ReClock and ASUS Xonar HDAV1.3

[nickf]

I am thinking about buying one of these cards to get the optimum Dolby TrueHD and DTS Master Audio experience - and before anyone tells me I won't hear the difference, you might be right but I won't know until I try!

The question is will ReClock work with this type of card where the player passes full bit rate bitstream through the card and HDMI or decodes and passes full rate LPCM to to the card for D to A conversion and analogue out?

I hope the answer is yes as I wouldn't want to give up ReClock!

Nick.

[davinleeds]

Go to AVS Xonar thread and do a search for reclock, BMueller says he uses 48Hz to solve his 24Hz problem and has no problem with Reclock. And I'm telling you there is a difference with just my 605. I've got two on XP and V32 and works great. Make sure you get one manufactured in 2009 as those have been flashed to enable 24Hz.

[nickf]

Thanks davinleeds. Yes, I raised the question on AVS which Bernd answered. The trouble is, I can't see how ReClock can resample a Dolby TrueHD or DTS Master Audio bitstream to correct the timing to correspond with the video. Perhaps the ASUS card deals with the synchronisation but that would mean there has to be some significant buffering involved. It may well be possible if TMT does the decoding so it is LPCM which ReClock deals with but it would still be at up to 192k/24bit.

Does anyone here have experience of this yet?

James, what is your view? I guess ReClock will need to handle this as these and the equivalent Auzentech cards will become more and more common.

[Jong]

James' view has been stated many times - that we should not use bitstreaming with Reclock, for exactly the reason you mention. As a consequence if the refresh rate is not very very close to an exact multiple of the frame rate (see the readme for more) you will get dropped/repeated audio packets that may be audible.

However, Reclock does have other benefits and if your refresh rate is very cloe to the frame rate, as it should be with 24p, you may find it works very well. Certainly it did for me and many others with AC3/DTS. Even the occasional one ot two dropped/repeated audio packets was completely inaudible (error correction in the amp).

[Lucifer1977]

Are you saying that people should not buy either the Asus or new Azuntech card coming out? I spent months trying to solve my lipsync issues until I found Reclock, but I would like True HD.

[Jong]

I do not know if bitstreaming HD audio works at all with Reclock (I just have not read authoritative feedback on way or the other). I know that James does not recommend it even for s/pdif and the last time I remember him posting on the matter he too did not know if HD audio bitstreaming would work at all. On the other hand, despite James' protestations there is quite a sizable community of people (I used to be one of them) who use s/pdif with Reclcok quite happily, after some considerable investment in time to get their video timings just right. If it works at all it is possible that the same will be true with HD audio. A few people need to try it. James is never going to support it though!

It is a fact though that the preferred way in the Blu-ray specification of handling TrueHD (and all HD audio) is to decode it on the player and pass uncompressed LPCM to the amp. This is because Blu-ray offers all kinds of options to mix audio from various streams e.g. for Picture-in-picture commentaries and none of this is possible if you send a bitstream to your amp.

In theory it should make no difference to quality. All the lossless formats are like zip files, there is only one way to unpack them. Your amp will do it the same way as PowerDVD. At the moment though the players are downmixing the few tracks that are not 48khz/16bit already to that, because of the lack of a protected audio path. Whether most people in most environments can hear this difference is a matter of debate.

[nickf]

Originally Posted by Jong

It is a fact though that the preferred way in the Blu-ray specification of handling TrueHD (and all HD audio) is to decode it on the player and pass uncompressed LPCM to the amp. This is because Blu-ray offers all kinds of options to mix audio from various streams e.g. for Picture-in-picture commentaries and none of this is possible if you send a bitstream to your amp.

In theory it should make no difference to quality. All the lossless formats are like zip files, there is only one way to unpack them. Your amp will do it the same way as PowerDVD. At the moment though the players are downmixing the few tracks that are not 48khz/16bit already to that, because of the lack of a protected audio path. Whether most people in most environments can hear this difference is a matter of debate.

We know that these cards can either send bitstream via HDMI or full bit rate decoded LPCM via their D to A and analogue out. The approved PAP capability on the card stops the player downmixing. So can ReClock handle the 96 or 192k 24bit LPCM if we go analogue out?

Nick.

[Jong]

It's a good question, I am out of my depth.

I would have thought PAP PCM would cause Reclock problems. Surely if its protected Reclock cannot work its magic with it. Either Reclock would interpret it like it does s/pdif and just pass it through, dropping/repeating packets as needed or it would try to adapt an encrypted stream and almost certainly destroy all sound. Frankly I've no idea. I am sure James will fill us in.

It raises a new question. If the next generation of ATI cards (maybe Nvidia too) support PAP will we be able to use Reclock? Will it work with it on? Will there be any way to turn it off otherwise? We may have to stock up on 4xxx series cards!?

[James]

Originally Posted by nickf

We know that these cards can either send bitstream via HDMI or full bit rate decoded LPCM via their D to A and analogue out. The approved PAP capability on the card stops the player downmixing. So can ReClock handle the 96 or 192k 24bit LPCM if we go analogue out?

I know it handles 96k/24 as I have tried it myself with great results (Baraka BD with TMT .125) via ATI 4850 HDMI.

Don't know about 192k but I see no reason why it shouldn't. I am not sure Windows supports it (96k/24 seems to be the max shared setting under Vista), and I don't know my amp supports it.

EDIT: This is without PAP, so my answer is misleading... I don't think ReClock will work with PAP.

[James]

Originally Posted by Jong

It's a good question, I am out of my depth.

I would have thought PAP PCM would cause Reclock problems. Surely if its protected Reclock cannot work its magic with it. Either Reclock would interpret it like it does s/pdif and just pass it through, dropping/repeating packets as needed or it would try to adapt an encrypted stream and almost certainly destroy all sound. Frankly I've no idea. I am sure James will fill us in.

It raises a new question. If the next generation of ATI cards (maybe Nvidia too) support PAP will we be able to use Reclock? Will it work with it on? Will there be any way to turn it off otherwise? We may have to stock up on 4xxx series cards!?

I am not sure, but I believe ReClock will not work with with PAP. Game over.