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#1 ·
The title says it all..

What exactly is the difference between Bitstream vs. Linear PCM? ... the two options you have to choose from when choosing HDMI Audio Out from the settings. What exactly do I need to choose in order for the sound to come out the way it should? Does Linear PCM need to be chosen in order for PCM soundtracks from a blu-ray disc to output at its optimum?


When I play Pursuit of Happyness in 5.1 PCM (Bitstream enabled), my receiver will show that PCM is active. When I play it in 5.1 English (Bitstream enabled), my receiver will whos that Dolby Digital is active. But the 5.1 English sounds louder than the 5.1 PCM. But shouldn't that be the other way around... 5.1 PCM is uncompressed. When I play both soundtracks with Linear PCM enabled, my receiver will only show PCM active (even if I play the 5.1 English soundtrack).


Any help is appreciated.


Thanks
 
#2 ·
Bitstream is basically the raw undecoded data being sent to the receiver for it to decode. PCM means that the PS3 is converting to PCM and sending it to the receiver which pretty much all receivers understand.


HDMI has the bandwidth for 8 channels of uncompressed pcm audio while optical only has capability for 2 channels of uncompressed audio.
 
#3 ·
You can think of the DD track like a .zip file on your computer and the PCM like a .wav file on your PC. The receiver can only play .wav sound (PCM) so at some point it needs to unzip (or decode) the DD track into a PCM stream in order to play it. Setting the PS3 to bitstream makes the PS3 send whatever's on the disc to the receiver, where setting to Linear PCM causes it to be converted to PCM in the player before sending to the receiver. Hence, when playing the PCM soundtrack, the receiver gets PCM regardless of the setting.


You might want to leave the setting as Bitstream so at least you know when you're accidently using the DD soundtrack because your receiver will tell you. In terms of volume, this is seperate from compression. Compression will cause the sound quality/clarity to decrease but it can still be recorded at a much higher volume to give you poor quality but very loud sound in comparison to the PCM soundtrack.
 
#4 ·
Assuming we have an receiver capable of accepting PCM audio via HDMI, which is the 'better' way?


Should we have the PS3 decode or have the receiver decode?


Would there be a difference?


I have a PS3 and a Sony DG810. I will try to do some testing tonight or tomorrow to see what my results are and if I can tell a difference or if I have any difficulties.


I just set it to use PCM because I wanted to have access to the PCM tracks when available. Learning new stuff everyday.
 
#5 ·
You'll get the multichannel PCM tracks over HDMI even when HDMI is set to bitstream on the PS3. However, you lose sounds mixed and overlayed by the PS3 (e.g., menu sounds seen in numerous BD titles currently available) when listening to DD or DTS on BDs.


With regards to legacy DD and DTS, there is no quality difference between the PCM and bitstream settings with my Denon AVR-4306. For me, setting the PS3 to decode DD or DTS results in the same quality as when letting my receiver directly handle the lossy codecs. I tested this by using numerous movie scenes that strongly engage all channels.


I have my PS3 set to PCM, because this way my Denon applies its AL24 processing regardless of what I'm listening to, and I always get sounds mixed by the PS3 itself.
 
#6 ·
Jiffylush,

I just want to clarify.. you probably already know this but just wanted to make sure you knew. The PCM tracks are available to play when I set the PS3 to bitstream... my receiver confirms it by showing "MPCM" when playing the 5.1 PCM track as opposed to "Dolby Digital" when playing the 5.1 Dolby track.


Please let us know what you're able to learn when testing.


Thanks
 
#7 ·

Quote:
Originally Posted by ase8776 /forum/post/0


The title says it all..

What exactly is the difference between Bitstream vs. Linear PCM? ... the two options you have to choose from when choosing HDMI Audio Out from the settings. What exactly do I need to choose in order for the sound to come out the way it should? Does Linear PCM need to be chosen in order for PCM soundtracks from a blu-ray disc to output at its optimum?

Linear PCM is recommended over regular DD.


Quote:
When I play Pursuit of Happyness in 5.1 PCM (Bitstream enabled), my receiver will show that PCM is active. When I play it in 5.1 English (Bitstream enabled), my receiver will whos that Dolby Digital is active. But the 5.1 English sounds louder than the 5.1 PCM. But shouldn't that be the other way around... 5.1 PCM is uncompressed. When I play both soundtracks with Linear PCM enabled, my receiver will only show PCM active (even if I play the 5.1 English soundtrack).

Did you switch from HDMI to Optical output when you noticed this difference?
 
#8 ·
wow.

Depending on which Thread I look at.. it's either bitstream is better or Linear PCM.


Can anyone give me the best answer?


I have a PS3. I use it for mostly regular DVD's...and right now just a few Blu-Ray titles.

I have a Denon AVR-4800 receiver. (It's about 7 or 8 years old now)

It doesn't have HDMI, so I have the audio hooked up via Optical wire.


Which should I have my settings at? Linear PCM or bitstream?
 
#9 ·
Using only optical, it isn't possible to get the best performance.


You have to choose between multichannel (5.1, 7.1) compressed sound (ie like MP3s) or lossless 2 channel sound (akin to CD or even as good as SACD or DVD-A with some movies).

You can fake multichannel using something like Dolby Prologic and still retain the benefits of lossless which some people like. You should try both methods and see which you like the better.


Nothing beats getting both lossless and discrete multichannel output. HDMI is the only way to achieve this. But if you can't hear the difference between lossless and lossy compression then all the better for you and your wallet.
 
#10 ·
linear pcm if you want uncompressed audio. bitstream if you want regular Dolby digital.


seriously, if you want uncompressed audio, go with pcm. not everything has this, but its worth it if it does. just played some folklore in uncompressed, and man, it has some good sound.
 
#11 ·

Quote:
Originally Posted by Mickaelmc /forum/post/11962499


wow.

Depending on which Thread I look at.. it's either bitstream is better or Linear PCM.


Can anyone give me the best answer?


I have a PS3. I use it for mostly regular DVD's...and right now just a few Blu-Ray titles.

I have a Denon AVR-4800 receiver. (It's about 7 or 8 years old now)

It doesn't have HDMI, so I have the audio hooked up via Optical wire.


Which should I have my settings at? Linear PCM or bitstream?

since no one has answered the question which is better bit stream or PCM, i will answer it for anyone that wants to know. pcm is better , it is loss less audio and it's the way the original is supposed to sound. typically DD double digital which is sent bit stream is around 600 kb and pcm loss less is usually sent around 5.0+ mbs . the pcm track will be much clearer and more i guess defined when compared to double digital, but you must have a receiver that excepts pcm audio like my onkyo tx-sr604. you can clearly hear a difference between DD vs PCM and pcm is better. hope this helps
 
#12 ·
The question is really about audio output modes on the PS3, not the audio formats on the disc. The audio track on the disc is either Linear PCM or a compressed format (which can be lossy, like DD/DTS, or lossless, like DD TrueHD or DTS-MA).


If you set the PS3 to output bitstream, then it will send exactly what's on the disc without modifying it at all, and it's up to your receiver to decode whatever needs decoding. If the PS3 is set to output PCM, then it will decode compressed formats into Linear PCM and send that LPCM stream to the receiver.


When you've selected a PCM soundtrack from the disc, then the PS3 will be sending PCM to the receiver regardless of the setting. However, as mentioned above, if the PS3 is set to bitstream then it won't be able to make any changes to the audio stream, such as mixing in menu sounds.


At this point, there's really no reason to select bitstream output on the PS3 unless your receiver has problems receiving multichannel PCM via HDMI. The PS3 is perfectly capable of decoding any of the available audio formats except DTS-MA (which is currently neither decoded nor passed as bitstream), and you get the ability for it to mix in additional audio.


The BD format is really designed for the player to do audio decoding anyway; the ability to pass the HD audio formats (DD TrueHD and DTS-MA) as bitstream to the receiver, which requires HDMI 1.3, is something that was demanded by the receiver manufacturers so that they could badge their receivers as "True-HD Capable" and "DTS-MA Capable". In reality, any receiver that can receive multichannel PCM over HDMI is capable of playing these formats, as long as the player does the decoding, which is what they're designed to do.
 
#13 ·
And having the player decode is usually a much better option anyway, because of the ease of firmware updates. New standards and audio formats can be created, but the receiver doesn't care, since it's getting it's pcm stream just like always.


About the only argument for going bitstream and letting the receiver doing it, is if you have a very advanced receiver that is processing the inbound signal, and adding additional speakers/effects. But, if your receiver is that advanced, it should be able to do the same thing with the pcm stream anyway. Now, if your receiver can process something that the player can't (i.e. DTS-MA), then I could understand switching to bitstream.
 
#14 ·
I have a question with regards to PCM vs Bitstream. My receiver can only do 2 channels of PCM (even over HDMI) and I recently found out that the movie SWAT has a 5.1 PCM track and no legacy tracks like DD or DTS. My question is how would I set up my PS3 to get some form of 5.1 sound out of it going into my receiver? Would I simply changing the audio output on the PS3 to bitstream or pcm remedy this?
 
#15 ·

Quote:
Originally Posted by ikecomp /forum/post/11966722


I have a question with regards to PCM vs Bitstream. My receiver can only do 2 channels of PCM (even over HDMI) and I recently found out that the movie SWAT has a 5.1 PCM track and no legacy tracks like DD or DTS. My question is how would I set up my PS3 to get some form of 5.1 sound out of it going into my receiver? Would I simply changing the audio output on the PS3 to bit stream or pcm remedy this?

well since your receiver can only do 2 channel pcm it will not process it that way. your probably better off going bit stream and letting the receiver process it that way. the way to do this without changing the setting on the ps3 is during the start of the movie hit the triangle button to bring up the on screen dvd/blu ray settings. then go to the far right and look for a symbol that looks a little like an oval with lines through it and hit x. next skip over the noise reduction ect.. setting and go to the bottom to the audio output setting and hit x and move it to bit stream if it's on pcm and then back out and play the movie and it should be good to go. i do this for my dvd's because they don't have pcm tracks just DD and dts tracks so it's a lot easier to do it that way then on the ps3 setting menu. oh course this will not work if your receiver doesn't do dd or dts ,but i assume yours does hope this helps
 
#16 ·

Quote:
Originally Posted by ikecomp /forum/post/11966722


I have a question with regards to PCM vs Bitstream. My receiver can only do 2 channels of PCM (even over HDMI) and I recently found out that the movie SWAT has a 5.1 PCM track and no legacy tracks like DD or DTS. My question is how would I set up my PS3 to get some form of 5.1 sound out of it going into my receiver? Would I simply changing the audio output on the PS3 to bitstream or pcm remedy this?

Ouch. I'm not sure there is a fix for that one. I don't believe the PS3, or any player, can actually do DD or DTS encoding on-the-fly, so I can't see any way for the PS3 to produce a 5.1 output stream that the receiver can handle.


The receiver should be advertising its capabilities to the PS3 over HDMI, so the PS3 should know to downmix to 2.0 PCM when its in PCM output mode. What happens if you set it to bitstream? I would imagine that either the PS3 would see that the receiver's not capable of receiving the 5.1 PCM and refuse to send it, or the receiver itself would fail to receive the bitstream. Do you get any sound at all with bitstream?
 
#17 ·

Quote:
Originally Posted by thebigdaddye /forum/post/11968979


well since your receiver can only do 2 channel pcm it will not process it that way. your probably better off going bit stream and letting the receiver process it that way. the way to do this without changing the setting on the ps3 is during the start of the movie hit the triangle button to bring up the on screen dvd/blu ray settings. then go to the far right and look for a symbol that looks a little like an oval with lines through it and hit x. next skip over the noise reduction ect.. setting and go to the bottom to the audio output setting and hit x and move it to bit stream if it's on pcm and then back out and play the movie and it should be good to go. i do this for my dvd's because they don't have pcm tracks just DD and dts tracks so it's a lot easier to do it that way then on the ps3 setting menu. oh course this will not work if your receiver doesn't do dd or dts ,but i assume yours does hope this helps

thanks, this was very helpful. I'll try it when my PS3 arrives. and yes, my receiver can do DD and DTS.

Quote:
Ouch. I'm not sure there is a fix for that one. I don't believe the PS3, or any player, can actually do DD or DTS encoding on-the-fly, so I can't see any way for the PS3 to produce a 5.1 output stream that the receiver can handle.


The receiver should be advertising its capabilities to the PS3 over HDMI, so the PS3 should know to downmix to 2.0 PCM when its in PCM output mode. What happens if you set it to bitstream? I would imagine that either the PS3 would see that the receiver's not capable of receiving the 5.1 PCM and refuse to send it, or the receiver itself would fail to receive the bitstream. Do you get any sound at all with bitstream?

Since I don't have my ps3 yet (it should arrive tuesday) I can't test it out but this was one of my concerns knowing the capabilities of my receiver. I'll report back once I've had a chance to test out the previously mentioned solution.
 
#18 ·

Quote:
Originally Posted by chartwel /forum/post/11962780


linear pcm if you want uncompressed audio. bitstream if you want regular Dolby digital.


seriously, if you want uncompressed audio, go with pcm. not everything has this, but its worth it if it does. just played some folklore in uncompressed, and man, it has some good sound.


totally agree..I have a PS3 and a Onkyo 705, when I set my PS3 to PCM, BD's sound better via the Multichannel PCM sound option, but when regular DVD's are played Bitstream option sounds better.
 
#19 ·
For me its pretty simple: If the disc has regular DD or DTS, I always set my PS3 to bitstream and let the receiver do the decoding, because the DD tracks are MUCH louder and sound better through my Yamaha RX-V2700 than a DD track that I let the PS3 decode and send as LPCM.


On the flipside, if the disc is uncompressed audio, I'll set the PS3 to LPCM.
 
#20 ·
Ok. I'm not sure if anyone knows anything about my receiver. It's a Denon AVR-4800 THX Ultra Surround EX receiver that requires a second amplifier if I wanted 7.1 surround sound. This was a $2000 amp 10 years ago.


So... Could I get an additional 2-channel amp with HDMI, and somehow get the Lossless audio sound?
 
#21 ·
Yes, but you wouldn't use the 4800 for anything except for an amp. Unless it has really great solid state amps in it, or just a sick amount of power, you won't need it.

I also doubt there are any 2 channel amps with HDMI in them.....2 channel amps are usually don't have digital inputs, only stereo. At least in the last few years, I've never seen anything like it. You would need to replace your receiver with a new one or a pre/pro and 7 channel amp setup to get 7.1 and LLAS.
 
#22 ·

Quote:
Originally Posted by Mickaelmc /forum/post/11962499


wow.

Depending on which Thread I look at.. it's either bitstream is better or Linear PCM.


Can anyone give me the best answer?


I have a PS3. I use it for mostly regular DVD's...and right now just a few Blu-Ray titles.

I have a Denon AVR-4800 receiver. (It's about 7 or 8 years old now)

It doesn't have HDMI, so I have the audio hooked up via Optical wire.


Which should I have my settings at? Linear PCM or bitstream?

When you use Optical Out connection, select Bitstream, NOT Linear PCM, which will downmix the audio track to 2.0!
 
#23 ·

Quote:
Originally Posted by Mickaelmc /forum/post/11973693


Ok. I'm not sure if anyone knows anything about my receiver. It's a Denon AVR-4800 THX Ultra Surround EX receiver that requires a second amplifier if I wanted 7.1 surround sound. This was a $2000 amp 10 years ago.


So... Could I get an additional 2-channel amp with HDMI, and somehow get the Lossless audio sound?

If you intend to keep the PS3 and want to hear lossless audio, get an HDMI 1.1 receiver.
 
#24 ·

Quote:
typically DD double digital which is sent bit stream is around 600 kb and pcm loss less is usually sent around 5.0+ mbs . the pcm track will be much clearer and more i guess defined when compared to double digital,

Hehe, Dolby son....Dolby.


If you use a PS3 with an hdmi receiver that can do multi pcm, select PCM, period.
 
#25 ·

Quote:
Originally Posted by Dixie Flatline /forum/post/11963528


The question is really about audio output modes on the PS3, not the audio formats on the disc. The audio track on the disc is either Linear PCM or a compressed format (which can be lossy, like DD/DTS, or lossless, like DD TrueHD or DTS-MA).


If you set the PS3 to output bitstream, then it will send exactly what's on the disc without modifying it at all, and it's up to your receiver to decode whatever needs decoding. If the PS3 is set to output PCM, then it will decode compressed formats into Linear PCM and send that LPCM stream to the receiver.


When you've selected a PCM soundtrack from the disc, then the PS3 will be sending PCM to the receiver regardless of the setting. However, as mentioned above, if the PS3 is set to bitstream then it won't be able to make any changes to the audio stream, such as mixing in menu sounds.


At this point, there's really no reason to select bitstream output on the PS3 unless your receiver has problems receiving multichannel PCM via HDMI. The PS3 is perfectly capable of decoding any of the available audio formats except DTS-MA (which is currently neither decoded nor passed as bitstream), and you get the ability for it to mix in additional audio.


The BD format is really designed for the player to do audio decoding anyway; the ability to pass the HD audio formats (DD TrueHD and DTS-MA) as bitstream to the receiver, which requires HDMI 1.3, is something that was demanded by the receiver manufacturers so that they could badge their receivers as "True-HD Capable" and "DTS-MA Capable". In reality, any receiver that can receive multichannel PCM over HDMI is capable of playing these formats, as long as the player does the decoding, which is what they're designed to do.

So, even though my receiver (Onkyo 605) can decode the DTS-MA codec, the PS3 cannot get it to the receiver?


Why does everyone want the PS3 to pass the sound bitstream if L-PCM is better?
 
#26 ·
Just to clarify for myself, if I'm using optical out then I should have it set to Bitstream correct? I am using a home theater in a box (the pioneer Xbox 360 surround sound system, I don't remember the model number)
 
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