AV out of sync by 325ms. Why?

[randyest]

I've been trying out SageTV for a few days and I like it a lot. Setup was easy, the controls are good (once you set them up, that is), and the guide is excellent. I'm thrilled that I can put the SageTV window (or ful-screen) on any of my 3 monitors with no problems (Creative's software seems to only want to display to the primary monitor).

Unfortunately, everything I record has a 325ms delay between the audio and video, regardless of codec used. This is fine for playback in SageTV, since I can set the audio delay to 325.

However, I do burn shows to DVD and CD, and sometimes play them back with other players, none of which provide me an option to offset the AV sync to fix this problem. Post-processing the MPEG in Premiere or similar to fix the problem is a time-consuming non-option.

FWIW, here are my specs:
Asus A7V8x, AMD XP 2400, 1GB RAM, Nvidia Ge4 ti4600, Creative DVCR, WinXP pro SP1, recording to an empty 200GB/7200rpm drive on its own ATA133 IDE port.

When running/recording, SageTV takes less than 20% of my CPU, usually around 10%. (not as good as the advertised 5%, but decent, and better than the Creative software).

If there is a way to fix this problem I will happily buy SageTV.

[Narflex]

NOTE: THIS IS NOT A GENERAL RECOMMENDATION, THIS ONLY APPLIES TO THE CREATIVE DVCR CARD AND SHOULD NOT NEED TO BE DONE IF YOUR HARDWARE IS BEHAVING CORRECTLY

Try changing the following registry key using regedit:
HKLM\Software\Frey Technologies\Common\DSFilters\MpegMux\InitialAudioPTS

It should be at
20000
you should change it to be
49250

That'll add a 325 msec delay to the audio encoding in the MPEG2 stream.

[randyest]

Thanks for the fast reply. Unfortunately, the audio synch issue on my system now seems chaotic, but only with SageTV -- this problem does not exist in Creative's DVCR software, TVHolic, myHTPC, or other apps.

Until now, SageTV regular live TV was in synch, but the recorded video files (played back with SageTV or other) were out of synch 325ms exactly. This consistent behavior led me to belive (and hope) that this was a systematic problem easily fixable with some offset like the one you suggested.

So, I changed the Setup/Advanced Config/Audio to 325 to play these back, and all seemed fine. But, then live TV was out of synch the other way, so I had to set it back to 0 to watch live tv.

But, now live TV seems slightly out of synch. Nothing as noticeable as 325ms, but noticeable (and extremely annoying). And, no matter how I change the offset in the config, it always looks slightly wrong. I assume I have to exit/restart SageTV to see a change (seems like that os the case), and I don't think decimal values make a difference (325.5ms?)

(*** update: during the 5 minutes I have been writing this post, the live TV seems to have regained sync. With offset = 0. And, with no reg change (yet). Let's see if it stays; if so, I will try the reg fix immediately ***).

What is the default value for this offset? 0?

Then, another file I recorded previously turned out to be off by 350ms instead of 325ms. I'm not sure of the units for reg value you suggested to change -- it seems like 1/90 ms? [( 49250
- 20000 ) / 325 = 90] right? I'd like to know so that, if I can get the offset to stabilize, I can try setting this registry offset for a permanent solution.

Of course, this sort of trial and error config hacking is something I'd expect to do with OSS software like myHTPC or TVholic, but not for a $60 commercial solution. I'll mess around as much as I can in the remaining 3 days of my trial, but I'm guessing this won't be very much since I have to use another app to do my recording, and running SageTV along with another recorder doesn't work well.

[randyest]

Bah, as sson as I hit "Submit Reply" live TV hiccupped slightly, then the sync went off again. Looks like ~325-350ms again, though I haven't tested (I'm getting pretty good at guessing AV sync offsets, but please note that this NOT a skill I sought to develop ).

If you have any suggestions, please provide as much info as possible. Is this a common problem (forum searches turned up a few co-sufferers, but little by way of resolution, and none with DVCR)? Is it a known issue with DVCR? What offset/reg entry do other DVCR users use?

Or, most importantly, does anyone have SageTV working well with a Creative DVCR?

Thanks again,
Randy

[randyest]

Hahaha, this forum is a great debug tool -- literally. This last time when I hit "Submit Reply", SageTV "encountered a problem and had to close". i.e., the WinXP euphamism for "crash".

[randyest]

If anyone here is using winXP and a creative DVCR, and has good audio synch, would you please tell me what options (codecs, mpeg option, whatever) you are using, especially non-default settings you've chosen?

I'm tired of doing this:



But, I'm really glad I checked out the trial version before sinking cash into this prg, and I'm also glad the trial is only 10 days -- otherwise I might keep wasting time debugging . . .

[pbarrette]

Hi RandyEst,

I agree. I've been reading your posts and I'd have to say that I am extremely disappointed with the support provided for the VB-DVCR. After seeing the change-log for the newest Beta version of SageTV, I can only assume that Frey has decided to completely neglect the improvement of existing functionality and instead, focus on new features.

Having just purchased the software, I can only hope that I am wrong on this subject.

That being said, I do have a certain level of stability with my DVCR setup, but only if I use the computer for absolutely nothing else while the system is recording.

So, here is what I am using to get these results:
Recording Quality = Great (2GB/hr)
Anything larger will create massive sync problems.
Anything lower will be of too low a quality to watch.

Special Sage.Properties settings:
seeker/fast_mux_switch=false
Absolutely essential to get sync back quickly!

I'm using "Default" for audio decoding, and "Cyberlink Video/SP Decoder" (from PowerDVD) for the video decoder. Not using Dscaler or any other decoders. I assume that since PowerDVD is my only deocder that it is also the "Default" when it comes to audio decoding, but I get worse performance with anything but "Default" for audio.

I'm using "Overlay" instead of VMR. Using VMR displays the video correctly, but the CPU usage shoots to 100% which results in jerky video and instant audio sync issues.

My audio delay is set to 0.

After all is said and done, I am still afraid to do anything while Sage is recording. I have played some previously recorded shows every once and a while, and all seems to be OK, but I'm not chancing it.

Every once and a while (about 1 show out of 10-15) the audio will jump out of sync and video frames will be dropped even when I am not using the system. These bad syncs usually correct themselves within 1-5 seconds, but they are still annoying. Even more so if they happen within a show that I am trying to get archived at high-quality.

Here's my Sage.Properties file if you wish to compare. Don't just do a drop-in replacement though. Our other hardware differences, combined with my custom UI changes probably wouldn't work well on your system.

Hopefully Narflex will address these DVCR issues and the problematic setup/tweaking issues in general. Not many people are willing to spend $60 on software that doesn't work out of the box.

[randyest]

Thanks for the info, but fortunately I did not waste my money on SageTV. Though I did waste a lot of time trying to get something to work that couldn't -- I mean, hey, the product info page said it supported DVCR. I guess technically, it didn't say it worked properly, just that it was supported, whatever that means. Whatever.

Frey tech seemed like a pretty decent company at first glance, what with the forum and taking user input and all, but advertising a software product as working with a specific piece of hardware when overwhelming evidence to the contrary exists and is known by the advertiser is unforgiveable in my opinion.

Now I wouldn't buy a glass of water from Frey technologies even if I were dying of thirst. Thanks for the ride, but I'm getting off now.

[pbarrette]

Hi Randyest,

If you're willing to give it one more shot, you can check out this post:
http://www.x-epg.net/forum/topic.asp?TOPIC_ID=82

This post and several others on that site suggest that using "Powerstrip" or your BIOS settings to increase the PCI latency for the VBDVCR can correct a number of issues with instability.

Hey, it's worth a shot. Especially since your audio sync issue doesn't seem to be related to CPU utilization issues like mine is.

Also, it wouldn't be a bad idea to check your IRQ's to ensure that you aren't having a conflict there as well. Since the capture card is so dependent on timing and throughput, a shared IRQ could be causing the audio delay problem as well.

pb