The difference between dvd and bluray in movie audio and channels

[HDOM]

Good day i hope

I have some questions about the audio and how it works in dvd or bluray movies! How many bits do dvd movies have? I believe bluray movies have a audio of 24 bit and never in 16 bit?

How many channels do dvd and bluray in general use to have? And what is the point when home i only have 2 speakers, meaning 2 channels! So if the bluray or dvd is mastered for to example 5.1 channels, then the sound that came out of my 2 speakers is not really accurate? Is more accurate for me when the movie is mastered for 2 channels, right?

Regards

 

[TLS Guy]

Good day i hope

I have some questions about the audio and how it works in dvd or bluray movies! How many bits do dvd movies have? I believe bluray movies have a audio of 24 bit and never in 16 bit?

How many channels do dvd and bluray in general use to have? And what is the point when home i only have 2 speakers, meaning 2 channels! So if the bluray or dvd is mastered for to example 5.1 channels, then the sound that came out of my 2 speakers is not really accurate? Is more accurate for me when the movie is mastered for 2 channels, right?

Regards

Wrong! If you have two channel then there will be a mix down of multi channel audio to 2 channel.

Now if the disc only has an an uncompressed 2 channel PCM track then in theory it will be higher quality. Usually in DVDs these two channel discs only use a low 192 kbs stream.

Now there are a few DVD discs that you can select a compressed multi channel audio or uncompressed 2 channel PCM.

Some DVDs can have a matrixed single rear channel in Dolby Digital or a discrete rear sixth channel in DTS.

BD offers uncompressed discrete 7.1 audio id Dolby True HD, or DTS MA. Most discs are mastered as 5.1.

Here is a good review of what is available and what you can expect from cheaper versus more expensive players.

 

[HDOM]

Hello there

You say :

"Most discs are mastered as 5.1"

So there is it almost never a movie mastered to 2 channels nowdays? what about VHS? How many channels do they used to Master the movie sound to?

What is the best format to choose if i want a 16 bit or 20 bit two channels or mono best quality format?

You see i am not interested so much about 24 bit in fact if possible i stay only in 16 or 18 bit max 20, because i belive 24 bit is bad for consumers like me that have a cheap analog amplifier and i guess even worst to human eras! se for example here:

http://www.head-fi.org/t/415361/24bit-vs-16bit-the-myth-exploded:


"So, 24bit does add more 'resolution' compared to 16bit but this added resolution doesn't mean higher quality, it just means we can encode a larger dynamic range. This is the misunderstanding made by many. There are no extra magical properties, nothing which the science does not understand or cannot measure. The only difference between 16bit and 24bit is 48dB of dynamic range (8bits x 6dB = 48dB) and nothing else. This is not a question for interpretation or opinion, it is the provable, undisputed logical mathematics which underpins the very existence of digital audio.

So, can you actually hear any benefits of the larger (48dB) dynamic range offered by 24bit? Unfortunately, no you can't. The entire dynamic range of some types of music is sometimes less than 12dB. The recordings with the largest dynamic range tend to be symphony orchestra recordings but even these virtually never have a dynamic range greater than about 60dB. All of these are well inside the 96dB range of the humble CD. What is more, modern dithering techniques (see 3 below), perceptually enhance the dynamic range of CD by moving the quantisation noise out of the frequency band where our hearing is most sensitive. This gives a percievable dynamic range for CD up to 120dB (150dB in certain frequency bands).

You have to realise that when playing back a CD, the amplifieris usually set so that the quietest sounds on the CD can just be heard above the noise floor of the listening environment (sitting room or cans). So if the average noise floor for a sitting room is say 50dB (or 30dB for cans) then the dynamic range of the CD starts at this point and is capable of 96dB (at least) above the room noise floor. If the full dynamic range of a CD was actually used (on top of the noise floor), the home listener (if they had the equipment) would almost certainly cause themselves severe pain and permanent hearing damage. If this is the case with CD, what about 24bit Hi-Rez. If we were to use the full dynamic range of 24bit and a listener had the equipment to reproduce it all, there is a fair chance, depending on age and general health, that the listener would die instantly. The most fit would probably just go into coma for a few weeks and wake up totally deaf. I'm not joking or exaggerating here, think about it, 144dB + say 50dB for the room's noise floor. But 180dB is the figure often quoted for sound pressure levels powerful enough to kill and some people have been killed by 160dB. However, this is unlikely to happen in the real world as no DACs on the market can output the 144dB dynamic range of 24bit (so they are not true 24bit converters), almost no one has a speaker system capable of 144dB dynamic range and as said before, around 60dB is the most dynamic range you will find on a commercial recording.

So, if you accept the facts, why does 24bit audio even exist, what's the point of it? There are some useful application for 24bit when recording and mixing music. In fact, when mixing it's pretty much the norm now to use 48bit resolution. The reason it's useful is due to summing artefacts, multiple processing in series and mainly headroom. In other words, 24bit is very useful when recording and mixing but pointless for playback. Remember, even a recording with 60dB dynamic range is only using 10bits of data, the other 6bits on a CD are just noise. So, the difference in the real world between 16bit and 24bit is an extra 8bits of noise."

I have more questions but i guess i see you again soon

 

[TLS Guy]

Hello there

You say :

"Most discs are mastered as 5.1"

So there is it almost never a movie mastered to 2 channels nowdays? what about VHS? How many channels do they used to Master the movie sound to?

What is the best format to choose if i want a 16 bit or 20 bit two channels or mono best quality format?

You see i am not interested so much about 24 bit in fact if possible i stay only in 16 or 18 bit max 20, because i belive 24 bit is bad for consumers like me that have a cheap analog amplifier and i guess even worst to human eras! se for example here:

http://www.head-fi.org/t/415361/24bit-vs-16bit-the-myth-exploded:


"So, 24bit does add more 'resolution' compared to 16bit but this added resolution doesn't mean higher quality, it just means we can encode a larger dynamic range. This is the misunderstanding made by many. There are no extra magical properties, nothing which the science does not understand or cannot measure. The only difference between 16bit and 24bit is 48dB of dynamic range (8bits x 6dB = 48dB) and nothing else. This is not a question for interpretation or opinion, it is the provable, undisputed logical mathematics which underpins the very existence of digital audio.

So, can you actually hear any benefits of the larger (48dB) dynamic range offered by 24bit? Unfortunately, no you can't. The entire dynamic range of some types of music is sometimes less than 12dB. The recordings with the largest dynamic range tend to be symphony orchestra recordings but even these virtually never have a dynamic range greater than about 60dB. All of these are well inside the 96dB range of the humble CD. What is more, modern dithering techniques (see 3 below), perceptually enhance the dynamic range of CD by moving the quantisation noise out of the frequency band where our hearing is most sensitive. This gives a percievable dynamic range for CD up to 120dB (150dB in certain frequency bands).

You have to realise that when playing back a CD, the amplifieris usually set so that the quietest sounds on the CD can just be heard above the noise floor of the listening environment (sitting room or cans). So if the average noise floor for a sitting room is say 50dB (or 30dB for cans) then the dynamic range of the CD starts at this point and is capable of 96dB (at least) above the room noise floor. If the full dynamic range of a CD was actually used (on top of the noise floor), the home listener (if they had the equipment) would almost certainly cause themselves severe pain and permanent hearing damage. If this is the case with CD, what about 24bit Hi-Rez. If we were to use the full dynamic range of 24bit and a listener had the equipment to reproduce it all, there is a fair chance, depending on age and general health, that the listener would die instantly. The most fit would probably just go into coma for a few weeks and wake up totally deaf. I'm not joking or exaggerating here, think about it, 144dB + say 50dB for the room's noise floor. But 180dB is the figure often quoted for sound pressure levels powerful enough to kill and some people have been killed by 160dB. However, this is unlikely to happen in the real world as no DACs on the market can output the 144dB dynamic range of 24bit (so they are not true 24bit converters), almost no one has a speaker system capable of 144dB dynamic range and as said before, around 60dB is the most dynamic range you will find on a commercial recording.

So, if you accept the facts, why does 24bit audio even exist, what's the point of it? There are some useful application for 24bit when recording and mixing music. In fact, when mixing it's pretty much the norm now to use 48bit resolution. The reason it's useful is due to summing artefacts, multiple processing in series and mainly headroom. In other words, 24bit is very useful when recording and mixing but pointless for playback. Remember, even a recording with 60dB dynamic range is only using 10bits of data, the other 6bits on a CD are just noise. So, the difference in the real world between 16bit and 24bit is an extra 8bits of noise."

I have more questions but i guess i see you again soon

I suspect that a lot of VHS tapes were actually mastered in multi channel, but I don't know.

In any event it is easy to mix the multi channel down to 2 channel and it won't affect the quality.

You are correct that the CD at 16 bit 44.1 sampling has enough dynamic range and frequency response for most music. So you can get 98 db dynamic range to 20 KHz. There are a few large choral works with massive orchestras, choirs and huge organs that can benefit to go out to 130 db dynamic range or so. It takes a very quiet room, massive speakers and very powerful amps to reproduce it though.

It is not correct the higher bit and sampling rates will make poor equipment sound worse, they will not be better. For that matter for most music it will not be better than 16 bit, 44.1 KHz on any equipment. Your comment that going from 16 to 24 bit is 8 db is 8 db of extra noise is nonsense. There is less noise, as the dither signal is less, and so the 100% error between one and zero occurs at a lower level. The question is only what bit rate is adequate for the program.

You really are going down a road with no useful destination.

 

[j_garcia]

VHS had Pro-logic encoding which encodes simulated surround into the stereo output. The receiver has a pro-logic decoder to extract that information and recreate the surround channels, aka matrix surround. The current formats are all discrete channels, which is a HUGE difference compared to the days of pro-logic, and that first showed up with DVD.

None of that matters when using a 2ch system. Configure the receiver to only have those two speakers and everything will be downmixed to those two channels so you do not lose any sound as TLS said.

 

[HDOM]

I suspect that a lot of VHS tapes were actually mastered in multi channel, but I don't know.

In any event it is easy to mix the multi channel down to 2 channel and it won't affect the quality.



It is not correct the higher bit and sampling rates will make poor equipment sound worse, they will not be better..... Your comment that going from 16 to 24 bit is 8 db is 8 db of extra noise is nonsense...

that is not really true you can here on the . intermod test http://people.xiph.org/~xiphmont/demo/neil-young.html hear clips when listen to 24 bit if you have a analog amplifier like me!

is not my comment about the noise is other guy comments on the other page i wrote not that!

now about 2 channel mix it says it self is a mix not a pure 2 channel mastering is like when you master a vinyl you master that master tape in a "vinyl way" just for good quality vinyl and you master a "cd master way" for good cd mastering

ps. what is good 130 db dynamic range? when:

"130dB is loud enough to damage hearing permanently in seconds to minutes. For reference purposes, a jackhammer at one meter is only about 100-110dB."

http://people.xiph.org/~xiphmont/demo/neil-young.html

 

[HDOM]

.... Configure the receiver to only have those two speakers and everything will be downmixed to those two channels so you do not lose any sound as TLS said.

the problem is i dont have a receiver (and i dont need to have it) i have only a analog amplifier.

 

[j_garcia]

Then it has stereo analog inputs, so when you use stereo analog outs to this device, it will have been downmixed to 2ch already. Where you will have a problem is blu-ray players today do not have analog outputs. I know this because my second system is this way also. I had to buy a used BD player that had analog outs to use in that system.

VCR had only stereo outs. Laserdisc had SPDIF and stereo analog and may potentially have had multichannel analog. DVD typically always had stereo analog, digital (SPDIF and/or HDMI) and some had multichannel analog as well as analog video outs. BD players may have all of these, but none of them have analog video outputs anymore.

 

[HDOM]

hi Garcia but i have a new blurayplayer that have analog output that i have conected to the analog input on the amplifier! and they still use to sell that pioneer bluray

 

[j_garcia]

hi Garcia but i have a new blurayplayer that have analog output that i have conected to the analog input on the amplifier! and they still use to sell that pioneer bluray

Right, so if you are using the stereo analog out then you are not missing any audio. All channels are automatically downmixed to 2ch output on that connection.

 

[HDOM]

yes Garcia i new that already i know also that the signal goes to the dac in the bluray so i dont need a dac in the amplifier but i am looking for truly 2 chanels mastering because i feel they sound better in my system i have to example the bluray alien and this movie have 2.0 dolby sorruound that sounds much much better than the sounds i fine in the same disc that are 5.1 dts ma and 4.1 dolby sorruond in my ears

 

[HDOM]

ps. i belive the original Alien was mastered for 2 channels in the old days?

 

[j_garcia]

I am pretty sure it did. The Blu-ray shows a Dolby Digital 2.0 track, which is not commonly there unless it had a 2.0 track originally.

 

[HDOM]

great stuff i like that 2 channel stuff i found also 2 channels in mono like the old Dracula movie that i have in bluray

ps. that soon i will compare to the dvd version

 

[markw]

ps. i belive the original Alien was mastered for 2 channels in the old days?

Alien was released in 1979. All they had then was two channels. This was long before true multi channel came about. "true" multi-channel movies weren't released until much later. Odds are it was "remixed" for multi channels then.

Stereo, in VCR's wasn't really available until the early 80's and even then it was mostly formatted for Dolby Surround, not even DPL.

And, if you' referring to the original Dracula, which came out around 1931, that was in mono via the glorious optical tracks they used in those days. And, if you're talking about the 1987 Dracula, that came out in 1987 and you can betcha it came our mixed for DPL or Dolby Surround.

 

[mtrycrafts]

Alien was released in 1979. All they had then was two channels. This was long before true multi channel came about....

From what I read a number of years back when Dolby made a list of movies processed in their method, Superman 1978 had a stereo back channel on the 70 mm film version for theaters. Some other 70 mm films had the same. But, that was a long time ago to remember.

 

[markw]

From what I read a number of years back when Dolby made a list of movies processed in their method, Superman 1978 had a stereo back channel on the 70 mm film version for theaters. Some other 70 mm films had the same. But, that was a long time ago to remember.

Both of our memories ar probably hazy from that time but, I think you're right. They were experimenting with the original "Dolby Surround" which matrixed a center and a mono surround channel into the base two channel format.

 

[HDOM]

Alien was released in 1979. All they had then was two channels....

And, if you' referring to the original Dracula, which came out around 1931, that was in mono via the glorious optical tracks they used in those days..

soon i will compare alien but until then you can see my Dracula comparition here in this part of the forum:

http://forums.audioholics.com/forums/threads/dracula-1931-dvd-and-bluray-comparision.98191/

all i can say the mono dolby in the dvd sound it good in my 2 channels even had echoes

terrific stuff