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Extracting DVD-A and SACD digitally: sollution found
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tigre
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3. December 2003 @ 00:10 |
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Prisoner
Suspended due to non-functional email address
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12. December 2003 @ 13:22 |
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I am not a number
I am a Free Man
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tigre
Moderator
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12. December 2003 @ 13:44 |
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Nope. It's something different.
Audigy 2 cards are able to play back high resolution DVD-A through their analog autputs only. DVD-A uses so far uncracked encryption and sometimes a proprietary lossless codec. Through USB only raw data is sent, no audio data readable by any 3rd party software. So there's no way to extract auido from high resolution DVD-A digitally (= bit perfect copy of audio data) using Audigy 2 cards.
Realtime analog rips (DVD-A player/Audigy 2 analog out -> soundcard analog in) are always possible; the quality should be still better than CD quality if high quality equipment is used (talking about measured quality, not audible quality, as there has been no proof yet that higher resolution than audio CD brings any noticable improvements).
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12. December 2003 @ 15:44 |
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Tigre, we had the Bank visit us today, and I blind played them some 24/88.2 stereo tracks MLP encoded and the same songs, from the same masters, at CD resolution. He spotted the high res 10 times out of 10, and told me he was expecting to have to say that he couldn't tell the difference.
The high res has far more clearly audible detail in the upper midrange & top end, much more depth & clarity. The CD was played on a separate CD player, not the DVD player, and the difference is truly audible.
I give you a standing invitation to come & hear for yourself if you are ever in London.
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tigre
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13. December 2003 @ 00:24 |
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Quote:
The CD was played on a separate CD player, not the DVD player.
With this setup the difference could be caused by
- differences due to superiority of higher resolution (=24/88.2 is truely better than 16/44.1) but also by
- differences caused by the different players used, can be e.g.:
-- output volume differences
-- different performance of DSPs used
-- anti-aliasing filter (less headroom between end of audible range and 1/2 sampling frequency) of CD player causing problems like phase shift, pre-echo/-ringing, high frequency attenuation in audible range, remaining aliasing because of lacking steepness of the filter used
- auidble problems caused by equipment/software used for 24/88.2 -> 16/44.1 conversion for CD mastering (don't take this personal, please ;) ).
10/10 in a blind test is a good result, though. I'd accept this as proof if this could be reproduced using the same equipment, i.e.:
- upsample the 16/44.1 to 24/88.2 and
- create a DVD-A containing these files mixed with the original 24/88.2 files
- switch (blindly for the listener) between both, the original + the resampled.
If it's done this way (similar to http://forums.afterdawn.com/thread_view.cfm/48914 BTW), you'll be sure that the differences you hear are caused by the formats and not by the equipment used.
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13. December 2003 @ 06:07 |
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No offence taken, I'm sure.
BTW - I do know what I am doing with all this - I mix & Master professionally for a living.]
Back to the point, I will do these tests you have posted, and write back in with results obtained from various people. It may take a few days or so to get enough people, but I will put this one to bed for once and all.
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tigre
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13. December 2003 @ 06:50 |
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Quote:
Back to the point, I will do these tests you have posted, ...
I'm looking forward to see the results. :)
If you or someone else performing the tests is able to spot differences, it would be great if you could upload short samples (~ 20 seconds, at least of the high resolution originals) of the positions where the difference is most obvious. A description of what the difference sounded like would be good too, to help others who want to hear it themselves.
Quote:
and write back in with results obtained from various people. It may take a few days or so to get enough people ...
IMO it would be already interesting if one single person passed the test(s), but if you want to perform it with many listeners, I won't complain.
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Senior Member
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13. December 2003 @ 09:40 |
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Tigre, I must have been asleep when I read the "test" details. Upsampling to 24/88.2 will never, ever improve anything as all you are doing is padding the stream with zeros.
The only way it can work is to prepare, or master, at 24/88.2 and write a DVD-A with these files, and downsample to 16/44.1 for CD.
This is the way it is done in ALL mastering houses - you work at the higher rates to avoid problems such as aliasing, plus you get the increased range in your processing from working at the higher rates. THEN you downsample for the CD.
This is the way I did the test, and it is the only way it can be done, because doing it your way there can never be a difference.
I think you are missing the point of the high resolution formats, and I would like to quote Bob Katz, and say "Post production processing, such as filtering, EQ and compression will result in less distortion in the audible band, as the errors are spread over twice the bandwidth, and half of that bandwidth is above 20KHz."
this has been confirmed by Sonic Solutions and dCS independantly. The higher rates can then be left as they are for DVD, and you then use the same masters for the CD version, downsampling of course. You will get better results - even on CD - than a straight 16/44.1 job.
Trust me on this if you won't believe me.
Working the other way around will increase your file size. Nothing more.
This message has been edited since posting. Last time this message was edited on 13. December 2003 @ 09:45
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tigre
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13. December 2003 @ 10:47 |
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Quote:
This is the way I did the test, and it is the only way it can be done, because doing it your way there can never be a difference.
I think there could be a misunderstanding. I'd like to repeat as clearly as possible:
I want to find out if 24bit/88.2kHz (or higher) stereo as a format can store anything audible that can't be stored in (properly done) 16bit/44.1kHz (stereo).
I don't want to compare different players / DACs
I don't want to compare DACs' performances at different sampling rates.
Because of this "my way" is:
Compare file A vs. file B
A = original, recorded + mastered at 24bit/88.2kHz (or higher resolution), stereo
B = A, downsampled + dithered to 16bit/44.1kHz/stereo using best available programs (now we have audio CD format, every information that can be stored by higher resolution additionally is lost)
then converted back to the same format as A
If this is what you referred to as "your way" when saying "... doing it your way there can never be a difference.", then higher resolution than 16bit/44.1kHz would be useless, because:
If I use a PC as CD player with foobar2000 + SSRC resampler to 24bit/88.2kHz (or higher) and pass the output digitally through a capable soundcard to a high quality DAC, the quality of my CD audio will be the same as e.g. 24/96 DVD-A using the same DAC, given that CD and DVD-A have been created from the same source.
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This is the way I did the test, and it is the only way it can be done, because doing it your way there can never be a difference.
I think you are missing the point of the high resolution formats, and I would like to quote Bob Katz, and say "Post production processing, such as filtering, EQ and compression will result in less distortion in the audible band, as the errors are spread over twice the bandwidth, and half of that bandwidth is above 20KHz."
this has been confirmed by Sonic Solutions and dCS independantly. The higher rates can then be left as they are for DVD, and you then use the same masters for the CD version, downsampling of course. You will get better results - even on CD - than a straight 16/44.1 job. "
I've never said that in music production all steps can be done at 16/44.1 and the result will be the same as when higher resolution is used. Of course not! I want to find out if reducing the resolution of the final product to 16/44.1 can sound different.
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Working the other way around will increase your file size.
This is for testing only. As I've said before, this is necessary to focus on testing of resolutions and to keep differences caused by equimpent out of the results.
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Senior Member
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14. December 2003 @ 04:35 |
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But surely this is the same thing!
If I have the original 24/88.2 files , and a properly dithered & downsampled version at 16/44.1, what would be the point of upsampling to 24/88.2 again?
The point, to me, is that staying in high res gives a better sound than the CD version.
Upsampling a downsampled file can only pad the file with extra zeros - the true test should be between DVDA & CD, using the same material.
Half of the argument for the higher sample rates is to avoid any nasty aliasing by using a gentler filter.
Okay, I'll grant that an upsamples version of the downsampled original will possibly level the playing field a little more, but I'm really only interested in the difference between CD & DVDA. Putting an upsamples version against the original will not say anything at all about the shortcomings of Red Book CD.
Yes, there probably has been a misundrstanding on my part - as I said, I must have been asleep when I read your original post that said Quote:
there has been no proof yet that higher resolution than audio CD brings any noticable improvements
, and you later go on to say Quote:
With this setup the difference could be caused by - differences due to superiority of higher resolution (=24/88.2 is truely better than 16/44.1)
.
I must have got a wire crossed, because it read to me in one post that you were saying it has never been proved that high res is superior, and in the next you admit that high res is "truely (sic) better".
I would appreciate if you could confirm just what the test is for, and what you are trying to prove/disprove?
It could be any of the following from what I am reading:-
1/. High Resolution DVDA is better/worse than CD
2/. Original high resolution audio is better/worse than downsampled material re-upsampled material played back on the same media
Wether or not the quality of the DAC comes into play is at this juncture irrelevant - we all know that cheap CD players are not as good as more expensive ones most of the time, so I understand the reluctance to base the test on comparative media, but this is exactly the point. DVDA players are a different animal to CD players, as CD players are a different animal to cassette players or vinyl, and yet these comparisons are made in favour of CD and digital audio in general on a daily basis. I am merely trying to answer the question of wether or not high resolution audio is sonically superior to CD audio.
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tigre
Moderator
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14. December 2003 @ 09:51 |
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quote:
-----------------
there has been no proof yet that higher resolution than audio CD brings any noticable improvements
, and you later go on to say
With this setup the difference could be caused by - differences due to superiority of higher resolution (=24/88.2 is truely better than 16/44.1)
I must have got a wire crossed, because it read to me in one post that you were saying it has never been proved that high res is superior, and in the next you admit that high res is "truely (sic) better".
---------------------------------------
"there has been no proof yet" means: "Maybe there is an audible difference, maybe not. So far noone has been able to prove that there is one. I'm interested in this question, that's why I'm here discussing how to set up a test."
You might want to re-read what I wrote:
Quote:
With this setup the difference could be caused by
- differences due to superiority of higher resolution (=24/88.2 is truely better than 16/44.1) but also by
- differences caused by the different players used ...
Translation ;) : If someone is able to hear a difference with the test setup you suggest, there are several possible reasons. One fo them: 24/88.2 *might* contain audible information that can't be stored in 16/44.1, so it *might* be superiour. The test is for finding out if this superiority exists or not.
This message has been edited since posting. Last time this message was edited on 14. December 2003 @ 09:52
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Prisoner
Suspended due to non-functional email address
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14. December 2003 @ 10:11 |
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Thanks for clearing up the miss understanding I had about the Creative product. I wasn't sure about this as companies always want to see they products like gold and your solution for everything.
Now to get off topic and join the discussion, I can see Tigre point. I honestly would like to see a person or persons with finely tuned ears test between CD and DVD-A/SACD formats. The test that I would like to see would be to get a track that is comercially available in CD, DVD-A and SACD format. Test the person first with the originals (all the same song and region). Then upsample the CD to DVD-A or SACD and test that with the DVD-A original. And finally downsample the DVD-A and SACD to CD format and test that. Speaking as a scientist, that would have all your controls for a true test. The originals, is there a difference off the shelf. The upsampleing, is there a point in buying DVD-A or SACD or could you get the same thing buy artifially increasing a CD. And the test of down sampling, how much sound do you lose when go down to the CD format. The reason why I through DVD-A and SACD in the test, Is I would like to also know if there is a noticable difference between these formats. Using a person with a trained ear and the same stereo, player and song section, then you could argue all your points. Ie SACD or DVD-A is better than CD and if SACD is different or better than DVD-A. This test I would like to see and the only song I can think of that would work is by Bob Dyalan. but using a Classical piece would be better as it would have a full orchestra with more range of musical notes to test. testing something like a punk song would be silly, as the Mp3 format would be good and scrachy.
Let me know if this would be possible.
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tigre
Moderator
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14. December 2003 @ 10:46 |
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@ wilkes:
Quote:
I would appreciate if you could confirm just what the test is for, and what you are trying to prove/disprove?
It could be any of the following from what I am reading:-
1/. High Resolution DVDA is better/worse than CD
2/. Original high resolution audio is better/worse than downsampled material re-upsampled material played back on the same media
Well, the test *setup* I suggest is "2/.". What I want to try to prove/disprove with it is this:
I want to test different sampling rates and bit depths of PCM audio, i.e.
16bit / 44.1kHz / stereo
vs.
24bit (or more) / 88.2kHz (or more) / stereo
I don't care about (physical) storage formats (audio CD vs. DVD-A vs. DVD-V vs. lossless compressed PC audio files on HDD etc.)
I don't want to test filters and DACs of CD players vs filters and DACs of DVD-A players.
I don't want to test the influence of different sampling frequencies >= 44 on performance of filters/DACs.
Here's a picture of your suggested test setup:
I want to know if there's an audible difference between 1/A and 1/B (= between 2/A and 2/B = between 3/A and 3B).
If someone is able to hear a difference between 6/A and 6/B we don't know where the difference has been created. Especially step 4 could be the "guilty". To avoid this insecurity, everything between step 3 (or 2) and step 5 must be done with identical equimpent and under identical conditions. The only way to achieve this is to upsample before D/A conversion using the best quality resampling algorithm available like this:
EDIT:
This message has been edited since posting. Last time this message was edited on 14. December 2003 @ 12:17
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Prisoner
Suspended due to non-functional email address
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14. December 2003 @ 11:50 |
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Tigre, did you mean my test? I like the picture but it confuses me a little. Just what i would like to see is if there is any audiable difference between the availble formats. And try to limit the amount a bias as much as possible. So I would like someone to listen to the following and tell me if any differences and which was thought to produce the best sound. Note all the same piece of music.
1. A DVD-A track
2. A SACD track
3. A CD track
4. DVD-A down sampled to CD format
5. SACD down sampled to CD format
6. CD upsampled to DVD-A format
7. CD upsampled to SACD format
Without telling the person anything and geting them to listen to it multiple times I think might be interesting. Sorry I didn't mean to affend you. Why I would to know this is if say the DVD-A was found to be the better one, Then I would look into it. However if an upsample format was enjoyed the most then I would look into that software option. If the downsampled was enjoyed the most, I would just be confused. But I would like to limit the amount of bias and enherit difference between formats tested. So I think this test would control all aspects of the tested music.
I am not a number
I am a Free Man
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tigre
Moderator
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14. December 2003 @ 12:06 |
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Prisoner:
Quote:
Tigre, did you mean my test?
No. I painted a little, trying to make myself understandable for wilkes.
Quote:
And try to limit the amount a bias as much as possible.
Important point. This is why blind testing is necessary IMO: The person who listens doesn't know what sample is played. If PCs are used for playback, there's ABX software available for this purpose (details see hydrogenaudio FAQ).
Quote:
So I would like someone to listen to the following and tell me if any differences and which was thought to produce the best sound. Note all the same piece of music.
1. A DVD-A track
2. A SACD track
3. A CD track
4. DVD-A down sampled to CD format
5. SACD down sampled to CD format
6. CD upsampled to DVD-A format
7. CD upsampled to SACD format
Good idea. 4. and 5. can only be done using digital->analog->digital conversion (unless the device from the 1st post is used), the equipment needed for 7. is very expensive. Ideally a player capable of playing back all 3 formats should be used to avoid "step 4." issues (-> picture) as far as possible.
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tigre
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14. December 2003 @ 12:10 |
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BTW: Prisoner, if you have a soundcard that supports 24/96 playback you can already test this yourself. I've started a test thread with instructions and links to 24/96 samples that can be used by anyone for this purpose (new samples added recently BTW).
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Prisoner
Suspended due to non-functional email address
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14. December 2003 @ 12:27 |
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Part of why I asked about the USB Creative device is that I have a SACD player, but no DVD-A player. So the only part to the test I have looked at was SACD versus CD using a SACD player with a Bob Dylan track that came with the player as a sampler. I did notice sound differences, but I question if I am suppose to, ie why they give me a sampler with both formats. It might have been made that way, so Sony would convince me that SACD is the best and can easily hear it versus CD format from the same disc. However the funny thing is that this player also plays Mp3 and the Mp3 quality seemed really good. I didn't have an Mp3 Bob Dylan track, but the Mp3 did seem better than the Cd sample. Thus why I question this. Currently this is the only SACD I own.
I am not a number
I am a Free Man
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tigre
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14. December 2003 @ 12:45 |
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Interesting story, Prisoner. It would be a nice test to record the analog out of the player with a good 24/96 sound card for both, SACD and CD playback, and do some comparison as you suggested.
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19. December 2003 @ 03:08 |
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