How to set negative audio delay?

[ByteMaster0]

I am using a Hauppauge WinTV-HVR-950 (USB) on an overclocked Q6600 with 8GB RAM running WinXP x64. Because of what I can only imagine are crappy drivers (they haven't been updated in over a year), I always experience A/V lag with this tuner. It is very significantly noticeable in SageTV - often about 500ms off (behind) or more. When I attempt to change the A/V delay to a negative value, I either get:

a.) With the SageTV audio decoder: picture freezes, then moves, alternatingly, and audio is about 5 seconds off. Eventually, it completely locks up.
b.) Any other decoder: no audio whatsoever.

This is a major selling point for me. I'm still a "trial user" of this software, and until there is a fix for this, I'm not intending to purchase it. The rest of the software is fantastic, but I need to be able to set a manual A/V offset that is negative. I'm using 6.3.10. Anyone else have more luck? Thanks

[stanger89]

What's your source, something is very wrong if you've got a half second difference between audio and video, especially if your source is OTA digital.

[ByteMaster0]

My apologies for the vagueness: Analog cable TV. There is most definitely no lag in digital (I haven't tried it, but if there were any lag with digital reception, I'd be highly surprised.) The lag is significantly more noticeable with SageTV than with WinTV (the Hauppauge default application). The lag can get quite severe, upto 1000ms or so at times. I still can't set the delay to negative, so I wonder why this feature even exists.

CPU utilization while recording is less than 15%, and while just viewing (say in WinTV) it drops below 10%, despite using a software decoder. At 14% overall CPU utilization, I'm loading one core to 56% utilization, if SageTV were single-threaded. However, I've noticed that it's multithreaded, so it shouldn't be an issue. Memory utilization and disk access are completely negligible.

[Opus4]

Originally Posted by ByteMaster0

I am using a Hauppauge WinTV-HVR-950 (USB)

Originally Posted by ByteMaster0

My apologies for the vagueness: Analog cable TV. There is most definitely no lag in digital

Isn't that a software encoder for the analog side? The software tuner part of that device may or may not work with SageTV, but it is recommended that you use a hardware encoder for recording analog TV -- software encoders don't work nearly as well, both in terms of using much more cpu than a hardware encoder & ending up with a lower quality recording.

But, while using the software tuner, how do you have it hooked up? Are you having this issue during live TV or after the file is recorded? Sometimes, people have the sound going directly to the speakers while only the video is getting recorded.

- Andy

[ByteMaster0]

Originally Posted by Opus4

Isn't that a software encoder for the analog side?

Indeed, it is a software encoder. With my Q6600, it doesn't use more than 14% or so of CPU, and while I agree that it is far from an ideal solution, I paid less than $50 for it, so I can't complain all that much.

The tuner is connected via USB, and audio as well as video are provided via that one USB connection. The problem occurs with the same severity both during live TV as well as during recording.

[Opus4]

I don't mean live TV vs during a recording (they are both recordings when using SageTV) -- I mean playing the recording after it is done recording. That might have been what you meant, though.

Anyway, that is not on the list of supported analog tuners & it has been previously posted that the audio is out of sync when using its analog tuner. It should probably only be used as a digital TV tuner.

- Andy

[ByteMaster0]

Fair enough. I realize that "watching live TV" in Sage is infact buffered recording and playback - but you're right, that's what I was referring to. Unfortunately, I have neither a free PCI-E or PCI slot, since my pair of 8800GTs and RAID card are blocking all available space other than one slot reserved for my X-Fi - I guess I just need to suck it up and get a decent hardware-encoding USB tuner.

[miriad]

There seems to be a problem with Sage 6.3 and software encoding with some cards that leads to audio or video lag on some recordings (I havent found a specific pattern yet). Try using sage 6.2.10 instead (6.2 uses an older software encoder that doesnt seem to have this problem).

Miriad

[Opus4]

BTW - to answer the question about negative audio delay times: no, that won't work, so I'll update the UI to not allow negative values to be entered.

- Andy