There are all these new graphic cards with sound cards on board (sometimes on the same chip) for HDMI output. Do any of them use single clock generator to drive both sound and video frequencies? This would make perfectly smooth playback possible without the use of ReClock.
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Any hardware that doesn't need ReClock?
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theshadowrunner
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I reckon the biggest culprit is Windows itself, the whole directshow architecture?
Btw my experience with vidcards with built-in audio processor has been disastrous, audio pops everywhere, a really below substandard sound chip with the most basic functions, no hardware buffers, extremely limited (that was nvidia btw). Long live s/pdif, seriously.
Btw my experience with vidcards with built-in audio processor has been disastrous, audio pops everywhere, a really below substandard sound chip with the most basic functions, no hardware buffers, extremely limited (that was nvidia btw). Long live s/pdif, seriously.
Why would that sound card do any processing, all it has to do is pass along digital signal to (digital) HDMI port? Perhaps there is a need to tell that sound driver NOT to do anything?
No doubt. But that's not what I asked. Is there any hardware which can provide smooth playback without ReClock? In other words, do you know your 5750 uses single hardware clock generator to drive both video and audio frequencies?
Separate clocks for GPU and audio are not the only reason for non smooth playback.
- Frequently you will find the refresh rate as measured by the CPU is not accurate, e.g. without Reclock the player may playback media at, say, 23.965Hz instead of 23.976Hz (sometimes worse, sometimes better). This disagreement between the CPU clock and the GPU will lead to periodic stutter.
- Even more importantly, most players (including all commercial players) do not yet have proper vsync control. This can lead to bursts of judder periodically during movie playback, or if clocks are sufficiently accurate (probably requiring Reclock anyway), the possibility (say 1 in 10 to 1 in 20) of at least one lengthy burst of judder after each start of playback and each seek. This is what Reclock vsync correction addresses and has nothing to do with GPU/Sound card synchronisation.
Lastly, many of us are now having to play back media from multiple sources, including PAL and NTSC sources. Without Reclock adapting playback speed and/or automating changes in refresh rate some media will be horrible judder-fests.
So, the answer to your question is ..... no. Whether things are good enough for any individual, of course, is down to them. Most Reclock users are pretty "hard core" and do not accept any possibility of judder during the course of a movie.
- Frequently you will find the refresh rate as measured by the CPU is not accurate, e.g. without Reclock the player may playback media at, say, 23.965Hz instead of 23.976Hz (sometimes worse, sometimes better). This disagreement between the CPU clock and the GPU will lead to periodic stutter.
- Even more importantly, most players (including all commercial players) do not yet have proper vsync control. This can lead to bursts of judder periodically during movie playback, or if clocks are sufficiently accurate (probably requiring Reclock anyway), the possibility (say 1 in 10 to 1 in 20) of at least one lengthy burst of judder after each start of playback and each seek. This is what Reclock vsync correction addresses and has nothing to do with GPU/Sound card synchronisation.
Lastly, many of us are now having to play back media from multiple sources, including PAL and NTSC sources. Without Reclock adapting playback speed and/or automating changes in refresh rate some media will be horrible judder-fests.
So, the answer to your question is ..... no. Whether things are good enough for any individual, of course, is down to them. Most Reclock users are pretty "hard core" and do not accept any possibility of judder during the course of a movie.
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theshadowrunner
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That's the thing, the embedded sound chip is actually recognized as a new audio card by Windows. It installs 4 "nVidia High Definition Audio" devices in the Device Manager (no idea why 4) and does all the sound processing on its own. When you install nVidia video drivers, it does actually update the driver of those 4 audio devices as well.
But there is absolutely no option anywhere for this new sound card, you can not tell it to do or not do anything, it's just forced on you and that's it. No settings. It's also la fiesta del "pops", pops everwhere during playback when even my mobo built-in realtek sound chip doesn't have such issue. I ended up selling the damn thing ^^;
Just to make sure, this is the question I asked:
Is this the question you answered?
If the cards with single hardware clock driving both video and audio indeed exist, even if the playback isn't smooth out of the box using existing players, it should be possible to develop a solution much smaller and simpler than Reclock to provide smooth playback on such hardware.
Sorry, I apparently incorrectly assumed the main question you wanted an answer too was the title of your thread!
The answer to that is "no, there is no (PC) hardware that doesn't need Reclock, even if you redefine this question so "need" means only "need for smooth playback"".
To answer the secondary question in your post, "yes, HDMI GPUs do use a single clock for audio and video, but it is a mistaken assumption to think this is sufficient to deliver smooth (set top box equivalent) playback on a PC."
All HDMI GPUs use single clock to drive audio and video frequencies? Can you please refer me to any specs where you got that information?
If the cards with single hardware clock driving both video and audio indeed exist, even if the playback isn't smooth out of the box using existing players, it should be possible to develop a solution much smaller and simpler than Reclock to provide smooth playback on such hardware.
Of course ReClock has many other advantages, and I have no doubt some people will continue to use it no matter what, and continue to persistently advertise this fact irrespective of the questions asked, and I sincerely hope these people will not interpret my specific technical questions as critique of ReClock's impressive abilities.
Sorry, don't have the specs. I believe they will be proprietary. However, it is widely (universally) assumed this is the case. I don't believe, for example, there are two crystals on any of the new GPUs.
However, you are still making a mistaken assumption. You are essentially saying
Well, yeah, that is self evidently true. But not very helpful as there is not yet one single player that does all the other stuff; Even the stuff exclusively to do with smooth playback. So Reclock is still very much needed for people attempting to get set top box quality playback from a PC and there is no technology even proposed that is going to change that.
However, you are still making a mistaken assumption. You are essentially saying
Well, yeah, that is self evidently true. But not very helpful as there is not yet one single player that does all the other stuff; Even the stuff exclusively to do with smooth playback. So Reclock is still very much needed for people attempting to get set top box quality playback from a PC and there is no technology even proposed that is going to change that.
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I should say that by HDMI GPUs, I meant the recent generation(s) that allow multi-channel PCM and bitstreaming. NOT the early (Nvidia?) implementations that merely allowed s/pdif from a sound card to be routed through the GPU over HDMI and I'm honestly not sure about the early ATI implementations that included onboard sound but only multi-channel s/pdif. All this is irrelevant though for all current generation GPUs.
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You do realize that $10 DVD player from your local grocery store allows perfectly smooth playback, even though it doesn't have many other no doubt very useful ReClock features? This is all I happen to be interested in this particular case, I want my $1000 HTPC to playback video as smoothly as my $10 DVD player. And I believe architecturally this should be relatively easy to achieve on a hardware with single clock driving both video and audio, using something MUCH simpler than ReClock, without any re-sampling, etc. I have no doubt that other people have other needs, and many will continue to use ReClock for various reasons.
I understand your desire and I totally agree.
Trouble is Wintel architecture makes it impossible. There are three clocks in a PC, not just two. Without Reclock the CPU clock will not supply frames at precisely the rate as the free-running GPU clock, even if the audio clock is taken out of the equation. and then we have the problem that vsync synchronisation does not work in any commercial players (and some open source attempts at fixing it are not perfect), that few players can automatically change refresh rate to match the frame rate (and even those that do do it imperfectly), that no players (not even stand-alone players, I think) will playback PAL material optimally on a 60Hz display or 24p/29.97Hz material optimally on a 50hz one.....
Only James could give the definitive answer here, but I believe that Reclock uses the CPU clock as its reference source, synchronising the other two using it. As a result it pulls all three into line. So even if GPU and audio clocks agree you still need almost all the same code to get CPU and GPU in line. Just solving the GPU/sound card issue does not, IMO, make the job Reclock does significantly simpler.
Trouble is Wintel architecture makes it impossible. There are three clocks in a PC, not just two. Without Reclock the CPU clock will not supply frames at precisely the rate as the free-running GPU clock, even if the audio clock is taken out of the equation. and then we have the problem that vsync synchronisation does not work in any commercial players (and some open source attempts at fixing it are not perfect), that few players can automatically change refresh rate to match the frame rate (and even those that do do it imperfectly), that no players (not even stand-alone players, I think) will playback PAL material optimally on a 60Hz display or 24p/29.97Hz material optimally on a 50hz one.....
Only James could give the definitive answer here, but I believe that Reclock uses the CPU clock as its reference source, synchronising the other two using it. As a result it pulls all three into line. So even if GPU and audio clocks agree you still need almost all the same code to get CPU and GPU in line. Just solving the GPU/sound card issue does not, IMO, make the job Reclock does significantly simpler.
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I believe that the key point here is not only whether the audio and video clocks are in sync but is also what is the refresh rate of the video card and how DirectShow deals with that. The card has to deal with non-video material that does not have an inherent frame rate. That alone says to me that the video and audio clocks have to be different. Say, for example, that the card refresh is set to 75 Hz, if the audio clock were locked to the frame rate at all times, the the pitch would be off. While it is certainly possible for a video card to be designed with a mode where you can tell it that it's getting video material and therefore set it's frame rate to that of the video material AND to sync the audio clock with the video frame rate, I don't believe that any cards have this option and it may even be that the driver interface does not even allow for it.
We can set the refresh rate to be very close to the frame rate but that's still not perfect and, since the audio clock has to be separate for non-video material it won't be exactly in sync.
EDIT: I see that Jong posted the reply above while I was writing this that says what I was trying to say in a different (and probably better) way.
We can set the refresh rate to be very close to the frame rate but that's still not perfect and, since the audio clock has to be separate for non-video material it won't be exactly in sync.
EDIT: I see that Jong posted the reply above while I was writing this that says what I was trying to say in a different (and probably better) way.
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ReClock may be using CPU as time source, but it is certainly not required for smooth playback on hardware with single clock for video and audio. DirectShow was designed to use sound clock as the reference clock (probably because Microsoft considered video stutter less noticeable than sound stutter). When video and audio are driven by different hardware clocks, 48KHz for sound and 25fps for video will soon go out of sync, simply because two different hardware clocks are used (one second for sound is not exactly the same as one second for video). So ReClock replaces DirectShow reference clock (sound hardware clock) with it's own floating clock (possibly based on CPU clock as you say). But then it has to re-sample audio to fit the constant rate of sound hardware. All this machinery is not necessary if both video are audio are driven by the same clock. You would just leave sound clock as DirectShow reference clock, and it would ALWAYS stay in perfect sync with video frame rate (because in this case one second for audio is EXACTLY the same as one second for video). VSync would also be MUCH less of an issue, because if you placed the first frame correctly from the VSync point of view, it will keep playing back correctly indefinitely (assuming your PC is fast enough to playback this content).
Sorry, you are just wrong on this. You seem to be working from a theoretical standpoint, not practical observation.
Yes, Directshow uses the "audio clock" as its reference and it is pretty good at it. Good for the old days of watching video on a PC screen, for sure. But it doesn't match the quality of a stand-alone, and that is what you say you want. As I mentioned in an earlier post, you may find a disagreement, frame rate to actual display refresh rate of +/-up to say 0.02Hz, e.g. 23.956Hz instead of 23.976Hz, using an "HDMI GPU". Now, as I said before, you may not care about that and that is fine, but for "stand-alone quality" it is not good enough.
And, yes, if players implemented robust vsync control things would be much better, but none of the mpc-hc methods (for example) are sufficiently robust. Both are susceptible to occasionally starting in judder. The only other player I know of that even attempts vsync control is MediaPortal. It's implementation may be better (I have heard some good things, but have not tested it myself) but it is only one player and not a complete solution (no Blu-ray full-disc playback, for example).
None of the commercial players deal with vsync at all. And one of the problems with vsync is that if you do have good agreement between the frame rate and refresh rate (even non-Reclock "good"), if the player starts "in judder" it stays there a long time. At least with bad sync between the frame rate and the GPU the judder was brief!
And then there are the other things, like switching frame rates between 24p movie material and associated on-disc 60Hz extras.
So, there you go! As I said a few posts ago, no one is criticising you if you think am HDMI GPU without Reclock is "good enough"; For many it will be. But is it stand-alone quality. Sadly..... no.
Yes, Directshow uses the "audio clock" as its reference and it is pretty good at it. Good for the old days of watching video on a PC screen, for sure. But it doesn't match the quality of a stand-alone, and that is what you say you want. As I mentioned in an earlier post, you may find a disagreement, frame rate to actual display refresh rate of +/-up to say 0.02Hz, e.g. 23.956Hz instead of 23.976Hz, using an "HDMI GPU". Now, as I said before, you may not care about that and that is fine, but for "stand-alone quality" it is not good enough.
And, yes, if players implemented robust vsync control things would be much better, but none of the mpc-hc methods (for example) are sufficiently robust. Both are susceptible to occasionally starting in judder. The only other player I know of that even attempts vsync control is MediaPortal. It's implementation may be better (I have heard some good things, but have not tested it myself) but it is only one player and not a complete solution (no Blu-ray full-disc playback, for example).
None of the commercial players deal with vsync at all. And one of the problems with vsync is that if you do have good agreement between the frame rate and refresh rate (even non-Reclock "good"), if the player starts "in judder" it stays there a long time. At least with bad sync between the frame rate and the GPU the judder was brief!
And then there are the other things, like switching frame rates between 24p movie material and associated on-disc 60Hz extras.
So, there you go! As I said a few posts ago, no one is criticising you if you think am HDMI GPU without Reclock is "good enough"; For many it will be. But is it stand-alone quality. Sadly..... no.
tried mVR recently? Its VSYNC control is first rate, in no way does it require Reclock's own VSYNC control. It even provides you w/ stats, and if your refresh rate is close enough to the video stream frame rate...you can easily see stats like "1 dropped frame every 12 hours".
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Oh, yeah I forgot mVR, sorry Madshi.
But, unless I've missed something else, still no full DVD menu support, let alone full Blu-ray Disc support, and it must still be considered a beta product. Not sure of its current DXVA capabilities either, although I know you do not care about that.
But, unless I've missed something else, still no full DVD menu support, let alone full Blu-ray Disc support, and it must still be considered a beta product. Not sure of its current DXVA capabilities either, although I know you do not care about that.