how to fault-isolate high dropped frame rate in busy scenes?

[stevech]

A chronic problem from day 1 for me with Sage is as follows. The problem yields an unpleasant viewing experience and I'm growing increasingly intolerant.

In viewing a recorded show, any show, in standard def (I have no HD), and when the camera pans, the pan is jerkey, as if there's about 30% dropped frames. I think this can be either the encoder is tossing frames because it cannot encode and deliver the frames fast enough, or the disk cannot write this fast, or the playback disk read speed is too slow, or the video card is overwhelmed.

The question is, how do I determine what the cause is, so I might fix it?

Hardware:
Hauppauge USB2 encoder - I'm aware of the issue of mixing USB1 and 2 on the same hub.
2.4GB/hr quality setting
USB2 hard disks - same hub. Formatted 64KB NTFS
PC is Pentium M laptop using the S-video out from its Nvidia onboard video at 800 x 600.
No other apps on this PC.

I tried an AMD2400 tower PC - with more USB hubs and $75 video card. No help. It was banished as it was too noisy.

[dvd_maniac]

I would burn a video to DVD and see if a STB plays it fine. If it does, then you it could be either slow hardware or try a different decoder, Or at least try the video on a different PC.

If it plays jerky in the STB as well then either Hard drive is too slow, bad setup or drivers for tuner or tuner is going bad.

[cummings66]

I would ask for more info, what kind of drivers do you have and what codecs are installed?

I have experienced similar issues with the stock mpeg decoder included and the problem went away once I switch to the Nvidia decoders. Sonic seemed to work fine as well.

[stanger89]

Sounds like a deinterlacing problem to me, what's your decoder setup?

[stevech]

Why do you think it is NOT an encoder problem?

I have the problem with Sage running on a tower AMD2400 with a $75 class ATI graphics board with S-video out to the std. def. TV.

Same issue with what I'm using now: laptop with s-video out, ATI graphics.

I am using the decoder that comes with Sage. the default. I have not tried NVidia decoder because (a) I don't know that this is a decoder vs. encoder vs. disk speed problem and I don't want to just flail around, and (b) I don't understand the impact or benefit of using the Nvidia decoder on a competitor's chipset.

[cummings66]

Play back the video in a small screen and see if the problem exists. Don't use Sage for it, just doubleclick the filename and see what happens.

That will tell you about the file that was recorded.

The Nvidia decoder does work on ATI graphics cards, but since you don't know what card you have beyond the fact it's a cheap ATI it's hard to say what would happen without trying.

At any rate it will not hurt to install the demo, it's time limited and so won't cost you unless you decide to purchase it. If it doesn't work then don't use it, no issue here to trying it.

And as to why I and others think it's something with decoding, past experience with similar problems. Sometimes settings like the automatic vs smart vs whatever cause similar problems with the Nvidia decoder as well.

[blade]

Originally Posted by stevech

Why do you think it is NOT an encoder problem?

Because if you're using hardware encoders you shouldn't have any issues with lack of CPU power and such. If your USB isn't being pushed to it's limits you shouldn't have a problem with the encoding or disk speed.

USB 2.0 has a max of 480Mbps, your USB2 capture card can do a maximum of 12Mbps (which you're using less than half of). That's like what 0.75MB/s being written to the HD? I know those are theoritical limits and my math may be wrong, but you get the idea. I'm not saying it's impossible for you to have some strange issue causing it, but there are much more common and likely reasons.

The Sage decoder is pretty bad IMO especially on pans. If you have a DVD burner then playing a recording back on a STB DVD player seems like a great way to see if it's a playback issue or not. I should try that myself sometime just to see how my HTPC's playback stacks up.

[stevech]

thanks for suggestion on burning a DVD.

Is there any way to get the Hauppauge USB2 product to reveal if it is having to drop frames? The high end gear does this - as a warning - in diagnostic data that one can access. And the reason for the dropped frames: cannot deliver data (via USB and file system) fast enough vs. encoder not fast enough for certain situations of busyness such as panning.

Recently, I noted one show where the camera dollied down a sidewalk pointed at the shops' window displays. It was terrible - very jerky and unpleasant to watch.
Same show, watching off the cable, no such problem (std def).

I hope I can find the cause and fix this.

[GKusnick]

Another cheap experiment would be to copy a short recording onto a CD or USB flash stick, find a friend with a high-end gaming rig, and try playing back the file in WMP on that machine.

As others have said, if you don't want to flail around, then the first logical step is to determine if the file itself is good or bad by trying it on several different decoders and playback devices. I know you've tried it on two different systems already, but with regard to graphics hardware they weren't actually all that different (low-end ATI graphics on both machines).

If it does turn out that the file is bad (i.e. you see the same artifacts on all playback devices), that would be the time to worry about how to improve your encoder performance.

[stevech]

ok thanks.

so no one has found a means to query diagnostic data from the Hauppauge USB device re performance and dropped frame rates?

[Wheemer]

Have you tried vmr 9 with FSE enabled?

[Lucas]

Stevech,

I also have USB2 and I find it highly unlikely that it is an encoder problem.

I used to experience such problems and they were related to decoding and scaling. Occasionally, when playing a video on my laptop I get such behaviour. In all cases these problems occured with 3D enabled and VMR9 rendering. You don't mention which ATI card you have, I use a 9600XT which in most cases is enough. A lesser card will almost certainly have problems with 3D and VMR9.

As a first step, disable 3D and use Overlay.
I noticed that you use 800x600, you should switch to 720x480 for NTSC or 720x576 for PAL.

[stevech]

Originally Posted by Wheemer

Have you tried vmr 9 with FSE enabled?

sorry- I don't know what FSE is

vmr9 - I think that's the overlay graphic support mode? I'll check

[stevech]

Originally Posted by Lucas

As a first step, disable 3D and use Overlay.
I noticed that you use 800x600, you should switch to 720x480 for NTSC or 720x576 for PAL.

The laptop says it's an ATI mobility 7500.
It is at 800x600 @ 32 bits. It has no option choices for less than 800 such as you mention above. Should I try to set it to 24 bits?

As I said earlier, I have the same dropped frame problem with the tower PC I tried which uses a $75 class video card.

I'm sorry, but I don't know how to do what you suggest: disable 3D and Overlay. Would this be among the video card's settings (right-click on deskop to view settings) ?

Thanks for the help so far.

[emok]

Sorry, I don't know how to get diagnostic data from the PVRUSB2.

I would think that an ATI7500 should be enough video card to do 3d Acceleration on SD content.

As others have suggested, I would try to first determine if the recorded file is good or bad either by playing back the video in a very small window or trying to playback the recorded file on a more powerful machine.

If the file is good it's related to the decoding and playback of the video:
1. Decoders
2. 3d Video Acceleration versus No acceleration
3. VMR9 versus Overlay
4. Full Screen Exclusive (FSE) versus non Full Screen Exclusive
All the above can be tweaked in the Sage Detailed Setup.

If you determine that the file is bad, I think there are several possibilities:
1. Not enough bandwidth over your current usb setup to store the data from the USB-encoder-->USB hub-->Computer-->USB hub-->USB Hard drive. See below.
2. Bad encoder (probably not at likely because many other people are using the PVRUSB2 without problems). Unless you have a lemon, this probably isn't the case.

Have you checked your USB setup:
1. Make sure you have the "Enhanced" controller driver setup in Windows (check DeviceManager-->USB controllers-->XXXXX Enhanced Host Controller)
2. Make sure you have a USB2 hub.
3. Remove any unnecessary devices from the hub.
4. Remove the hub from the setup completely.

Edit: Hmm.. thinking about it a little more, since it's only happening on busy scenes, it's likely related to decoding/playback. Is it only happening on busy scenes, or is just more noticeable on busy scenes?

[stanger89]

I would probably avoid VMR9 and 3D Accelleration on a 7500, that's a DX8 (or is it 7) card. VMR9/3D Accelleration use DX9.

[Lucas]

Originally Posted by stevech

The laptop says it's an ATI mobility 7500.
It is at 800x600 @ 32 bits. It has no option choices for less than 800 such as you mention above. Should I try to set it to 24 bits?

As I said earlier, I have the same dropped frame problem with the tower PC I tried which uses a $75 class video card.

I'm sorry, but I don't know how to do what you suggest: disable 3D and Overlay. Would this be among the video card's settings (right-click on deskop to view settings) ?

Thanks for the help so far.

If the driver doesnt support other than 800x600 then ignore my comment. It can only be done via powerstrip but best to stay away from it at the moment.

3d and overlay are set from SageTV setup in advanced settings and video settings respectively.

[blade]

What does Fox News look like? Does the news ticker scroll smooth across or the screen or does it studder? That's what I normally go by when trying to tweak my playback setting because if it plays back smooth most everything else usually will. At least that's been my experience.

Originally Posted by stanger89

I would probably avoid VMR9 and 3D Accelleration on a 7500, that's a DX8 (or is it 7) card. VMR9/3D Accelleration use DX9.

I have a GeForce3 (DX8.1 compliant) running at 1280*1024 VMR7 (I assume it's 7) with 3D Accelleration enabled, but it took a lot of tweaking to get smooth playback. Both 3D accelleration an FSE make a difference on my setup.

I totally agree though that Overlay and 3d accelleration disabled is the easiest way to get smooth playback on older hardware. I get better quality with my settings, but it's much more difficult to get it smooth.

[stevech]

Originally Posted by emok

Edit: Hmm.. thinking about it a little more, since it's only happening on busy scenes, it's likely related to decoding/playback. Is it only happening on busy scenes, or is just more noticeable on busy scenes?

Thanks much!
Only on scenes where the camera pans moderately fast - like a travel show where they pan a scenic view. Don't see evidence of dropped frames in scene changes (but I guess I wouldn't) and no breakup with motion of the actors in a scene with the camera not panning.

I didn't know about the "enhanced" USB drivers for Windoze. Wouldn't that be part of SP2? I'll check.

I have Sage take over the PC's screen. Is that "FSE"?

USB hub is USB2. Laptop has only 2 USB ports so I have to use a hub. I need to be mindful of how to connect a keyboard - since it's USB1 I suppose. With just two USB ports on the laptop, I guess it has just one hub internally. So any USB1 device would slow the whole hub and all external hubs to USB1, I think. I don't have the keyboard plugged in as a rule. I also have a UPS's USB to look at - I don't think it's plugged in either. It's likely USB1.

So the focus is on the video card at 800x600 (not similar to NTSC), I guess.

Assuming I can play the encoded files on some other PC without the dropped frame problems. I guess I can do that with windows media player on another PC and copy the mpeg file to that PC's disk.

[stevech]

Originally Posted by blade

I totally agree though that Overlay and 3d accelleration disabled is the easiest way to get smooth playback on older hardware. I get better quality with my settings, but it's much more difficult to get it smooth.

How do you disable Overlay and 3D accel?