Uncompressed or Dolby Digital?

[Gallis]

Hello folks, I am brand spankin new to the forum and Blu-ray. Just got my home theater installed yesterday. PS3 is my Blu-ray player. I just purchased my first Blu-ray movie, Apocalypto (did I spell that right?).

Under set-up menu, I had the option of uncompressed or Dolby Digital. Which is better? I went with uncompressed, sounds purty good so far. What do you experts recommend? Thanks at ton and this picture is fantastic!

I swore to myself that I will not re-purchase any movies I already own, this is going to be hard not to do. Thanks in advance.

Gallis

[BozQ]

Originally Posted by Gallis

Hello folks, I am brand spankin new to the forum and Blu-ray. Just got my home theater installed yesterday. PS3 is my Blu-ray player. I just purchased my first Blu-ray movie, Apocalypto (did I spell that right?).

Under set-up menu, I had the option of uncompressed or Dolby Digital. Which is better? I went with uncompressed, sounds purty good so far. What do you experts recommend? Thanks at ton and this picture is fantastic!

I swore to myself that I will not re-purchase any movies I already own, this is going to be hard not to do. Thanks in advance.

Gallis

Dolby Digital is compressed. So which do you think is better?

[Gallis]

Not a clue...that's why I am asking. Are you saying Dolby Digital is better? I repeat, this is my first time EVER watching a Blu-ray...thanks.

[gand41f]

Originally Posted by Gallis

Hello folks, I am brand spankin new to the forum and Blu-ray. Just got my home theater installed yesterday. PS3 is my Blu-ray player. I just purchased my first Blu-ray movie, Apocalypto (did I spell that right?).

Under set-up menu, I had the option of uncompressed or Dolby Digital. Which is better? I went with uncompressed, sounds purty good so far. What do you experts recommend? Thanks at ton and this picture is fantastic!

I swore to myself that I will not re-purchase any movies I already own, this is going to be hard not to do. Thanks in advance.

Gallis

Welcome!

Yes you spelled "Apocalypto" right.

Which you want may depend on your home theater setup. If you are using coax (which PS3 doesn't have) or optical, you can only get 2 channels of PCM. That means you will get more surround effects from DD5.1 but more sound clarity from PCM. If you are running audio through the receiver with HDMI, you can get all channels with PCM.

Or something like that. Please search the archives for details, I'm sure there are better answers than mine.

enjoy
gandalf

[Gallis]

Gandalf, thanks for that info. I am running HDMI in my home theater set-up. I just finished watching the movie in uncompressed and I think it sounded damn good. I'm guessing the only way I can find out is to re-watch it in Dolby Digital.

You also mentioned PCM, what's that stand for? Thanks again...

[Zaphod]

Originally Posted by BozQ

Dolby Digital is compressed. So which do you think is better?

Wow...

[Zaphod]

Uncompressed is definately the best you can get when it comes to audio...right now. PCM stands for pulse-code modulation, which is what uncompressed is sent out as from the PS3. The other type is bit-stream which is sent out via optical on the PS3.

You can re-watch it with DD, but after the first 5 minutes you will realize that uncompressed PCM will not be beat!

Welcome and as a side note we are not all like BozQ and give such smart ass answers to legitimite questions.

[PeterTHX]

Uncompressed PCM is basically the original master.
The Dolby Digital track is there to provide folks without HDMI audio a way to get 5.1 surround sound thru the optical digital output. It's backwards compatible with basically every surround sound receiver made in the last 10 years. DD takes up very little space, is very efficient, and mandatory for DVD and HDTV. But if you have the means, uncompressed is the way to go.

[HDJK]

Originally Posted by Zaphod

Uncompressed is definately the best you can get when it comes to audio...right now. PCM stands for pulse-code modulation, which is what uncompressed is sent out as from the PS3. The other type is bit-stream which is sent out via optical on the PS3.

You can re-watch it with DD, but after the first 5 minutes you will realize that uncompressed PCM will not be beat!

Welcome and as a side note we are not all like BozQ and give such smart ass answers to legitimite questions.

I totally agree with the bolded text

However, there is a slight correction for your statement. You can output bitstream over HDMI as well. This way the receiver will decode the audio for you. This is only possible for DD and DTS though, you cannot bitstream DD TrueHD or DTS HD Master Audio,... yet.

[Zaphod]

Originally Posted by HDJK

I totally agree with the bolded text

However, there is a slight correction for your statement. You can output bitstream over HDMI as well. This way the receiver will decode the audio for you. This is only possible for DD and DTS though, you cannot bitstream DD TrueHD or DTS HD Master Audio,... yet.

Sorry...and thanks for the correction HDJK.

[WriteSimply]

To the OP: If you have a HDMI receiver capable of passing through video and amplifying audio, set the PS3 to Multichannel LPCM under Audio->HDMI.

We need a NEWBIE sticky for BD player setups.


fuad

[Deciazulado]

LPCM = Linear Pulse Code Modulation = uncompressed

example: CD audio is 2 channel x 44,100 samples per second x 16 bits resolution LPCM = 1,411,200 bits per second (or 1,411 kb/s or 1.4 Mb/s)

Blu-ray LPCM can have more channels x higher samples per second x higher bit resolutions

for example 5 channels x 48,000 samples per second x 24 bits = 5,760,000 bits per second (or 5,760 kb/s or 5.8 Mb/s)

DolbyDigital is an lossy audio compresion codec (like mp3s)

example: DolbyDigital DVD audio 2 channel = 192 kb/s, or DVD audio 5.1 channel 448 kb/s, or BD audio 5.1 channel 640 kb/s

There are other flavors of Dolby audio on High Definition discs like:
DolbyDigital+ (can have more channels, and higher bitrates) and DolbyTrueHD (this has lossless compressed audio which means it's like a zipped file on a computer: It's packed more efficiently (so it's compressed) but it doesn't lose data so is equivalent to uncompressed LPCM, but takes less disc space.)

There's also DTS audio, which has its lossy compressed flavors like DTS at 1.5 Mb/s, DTS-HD at 3 Mb/s and a lossless compressed version too called DTS-HD MA

[bferr1]

I just wanted to chime in here and say that YMMV when using uncompressed PCM versus Dolby Digital, depending on your receiver's capabilities. Until recently, many receivers have had issues wrt the LFE signals on PCM audio over HDMI being weak, lost or misdirected. Pioneer even upgraded their Elite receivers with new firmware to correct this problem. Picking out a good receiver that can handle the LFE on PCM is, IMO, among the biggest make-or-break decisions you face wrt to your home theater set-up.

I went through many a receiver from Pioneer, Yamaha and Denon before finding a Pioneer Elite with the new firmware pre-installed. Believe me, it was worth the effort.

For lots more info on this topic, see the first post here: http://www.avsforum.com/avs-vb/showthread.php?t=748147

[leukoplast]

Uncompressed will give you much better audio quality than standard Dolby Digital. In fact regular DD is the worse surround sound you can get.

So the difference in uncompressed PCM vs DD is like day and night.

[aqupunk]

Ok I know this has been thrown out before but for my own info is pcm better or the same as true dolby hd?

[GoldenRedux]

Originally Posted by Deciazulado

LPCM = Linear Pulse Code Modulation = uncompressed

example: CD audio is 2 channel x 44,100 samples per second x 16 bits resolution LPCM = 1,411,200 bits per second (or 1,411 kb/s or 1.4 Mb/s)

Blu-ray LPCM can have more channels x higher samples per second x higher bit resolutions

for example 5 channels x 48,000 samples per second x 24 bits = 5,760,000 bits per second (or 5,760 kb/s or 5.8 Mb/s)

DolbyDigital is an lossy audio compresion codec (like mp3s)

example: DolbyDigital DVD audio 2 channel = 192 kb/s, or DVD audio 5.1 channel 448 kb/s, or BD audio 5.1 channel 640 kb/s

There are other flavors of Dolby audio on High Definition discs like:
DolbyDigital+ (can have more channels, and higher bitrates) and DolbyTrueHD (this has lossless compressed audio which means it's like a zipped file on a computer: It's packed more efficiently (so it's compressed) but it doesn't lose data so is equivalent to uncompressed LPCM, but takes less disc space.)

There's also DTS audio, which has its lossy compressed flavors like DTS at 1.5 Mb/s, DTS-HD at 3 Mb/s and a lossless compressed version too called DTS-HD MA

[GoldenRedux]

Originally Posted by aqupunk

Ok I know this has been thrown out before but for my own info is pcm better or the same as true dolby hd?

TrueHD upon decompression is a bit-for-bit identical copy of the uncompressed PCM source from which it is taken, so it should be no better or no worse. See the post directly above.

[Jagster]

Originally Posted by GoldenRedux

TrueHD upon decompression is a bit-for-bit identical copy of the uncompressed PCM source from which it is taken, so it should be no better or no worse. See the post directly above.

Guys correct me if I am wrong, but to enjoy PCM don't you have to have a HDMI input on your receiver? I thought the PS3 passes the PCM audio only through the HDMI cable. My receiver does not have HDMI, so I had to use the optical input. Because of this I chose bit-stream and not PCM on my PS3. I could be totally wrong here, so let me know as I would like to enjoy the best audio for my home theatre set-up.

[GoldenRedux]

Originally Posted by Jagster

Guys correct me if I am wrong, but to enjoy PCM don't you have to have a HDMI input on your receiver? I thought the PS3 passes the PCM audio only through the HDMI cable. My receiver does not have HDMI, so I had to use the optical input. Because of this I chose bit-stream and not PCM on my PS3. I could be totally wrong here, so let me know as I would like to enjoy the best audio for my home theatre set-up.

For the PS3, you are correct, but for other players such as mine - the Panasonic DMP-BD10 - HDMI is not required, because the Panasonic, and every other stand-alone Blu-ray player has analogue multichannel outputs. In this case, all you would need is a receiver or pre/pro with analogue multichannel inputs, as I do.

[dobyblue]

Originally Posted by BozQ

Dolby Digital is compressed. So which do you think is better?

It's not the compression that matters, it's whether or not it's losslessly compressed.