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Author Topic: madVR demands, video system demands, system demands, bitstreaming  (Read 7296 times)

bblue

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Hi -

I've been primarily using MC (19.136 now) for audio purposes and am now extending its usage into video.  I have a variety of video source FPS 23.97, 24, 30, 50, 60 across wms, ts, m2ts, mkv, EVO and native BluRay.  Audio is mostly FLAC to 192k and DSD.

On my main server I run a MC server, and three other computers (2 primarily audio, 1 primarily video) each run MC as a client.  Also, all computers share a common SMB mount path for all source: E:\<hierarchy> since making the media server MC dish out the streams is erratic at best.  So I'm set for any client to look for a 'local' copy of the file requested.  Audio-wise, everything works very well.  My network is a switched GigE net with no issues.  I routinely transfer 800-900Mbit between machines with no issues.

Video wise, performance is quite variable depending on the resources of the client MC.  So some basic questions on this.

1. For the video client, should a motherboard with an Intel Core 2 Quad at 2.7Ghz and 8G DDR2 RAM be sufficient given a suitable display card?  That machine also runs WMC for TV recording from a Ceton quad cable-card, and supports two Ceton media extenders for other areas of the house.  The MC client installation is running simultaneously for movie video fed by HDMI to a projector.  Or should I be considering an i5 or i7 fourth gen DDR3 board instead?  I can't do TV in MC because many of the channels recorded are premium and have DHCP copy protection enabled.

2. For the video client, how much of an NVidia-type video card is really need for ideal performance?  6233638 is using a gtx570 which looks really nice, but is a hot-running power-consuming two-slot card I'd rather not have to deal with.  Please tell me that much card isn't really needed for good madVR performance?  If not, what is the minimum perfomance NVidea/GeForce card that would do an excellent job on all counts?  I have a couple of 9500GT and an extra 9600GT, but I suspect those aren't quite up to the task.  The current AMD 5400 HD certainly isn't.

3. One obstacle I'm facing regardless of the motherboard, is streaming the movie audio as-is (5.1,7.1,2.0 etc) to my external Meridan controller, which expects undecoded native Dolby or DTS 48k-96k streams.  On the current system, there doesn't seem to be any way to allow the unmodified digital signal to S/PDIF without enabling the Bitstreaming audio option in MC.  But doing that, precludes the use of advanced frame rate timing and manipulation in madVR. 

So what is necessary to get the digital audio stream out of MC without Bitstreaming on, so madVR can be used?  Suggestions as to how this could be handled?

I hope someone with first hand information/knowledge on any of these issues can respond.

Thanks.

--Bill
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Hendrik

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Re: madVR demands, video system demands, system demands, bitstreaming
« Reply #1 on: June 02, 2014, 02:01:56 pm »

1. For the video client, should a motherboard with an Intel Core 2 Quad at 2.7Ghz and 8G DDR2 RAM be sufficient given a suitable display card?  That machine also runs WMC for TV recording from a Ceton quad cable-card, and supports two Ceton media extenders for other areas of the house.  The MC client installation is running simultaneously for movie video fed by HDMI to a projector.  Or should I be considering an i5 or i7 fourth gen DDR3 board instead?  I can't do TV in MC because many of the channels recorded are premium and have DHCP copy protection enabled.

Thats probably going to be fine for video use, if you don't watch any "extreme" materials, like extremely high bitrate or new-fangled 10-bit encodes. Those would need a bit more beef on the CPU.

2. For the video client, how much of an NVidia-type video card is really need for ideal performance?  6233638 is using a gtx570 which looks really nice, but is a hot-running power-consuming two-slot card I'd rather not have to deal with.  Please tell me that much card isn't really needed for good madVR performance?  If not, what is the minimum perfomance NVidea/GeForce card that would do an excellent job on all counts?  I have a couple of 9500GT and an extra 9600GT, but I suspect those aren't quite up to the task.  The current AMD 5400 HD certainly isn't.

madVR is quite flexible and can adapt to any class of performance really. The defaults that MC ships with should run fine on something like a GT 640 or a similar card in that performance class. For NVIDIA, the 750 or 750 Ti are excellent silent and efficient GPUs, but you won't get the absolute high-end out of it - if thats needed for you, only you can answer.

3. One obstacle I'm facing regardless of the motherboard, is streaming the movie audio as-is (5.1,7.1,2.0 etc) to my external Meridan controller, which expects undecoded native Dolby or DTS 48k-96k streams.  On the current system, there doesn't seem to be any way to allow the unmodified digital signal to S/PDIF without enabling the Bitstreaming audio option in MC.  But doing that, precludes the use of advanced frame rate timing and manipulation in madVR.  

So what is necessary to get the digital audio stream out of MC without Bitstreaming on, so madVR can be used?  Suggestions as to how this could be handled?

Bitstreaming is the only way to get the original undecoded audio out of the PC, and by definiton its impossible to bitstream if you need/want to apply advanced processing like Video Clock (which I assume is what your frame rate timing refers to).
If all you have is a S/PDIF connection, you could task MC to re-encode the audio back to AC3/Dolby Digital after all this processing, and send this over the S/PDIF link instead. You can select this in the DSP Studio under Output Format.
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bblue

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Re: madVR demands, video system demands, system demands, bitstreaming
« Reply #2 on: June 02, 2014, 02:55:18 pm »

Bitstreaming is the only way to get the original undecoded audio out of the PC, and by definiton its impossible to bitstream if you need/want to apply advanced processing like Video Clock (which I assume is what your frame rate timing refers to).
If all you have is a S/PDIF connection, you could task MC to re-encode the audio back to AC3/Dolby Digital after all this processing, and send this over the S/PDIF link instead. You can select this in the DSP Studio under Output Format.

Thanks for some answers, Hendrik.

The issue I quoted is interesting, as MC is the only software I have on my video machine that does NOT pass the digital audio through transparently by default.  VLC, PowerDVD, MediaPlayer and others all do the right thing with little 'to do' about it.  Might it be possible to link two zones together using the primary one for madVR processing and the link as one that is bitstreamed?  Or some variation of that?  It seems like such a compromise to have it an either/or situation.

I've read the entire descriptive madVR Guide thread that 6233638 started, and have experimented accordingly.  It seems that without madVR using the audio stream, some of the advanced frame rate and pulldown manipulations can't be achieved, or can but with significant overhead.

Can you actually achieve good control of the desktop frame rate based on data in the tags or file?  Or is madVR just trying to simulate it by dropping/adding frames as needed based on the desktop rate?  I would really love to be able to play an interlaced 50Hz source with no issues, as well as a progressive 23.97 in a native 60Hz desktop, for example.  Are you suggesting that this is possible automatically without sampling the audio stream?

I guess I'll have to get a decent video card and then experiment.

Is there any more written about the MC Videoclock function?  I see it referred to occasionally in the madVR guide...
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Hendrik

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Re: madVR demands, video system demands, system demands, bitstreaming
« Reply #3 on: June 02, 2014, 03:41:28 pm »

The issue I quoted is interesting, as MC is the only software I have on my video machine that does NOT pass the digital audio through transparently by default.  VLC, PowerDVD, MediaPlayer and others all do the right thing with little 'to do' about it.

It can be argued if its the "right thing". You don't need to do much to enable it, just tick the checkboxes under the Bitstream options, and you're done.

Like I said, its impossible to do any processing on the audio if you bitstream, which is why around these parts we do NOT consider it the "right thing" for the generic case, but offer the option anyway due to popular demand.

The same argument wouldn't apply to most other players that you named, as their audio processing is somewhat limited.

And no, you cannot link zones and do what you suggest. It wouldn't make sense the way Video Clock works, it relies on changing the audio - if you cannot change the audio you would get sync problems between audio and video.
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bblue

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Re: madVR demands, video system demands, system demands, bitstreaming
« Reply #4 on: June 03, 2014, 05:09:07 pm »

It can be argued if its the "right thing". You don't need to do much to enable it, just tick the checkboxes under the Bitstream options, and you're done.
Like I said, its impossible to do any processing on the audio if you bitstream, which is why around these parts we do NOT consider it the "right thing" for the generic case, but offer the option anyway due to popular demand.

The same argument wouldn't apply to most other players that you named, as their audio processing is somewhat limited.

And no, you cannot link zones and do what you suggest. It wouldn't make sense the way Video Clock works, it relies on changing the audio - if you cannot change the audio you would get sync problems between audio and video.

Hmm.  So ultimately you have to make a choice on any 'problem' video or video whose characteristics don't match those of your desktop.  That depending on how much processing it requires to get smooth video display, you end up with either good video but incorrect audio (or limit to 2 channel), or the right audio and bad video...

I tried the re-encode to Dolby output in DSP settings to regain the correct channel layout and still be able to process video.  Through various options I was able to get video that was reasonably smooth with no frame loss, but any attempt to do better than that (by removing a small amount of what looks like a form of frame jitter horizontally) resulted in frame loss.  That's more than likely my currently funky video card not having enough ummph.  A GT640 is on the way.

There is a noticeable audio quality degradation when encoding to dolby/AC3 a second time (at dsp output), as it is a lossy process.  Listening to that frequently is not at all something I would enjoy.

I realize that the method of video/madVR processing employed by MC is superior in many ways to alternative methods, but if matching the frame rate of the desktop to the frame rate of the video, and for the most part turning de-interlacing off (since my video processor can do the rest), couldn't just using the basic Red October Standard with audio Bitstreaming enabled, and then use reclock externally be at least a partial solution to video correction and correct audio at the same time?

Maybe you and other geniuses at JR (seriously) could come up with a more all-encompassing solution?  It seems like there should be a way.

--Bill

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Hendrik

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Re: madVR demands, video system demands, system demands, bitstreaming
« Reply #5 on: June 03, 2014, 05:16:09 pm »

I'm afraid there isn't a better way. If you need to correct a difference between your screen refresh and your video frame rate, the only reliable way is to mess with the audio. All tools that offer such a feature work like this really.
The second method is messing with the video. madVR offers a "smooth motion" mode that can practically do this, but it can easily result in image degredation in the form of ghosting - depending on your setup and the combination of monitor refresh and video frame rate.

The problem you are facing goes away when you use HDMI or USB or even analog to connect your audio to your receiver/DAC/Amp, as you can just send multi-channel uncompressed PCM, and the extra lossy compression to AC3/Dolby Digital is avoided.
But alas, S/PDIF only supports stereo uncompressed.
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bblue

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Re: madVR demands, video system demands, system demands, bitstreaming
« Reply #6 on: June 04, 2014, 02:19:29 pm »

I'm afraid there isn't a better way. If you need to correct a difference between your screen refresh and your video frame rate, the only reliable way is to mess with the audio. All tools that offer such a feature work like this really.

Several years ago I used reclock with vlc and media player classic (not the Windows version) with audio output directly to S/PDIF.  Reclock seemed to do its job very well without any audio issues, and no bitstreaming (that I know of).  How could it have managed that and kept the AC3 5.1 audio package intact?

Quote
The second method is messing with the video. madVR offers a "smooth motion" mode that can practically do this, but it can easily result in image degredation in the form of ghosting - depending on your setup and the combination of monitor refresh and video frame rate.

Understood.

Quote
The problem you are facing goes away when you use HDMI or USB or even analog to connect your audio to your receiver/DAC/Amp, as you can just send multi-channel uncompressed PCM, and the extra lossy compression to AC3/Dolby Digital is avoided.
But alas, S/PDIF only supports stereo uncompressed.

So are you saying that with bitstreaming off MC will deliver the decoded AC3 streams as LPCM [57].1 to a device such as an LPCM aware HDMI driver for say, an NVidia video card?  If that is possible, then there's a nifty device from Gefen model number TV-HDMI-2-HDMIAUD which can be inserted in the video HDMI run, and will extract whatever is on the audio signal lines to either 2-channel TOSlink or up to eight analog channels representing the LPCM content.  The best price I found on it is here .

No idea about the actual quality of D/A conversion in that unit, but I doubt it's pro standard.  Still probably better than another AC3 encoding.

Does this sound like a workable approach?

--Bill
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Hendrik

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Re: madVR demands, video system demands, system demands, bitstreaming
« Reply #7 on: June 04, 2014, 05:31:39 pm »

Several years ago I used reclock with vlc and media player classic (not the Windows version) with audio output directly to S/PDIF.  Reclock seemed to do its job very well without any audio issues, and no bitstreaming (that I know of).  How could it have managed that and kept the AC3 5.1 audio package intact?
ReClock does exactly the same thing that MCs Video Clock does, it resamples the audio to match the video timings more closely.
As a result, you cannot bitstream, and without bitstreaming, you cannot pass the original AC3 or DTS.

The whole concept of passing encoded audio untouched is called "bitstreaming", you cannot do the same without "bitstreaming".

Additionally, ReClock offers its own solution to re-encode the audio back into AC3 after processing, as MC does.

So really, it behaves rather similarly and offers similar features to MC in this regard.


So are you saying that with bitstreaming off MC will deliver the decoded AC3 streams as LPCM [57].1 to a device such as an LPCM aware HDMI driver for say, an NVidia video card?  If that is possible, then there's a nifty device from Gefen model number TV-HDMI-2-HDMIAUD which can be inserted in the video HDMI run, and will extract whatever is on the audio signal lines to either 2-channel TOSlink or up to eight analog channels representing the LPCM content.  The best price I found on it is here .

No idea about the actual quality of D/A conversion in that unit, but I doubt it's pro standard.  Still probably better than another AC3 encoding.

Does this sound like a workable approach?


If all you want is analog audio, don't you have a sound card in your PC with analog outs?
And for the money that device costs, you could even get a mid-class USB DAC or a decent PCIe sound card with a not-so-bad DAC.
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6233638

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Re: madVR demands, video system demands, system demands, bitstreaming
« Reply #8 on: June 04, 2014, 05:53:34 pm »

I think ReClock did offer "true" bitstreaming with some amount of tolerance in which it would drop or repeat frames in the bitstream to keep audio in sync, which may be what bblue is referring to.
 
Obviously this is a terrible solution.
 
 
The best option would be to decode in the player and output multichannel PCM if you can (typically via HDMI) but re-encoding to Dolby Digital is probably fine, or perhaps you could buy a sound card with DTS Connect support and use that for DTS encoding.
 
(disclaimer: I don't know if DTS-Connect requires application support - I'm assuming that the driver handles the encoding and it just shows up as a normal sound device to other applications)
 
And for the money that device costs, you could even get a mid-class USB DAC or a decent PCIe sound card with a not-so-bad DAC.
Well that device is effectively an HDMI DAC - and it's not a bad price for something like that really, if the audio performance is any good.
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