shows the correct audio format "DTS HD MA" "Dolby Atmos" ect. My question is..... What the heck was i listening to for 6 months??? I would imagine the PS4 was taking the DTS HD MA track and doing something with it. My 2nd question is since PCM is uncompressed would it be a better option vs the bitstream?

Thanks!

 

[James S.]

Hi David,
Essentially, Pcm and bitstream are the same. PCM means the source is decoding the soundtrack and just telling the receiver to amplify it. Bitstream sends the soundtrack to the receiver which does the decoding. You were basically listening to the same thing, just a different component doing the decoding. I used to use PCM and have my bluray player decode dolby true hd and dts:ma as my older sony receiver could not decode those. Now I use bitstream and let my new Yamaha receiver decode it.

 

[Seth=L]

Uncompressed multichannel PCM. Essentially your PS4 was decoding the selected audio format (DTS-HD or Dolby Digital Plus/TrueHD/Atmos, etc) and converting it to multichannel PCM. The process tree looks like this.

Codec - PCM - Analog

So the codec has to be unpacked and converted to pulse code modulation before it can be converted to analog for final output. A good analogy is that you can't print a zip file of a jpeg, but once the file is unpacked it can be printed.

Bitstream is probably what I would use because I'm not sure what all the PS4 can unpack on its own. The receiver can unpack just about any bitstream.

 

[Seth=L]

Hi David,
Essentially, Pcm and bitstream are the same.

It might just be your wording here, but they are not essentially the same.

 

[James S.]

Sorry, I meant sound. I don't notice any difference between my bluray player or my receiver doing the decoding as far as the sound.

 

[Alvin Cole]

So, is there any benefit to one vs the other doing the decoding?

 

[lovinthehd]

So, is there any benefit to one vs the other doing the decoding?

If both units are capable flip a coin. I've used both on my PS3, but generally use bitstream, and for some content the PS3 just does PCM anyways, not sure about the PS4. Your avr may offer more sound modes for the bitstreamed signal, tho.