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Topic: DTS 1536kbps, how transparent it manages to be? (Read 34810 times) previous topic - next topic
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DTS 1536kbps, how transparent it manages to be?

Reply #25
Thks, but no  Read more carefully I edited the post in which I was saying that I couldn't grab an Aften binary. Since, I found it elsewhere & I tested it ... my ears don't want to listen to it anymore  there is no good AC3 encoder available, that just doesn't exist. The codec itself is too weak. I used SurCode V1.0.21 as it is clearly superior to Aften IMHO.
The only hope is that the AC3 codec used by professionnal studio is better than those available for end user. If I have some doubt about my methodology for DTS, I have absolutly no doubt about AC3.

What I am saying is that AC3 is bad for specific problem music samples. It doesn't mean that any AC3 stream in video sounds terrible. Castanets is very specific (I don't use it ramdomly) & music is not voice. Still what I am saying for AC3 is true for castanets & cannot be denied within the strict area of the test. For DTS it is most likely valid but the method is unusual & weird. The only thing I could have done wrong I think is if there is special parameters whithin the encoders ... I used everything at default setting. (except bitrate & samplerate indeed)

While it may be true that AC3 algorithms are superior to DTS technically. Due to the high bitrate of DTS, this is an irrevelant argument to compare against AC3. Furthermore at similar bitrate it isn't possible to say that AC3 is really superior to DTS. At 640 vs. 768Kbps 5.1 both are bad. So the technical efficiency difference on paper between both is far less dramatical in real life than what I heard sometime.

For me AC3 640Kbps clearly doesn't compete with DTS 1536Kbps, the dolby competitor against DTS 1536Kbps must be E-AC3, which I didn't tested.

Furthermore I noticed that the quality between various AC3 settings drop dramatically quick so if BD 640Kbps 5.1 is not transparent. DVD & HD-DVD streams are even less.
People at doom9 just don't care as much for audio quality as we do here on HA.

DTS 1536kbps, how transparent it manages to be?

Reply #26
I came across this before but dismissed it as pointless hype from the codec developers http://www.hemagazine.com/node/Dolby_TrueH...ncompressed_PCM

Reading it more carefully, it looks like the system is set up for proper A/B and ABX testing and that in the Dolby case A/B (or more accurately ABCD...) this was used. For DTS it's not apparently blind so far less useful. But what interested me was they found that while DD640 was not transparent, it was supposedly better then DTS (although given that DTS was not blind and was conducted on different source material, at a different time and in a different location it's perhaps not the most useful comparison). Another annoying things is it's not clear if they mean 768k or 1.5mbps or both. Interesting too, DD640 was only (seemingly) not transparent to one of their listeners...

While probably no surprise to anyone here, they did find that Dolby Digital Plus and DTS-HD (at whatever bitrate is unclear) was transparent to them in these professional studio settings :-)

DTS 1536kbps, how transparent it manages to be?

Reply #27
Thks, but no  Read more carefully I edited the post in which I was saying that I couldn't grab an Aften binary. Since, I found it elsewhere & I tested it ... my ears don't want to listen to it anymore  there is no good AC3 encoder available, that just doesn't exist. The codec itself is too weak. I used SurCode V1.0.21 as it is clearly superior to Aften IMHO.
The only hope is that the AC3 codec used by professionnal studio is better than those available for end user. If I have some doubt about my methodology for DTS, I have absolutly no doubt about AC3.

What I am saying is that AC3 is bad for specific problem music samples. It doesn't mean that any AC3 stream in video sounds terrible. Castanets is very specific (I don't use it ramdomly) & music is not voice. Still what I am saying for AC3 is true for castanets & cannot be denied within the strict area of the test. For DTS it is most likely valid but the method is unusual & weird. The only thing I could have done wrong I think is if there is special parameters whithin the encoders ... I used everything at default setting. (except bitrate & samplerate indeed)

While it may be true that AC3 algorithms are superior to DTS technically. Due to the high bitrate of DTS, this is an irrevelant argument to compare against AC3. Furthermore at similar bitrate it isn't possible to say that AC3 is really superior to DTS. At 640 vs. 768Kbps 5.1 both are bad. So the technical efficiency difference on paper between both is far less dramatical in real life than what I heard sometime.

For me AC3 640Kbps clearly doesn't compete with DTS 1536Kbps, the dolby competitor against DTS 1536Kbps must be E-AC3, which I didn't tested.

Furthermore I noticed that the quality between various AC3 settings drop dramatically quick so if BD 640Kbps 5.1 is not transparent. DVD & HD-DVD streams are even less.
People at doom9 just don't care as much for audio quality as we do here on HA.



You might perhaps consider it pointless, but it would be interesting to me to see if you could get positive ABX results using some non-killer samples.  Most commercial DD and DTS content isn't likely to be as revealing as Castanets, but it would be nice to see some data about that.

 

DTS 1536kbps, how transparent it manages to be?

Reply #28
Ah, but if you believe the anecdotes of the people involved, there's lots of transcoding involved before it reaches the disc - people don't always take the trouble to acquire the elements in LPCM.

It's worse still in PAL countries for DVD, where mastering houses expect to receive a 6-channel LPCM master, but often receive a 448kbps AC-3 encode, especially for lesser titles. So they have to decode 448kbps AC-3, time/pitch shift it to match the 25p master, and re-encode to 384kbps (more sound track options in Europe = lower audio bitrate).

Cheers,
David.