HD-PVR vs stuttering

[ehfortin]

Hi,

I've read a lot of posts in multiple forums regarding the HD-PVR and the stuttering issue. I can see that some people are having major issues, others have minor issues. However, I'm unable to tell if there is anybody not having any stuttering at all, not even micro-stuttering after a channel change (for example).

Right now, my setup is pretty much stable except for that micro-stuttering after channel change. Until I actually do a rewind of a few seconds or pause the live tv for a few seconds, I have this unpleasant micro-stuttering going on. I know how to get rid of it but... I have a wife, kids and guest that are not so comprehensive regarding technology issues as I can be. Actually, even I am becoming unhappy about it.

The reason I'm asking is that if some people are really getting a perfect display all the time, well, can you publish any change you've made to the original sageTV in order to get it perfect?

Assuming that most still have this kind of issue and that the pause/rewind works for the majority, wouldn't be some kind of quick fix for now to implement in SageTV that would automatically go back or wait a little bit longer before starting to playback so that we are not trying to read/write the same block at the same time? Actually, I would add the option to use a memory buffer to record to before writing to disk and that's where the playback could take place instead of actually reading from disk until somebody pause or rewind the current recording. It may be already how it works but, based on my disk activity when changing channel, I suspect that it's going direct to disk without any memory buffer in the middle.

Is that something that is already done? If so, can it be improved?

I also have a small annoyance and a WAF issue. The small annoyance is that if I go to live TV, sometime, it will get back to the menu with just the small live TV screen in the corner so I have to go back to the live TV. Is that a known problem with a cure?

The WAF issue is the damn delay once you change the channel. It get at least 3 seconds before starting to playback and it even seems to redisplay a few frames of previous recording after seeing the channel change. Is there any way to reduce this? Would the memory buffer suggested above be a way to improve this? Again, right now, it seems that we have to await for the HD-PVR to start filling the newly created file and make sure there is enough of the file filled to start reading from it. With a memory buffer, this could be completed in the background.

I may be completely out of track or it may already be done that way or there is possibly some issue with implementing it this way but I didn't see anything on the subject yet but I may have missed it. There is so much posts in here...

Let see what you have to say. Sorry if this is old idea. I'm just trying to get WAF up there and it's not fully happening right now


Etienne

[jerryt]

Try this;
"I went from choppy to smooth by changing some registry settings.

HKey_L_M\SOFTWARE\Frey Technologies\Common\DSFilters\MpegDeMux values NumBuffers and BufferSize.
I currently have these set to 100 and 20000 hex, respectively.

(Up from 40 and 10000)"

or

Arcsoft Video Decoder which does not seem to need the above registry change. Note everytime you upgrade Sage, you will need to do the registry change again.

[ghostlobster]

Actually, Andy (Opus) posted a neat little tweak for this one as follows:

It sounds like you are playing too close to the end of the live recording. You could try changing these properties (the time is in milliseconds):
videoframe/local_encoding_to_playback_delay=2000
videoframe/time_behind_live_to_disable_fast_forward=6000
videoframe/time_behind_live_to_disable_skip_forward=4000

Tinker around with that setting for a but and see what you come up with. I gotta remember to add this to my migration guide when I get a chance to breath.

[ehfortin]

I'll certainly try both changes to see if it helps.

jerryt: is that tweak related to DScaler or it has nothing to do with it?

BTW, is DScaler now included with the latest official release (6.4.8)? Before it was not available where now, it's a button "configure" and nothing is greyed out. If it's not, is it something to consider, if not for the HD-PVR, maybe for my PVR-150?

ghostlobster: this may help directly as it would do what I've described (let us read a little bit later). However, the downside is that it will increase the "wait" period to first scene. As a temporary measure, it may be acceptable but would still prefer having some kind of long term solution to reduce the lag between changing a channel and getting the image. My PVR-150 is a lot faster then doing this with HD-PVR and, as both are able to capture on the fly, I would think that both should be as fast to produce initial image of the new channel.


Any comment on the strange problem where after a few minutes my full screen live TV is returning back to first menu (I'm using the MC kit) by itself? I've not tried without MC because I don't want to use the default menu but it would be nice to know what is causing this and fixing it.

A quick question, what kind of CPU usage are you seeing while viewing HD content? Anybody successfully got the ATI Radeon 2x00 serie to do hardware decoding? It works in WMP or TME but not in SageTV so I'm using 65-72% of my dual core 2 Ghz Intel CPU against about 10% when hardware decoding works.

Thank you for your help. I'll let you know the result soon.


Etienne

[ghostlobster]

Regarding speeding up the channel change and image presentation with the HD-PVR, let me know if you find a solution for it! I personally hate it! My wife loves to channel surf, constantly clicking through channels and flipping all over the place, and I'm forever getting the circle of death when she does that. Unfortunately, I believe it's a consequence of being an early adopter. She's gradually learning to use the mini-guide and things like that to find what she wants to watch, but I get reminded daily that she was able to flip to her heart's content with the cable co. DVR.

Regarding CPU usage...actually, I'm seeing very low CPU usage on my machine. Under 30% when viewing HD content in most cases. Im running an ATI 2600XT, with just the included ArcSoft encoders and hardware acceleration disabled. Yeah, true hardware acceleration with h.264 would be great, but it's not the first item on my wish list. I'd much rather see a better channel changing solution.

[Deacon Crusher]

I don't have stuttering, but I have audio sync issues that get worse whenever I skip forward in a show and once they are bad I can't seem to fix them (pause, stop etc, don't help,) however, it doesn't seem to exist with all shows recorded by the hd-pvr.

Running the latest sage and do all my playback on extenders.

Any tips/thoughts?

Thanks

[kingwr]

What are the relative, official positions of SageTv and Hauppauge on these issues? Does Hauppauge acknowledge the stuttering and slow channel change as being a problem in the ArcSoft decoder and/or hardware? Does SageTV acknowledge the playback problem as well? Has either promised a fix or patch?

Resolution of this issue will certainly be a major factor in my decision to migrate from MCE 2005.

[jerryt]

Ehfortin - Tweak is not related to DScaler.

Deacon Crusher - Try the -180ms delay with the AC3filter audio codec.

Kingwr - SageTV Support states that the audio sync problem is with Hauppauge's driver. The Beta driver appears to correct the audio sync (but ...).

I don't have the stuttering problem, but would guess that it is codec, configuration or Sage's graph.

I am afraid that slow channel changes is the norm with Sage. It kept me away for a long time, but Sage's power is as a DVR, where nothing is watched live. I had to learn to not channel surf and instead use the guide.

[Chriscic]

Stuttering dominates in all my PC playback. On the HD100, the playback is pretty smooth.

[ehfortin]

Thank you Jerryt for the precision.

I have an interesting twist since I wrote my initial post. I had to reinstall my Vista Home Premium and SageTV so I went directly to the official 6.4.8. I noticed some changes compared to doing an upgrade from 6.3.x to 6.4.x and then to the final 6.4.8. I saw things like the volume icon is different (was a round "sun" and is now a rectangular box) and new item in the menu like "SageTV playback using hardware decoder" that were not there before. I've reconfigured my PVR-150 and HD-PVR, use the same settings (which was mostly putting it in overlay) and since... I've not experience stuttering at all without even doing any other tweak. I've not touched the default sagetv.properties file, not even to add Arcsoft decoder. Everything was there and everything seems to work just fine. I'm happy but it's kind of strange.

I still have the small annoyance where my full liveTV will sometime return to the main menu by itself (like if I was pressing the green button on the MCE remote) but that seems to only happens one time after I select Live TV.

I'll monitor closely the system for a few days because I'm really surprised of the behaviour change on the same hardware/software just because the path I've used to do it (fresh install vs upgrade for sageTV).

Is there any news on the driver update to support SPDIF as audio source instead of analog?

Now, reducing the delay for channel changing would still be appreciated

BTW, at some point I found tweak for the PVR-150 to increase the image quality. I remember I've implemented and tried multiple of these but can't remember which one actually improved it. Is there an official recognized FAQ or posts somewhere that would summarize which tweaks are good for PVR-150 with SageTV?

Thank you.


Etienne

[paulbeers]

Originally Posted by ehfortin

Is there any news on the driver update to support SPDIF as audio source instead of analog?

Etienne

As soon as the new beta drivers come out, it supposedly fixes the audio delay and adds 5.1 capture w/ spdif.