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Discussion Starter · #1 ·
I submitted the following question to Arcsoft:

Quote:
I recently upgraded my video card to an ATI 4850, which supports the transmission of lossless PCM audio. Will TMT be able to either bitstream HD audio formats like DTS-HD and Dolby TrueHD or output them as lossless PCM? I understand that TMT currently downsamples all audio to 44Khz/16 bit. Is this true?

Today, I received the following reply:

Quote:
We are sorry for the delay in replying you.


Regarding your question, we will provide a user-selectable option "Enable Audio Mixer" in the next release (in setup -> audio), to control this feature. TMT will be able to bitstream HD audio formats like DTS-HD and Dolby TrueHD if you uncheck the "Enable Audio Mixer" option.


Currently TMT downsamples HD audio stream to 48Khz - 96Khz if you check the "Enable down sample rate (192KHZ)" option (in setup -> audio), AND the audio card doesn't support the HD audio stream.


We hope this helps answer your question.


Thank you.


Regards,

ArcSoft Support

I read this to mean that TMT does NOT currently downsample unless you request it and/or your card does not support it. Also, the fact that bitstreaming HD audio formats will be supported in the next release is, in my opinion, excellent news and the fact that it will be supported on my ATI 4850 is even better.


Thank you to Arcsoft!
 

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Interesting, that does sound like it does unmolested full resolution audio playback if card is capable. I sure wish there was some kind of app that could show whats actually being sent to the audio card to prove it.
 

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Those are great news! Let's hope that it will work as promised...
 

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Discussion Starter · #4 ·

Quote:
Originally Posted by Socio /forum/post/14348919


Interesting, that does sound like it does unmolested full resolution audio playback if card is capable. I sure wish there was some kind of app that could show whats actually being sent to the audio card to prove it.


Well, if, in fact, the next release supports bitstreaming, there will be no further issue about it. I still suspect that there is currently an issue with the Dolby TrueHD format. Notice that there is not yet a TrueHD badge shown on TMT startup. I suspect that this is currently under development. I have no clue about what TMT is currently doing with TrueHD, probably just playing the normal Dolby Digital track. Just a guess.


To me, this seems like the real buyer for the new ASUS Xonar will be people who either don't want to upgrade their existing video card or those who want analog audio output. If you have a 4XXX series ATI card, you don't need it unless you want analog output.
 

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Quote:
Originally Posted by Lawguy /forum/post/14348785


I read this to mean that TMT does NOT currently downsample unless you request it and/or your card does not support it. Also, the fact that bitstreaming HD audio formats will be supported in the next release is, in my opinion, excellent news and the fact that it will be supported on my ATI 4850 is even better.

TBH I thought that reply was pretty unclear and I wouldn't count on it.


It seemed to me they were referring to your card supporting bitsreaming in order to disable the downsampling, which it does not.


However, that is just the way I read it



Adam
 

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Discussion Starter · #6 ·

Quote:
Originally Posted by AngelEyes /forum/post/14349387


TBH I thought that reply was pretty unclear and I wouldn't count on it.


It seemed to me they were referring to your card supporting bitsreaming in order to disable the downsampling, which it does not.


However, that is just the way I read it



Adam

The answers were clear, whether you can count on them; that's another issue.



They spoke of two things. The first is bitstreaming (which will be enabled in the next release). The second is what they "currently" do with downsampling (they don't unless you check the downsampling box or your audio card does not support the higher bitrates).



Again, who knows whether the answers are correct? I think Arcsoft is entitled to the benefit of the doubt on this.
 

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Maybe I'm missing something, but why would you want to downsample the audio? I mean, why give the user an option even? What benefit does that give an HTPC user?


I'm excited to about this news, I wonder why we haven't asked this question before?!
 

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Discussion Starter · #8 ·

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Originally Posted by redtyler1 /forum/post/14349560


Maybe I'm missing something, but why would you want to downsample the audio? I mean, why give the user an option even? What benefit does that give an HTPC user?


I'm excited to about this news, I wonder why we haven't asked this question before?!


Some receivers won't accept a 192Khz signal at all. If you own that kind of receiver, Arcsoft gives you the option of downsampling it to one that your receiver presumably can handle. If they didn't do this and a disk only had a 192Khz soundtrack, you would get no audio. This makes sense.
 

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Quote:
Originally Posted by Lawguy /forum/post/14349408


The answers were clear, whether you can count on them; that's another issue.



They spoke of two things. The first is bitstreaming (which will be enabled in the next release). The second is what they "currently" do with downsampling (they don't unless you check the downsampling box or your audio card does not support the higher bitrates).

When they talk about whether your card can handle it they mention 'stream' so by this dio they mean bitstream? If so then all of us are in the same position until we get new hardware that supports either Arcsoft or Cyberlinks propriety versions of PAP.


Why would Arcsoft be working on PAP if they currently allowed users to bypass downsampling, doesn't make sense? What is far more likely is that the support answer was from someone whos first language is not English, leading to confusion.


Adam
 

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Discussion Starter · #10 ·
Why is it not correct to refer to the transfer of LPCM as an "audio stream?" Seems accurate to me. A bitstream is just one specific kind of an audio stream.


I have already speculated that the 4xxx series of ATI cards already provides a PAP, at least if you accept what Realtek has to say about it.


I don't read this as an English translation issue. In fact, it seems much more clear to me than many things that I read that were written by native speakers.


You are, of course, free to believe what you want, but this is the only proof that we have about what Arcsoft says is going on. I am satisfied. Plus, if the next release really bitstreams, I consider the question definitively answered.
 

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Quote:
Regarding your question, we will provide a user-selectable option "Enable Audio Mixer" in the next release (in setup -> audio), to control this feature. TMT will be able to bitstream HD audio formats like DTS-HD and Dolby TrueHD if you uncheck the "Enable Audio Mixer" option.

This answer is talking about TMT's capability of bitsreaming DTS-HD/Dolby TrueHD in general. But we don't know yet if HD 4850 supports DTS-HD/Dolby TrueHD bitstreams ( "Subject to digital rights management limitations" ).

Quote:
Currently TMT downsamples HD audio stream to 48Khz - 96Khz if you check the "Enable down sample rate (192KHZ)" option (in setup -> audio), AND the audio card doesn't support the HD audio stream.

Apparently this sentence is talking about LPCM. According to AMD, HD 4850 does not support "HD audio stream" ( "maximum supported audio stream bandwidth is 6.144 Mbps" ; 6.144Mbps is the bandwidth of 7.1 channel 16bit/48kHz LPCM [8x16x48/1000=6.144]). Have we confirmed that this is wrong?
 

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Discussion Starter · #12 ·
LPCM as a rule is capped at 6.144 mbps, at least according to what a quick googling of "6.144 mbps lpcm" reveals. This is not unique to ATI. From what I read, it seems apparent that that is enough bandwidth in the real world to transmit decoded TrueHD or DTS-HD soundtracks.


I am not an expert on this so if someone who is can weigh in, it would be nice.


Also, ATI says this about the 4850:

Quote:
Integrated HD audio controller with support for stereo and multi-channel (up to 7.1) audio formats, including AC-3, AAC, DTS, DTS-HD & Dolby True-HD4, enabling a plug-and-play audio solution over HDMI
 

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Discussion Starter · #13 ·
I submitted a question to ATI in an attempt to discover what exactly is meant by the 6.144 mbps bandwidth cap. I suspect that it much be a per channel cap.


I output 192 khz/24 bit LPCM audio from the card into my receiver right now so the bandwidth must be there, correct? Am I missing something?
 

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When is their next release scheduled to be out?


There is absolutely no need to do any downsampling (PAP or not) if the content is not AACS protected. If they fix that alone they will win the hearts and minds of the HTPC users away from Cyberlink.
 

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Discussion Starter · #15 ·

Quote:
Originally Posted by MikeSM /forum/post/14352329


When is their next release scheduled to be out?

My guess is the end of August, which is when I heard that the Asus solution will be released.


If you believe the response, no downsampling is taking place at all unless you are requesting that it be done (or your audio card can't support the output).
 

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Quote:
Originally Posted by Lawguy /forum/post/14352489


My guess is the end of August, which is when I heard that the Asus solution will be released.


If you believe the response, no downsampling is taking place at all unless you are requesting that it be done (or your audio card can't support the output).

Do you read that response as saying that the current version of TMT doesn't downsample if the card can handle it? That doesn't seem to make sense to me, though it would be easy enough for a 4850 owner to download a trial version and test it.
 

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Quote:
Originally Posted by Lawguy /forum/post/14352489


My guess is the end of August, which is when I heard that the Asus solution will be released.


If you believe the response, no downsampling is taking place at all unless you are requesting that it be done (or your audio card can't support the output).

It doesn't seem that long ago you were questioning the accuracy of support transcripts I posted in another thread. Funny how you have no trouble accepting this one at face value, just because it does go with your personal opinion.



With all the information I have read over the last year saying all the players downsample and also the fact that both Cyberlink and Arcsoft have confirmed development of proprietry PAP for particular hardware in order to remove the downsampling, it just doesn't make any sense that the downsampling is currently optional in TMT.



I would love to think your speculation is correct but just don't at the moment. However I will be more than happy to be proven wrong



Adam
 

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Discussion Starter · #18 ·

Quote:
Originally Posted by MikeSM /forum/post/14352861


Do you read that response as saying that the current version of TMT doesn't downsample if the card can handle it? That doesn't seem to make sense to me, though it would be easy enough for a 4850 owner to download a trial version and test it.

Yes. How do you read it when they say:


Quote:
Currently TMT downsamples HD audio stream to 48Khz - 96Khz if you check the "Enable down sample rate (192KHZ)" option (in setup -> audio), AND the audio card doesn't support the HD audio stream.

I have a 4850 and TMT. I have thought for some time that TMT did not downsample (with the exception of Dolby True HD because that portion of the software is not ready yet). It definitely sounds very different if I use a DTS track as opposed to a DTS-HD track, even when both are output to my receiver at 192 khz, 24 bit.
 

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Quote:
Originally Posted by Lawguy /forum/post/14349408


The answers were clear, whether you can count on them; that's another issue.

Not as clear as some might think.

Quote:
They spoke of two things. The first is bitstreaming (which will be enabled in the next release). The second is what they "currently" do with downsampling (they don't unless you check the downsampling box or your audio card does not support the higher bitrates).

However despite how 99% of posts are worded, downsampling isn't really a problem, there are only a handful of Blu-ray Discs with >48kHz audio, the real problem that we're 'suffering' from is the reduction in bid depth from 20 or 24bits to 16 bits.


I find it hard to believe TMT isn't reducing bit depth as they'd be in violation of their AACS Adopter Agreement that says audio must be restricted to 16bit/48kHz unless over an approved digital output (ie HDCP).


Seems to me the didn't answer the question about bit depth/sample rate capping at all, they just quoted a feature that's available.
 

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Discussion Starter · #20 ·

Quote:
Originally Posted by AngelEyes /forum/post/14352909


It doesn't seem that long ago you were questioning the accuracy of support transcripts I posted in another thread. Funny how you have no trouble accepting this one at face value, just because it does go with your personal opinion.

I didn't question the accuracy of those. Once you showed them to me, I accepted that that is what Cyberlink was doing.


Assuming that you are right, are you not now doing the same thing (ie, rejecting what Arcsoft has to say because it is against your personal opinion)?
 
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